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Sample records for electronic energy band

  1. Plasmon enhanced heterogeneous electron transfer with continuous band energy model

    NASA Astrophysics Data System (ADS)

    Zhao, Dandan; Niu, Lu; Wang, Luxia

    2017-08-01

    Photoinduced charge injection from a perylene dye molecule into the conduction band of a TiO2 system decorated by a metal nanoparticles (MNP) is studied theoretically. Utilizing the density matrix theory the charge transfer dynamics is analyzed. The continuous behavior of the TiO2 conduction band is accounted for by a Legendre polynomials expansion. The simulations consider optical excitation of the dye molecule coupled to the MNP and the subsequent electron injection into the TiO2 semiconductor. Due to the energy transfer coupling between the molecule and the MNP optical excitation and subsequent charge injection into semiconductor is strongly enhanced. The respective enhancement factor can reach values larger than 103. Effects of pulse duration, coupling strength and energetic resonances are also analyzed. The whole approach offers an efficient way to increase charge injection in dye-sensitized solar cells.

  2. Determining the band gap and mean kinetic energy of atoms from reflection electron energy loss spectra

    SciTech Connect

    Vos, M.; Marmitt, G. G.; Finkelstein, Y.; Moreh, R.

    2015-09-14

    Reflection electron energy loss spectra from some insulating materials (CaCO{sub 3}, Li{sub 2}CO{sub 3}, and SiO{sub 2}) taken at relatively high incoming electron energies (5–40 keV) are analyzed. Here, one is bulk sensitive and a well-defined onset of inelastic excitations is observed from which one can infer the value of the band gap. An estimate of the band gap was obtained by fitting the spectra with a procedure that includes the recoil shift and recoil broadening affecting these measurements. The width of the elastic peak is directly connected to the mean kinetic energy of the atom in the material (Doppler broadening). The experimentally obtained mean kinetic energies of the O, C, Li, Ca, and Si atoms are compared with the calculated ones, and good agreement is found, especially if the effect of multiple scattering is taken into account. It is demonstrated experimentally that the onset of the inelastic excitation is also affected by Doppler broadening. Aided by this understanding, we can obtain a good fit of the elastic peak and the onset of inelastic excitations. For SiO{sub 2}, good agreement is obtained with the well-established value of the band gap (8.9 eV) only if it is assumed that the intensity near the edge scales as (E − E{sub gap}){sup 1.5}. For CaCO{sub 3}, the band gap obtained here (7 eV) is about 1 eV larger than the previous experimental value, whereas the value for Li{sub 2}CO{sub 3} (7.5 eV) is the first experimental estimate.

  3. Determining the band gap and mean kinetic energy of atoms from reflection electron energy loss spectra

    NASA Astrophysics Data System (ADS)

    Vos, M.; Marmitt, G. G.; Finkelstein, Y.; Moreh, R.

    2015-09-01

    Reflection electron energy loss spectra from some insulating materials (CaCO3, Li2CO3, and SiO2) taken at relatively high incoming electron energies (5-40 keV) are analyzed. Here, one is bulk sensitive and a well-defined onset of inelastic excitations is observed from which one can infer the value of the band gap. An estimate of the band gap was obtained by fitting the spectra with a procedure that includes the recoil shift and recoil broadening affecting these measurements. The width of the elastic peak is directly connected to the mean kinetic energy of the atom in the material (Doppler broadening). The experimentally obtained mean kinetic energies of the O, C, Li, Ca, and Si atoms are compared with the calculated ones, and good agreement is found, especially if the effect of multiple scattering is taken into account. It is demonstrated experimentally that the onset of the inelastic excitation is also affected by Doppler broadening. Aided by this understanding, we can obtain a good fit of the elastic peak and the onset of inelastic excitations. For SiO2, good agreement is obtained with the well-established value of the band gap (8.9 eV) only if it is assumed that the intensity near the edge scales as (E - Egap)1.5. For CaCO3, the band gap obtained here (7 eV) is about 1 eV larger than the previous experimental value, whereas the value for Li2CO3 (7.5 eV) is the first experimental estimate.

  4. Electron energy band alignment at the (100)Si/MgO interface

    NASA Astrophysics Data System (ADS)

    Afanas'ev, V. V.; Stesmans, A.; Cherkaoui, K.; Hurley, P. K.

    2010-02-01

    The electron energy band diagram at the (100)Si/MgO interface is characterized using internal photoemission of electrons and holes from Si into the oxide. For the as-deposited amorphous MgO the interface barriers correspond to a band gap width of 6.1 eV, i.e., much lower than the conventionally assumed bulk crystal value (7.83 eV). The annealing-induced crystallization of MgO mostly affects the energy of the valence band while the conduction band bottom retains its energy position at 3.37±0.05 eV above the top of the silicon valence band.

  5. Nanoscale mapping of optical band gaps using monochromated electron energy loss spectroscopy.

    PubMed

    Zhan, W; Granerød, C S; Venkatachalapathy, V; Johansen, K M H; Jensen, I J T; Kuznetsov, A Yu; Prytz, Ø

    2017-03-10

    Using monochromated electron energy loss spectroscopy in a probe-corrected scanning transmission electron microscope we demonstrate band gap mapping in ZnO/ZnCdO thin films with a spatial resolution below 10 nm and spectral precision of 20 meV.

  6. Nanoscale mapping of optical band gaps using monochromated electron energy loss spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhan, W.; Granerød, C. S.; Venkatachalapathy, V.; Johansen, K. M. H.; Jensen, I. J. T.; Kuznetsov, A. Yu; Prytz, Ø.

    2017-03-01

    Using monochromated electron energy loss spectroscopy in a probe-corrected scanning transmission electron microscope we demonstrate band gap mapping in ZnO/ZnCdO thin films with a spatial resolution below 10 nm and spectral precision of 20 meV.

  7. Electronic energy band structure of the double perovskite Ba2MnWO6.

    PubMed

    Fujioka, Yukari; Frantti, Johannes; Nieminen, Risto M

    2008-06-05

    The electronic and magnetic structures of the double perovskite oxide Ba 2MnWO6 (BMW) were determined by employing the density functional theory within the generalized gradient approximation (GGA) + U approach. BMW is considered a prototype double perovskite due to its high degree of B-site ordering and is a good case study for making a comparison between computations and experiments. By adjusting the U-parameter, the electronic energy band structure and magnetic properties, which were consistent with the experimental results, were obtained. These computations revealed that the valence bands are mainly formed from Mn 3d and O 2p states, while the conduction bands are derived from W 5d and O 2p states. The localized bands composed from Mn 3d states are located in the bandgap. The results imply that the formation of polarons in the conduction band initiate the resonance Raman modes observed as a series of equidistant peaks.

  8. Vanishing Electronic Energy Loss of Very Slow Light Ions in Insulators with Large Band Gaps

    SciTech Connect

    Markin, S. N.; Primetzhofer, D.; Bauer, P.

    2009-09-11

    Electronic energy loss of light ions in nanometer films of materials with large band gaps has been studied for very low velocities. For LiF, a threshold velocity is observed at 0.1 a.u. (250 eV/u), below which the ions move without transferring energy to the electronic system. For KCl, a lower (extrapolated) threshold velocity is found, identical for H and He ions. For SiO{sub 2}, no clear velocity threshold is observed for He particles. For protons and deuterons, electronic stopping is found to perfectly fulfill velocity scaling, as expected for binary ion-electron interaction.

  9. The optical band gap and surface free energy of polyethylene modified by electron beam irradiations

    NASA Astrophysics Data System (ADS)

    Abdul-Kader, A. M.

    2013-04-01

    In this study, investigations have been carried out on electron beam irradiated ultra high molecular weight polyethylene (UHMWPE). Polyethylene samples were irradiated with 1.5 MeV electron beam at doses ranging from 50 to 500 kGy. Modifications in optical properties and photoluminescence behavior of the polymer were evaluated by UV-vis and photoluminescence techniques. Changes of surface layer composition of UHMWPE produced by electron irradiations were studied by Rutherford back scattering spectrometry (RBS). The change in wettability and surface free energy induced by irradiations was also investigated. The optical absorption studies reveal that both optical band gap and Urbach's energy decreases with increasing electron dose. A correlation between energy gap and the number of carbon atoms in clusters is discussed. Photoluminescence spectra were reveal remarkable decrease in the integrated luminescence intensity with increasing irradiation dose. Contact angle measurements showed that wettability and surface free energy increases with increasing the irradiation dose.

  10. Band gap widening at random CIGS grain boundary detected by valence electron energy loss spectroscopy

    NASA Astrophysics Data System (ADS)

    Keller, Debora; Buecheler, Stephan; Reinhard, Patrick; Pianezzi, Fabian; Bissig, Benjamin; Carron, Romain; Hage, Fredrik; Ramasse, Quentin; Erni, Rolf; Tiwari, Ayodhya N.

    2016-10-01

    Cu(In,Ga) Se2 (CIGS) thin film solar cells have demonstrated very high efficiencies, but still the role of nanoscale inhomogeneities in CIGS and their impact on the solar cell performance are not yet clearly understood. Due to the polycrystalline structure of CIGS, grain boundaries are very common structural defects that are also accompanied by compositional variations. In this work, we apply valence electron energy loss spectroscopy in scanning transmission electron microscopy to study the local band gap energy at a grain boundary in the CIGS absorber layer. Based on this example, we demonstrate the capabilities of a 2nd generation monochromator that provides a very high energy resolution and allows for directly relating the chemical composition and the band gap energy across the grain boundary. A band gap widening of about 20 meV is observed at the grain boundary. Furthermore, the compositional analysis by core-loss EELS reveals an enrichment of In together with a Cu, Ga and Se depletion at the same area. The experimentally obtained results can therefore be well explained by the presence of a valence band barrier at the grain boundary.

  11. Theoretical modeling of low-energy electronic absorption bands in reduced cobaloximes.

    PubMed

    Bhattacharjee, Anirban; Chavarot-Kerlidou, Murielle; Dempsey, Jillian L; Gray, Harry B; Fujita, Etsuko; Muckerman, James T; Fontecave, Marc; Artero, Vincent; Arantes, Guilherme M; Field, Martin J

    2014-10-06

    The reduced Co(I) states of cobaloximes are powerful nucleophiles that play an important role in the hydrogen-evolving catalytic activity of these species. In this work we analyze the low-energy electronic absorption bands of two cobaloxime systems experimentally and use a variety of density functional theory and molecular orbital ab initio quantum chemical approaches. Overall we find a reasonable qualitative understanding of the electronic excitation spectra of these compounds but show that obtaining quantitative results remains a challenging task.

  12. Theoretical Modeling of Low Energy Electronic Absorption Bands in Reduced Cobaloximes

    PubMed Central

    Bhattacharjee, Anirban; Chavarot-Kerlidou, Murielle; Dempsey, Jillian L.; Gray, Harry B.; Fujita, Etsuko; Muckerman, James T.; Fontecave, Marc; Artero, Vincent; Arantes, Guilherme M.; Field, Martin J.

    2015-01-01

    The reduced Co(I) states of cobaloximes are powerful nucleophiles that play an important role in the hydrogen-evolving catalytic activity of these species. In this work we have analyzed the low energy electronic absorption bands of two cobaloxime systems experimentally and using a variety of density functional theory and molecular orbital ab initio quantum chemical approaches. Overall we find a reasonable qualitative understanding of the electronic excitation spectra of these compounds but show that obtaining quantitative results remains a challenging task. PMID:25113847

  13. Theoretical modeling of low-energy electronic absorption bands in reduced cobaloximes

    DOE PAGES

    Bhattacharjee, Anirban; Chavarot-Kerlidou, Murielle; Dempsey, Jillian L.; ...

    2014-08-11

    Here, we report that the reduced Co(I) states of cobaloximes are powerful nucleophiles that play an important role in the hydrogen-evolving catalytic activity of these species. In this work we have analyzed the low energy electronic absorption bands of two cobaloxime systems experimentally and using a variety of density functional theory and molecular orbital ab initio quantum chemical approaches. Overall we find a reasonable qualitative understanding of the electronic excitation spectra of these compounds but show that obtaining quantitative results remains a challenging task.

  14. Theoretical modeling of low-energy electronic absorption bands in reduced cobaloximes

    SciTech Connect

    Bhattacharjee, Anirban; Chavarot-Kerlidou, Murielle; Dempsey, Jillian L.; Gray, Harry B.; Fujita, Etsuko; Muckerman, James T.; Fontecave, Marc; Artero, Vincent; Arantes, Guilherme M.; Field, Martin J.

    2014-08-11

    Here, we report that the reduced Co(I) states of cobaloximes are powerful nucleophiles that play an important role in the hydrogen-evolving catalytic activity of these species. In this work we have analyzed the low energy electronic absorption bands of two cobaloxime systems experimentally and using a variety of density functional theory and molecular orbital ab initio quantum chemical approaches. Overall we find a reasonable qualitative understanding of the electronic excitation spectra of these compounds but show that obtaining quantitative results remains a challenging task.

  15. Low-energy electronic excitations and band-gap renormalization in CuO

    NASA Astrophysics Data System (ADS)

    Rödl, Claudia; Ruotsalainen, Kari O.; Sottile, Francesco; Honkanen, Ari-Pekka; Ablett, James M.; Rueff, Jean-Pascal; Sirotti, Fausto; Verbeni, Roberto; Al-Zein, Ali; Reining, Lucia; Huotari, Simo

    2017-05-01

    Combining nonresonant inelastic x-ray scattering experiments with state-of-the-art ab initio many-body calculations, we investigate the electronic screening mechanisms in strongly correlated CuO in a large range of energy and momentum transfers. The excellent agreement between theory and experiment, including the low-energy charge excitations, allows us to use the calculated dynamical screening as a safe building block for many-body perturbation theory and to elucidate the crucial role played by d -d excitations in renormalizing the band gap of CuO. In this way we can dissect the contributions of different excitations to the electronic self-energy which is illuminating concerning both the general theory and this prototypical material.

  16. High-energy electronic interaction in the 3 d band of high-temperature iron-based superconductors

    NASA Astrophysics Data System (ADS)

    Evtushinsky, D. V.; Yaresko, A. N.; Zabolotnyy, V. B.; Maletz, J.; Kim, T. K.; Kordyuk, A. A.; Viazovska, M. S.; Roslova, M.; Morozov, I.; Beck, R.; Aswartham, S.; Harnagea, L.; Wurmehl, S.; Berger, H.; Rogalev, V. A.; Strocov, V. N.; Wolf, T.; Zhigadlo, N. D.; Büchner, B.; Borisenko, S. V.

    2017-08-01

    One of the most unique and robust experimental facts about iron-based superconductors is the renormalization of the electronic band dispersion by factor of 3 and more near the Fermi level. Obviously related to the electron pairing, this prominent deviation from the band theory lacks understanding. Experimentally studying the entire spectrum of the valence electrons in iron arsenides, we have found an unexpected depletion of the spectral weight in the middle of the iron-derived band, which is accompanied by a drastic increase of the scattering rate. At the same time, the measured arsenic-derived band exhibits very good agreement with theoretical calculations. We show that the low-energy Fermi velocity renormalization should be viewed as a part of the modification of the spectral function by a strong electronic interaction. Such an interaction with an energy scale of the whole d band appears to be a hallmark of many families of unconventional superconductors.

  17. Energy band alignment and electronic states of amorphous carbon surfaces in vacuo and in aqueous environment

    SciTech Connect

    Caro, Miguel A.; Määttä, Jukka; Lopez-Acevedo, Olga; Laurila, Tomi

    2015-01-21

    In this paper, we obtain the energy band positions of amorphous carbon (a–C) surfaces in vacuum and in aqueous environment. The calculations are performed using a combination of (i) classical molecular dynamics (MD), (ii) Kohn-Sham density functional theory with the Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional, and (iii) the screened-exchange hybrid functional of Heyd, Scuseria, and Ernzerhof (HSE). PBE allows an accurate generation of a-C and the evaluation of the local electrostatic potential in the a-C/water system, HSE yields an improved description of energetic positions which is critical in this case, and classical MD enables a computationally affordable description of water. Our explicit calculation shows that, both in vacuo and in aqueous environment, the a-C electronic states available in the region comprised between the H{sub 2}/H{sub 2}O and O{sub 2}/H{sub 2}O levels of water correspond to both occupied and unoccupied states within the a-C pseudogap region. These are localized states associated to sp{sup 2} sites in a-C. The band realignment induces a shift of approximately 300 meV of the a-C energy band positions with respect to the redox levels of water.

  18. Complete description of ionization energy and electron affinity in organic solids: Determining contributions from electronic polarization, energy band dispersion, and molecular orientation

    NASA Astrophysics Data System (ADS)

    Yoshida, Hiroyuki; Yamada, Kazuto; Tsutsumi, Jun'ya; Sato, Naoki

    2015-08-01

    Ionization energy and electron affinity in organic solids are understood in terms of a single molecule perturbed by solid-state effects such as polarization energy, band dispersion, and molecular orientation as primary factors. However, no work has been done to determine the individual contributions experimentally. In this work, the electron affinities of thin films of pentacene and perfluoropentacene with different molecular orientations are determined to a precision of 0.1 eV using low-energy inverse photoemission spectroscopy. Based on the precisely determined electron affinities in the solid state together with the corresponding data of the ionization energies and other energy parameters, we quantitatively evaluate the contribution of these effects. It turns out that the bandwidth as well as the polarization energy contributes to the ionization energy and electron affinity in the solid state while the effect of the surface dipole is at most a few eV and does not vary with the molecular orientation. As a result, we conclude that the molecular orientation dependence of the ionization energy and electron affinity of organic solids originates from the orientation-dependent polarization energy in the film.

  19. Band gap and defect states of MgO thin films investigated using reflection electron energy loss spectroscopy

    SciTech Connect

    Heo, Sung; Cho, Eunseog; Lee, Hyung-Ik; Park, Gyeong Su; Kang, Hee Jae; Nagatomi, T.; Choi, Pyungho; Choi, Byoung-Deog

    2015-07-15

    The band gap and defect states of MgO thin films were investigated by using reflection electron energy loss spectroscopy (REELS) and high-energy resolution REELS (HR-REELS). HR-REELS with a primary electron energy of 0.3 keV revealed that the surface F center (FS) energy was located at approximately 4.2 eV above the valence band maximum (VBM) and the surface band gap width (E{sub g}{sup S}) was approximately 6.3 eV. The bulk F center (F{sub B}) energy was located approximately 4.9 eV above the VBM and the bulk band gap width was about 7.8 eV, when measured by REELS with 3 keV primary electrons. From a first-principles calculation, we confirmed that the 4.2 eV and 4.9 eV peaks were F{sub S} and F{sub B}, induced by oxygen vacancies. We also experimentally demonstrated that the HR-REELS peak height increases with increasing number of oxygen vacancies. Finally, we calculated the secondary electron emission yields (γ) for various noble gases. He and Ne were not influenced by the defect states owing to their higher ionization energies, but Ar, Kr, and Xe exhibited a stronger dependence on the defect states owing to their small ionization energies.

  20. Quest for band renormalization and self-energy in correlated f-electron systems

    SciTech Connect

    Durakiewicx, Tomasz

    2009-01-01

    Coexisting energy scales are observed in f-electron materials. Information about some of the low-energy scales is imprinted in the electron self-energy which can be measured by angle-resolved photoemission (ARPES). Such measurements in d-electron materials over the last decade were based on high energy- and momentum-resolution ARPES techniques used to extract the self-energy information from measured spectra. Simultaneously, many-body theoretical approaches have been developed to find a link between self-energy and many-body interactions. Here we show the transcription of such methods from d-electrons to f-electrons by presenting the first example of low energy scales in f-electron material USb{sub 2}, measured with synchrotron-based ARPES. Proposed approach will help in answering the fundamental questions about the complex nature of the heavy fermion state.

  1. Electron mean free path and conduction-band density-of-states in solid methane as determined from low-energy electron transmission experiments

    NASA Astrophysics Data System (ADS)

    Jay-Gerin, J.-P.; Plenkiewicz, B.; Plenkiewicz, P.; Perluzzo, G.; Sanche, L.

    1985-09-01

    Recently, Plenkiewicz et al. developed a theoretical model for analyzing the current I t transmitted by a thin dielectric film as a function of incident electron energy E. The purpose of this paper is to apply this model to the analysis of recent I t( E) results for solid methane. The analysis permits the determination of both the electron mean free path as a function of energy and the electronic conduction-band density-of-states in the quasi-elastic scattering region. The differences between our results and Kunz's solid methane band structure calculations are also discussed.

  2. Finite-energy spin fluctuations as a pairing glue in systems with coexisting electron and hole bands

    NASA Astrophysics Data System (ADS)

    Nakata, Masahiro; Ogura, Daisuke; Usui, Hidetomo; Kuroki, Kazuhiko

    2017-06-01

    We study, within the fluctuation-exchange approximation, the spin-fluctuation-mediated superconductivity in Hubbard-type models possessing electron and hole bands, and compare them with a model on a square lattice with a large Fermi surface. In the large Fermi surface model, superconductivity is more enhanced for better nesting for a fixed band filling. By contrast, in the models with electron and hole bands, superconductivity is optimized when the Fermi surface nesting is degraded to some extent, where finite-energy spin fluctuations around the nesting vector develop. The difference lies in the robustness of the nesting vector, namely, in models with electron and hole bands, the wave vector at which the spin susceptibility is maximized is fixed even when the nesting is degraded, whereas when the Fermi surface is large, the nesting vector varies with the deformation of the Fermi surface. We also discuss the possibility of realizing in actual materials the bilayer Hubbard model, which is a simple model with electron and hole bands, and is expected to have a very high Tc.

  3. Isolated energy level in the band gap of Yb2Si2O7 identified by electron energy-loss spectroscopy

    NASA Astrophysics Data System (ADS)

    Ogawa, Takafumi; Kobayashi, Shunsuke; Wada, Masashi; Fisher, Craig A. J.; Kuwabara, Akihide; Kato, Takeharu; Yoshiya, Masato; Kitaoka, Satoshi; Moriwake, Hiroki

    2016-05-01

    We report the detection of an isolated energy level in the band gap of crystalline Yb2Si2O7 in the low-energy-loss region of its electron energy-loss (EEL) spectrum, obtained using a monochromated scanning transmission electron microscope. The experimental results are corroborated by first-principles calculations of the theoretical EEL spectrum. The calculations reveal that unoccupied Yb 4 f orbitals constitute an isolated energy level about 1 eV below the conduction band minimum (CBM), resulting in a terrace about 1 eV wide at the band edge of the EEL spectrum. In the case of Yb2O3 , no band edge terrace is present because the unoccupied f level lies just below the CBM. We also examined optical absorption properties of Yb2Si2O7 using UV-vis diffuse reflectance spectroscopy, which shows that the isolated energy level could not be detected in the band edge of the obtained absorbance spectrum. These findings demonstrate the utility of low-loss EEL spectroscopy with high energy resolution for probing semilocalized electronic features.

  4. Transition metal d -band occupancy in skutterudites studied by electron energy-loss spectroscopy

    NASA Astrophysics Data System (ADS)

    Prytz, Ø.; Taftø, J.; Ahn, C. C.; Fultz, B.

    2007-03-01

    The transition-metal 3d occupancy of a series of thermoelectric skutterudites is investigated using electron energy-loss spectroscopy. We find that bonding causes an emptying of the 3d states in the binary skutterudites CoP3 , CoAs3 , CoSb3 , and NiP3 , while compared to the pure Fe the 3d occupancy in LaFe4P12 is significantly increased, consistent with the idea that each interstitial La atom (rattler) donates three electrons to compensate for missing valence electron of Fe as compared to Co. These experimental results are in agreement with previous models suggesting a predominantly covalent bonding between transition metal and pnictogen atoms in skutterudites, and provide evidence of charge transfer from La to the Fe-P complex in LaFe4P12 .

  5. Electronic structure of cerium hydrides: Augmented-plane-wave linear-combination-of-atomic-orbitals energy bands

    NASA Astrophysics Data System (ADS)

    Fujimori, A.; Minami, F.; Tsuda, N.

    1980-10-01

    Electronic energy bands have been calculated for CeH2 and CeH3 using the augmented-plane-wave method and have been fitted by the linear-combination-of-atomic-orbitals interpolation scheme. The partial densities of states and the numbers of electrons on atomic orbitals indicate that hydrogen in CeH2 is almost anionlike. When going from CeH2 to CeH3, shallow bonding levels are found to form between the third hydrogen state and conduction electrons of CeH2, other features of CeH2 being little affected by it. Thus the rare-earth dihydrides are regarded as ionic compounds similar to the saline-element dihydrides except for the presence of d-like conduction electrons.

  6. Design study of an S-band RF cavity of a dual-energy electron LINAC for the CIS

    NASA Astrophysics Data System (ADS)

    Lee, Byeong-No; Park, Hyungdal; Song, Ki-baek; Li, Yonggui; Lee, Byung Cheol; Cha, Sung-su; Lee, Jong-Chul; Shin, Seung-Wook; Chai, Jong-seo

    2014-01-01

    The design of a resonance frequency (RF) cavity for the dual-energy S-band electron linear accelerator (LINAC) has been carried out for the cargo inspection system (CIS). This Standing-wave-type RF cavity is operated at a frequency under the 2856-MHz resonance frequency and generates electron beams of 9 MeV (high mode) and 6 MeV (low mode). The electrons are accelerated from the initial energy of the electron gun to the target energy (9 or 6 MeV) inside the RF cavity by using the RF power transmitted from a 5.5-MW-class klystron. Then, electron beams with a 1-kW average power (both high mode and low mode) bombard an X-ray target a 2-mm spot size. The proposed accelerating gradient was 13 MV/m, and the designed Q value was about 7100. On going research on 15-MeV non-destructive inspections for military or other applications is presented.

  7. Effect of energy band gap in graphene on negative refraction through the veselago lens and electron conductance

    NASA Astrophysics Data System (ADS)

    Dahal, Dipendra; Gumbs, Godfrey

    2017-01-01

    A remarkable property of intrinsic graphene is that upon doping, electrons and holes travel through the monolayer thick material with constant velocity which does not depend on energy up to about 0.3 eV (Dirac fermions), as though the electrons and holes are massless particles and antiparticles which move at the Fermi velocity vF. Consequently, there is Klein tunneling at a p-n junction, in which there is no backscattering at normal incidence of massless Dirac fermions. However, this process yielding perfect transmission at normal incidence is expected to be affected when the group velocity of the charge carriers is energy dependent and there is non-zero effective mass for the target particle. We investigate how away from normal incidence the combined effect of incident electron energy ɛ and band gap parameter Δ can determine whether a p-n junction would allow focusing of an electron beam by behaving like a Veselago lens with negative refractive index. We demonstrate that there is a specific region in ɛ - Δ space where the index of refraction is negative, i.e., where monolayer graphene behaves as a metamaterial. Outside this region, the refractive index may be positive or there may be no refraction at all. We compute the ballistic conductance across a p-n junction as a function of Δ and ɛ and compare our results with those for a single electrostatic potential barrier and multiple barriers.

  8. First-principles determination of band-to-band electronic transition energies in cubic and hexagonal AlGaInN alloys

    SciTech Connect

    Freitas, F. L. Marques, M.; Teles, L. K.

    2016-08-15

    We provide approximate quasiparticle-corrected band gap energies for quaternary cubic and hexagonal Al{sub x}Ga{sub y}In{sub 1–x–y}N semiconductor alloys, employing a cluster expansion method to account for the inherent statistical disorder of the system. Calculated values are compared with photoluminescence measurements and discussed within the currently accepted model of emission in these materials by carrier localization. It is shown that bowing parameters are larger in the cubic phase, while the range of band gap variation is bigger in the hexagonal one. Experimentally determined transition energies are mostly consistent with band-to-band excitations.

  9. Discrete energy bands in bulk semiconductors

    NASA Astrophysics Data System (ADS)

    Du, Maohua; Shi, Hongliang

    2015-03-01

    Bulk semiconductors typically have continuous valence and conduction bands. Discrete energy levels and bands have been sought after for various applications. For instance, discrete energy levels existing in semiconductor nanocrystals, or quantum does (QDs) have been proposed as a mechanism to suppress hot carrier thermalization and to enhance carrier multiplication in QD solar cells. Impurity bands in the band gap have been introduced for intermediate-band solar cells and for efficient visible light absorption and photocatalysis. In this talk, we show by first principles calculations that, in a multinary compound, a combination of large electronegativity difference between different cations (anions) and large nearest-neighbor distances in cation (anion) sublattices can lead to the splitting of the conduction (valence) band, resulting in several discrete and narrow energy bands separated by large energy gaps. We also discuss applications that may benefit from such electronic structure.

  10. Absolutely continuous energy bands in the electronic spectrum of quasiperiodic ladder networks

    NASA Astrophysics Data System (ADS)

    Pal, Biplab; Chakrabarti, Arunava

    2014-06-01

    The energy spectra of quasi-one-dimensional quasiperiodic ladder networks are analyzed within a tight binding description. In particular, we show that if a selected set of sites in each strand of a ladder is tunnel-coupled to quantum dots attached from a side, absolutely continuous subbands can be generated in the spectrum if one tunes the dot potential and the dot-strand coupling appropriately. Typical cases with two and three strand Fibonacci ladders in the off-diagonal model are discussed in details. We also discuss the possibility of re-entrant insulator-metal transition for a general n-strand ladder network when n becomes large. The observations remain valid even in the case of a disordered ladder network with the same constituents. The results are analytically exact.

  11. Calculation of the Energy-Band Structure of the Kronig-Penney Model Using the Nearly-Free and Tightly-Bound-Electron Approximations

    ERIC Educational Resources Information Center

    Wetsel, Grover C., Jr.

    1978-01-01

    Calculates the energy-band structure of noninteracting electrons in a one-dimensional crystal using exact and approximate methods for a rectangular-well atomic potential. A comparison of the two solutions as a function of potential-well depth and ratio of lattice spacing to well width is presented. (Author/GA)

  12. Calculation of the Energy-Band Structure of the Kronig-Penney Model Using the Nearly-Free and Tightly-Bound-Electron Approximations

    ERIC Educational Resources Information Center

    Wetsel, Grover C., Jr.

    1978-01-01

    Calculates the energy-band structure of noninteracting electrons in a one-dimensional crystal using exact and approximate methods for a rectangular-well atomic potential. A comparison of the two solutions as a function of potential-well depth and ratio of lattice spacing to well width is presented. (Author/GA)

  13. The influence of heat excitations, vacancies and impurities on the energy electronic band-structure of metallic lithium

    SciTech Connect

    Popov, V.A.

    1999-07-01

    The Korringa-Kohn-Rostoker method with Green's function averaged over the atomic configurations in a complex Ising lattice and a muffin-tin potential was used to calculate the electronic-band structure in lithium containing vacancies and s, p, and d impurities. It is shown that substantial changes in the profile of the Fermi surface do not lead to necking, as was postulated previously, but cause splitting of the electronic states at the face of the Brillouin zone. This is attributed to the reduced symmetry of the crystal lattice with impurity excitation of the electronic-subsystem.

  14. A shock-tube determination of the CN ground state dissociation energy and electronic transition moments for the CN violet and red band systems

    NASA Technical Reports Server (NTRS)

    Arnold, J. O.; Nicholls, R. W.

    1973-01-01

    The CN ground state dissociation energy and the sum of squares of the electronic transition moments of the CN violet bands have been simultaneously determined from spectral emission measurements behind incident shock waves. The unshocked test gases were composed of various CO2-CO-N2-Ar mixtures, and the temperatures behind the incident shocks ranged from 3500 to 8000 K. The variation of the electronic transition moment with internuclear separation was found to be small for both the CN violet and red band systems.

  15. A shock-tube determination of the CN ground state dissociation energy and electronic transition moments for the CN violet and red band systems

    NASA Technical Reports Server (NTRS)

    Arnold, J. O.; Nicholls, R. W.

    1973-01-01

    The CN ground state dissociation energy and the sum of squares of the electronic transition moments of the CN violet bands have been simultaneously determined from spectral emission measurements behind incident shock waves. The unshocked test gases were composed of various CO2-CO-N2-Ar mixtures, and the temperatures behind the incident shocks ranged from 3500 to 8000 K. The variation of the electronic transition moment with internuclear separation was found to be small for both the CN violet and red band systems.

  16. Electron energies in metals

    SciTech Connect

    Mahan, G.D. Tennessee Univ., Knoxville, TN . Dept. of Physics and Astronomy)

    1991-07-10

    The modern era of electron-electron interactions began a decade ago. Plummer's group initiated a program of using angular resolved photoemission to examine the band structure of the simple metals. Beginning with aluminum, and carrying on to sodium and potassium, they always found that the occupied energy bands were much narrower than expected. For example, the compressed energy bands for metallic potassium suggest a band effective mass of m* = 1.33m{sub e}. This should be compared to the band mass found from optical conductivity m*/m{sub e} = 1.01 {plus minus} 0.01. The discrepancy between these results is startling. It was this great difference which started my group doing calculations. Our program was two-fold. On one hand, we reanalyzed the experimental data, in order to see if Plummer's result was an experimental artifact. On the other hand, we completely redid the electron-electron self-energy calculations for simple metals, using the most modern choices of local-field corrections and vertex corrections. Our results will be reported in these lectures. They can be summarized as following: Our calculations give the same effective masses as the older calculations, so the theory is relatively unchanged; Our analysis of the experiments suggests that the recent measurements of band narrowing are an experimental artifact. 38 refs., 9 figs.

  17. Reconstructing the energy band electronic structure of pulsed laser deposited CZTS thin films intended for solar cell absorber applications

    NASA Astrophysics Data System (ADS)

    Pandiyan, Rajesh; Oulad Elhmaidi, Zakaria; Sekkat, Zouheir; Abd-lefdil, Mohammed; El Khakani, My Ali

    2017-02-01

    We report here on the use of pulsed KrF-laser deposition (PLD) technique for the growth of high-quality Cu2ZnSnS4 (CZTS) thin films onto Si, and glass substrates without resorting to any post sulfurization process. The PLD-CZTS films were deposited at room temperature (RT) and then subjected to post annealing at different temperatures ranging from 200 to 500 °C in Argon atmosphere. The X-ray diffraction and Raman spectroscopy confirmed that the PLD films crystallize in the characteristic kesterite CZTS structure regardless of their annealing temperature (Ta), but their crystallinity is much improved for Ta ≥ 400 °C. The PLD-CZTS films were found to exhibit a relatively dense morphology with a surface roughness (RMS) that increases with Ta (from ∼14 nm at RT to 70 nm at Ta = 500 °C with a value around 40 nm for Ta = 300-400 °C). The optical bandgap of the PLD-CZTS films, was derived from UV-vis transmission spectra analysis, and found to decrease from 1.73 eV for non-annealed films to ∼1.58 eV for those annealed at Ta = 300 °C. These band gap values are very close to the optimum value needed for an ideal solar cell absorber. In order to achieve a complete reconstruction of the one-dimensional energy band structure of these PLD-CZTS absorbers, we have combined both XPS and UPS spectroscopies to determine their chemical bondings, the position of their valence band maximum (relative to Fermi level), and their work function values. This enabled us to sketch out, as accurately as possible, the band alignment of the heterojunction interface formed between CZTS and both CdS and ZnS buffer layer materials.

  18. Electron paramagnetic resonance of conduction-band electrons in silicon

    NASA Astrophysics Data System (ADS)

    Young, C. F.; Poindexter, E. H.; Gerardi, G. J.; Warren, W. L.; Keeble, D. J.

    1997-06-01

    The g value of conduction-band electrons in silicon was properly determined by using electron paramagnetic resonance. A linear empirical relationship was first found between the g values and the thermal ionization energies of several well-known group-V substitutional shallow donors in silicon. An extrapolation of the empirical relation to zero ionization energy predicted the g value of conduction-band (CB) electrons, gCB=1.9995, which is slightly but definitely different from that of conduction electrons in the donor-impurity band of degenerate n-type silicon; although both g values have been tacitly accepted to be identical for nearly four decades. The prediction was directly verified by measuring the g value of CB electrons created either by thermal emission from shallow donors in phosphorus-doped silicon at T=125 K and by above-band-gap optical excitation in high-purity p-type silicon at T=3.5 K; the measured g value in both experiments was precisely gCB=1.9995(1). The empirical relation is still not theoretically explained.

  19. Theoretical study on electronic structure of bathocuproine: Renormalization of the band gap in the crystalline state and the large exciton binding energy

    NASA Astrophysics Data System (ADS)

    Yanagisawa, Susumu; Hatada, Shin-No-Suke; Morikawa, Yoshitada

    Bathocuproine (BCP) is a promising organic material of a hole blocking layer in organic light-emitting diodes or an electron buffer layer in organic photovoltaic cells. The nature of the unoccupied electronic states is a key characteristic of the material, which play vital roles in the electron transport. To elucidate the electronic properties of the molecular or crystalline BCP, we use the GW approximation for calculation of the fundamental gap, and the long-range corrected density functional theory for the molecular optical absorption. It is found that the band gap of the BCP single crystal is 4.39 eV, and it is in agreement with the recent low-energy inverse photoemission spectroscopy measurement. The polarization energy is estimated to be larger than 1 eV, demonstrating the large polarization effects induced by the electronic clouds surrounding the injected charge. The theoretical optical absorption energy is 3.68 eV, and the exciton binding energy is estimated to be 0.71 eV, implying the large binding in the eletron-hole pair distributed around the small part of the molecular region. This work was supported by the Grants-in-Aid for Young Scientists (B) (No. 26810009), and for Scientific Research on Innovative Areas ``3D Active-Site Science'' (No. 26105011) from Japan Society for the Promotion of Science.

  20. Probing optical band gaps at the nanoscale in NiFe₂O₄ and CoFe₂O₄ epitaxial films by high resolution electron energy loss spectroscopy

    SciTech Connect

    Dileep, K.; Loukya, B.; Datta, R.; Pachauri, N.; Gupta, A.

    2014-09-14

    Nanoscale optical band gap variations in epitaxial thin films of two different spinel ferrites, i.e., NiFe₂O₄ (NFO) and CoFe₂O₄ (CFO), have been investigated by spatially resolved high resolution electron energy loss spectroscopy. Experimentally, both NFO and CFO show indirect/direct band gaps around 1.52 eV/2.74 and 2.3 eV, and 1.3 eV/2.31 eV, respectively, for the ideal inverse spinel configuration with considerable standard deviation in the band gap values for CFO due to various levels of deviation from the ideal inverse spinel structure. Direct probing of the regions in both the systems with tetrahedral A site cation vacancy, which is distinct from the ideal inverse spinel configuration, shows significantly smaller band gap values. The experimental results are supported by the density functional theory based modified Becke-Johnson exchange correlation potential calculated band gap values for the different cation configurations.

  1. High energy electron irradiation of interstellar carbonaceous dust analogs: Cosmic ray effects on the carriers of the 3.4 µm absorption band.

    PubMed

    Maté, Belén; Molpeceres, Germán; Jiménez-Redondo, Miguel; Tanarro, Isabel; Herrero, Víctor J

    2016-11-01

    The effects of cosmic rays on the carriers of the interstellar 3.4 μm absorption band have been investigated in the laboratory. This band is attributed to stretching vibrations of CH3 and CH2 in carbonaceous dust. It is widely observed in the diffuse interstellar medium (ISM), but disappears in dense clouds. Destruction of CH3 and CH2 by cosmic rays could become relevant in dense clouds, shielded from the external ultraviolet field. For the simulations, samples of hydrogenated amorphous carbon (a-C:H) have been irradiated with 5 keV electrons. The decay of the band intensity vs electron fluence reflects a-C:H dehydrogenation, which is well described by a model assuming that H2 molecules, formed by the recombination of H atoms liberated through CH bond breaking, diffuse out of the sample. The CH bond destruction rates derived from the present experiments are in good accordance with those from previous ion irradiation experiments of HAC. The experimental simplicity of electron bombardment has allowed the use of higher energy doses than in the ion experiments. The effects of cosmic rays on the aliphatic components of cosmic dust are found to be small. The estimated cosmic ray destruction times for the 3.4 μm band carriers lie in the 10(8) yr range and cannot account for the disappearance of this band in dense clouds, which have characteristic lifetimes of 3 × 10(7) yr. The results invite a more detailed investigation of the mechanisms of CH bond formation and breaking in the intermediate region between diffuse and dense clouds.

  2. High energy electron irradiation of interstellar carbonaceous dust analogs: Cosmic ray effects on the carriers of the 3.4 µm absorption band

    PubMed Central

    Maté, Belén; Molpeceres, Germán; Jiménez-Redondo, Miguel; Tanarro, Isabel; Herrero, Víctor J.

    2017-01-01

    The effects of cosmic rays on the carriers of the interstellar 3.4 μm absorption band have been investigated in the laboratory. This band is attributed to stretching vibrations of CH3 and CH2 in carbonaceous dust. It is widely observed in the diffuse interstellar medium (ISM), but disappears in dense clouds. Destruction of CH3 and CH2 by cosmic rays could become relevant in dense clouds, shielded from the external ultraviolet field. For the simulations, samples of hydrogenated amorphous carbon (a-C:H) have been irradiated with 5 keV electrons. The decay of the band intensity vs electron fluence reflects a-C:H dehydrogenation, which is well described by a model assuming that H2 molecules, formed by the recombination of H atoms liberated through CH bond breaking, diffuse out of the sample. The CH bond destruction rates derived from the present experiments are in good accordance with those from previous ion irradiation experiments of HAC. The experimental simplicity of electron bombardment has allowed the use of higher energy doses than in the ion experiments. The effects of cosmic rays on the aliphatic components of cosmic dust are found to be small. The estimated cosmic ray destruction times for the 3.4 μm band carriers lie in the 108 yr range and cannot account for the disappearance of this band in dense clouds, which have characteristic lifetimes of 3 × 107 yr. The results invite a more detailed investigation of the mechanisms of CH bond formation and breaking in the intermediate region between diffuse and dense clouds. PMID:28133388

  3. High-energy Electron Irradiation of Interstellar Carbonaceous Dust Analogs: Cosmic-ray Effects on the Carriers of the 3.4 μm Absorption Band

    NASA Astrophysics Data System (ADS)

    Maté, Belén; Molpeceres, Germán; Jiménez-Redondo, Miguel; Tanarro, Isabel; Herrero, Víctor J.

    2016-11-01

    The effects of cosmic rays on the carriers of the interstellar 3.4 μm absorption band have been investigated in the laboratory. This band is attributed to stretching vibrations of CH3 and CH2 in carbonaceous dust. It is widely observed in the diffuse interstellar medium, but disappears in dense clouds. Destruction of CH3 and CH2 by cosmic rays could become relevant in dense clouds, shielded from the external ultraviolet field. For the simulations, samples of hydrogenated amorphous carbon (a-C:H) have been irradiated with 5 keV electrons. The decay of the band intensity versus electron fluence reflects a-C:H dehydrogenation, which is well described by a model assuming that H2 molecules, formed by the recombination of H atoms liberated through CH bond breaking, diffuse out of the sample. The CH bond destruction rates derived from the present experiments are in good accordance with those from previous ion irradiation experiments of HAC. The experimental simplicity of electron bombardment has allowed the use of higher-energy doses than in the ion experiments. The effects of cosmic rays on the aliphatic components of cosmic dust are found to be small. The estimated cosmic-ray destruction times for the 3.4 μm band carriers lie in the 108 yr range and cannot account for the disappearance of this band in dense clouds, which have characteristic lifetimes of 3 × 107 yr. The results invite a more detailed investigation of the mechanisms of CH bond formation and breaking in the intermediate region between diffuse and dense clouds.

  4. Energy ranges and pitch angles of outer radiation belt electrons depleted by an intense dayside hydrogen band EMIC wave event on February 23, 2014

    NASA Astrophysics Data System (ADS)

    Engebretson, M. J.; Posch, J. L.; Huang, C. L.; Kanekal, S. G.; Fok, M. C. H.; Rodger, C. J.; Smith, C. W.; Spence, H. E.; Baker, D. N.; Kletzing, C.; Wygant, J. R.

    2015-12-01

    Although most studies of the effect of EMIC waves on relativistic electrons have focused on wave events in the afternoon sector in the outer plasmasphere or plume region, strong magnetospheric compressions provide an additional stimulus for EMIC wave generation across a large range of local times and L shells. We present here observations of the effects of an intense, long-duration hydrogen band EMIC wave event on February 23, 2014 that was stimulated by a gradual 4-hour rise and subsequent sharp increases in solar wind pressure. Large-amplitude linearly polarized hydrogen band EMIC waves (up to 25 nT p-p) that included triggered emissions appeared for over 4 hours at both Van Allen Probes while these spacecraft were outside the plasmapause, in a region with densities ~5-20 cm-3, as they passed near apogee from late morning through local noon. Observations of radiation belt electrons by the REPT and MagEIS instruments on these spacecraft showed that these waves caused significant depletions of more field-aligned electrons at ultrarelativistic energies from 5.2 MeV down to ~2 MeV, and some depletions at energies down to below 1 MeV as well.

  5. Engineering the Electronic Band Structure for Multiband Solar Cells

    SciTech Connect

    Lopez, N.; Reichertz, L.A.; Yu, K.M.; Campman, K.; Walukiewicz, W.

    2010-07-12

    Using the unique features of the electronic band structure of GaNxAs1-x alloys, we have designed, fabricated and tested a multiband photovoltaic device. The device demonstrates an optical activity of three energy bands that absorb, and convert into electrical current, the crucial part of the solar spectrum. The performance of the device and measurements of electroluminescence, quantum efficiency and photomodulated reflectivity are analyzed in terms of the Band Anticrossing model of the electronic structure of highly mismatched alloys. The results demonstrate the feasibility of using highly mismatched alloys to engineer the semiconductor energy band structure for specific device applications.

  6. Engineering the electronic band structure for multiband solar cells.

    PubMed

    López, N; Reichertz, L A; Yu, K M; Campman, K; Walukiewicz, W

    2011-01-14

    Using the unique features of the electronic band structure of GaN(x)As(1-x) alloys, we have designed, fabricated and tested a multiband photovoltaic device. The device demonstrates an optical activity of three energy bands that absorb, and convert into electrical current, the crucial part of the solar spectrum. The performance of the device and measurements of electroluminescence, quantum efficiency and photomodulated reflectivity are analyzed in terms of the band anticrossing model of the electronic structure of highly mismatched alloys. The results demonstrate the feasibility of using highly mismatched alloys to engineer the semiconductor energy band structure for specific device applications.

  7. Toward Revealing the Critical Role of Perovskite Coverage in Highly Efficient Electron-Transport Layer-Free Perovskite Solar Cells: An Energy Band and Equivalent Circuit Model Perspective.

    PubMed

    Huang, Like; Xu, Jie; Sun, Xiaoxiang; Du, Yangyang; Cai, Hongkun; Ni, Jian; Li, Juan; Hu, Ziyang; Zhang, Jianjun

    2016-04-20

    Currently, most efficient perovskite solar cells (PVKSCs) with a p-i-n structure require simultaneously electron transport layers (ETLs) and hole transport layers (HTLs) to help collecting photogenerated electrons and holes for obtaining high performance. ETL free planar PVKSC is a relatively new and simple structured solar cell that gets rid of the complex and high temperature required ETL (such as compact and mesoporous TiO2). Here, we demonstrate the critical role of high coverage of perovskite in efficient ETL free PVKSCs from an energy band and equivalent circuit model perspective. From an electrical point of view, we confirmed that the low coverage of perovskite does cause localized short circuit of the device. With coverage optimization, a planar p-i-n(++) device with a power conversion efficiency of over 11% was achieved, implying that the ETL layer may not be necessary for an efficient device as long as the perovskite coverage is approaching 100%.

  8. Banded Electron Structure Formation in the Inner Magnetosphere

    NASA Technical Reports Server (NTRS)

    Liemohn, M. W.; Khazanov, G. V.

    1997-01-01

    Banded electron structures in energy-time spectrograms have been observed in the inner magnetosphere concurrent with a sudden relaxation of geomagnetic activity. In this study, the formation of these banded structures is considered with a global, bounce-averaged model of electron transport, and it is concluded that this structure is a natural occurrence when plasma sheet electrons are captured on closed drift paths near the Earth. These bands do not appear unless there is capture of plasma sheet electrons; convection along open drift paths making open pass around the Earth do not have time to develop this feature. The separation of high-energy bands from the injection population due to the preferential advection of the gradient-curvature drift creates spikes in the energy distribution, which overlap to form a series of bands in the energy spectrograms. The lowest band is the bulk of the injected population in the sub-key energy range. Using the Kp history for an observed banded structure event, a cloud of plasma sheet electrons is captured and the development of their distribution function is examined and discussed.

  9. Electronic band structure of defect chalcopyrites

    NASA Astrophysics Data System (ADS)

    Jiang, Xiaoshu; Lambrecht, Walter R. L.

    2001-03-01

    The defect chalcopyrites of chemical composition II-III-VI4 in which II, III and VI mean group-II elements such as Cd or Hg, group-III elements such as Al and Ga and group-VI elements such as S, Se, Te, form an interesting family of semiconductor compounds with potential nonlinear optical applications. They can be thought of as derived from the regular I-III-VI2 chalcopyrites by doubling the formula unit and replacing the group I element, for example, Ag by the group-II element and a vacancy in an ordered manner. The chalcopyrites themselves are derived from II-VI compounds by replacing the group-II by a group I and a group-III element. In this contribution we present electronic band structure calculations of some of these compounds, calculated using the linear muffin-tin orbital method combined with the local density functional approximation. We discuss the relation of the band structures of the corresponding zincblende, chalcopyrite and defect chalcopyrite compounds. In particular, the role of the group I or group II d-band energy will be shown to be important. The trends with chemical substutions and the effects of structural distortions c/a and internal parameters accompanying the chemical distortion will be discussed.

  10. Electronic band structure of surface-doped black phosphorus

    NASA Astrophysics Data System (ADS)

    Kim, Jimin; Ryu, Sae Hee; Sohn, Yeongsup; Kim, Keun Su

    2015-03-01

    There are rapidly growing interests in the study of few-layer black phosphorus owing to its promising device characteristics that may impact our future electronics technology. The low-energy band structure of black phosphorus has been widely predicted to be controllable by external perturbations, such as strain and doping. In this work, we attempt to control the electronic band structure of black phosphorous by in-situ surface deposition of alkali-metal atoms. We found that surface doping induces steep band bending towards the bulk, leading to the emergence of new 2D electronic states that are confined within only few phosphorene layers of black phosphorus. Using angle-resolved photoemission spectroscopy, we directly measured the electronic band structure and its evolution as a function of dopant density. Supported by IBS.

  11. Direct band gap measurement of Cu(In,Ga)(Se,S){sub 2} thin films using high-resolution reflection electron energy loss spectroscopy

    SciTech Connect

    Heo, Sung; Lee, Hyung-Ik; Park, Jong-Bong; Ko, Dong-Su; Chung, JaeGwan; Kim, KiHong; Kim, Seong Heon; Yun, Dong-Jin; Ham, YongNam; Park, Gyeong Su; Song, Taewon; Lee, Dongho Nam, Junggyu; Kang, Hee Jae; Choi, Pyung-Ho; Choi, Byoung-Deog

    2015-06-29

    To investigate the band gap profile of Cu(In{sub 1−x},Ga{sub x})(Se{sub 1−y}S{sub y}){sub 2} of various compositions, we measured the band gap profile directly as a function of in-depth using high-resolution reflection energy loss spectroscopy (HR-REELS), which was compared with the band gap profile calculated based on the auger depth profile. The band gap profile is a double-graded band gap as a function of in-depth. The calculated band gap obtained from the auger depth profile seems to be larger than that by HR-REELS. Calculated band gaps are to measure the average band gap of the spatially different varying compositions with respect to considering its void fraction. But, the results obtained using HR-REELS are to be affected by the low band gap (i.e., out of void) rather than large one (i.e., near void). Our findings suggest an analytical method to directly determine the band gap profile as function of in-depth.

  12. Energy band alignment at the nanoscale

    NASA Astrophysics Data System (ADS)

    Deuermeier, Jonas; Fortunato, Elvira; Martins, Rodrigo; Klein, Andreas

    2017-01-01

    The energy band alignments at interfaces often determine the electrical functionality of a device. Along with the size reduction into the nanoscale, functional coatings become thinner than a nanometer. With the traditional analysis of the energy band alignment by in situ photoelectron spectroscopy, a critical film thickness is needed to determine the valence band offset. By making use of the Auger parameter, it becomes possible to determine the energy band alignment to coatings, which are only a few Ångström thin. This is demonstrated with experimental data of Cu2O on different kinds of substrate materials.

  13. Mapping the Copper energy band using the quantum well states

    NASA Astrophysics Data System (ADS)

    Wu, J.; Choi, J.; Owens, T.; Qiu, Z. Q.; Rotenberg, E.; Smith, N. V.

    2006-03-01

    Quantum well states (QWS) of copper electrons in Cu/Co/Cu(100) system are investigated using Angle Resolved Photoemission Electron Spectroscopy (ARPES). The samples were grown epitaxially at room temperature and measured in situ at beamlime 7 of the Advanced Light Source (ALS). Photoemission intensity oscillates with both the electron energy and the Cu film thickness. By counting the thickness oscillation periodicity at a given energy, we can determine the out-of-plane electron momentum without the need of the phase value in the phase accumulation model. This allows the experimental determination of the E-k relation (energy band) for the Cu film. We here report the Cu energy band determined in this way at different in-plane momentum. In addition, by fitting the oscillation as a function of the Cu thickness, we also determined the phase value of the quantization condition as a function of the energy and in-plane momentum.

  14. Density of states in a two-dimensional electron gas: Impurity bands and band tails

    NASA Astrophysics Data System (ADS)

    Gold, A.; Serre, J.; Ghazali, A.

    1988-03-01

    We calculate the density of states of a two-dimensional electron gas in the presence of charged impurities within Klauder's best multiple-scattering approach. The silicon metal-oxide-semiconductor (MOS) system with impurities at the interface is studied in detail. The finite extension of the electron wave function into the bulk is included as well as various dependences of the density of states on the electron, the depletion, and the impurity densities. The transition from an impurity band at low impurity concentration to a band tail at high impurity concentration is found to take place at a certain impurity concentration. If the screening parameter of the electron gas is decreased, the impurity band shifts to lower energy. For low impurity density we find excited impurity bands. Our theory at least qualitatively explains conductivity and infrared-absorption experiments on impurity bands in sodium-doped MOS systems and deep band tails in the gap observed for high doping levels in these systems.

  15. Impurity levels, impurity bands, excited impurity bands, and band tails: The electronic density of states in quantum wells and heterostructures

    NASA Astrophysics Data System (ADS)

    Serre, J.; Ghazali, A.; Gold, A.

    1989-04-01

    We have investigated in quantum wells (QW's) and heterostructures (HS's) the modification of the electronic structure near the band edge, which is induced by selective doping. The density of states has been calculated as a function of the relevant parameters, namely, carrier and impurity concentrations (and depletion concentrations for HS's), QW width, and impurity position. Using a multiple-scattering method which includes a finite-range screened potential and impurity concentration to all orders, we have succeeded in obtaining ground-state and excited-state impurity bands (IB's). We observed these bands merging gradually with the lowest conduction subband as the impurity concentration is increased, leading to the formation of a band tail into the energy gap. Other main results obtained for different values of the parameters are the binding energy for a single impurity, the widths and energy shifts of ground- and excited-state IB's, and the contribution of the electron-impurity interaction to the gap shrinkage in the band-tail regime. Our results are compared with experiments and other theories.

  16. Electronic band structure of magnetic bilayer graphene superlattices

    SciTech Connect

    Pham, C. Huy; Nguyen, T. Thuong

    2014-09-28

    Electronic band structure of the bilayer graphene superlattices with δ-function magnetic barriers and zero average magnetic flux is studied within the four-band continuum model, using the transfer matrix method. The periodic magnetic potential effects on the zero-energy touching point between the lowest conduction and the highest valence minibands of pristine bilayer graphene are exactly analyzed. Magnetic potential is shown also to generate the finite-energy touching points between higher minibands at the edges of Brillouin zone. The positions of these points and the related dispersions are determined in the case of symmetric potentials.

  17. Density of States for Warped Energy Bands.

    PubMed

    Mecholsky, Nicholas A; Resca, Lorenzo; Pegg, Ian L; Fornari, Marco

    2016-02-24

    Warping of energy bands can affect the density of states (DOS) in ways that can be large or subtle. Despite their potential for significant practical impacts on materials properties, these effects have not been rigorously demonstrated previously. Here we rectify this using an angular effective mass formalism that we have developed. To clarify the often confusing terminology in this field, "band warping" is precisely defined as pertaining to any multivariate energy function E(k) that does not admit a second-order differential at an isolated critical point in k-space, which we clearly distinguish from band non-parabolicity. We further describe band "corrugation" as a qualitative form of band warping that increasingly deviates from being twice differentiable at an isolated critical point. These features affect the density-of-states and other parameters ascribed to band warping in various ways. We demonstrate these effects, providing explicit calculations of DOS and their effective masses for warped energy dispersions originally derived by Kittel and others. Other physical and mathematical examples are provided to demonstrate fundamental distinctions that must be drawn between DOS contributions that originate from band warping and contributions that derive from band non-parabolicity. For some non-degenerate bands in thermoelectric materials, this may have profound consequences of practical interest.

  18. Unusual Changes in Electronic Band-Edge Energies of the Nanostructured Transparent n-Type Semiconductor Zr-Doped Anatase TiO2 (Ti1-xZrxO2; x < 0.3).

    PubMed

    Mieritz, Daniel G; Renaud, Adèle; Seo, Dong-Kyun

    2016-07-05

    By the establishment of highly controllable synthetic routes, electronic band-edge energies of the n-type transparent semiconductor Zr-doped anatase TiO2 have been studied holistically for the first time up to 30 atom % Zr, employing powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen gas sorption measurements, UV/vis spectroscopies, and Mott-Schottky measurements. The materials were produced through a sol-gel synthetic procedure that ensures good compositional homogeneity of the materials, while introducing nanoporosity in the structure, by achieving a mild calcination condition. Vegard's law was discovered among the homogeneous samples, and correlations were established between the chemical compositions and optical and electronic properties of the materials. Up to 20% Zr doping, the optical energy gap increases to 3.29 eV (vs 3.19 eV for TiO2), and the absolute conduction band-edge energy increases to -3.90 eV (vs -4.14 eV). The energy changes of the conduction band edge are more drastic than what is expected from the average electronegativities of the compounds, which may be due to the unnatural coordination environment around Zr in the anatase phase.

  19. Observation of mini-band formation in the ground and high-energy electronic states of super-lattice solar cells

    NASA Astrophysics Data System (ADS)

    Usuki, Takanori; Matsuochi, Kouki; Nakamura, Tsubasa; Toprasertpong, Kasidit; Fukuyama, Atsuhiko; Sugiyama, Masakazu; Nakano, Yoshiaki; Ikari, Tetsuo

    2016-03-01

    Multiple Quantum wells (MQWs) have been studied as one promising material for high-efficiency nextgeneration solar cells. However, a portion of photo-excited carriers recombine in MQWs, resulting in the degradation of cell performance. Super-lattice (SL) structures, where quantum states in neighboring quantum wells strongly couple with each other, have been proposed for the carrier collection improvement via the tunneling transport through mini-bands. Therefore, it is important to characterize mini-band formation in various types of SL structures. We examined p-i-n GaAs-based solar cells whose i layers contain 20 stacks of InGaAs/GaAsP MQW structures with 2.1-nm GaAsP barriers (thin-barrier cell), with 2.1-nm barriers and 3-nm GaAs interlayers in between GaAsP barriers and InGaAs wells (stepbarrier cell), and with 7.8-nm barriers (thick-barrier cell). We investigated the optical absorption spectra of the SL solar cells using piezoelectric photo-thermal (PPT) spectroscopy. In the thick-barrier cell, one exciton peak was observed near the absorption edge of MQWs. On the other hand, we confirmed a split of the exciton peak for the thin-barrier SL, suggesting the formation of mini-band. Moreover, in the step-barrier cell, the mini-band at the ground state disappears since thick GaAs interlayers isolate each quantum-well ground state and, instead, the mini-band formation of highenergy states could be observed. By estimating from the energy-level calculation, this is attributed to the mini-band formation of light-hole states. This can well explain the improvement of carrier collection efficiency (CCE) of the thinbarrier and the step-barrier cells compared with the thick-barrier cell.

  20. Intrinsic evolutions of optical functions, band gap, and higher-energy electronic transitions in VO2 film near the metal-insulator transition region

    NASA Astrophysics Data System (ADS)

    Li, W. W.; Yu, Q.; Liang, J. R.; Jiang, K.; Hu, Z. G.; Liu, J.; Chen, H. D.; Chu, J. H.

    2011-12-01

    Transmittance spectra of (011) vanadium dioxide (VO2) film have been studied in the temperature range of 45-80 °C. Owing to increasing carrier concentration, the near-infrared extinction coefficient and optical conductivity around metal-insulator transition (MIT) rapidly increase with the temperature. Moreover, three electronic transitions can be uniquely assigned and show the hysteresis behavior near the MIT region. It was found that the optical band gap decreases from 0.457 to 0.042 eV before the MIT, then reduces to zero for the metal state. This confirms the fact that the a1g and egπ bands are moved close and finally overlap with the temperature.

  1. Engineering flat electronic bands in quasiperiodic and fractal loop geometries

    NASA Astrophysics Data System (ADS)

    Nandy, Atanu; Chakrabarti, Arunava

    2015-11-01

    Exact construction of one electron eigenstates with flat, non-dispersive bands, and localized over clusters of various sizes is reported for a class of quasi-one-dimensional looped networks. Quasiperiodic Fibonacci and Berker fractal geometries are embedded in the arms of the loop threaded by a uniform magnetic flux. We work out an analytical scheme to unravel the localized single particle states pinned at various atomic sites or over clusters of them. The magnetic field is varied to control, in a subtle way, the extent of localization and the location of the flat band states in energy space. In addition to this we show that an appropriate tuning of the field can lead to a re-entrant behavior of the effective mass of the electron in a band, with a periodic flip in its sign.

  2. Layer specific optical band gap measurement at nanoscale in MoS{sub 2} and ReS{sub 2} van der Waals compounds by high resolution electron energy loss spectroscopy

    SciTech Connect

    Dileep, K. E-mail: ranjan@jncasr.ac.in; Sahu, R.; Datta, R. E-mail: ranjan@jncasr.ac.in; Sarkar, Sumanta; Peter, Sebastian C.

    2016-03-21

    Layer specific direct measurement of optical band gaps of two important van der Waals compounds, MoS{sub 2} and ReS{sub 2}, is performed at nanoscale by high resolution electron energy loss spectroscopy. For monolayer MoS{sub 2}, the twin excitons (1.8 and 1.95 eV) originating at the K point of the Brillouin zone are observed. An indirect band gap of 1.27 eV is obtained from the multilayer regions. Indirect to direct band gap crossover is observed which is consistent with the previously reported strong photoluminescence from the monolayer MoS{sub 2}. For ReS{sub 2}, the band gap is direct, and a value of 1.52 and 1.42 eV is obtained for the monolayer and multilayer, respectively. The energy loss function is dominated by features due to high density of states at both the valence and conduction band edges, and the difference in analyzing band gap with respect to ZnO is highlighted. Crystalline 1T ReS{sub 2} forms two dimensional chains like superstructure due to the clustering between four Re atoms. The results demonstrate the power of HREELS technique as a nanoscale optical absorption spectroscopy tool.

  3. High energy electron cooling

    SciTech Connect

    Parkhomchuk, V.

    1997-09-01

    High energy electron cooling requires a very cold electron beam. The questions of using electron cooling with and without a magnetic field are presented for discussion at this workshop. The electron cooling method was suggested by G. Budker in the middle sixties. The original idea of the electron cooling was published in 1966. The design activities for the NAP-M project was started in November 1971 and the first run using a proton beam occurred in September 1973. The first experiment with both electron and proton beams was started in May 1974. In this experiment good result was achieved very close to theoretical prediction for a usual two component plasma heat exchange.

  4. Potential energy surfaces for ground and excited electronic states of the CF3I molecule and their relevance to its A-band photodissociation.

    PubMed

    Alekseyev, Aleksey B; Liebermann, Heinz-Peter; Buenker, Robert J

    2013-05-14

    The multireference spin-orbit (SO) configuration interaction (CI) method in its Λ-S contracted SO-CI version is employed to calculate two-dimensional potential energy surfaces for the ground and low-lying excited states of CF3I relevant to its photodissociation in the lowest absorption band (A band). The computed equilibrium geometry for the X̃A1 ground state and vibrational frequency ν3 for the C-I stretch mode agree well with available experimental data. The (3)Q0(+) state dissociating to the excited I((2)P1/2) limit is found to have a minimum of 1570 cm(-1) significantly shifted to larger internuclear distances (RC-I = 5.3 a0) relative to the ground state. Similar to the CH3I case, this makes a single-exponent approximation commonly employed for analysis of the CF3I recoil dynamics unsuitable. The 4E((3)A1) state possessing an allowed transition from the ground state and converging to the same atomic limit as (3)Q0(+) is calculated to lie too high in the Franck-Condon region to have any significant impact on the A-band absorption. The computed vertical excitation energies for the (3)Q1, (3)Q0(+), and (1)Q states indicate that the A-band spectrum must lie approximately between 31,300 and 45,200 cm(-1), i.e., between 220 and 320 nm. This result is in very good agreement with the measured absorption spectrum.

  5. Energy-banded ions in Saturn's magnetosphere

    NASA Astrophysics Data System (ADS)

    Thomsen, M. F.; Badman, S. V.; Jackman, C. M.; Jia, X.; Kivelson, M. G.; Kurth, W. S.

    2017-05-01

    Using data from the Cassini Plasma Spectrometer ion mass spectrometer, we report the first observation of energy-banded ions at Saturn. Observed near midnight at relatively high magnetic latitudes, the banded ions are dominantly H+, and they occupy the range of energies typically associated with the thermal pickup distribution in the inner magnetosphere (L < 10), but their energies decline monotonically with increasing radial distance (or time or decreasing latitude). Their pitch angle distribution suggests a source at low (or slightly southern) latitudes. The band energies, including their pitch angle dependence, are consistent with a bounce-resonant interaction between thermal H+ ions and the standing wave structure of a field line resonance. There is additional evidence in the pitch angle dependence of the band energies that the particles in each band may have a common time of flight from their most recent interaction with the wave, which may have been at slightly southern latitudes. Thus, while the particles are basically bounce resonant, their energization may be dominated by their most recent encounter with the standing wave.Plain Language SummaryDuring an outbound passage by the Cassini spacecraft through Saturn's inner magnetosphere, ion <span class="hlt">energy</span> distributions were observed that featured discrete flux peaks at regularly spaced <span class="hlt">energies</span>. The peaks persisted over several hours and several Saturn radii of distance away from the planet. We show that these "<span class="hlt">bands</span>" of ions are plausibly the result of an interaction between the Saturnian plasma and standing waves that form along the magnetospheric magnetic field lines. These observations are the first reported evidence that such standing waves may be present in the inner magnetosphere, where they could contribute to the radial transport of Saturn's radiation belt particles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARS51014T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARS51014T"><span><span class="hlt">Electron</span>-Phonon Renormalization of <span class="hlt">Electronic</span> <span class="hlt">Band</span> Structures of C Allotropes and BN Polymorphs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tutchton, Roxanne M.; Marchbanks, Christopher; Wu, Zhigang</p> <p></p> <p>The effect of lattice vibration on <span class="hlt">electronic</span> <span class="hlt">band</span> structures has been mostly neglected in first-principles calculations because the <span class="hlt">electron</span>-phonon (e-ph) renormalization of quasi-particle <span class="hlt">energies</span> is often small (< 100 meV). However, in certain materials, such as diamond, the <span class="hlt">electron</span>-phonon coupling reduces the <span class="hlt">band</span> gap by nearly 0.5 eV, which is comparable to the many-body corrections of the <span class="hlt">electronic</span> <span class="hlt">band</span> structures calculated using the density functional theory (DFT). In this work, we compared two implementations of the Allen-Heine-Cardona theory in the EPW code and the ABINIT package respectively. Our computations of Si and diamond demonstrate that the ABINIT implementation converges much faster. Using this method, the e-ph renormalizations of <span class="hlt">electronic</span> structures of three C allotropes (diamond, graphite, graphene) and four BN polymorphs (zincblend, wurtzite, mono-layer, and layered-hexagonal) were calculated. Our results suggest that (1) all of the zero-point renormalizations of <span class="hlt">band</span> gaps in these materials, except for graphene, are larger than 100 meV, and (2) there are large variations in e-ph renormalization of <span class="hlt">band</span> gaps due to differences in crystal structure. This work was supported by a U.S. DOE Early Career Award (Grant No. DE-SC0006433). Computations were carried out at the Golden <span class="hlt">Energy</span> Computing Organization at CSM and the National <span class="hlt">Energy</span> Research Scientific Computing Center (NERSC).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhLA..380.3430M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhLA..380.3430M"><span><span class="hlt">Energy</span> <span class="hlt">bands</span> and gaps near an impurity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mihóková, E.; Schulman, L. S.</p> <p>2016-10-01</p> <p>It has been suggested that in the neighborhood of a certain kind of defect in a crystal there is a bend in the <span class="hlt">electronic</span> <span class="hlt">band</span>. We confirm that this is indeed possible using the Kronig-Penney model. Our calculations also have implications for photonic crystals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/951092','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/951092"><span>Eastern <span class="hlt">Band</span> of Cherokee Strategic <span class="hlt">Energy</span> Plan</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Souther Carolina Institute of energy Studies-Robert Leitner</p> <p>2009-01-30</p> <p>The Eastern <span class="hlt">Band</span> of Cherokee Indians was awarded a grant under the U.S. Department of <span class="hlt">Energy</span> Tribal <span class="hlt">Energy</span> Program (TEP) to develop a Tribal Strategic <span class="hlt">Energy</span> Plan (SEP). The grant, awarded under the “First Steps” phase of the TEP, supported the development of a SEP that integrates with the Tribe’s plans for economic development, preservation of natural resources and the environment, and perpetuation of Tribal heritage and culture. The Tribe formed an <span class="hlt">Energy</span> Committee consisting of members from various departments within the Tribal government. This committee, together with its consultant, the South Carolina Institute for <span class="hlt">Energy</span> Studies, performed the following activities: • Develop the Tribe’s <span class="hlt">energy</span> goals and objectives • Establish the Tribe’s current <span class="hlt">energy</span> usage • Identify available renewable <span class="hlt">energy</span> and <span class="hlt">energy</span> efficiency options • Assess the available options versus the goals and objectives • Create an action plan for the selected options</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760014923&hterms=energy+derivatives&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Denergy%2Bderivatives','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760014923&hterms=energy+derivatives&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Denergy%2Bderivatives"><span><span class="hlt">Electronic</span> <span class="hlt">energy</span> states</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1976-01-01</p> <p>One-<span class="hlt">electron</span> wave functions are reviewed and approximate solutions of two-<span class="hlt">electron</span> systems are given in terms of these one-<span class="hlt">electron</span> functions. The symmetry effects associated with <span class="hlt">electron</span> spin are reviewed and the effects of <span class="hlt">electron</span> exchange on <span class="hlt">energy</span> levels of the two-<span class="hlt">electron</span> system are given. The coupling of <span class="hlt">electronic</span> orbital and spin angular momentum is considered next and the Lande interval rule for Russell-Saunders or LS coupling is derived. The configurations possible for various multi-<span class="hlt">electron</span> LS couplings are enumerated (examples from the first two rows of the periodic table are given), and the meaning of the spectroscopic nomenclature is discussed, particularly with respect to the degeneracies of the <span class="hlt">electron</span> states involved. Next the nomenclature, symmetries, and degeneracies for <span class="hlt">electron</span> states of diatomic molecules are discussed, and some examples for N2, O2, and NO are presented. The <span class="hlt">electronic</span> partition functions and derivative thermodynamic properties are expressed in terms of these <span class="hlt">energies</span> and degeneracies, and examples are given for some of the simple gas species encountered in the earth's atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JAP...120i5701S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JAP...120i5701S"><span>The sensitivity of the <span class="hlt">electron</span> transport within bulk zinc-blende gallium nitride to variations in the crystal temperature, the doping concentration, and the non-parabolicity coefficient associated with the lowest <span class="hlt">energy</span> conduction <span class="hlt">band</span> valley</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siddiqua, Poppy; O'Leary, Stephen K.</p> <p>2016-09-01</p> <p>Within the framework of a semi-classical three-valley Monte Carlo simulation approach, we analyze the steady-state and transient <span class="hlt">electron</span> transport that occurs within bulk zinc-blende gallium nitride. In particular, we examine how the steady-state and transient <span class="hlt">electron</span> transport that occurs within this material changes in response to variations in the crystal temperature, the doping concentration, and the non-parabolicity coefficient associated with the lowest <span class="hlt">energy</span> conduction <span class="hlt">band</span> valley. These results are then contrasted with those corresponding to a number of other compound semiconductors of interest.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22598820','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22598820"><span>The sensitivity of the <span class="hlt">electron</span> transport within bulk zinc-blende gallium nitride to variations in the crystal temperature, the doping concentration, and the non-parabolicity coefficient associated with the lowest <span class="hlt">energy</span> conduction <span class="hlt">band</span> valley</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Siddiqua, Poppy; O'Leary, Stephen K.</p> <p>2016-09-07</p> <p>Within the framework of a semi-classical three-valley Monte Carlo simulation approach, we analyze the steady-state and transient <span class="hlt">electron</span> transport that occurs within bulk zinc-blende gallium nitride. In particular, we examine how the steady-state and transient <span class="hlt">electron</span> transport that occurs within this material changes in response to variations in the crystal temperature, the doping concentration, and the non-parabolicity coefficient associated with the lowest <span class="hlt">energy</span> conduction <span class="hlt">band</span> valley. These results are then contrasted with those corresponding to a number of other compound semiconductors of interest.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998JMoSp.190...78L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998JMoSp.190...78L"><span>The Torsion-Inversion-Bending <span class="hlt">Energy</span> Levels in the S1( n, π*) <span class="hlt">Electronic</span> State of Acetaldehyde . A High-Resolution Study of the <span class="hlt">Bands</span> #7 to #20 in the Jet-Cooled Fluorescence Excitation Spectrum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Haisheng; Lim, Edward C.; Niño, Alfonso; Muñoz-Caro, Camelia; Judge, Richard H.; Moule, David C.</p> <p>1998-07-01</p> <p>The <span class="hlt">band</span> assignments and analyses of the jet-cooled high-resolution laser-induced fluorescence excitation spectrum of acetaldehyde that results from theS1(n, π*) <span class="hlt">electronic</span> state have been extended to +600 cm-1from the 000system origin. The new assignments start at <span class="hlt">Band</span> #7 and finish at <span class="hlt">Band</span> #21. <span class="hlt">Bands</span> #8 and #9, originally assigned to 1420, have now been assigned to 1530. The assignments of the lower <span class="hlt">energy</span> <span class="hlt">bands</span> remain unaltered. The origins of the <span class="hlt">bands</span> that involve the torsional modes ν15(v= 1 to 4) in combination with the wagging mode ν14(v= 1 and 2) and the ν10(v= 1) were determined by analyses with a rigid rotational Hamiltonian. These origins were fitted to a set of levels that were derived from a torsion-wagging-bending Hamiltonian that employed flexible large amplitude coordinates. The resulting potential surface was found to have barriers to torsion and inversion of 712.5 and 638.6 cm-1, respectively, with minima in the potential hypersurface at θ = 59.9° and α = 33.5° for the torsion and wagging coordinates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PSSBR.25400035K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PSSBR.25400035K"><span><span class="hlt">Electronic</span> structure of graphene: (Nearly) free <span class="hlt">electron</span> <span class="hlt">bands</span> versus tight-binding <span class="hlt">bands</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kogan, E.; Silkin, V. M.</p> <p>2017-09-01</p> <p>In our previous paper (Phys. Rev. B {\\bf 89}, 165430 (2014)) we have found that in graphene, in distinction to the four occupied <span class="hlt">bands</span>, which can be described by the simple tight-binding model (TBM) with four atomic orbitals per atom, the two lowest lying at the $\\Gamma$-point unoccupied <span class="hlt">bands</span> (one of them of a $\\sigma$ type and the other of a $\\pi$ type) can not be described by such model. In the present work we suggest a minimalistic model for these two <span class="hlt">bands</span>, based on (nearly) free <span class="hlt">electrons</span> model (FEM), which correctly describes the symmetry of these <span class="hlt">bands</span>, their dispersion law and their localization with respect to the graphene plane.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhCS.709a2009B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhCS.709a2009B"><span>Experimental study of <span class="hlt">energy</span> harvesting in UHF <span class="hlt">band</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bernacki, Ł.; Gozdur, R.; Salamon, N.</p> <p>2016-04-01</p> <p>A huge progress of down-sizing technology together with trend of decreasing power consumption and, on the other hand, increasing efficiency of <span class="hlt">electronics</span> give the opportunity to design and to implement the <span class="hlt">energy</span> harvesters as main power sources. This paper refers to the <span class="hlt">energy</span> that can be harvested from electromagnetic field in the unlicensed frequency <span class="hlt">bands</span>. The paper contains description of the most popular techniques and transducers that can be applied in <span class="hlt">energy</span> harvesting domain. The overview of current research and commercial solutions was performed for <span class="hlt">bands</span> in ultra-high frequency range, which are unlicensed and where transmission is not limited by administrative arrangements. During the experiments with Powercast’s receiver, the same <span class="hlt">bands</span> as sources of electromagnetic field were taken into account. This power source is used for conducting radio-communication process and excess <span class="hlt">energy</span> could be used for powering the extra <span class="hlt">electronic</span> circuits. The paper presents elaborated prototype of <span class="hlt">energy</span> harvesting system and the measurements of power harvested in ultra-high frequency range. The evaluation of RF <span class="hlt">energy</span> harvesters for powering ultra-low power (ULP) <span class="hlt">electronic</span> devices was performed based on survey and results of the experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94w5308L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94w5308L"><span>Effects of <span class="hlt">electron</span>-impurity scattering on density of states in silicene: Impurity <span class="hlt">bands</span> and <span class="hlt">band</span>-gap narrowing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, S. Y.; Zeng, Y. C.; Lei, X. L.</p> <p>2016-12-01</p> <p>Considering the interband correlation, we present a generalized multiple-scattering approach of Green's function to investigate the effects of <span class="hlt">electron</span>-impurity scattering on the density of states in silicene at zero temperature. The reduction of <span class="hlt">energy</span> gaps in the case of relatively high chemical potential and the transformation of split-off impurity <span class="hlt">bands</span> into <span class="hlt">band</span> tails for low chemical potential are found. The dependency of optical conductivity on the impurity concentration is also discussed for frequency within the terahertz regime.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/936467','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/936467"><span>Ionization By Impact <span class="hlt">Electrons</span> in Solids: <span class="hlt">Electron</span> Mean Free Path Fitted Over A Wide <span class="hlt">Energy</span> Range</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ziaja, B; London, R A; Hajdu, J</p> <p>2005-06-09</p> <p>We propose a simple formula for fitting the <span class="hlt">electron</span> mean free paths in solids both at high and at low <span class="hlt">electron</span> <span class="hlt">energies</span>. The free-<span class="hlt">electron</span>-gas approximation used for predicting <span class="hlt">electron</span> mean free paths is no longer valid at low <span class="hlt">energies</span> (E < 50 eV), as the <span class="hlt">band</span> structure effects become significant at those <span class="hlt">energies</span>. Therefore we include the results of the <span class="hlt">band</span> structure calculations in our fit. Finally, we apply the fit to 9 elements and 2 compounds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22490442','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22490442"><span>Tuning the <span class="hlt">electronic</span> <span class="hlt">band</span> gap of graphene by oxidation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dabhi, Shweta D.; Jha, Prafulla K.</p> <p>2015-06-24</p> <p>Using plane wave pseudo potential density functional theory, we studied the <span class="hlt">electronic</span> properties of graphene with different C:O ratio. In this work, we discussed the changes that occur in <span class="hlt">electronic</span> <span class="hlt">band</span> structure of graphene functionalized with different amount of epoxy group. <span class="hlt">Electronic</span> <span class="hlt">band</span> gap depends on C:O ratio in graphene oxide containing epoxy group. The present work will have its implication for making devices with tunable <span class="hlt">electronic</span> properties by oxidizing graphene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NanoL..17..740W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NanoL..17..740W"><span>Probing the Spin-Polarized <span class="hlt">Electronic</span> <span class="hlt">Band</span> Structure in Monolayer Transition Metal Dichalcogenides by Optical Spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Zefang; Zhao, Liang; Mak, Kin Fai; Shan, Jie</p> <p>2017-02-01</p> <p>We study the <span class="hlt">electronic</span> <span class="hlt">band</span> structure in the K/K' valleys of the Brillouin zone of monolayer WSe2 and MoSe2 by optical reflection and photoluminescence spectroscopy on dual-gated field-effect devices. Our experiment reveals the distinct spin polarization in the conduction <span class="hlt">bands</span> of these compounds by a systematic study of the doping dependence of the A and B excitonic resonances. <span class="hlt">Electrons</span> in the highest-<span class="hlt">energy</span> valence <span class="hlt">band</span> and the lowest-<span class="hlt">energy</span> conduction <span class="hlt">band</span> have antiparallel spins in monolayer WSe2, and parallel spins in monolayer MoSe2. The spin splitting is determined to be hundreds of meV for the valence <span class="hlt">bands</span> and tens of meV for the conduction <span class="hlt">bands</span>, which are in good agreement with first principles calculations. These values also suggest that both n- and p-type WSe2 and MoSe2 can be relevant for spin- and valley-based applications</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28103668','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28103668"><span>Probing the Spin-Polarized <span class="hlt">Electronic</span> <span class="hlt">Band</span> Structure in Monolayer Transition Metal Dichalcogenides by Optical Spectroscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Zefang; Zhao, Liang; Mak, Kin Fai; Shan, Jie</p> <p>2017-02-08</p> <p>We study the <span class="hlt">electronic</span> <span class="hlt">band</span> structure in the K/K' valleys of the Brillouin zone of monolayer WSe2 and MoSe2 by optical reflection and photoluminescence spectroscopy on dual-gated field-effect devices. Our experiment reveals the distinct spin polarization in the conduction <span class="hlt">bands</span> of these compounds by a systematic study of the doping dependence of the A and B excitonic resonances. <span class="hlt">Electrons</span> in the highest-<span class="hlt">energy</span> valence <span class="hlt">band</span> and the lowest-<span class="hlt">energy</span> conduction <span class="hlt">band</span> have antiparallel spins in monolayer WSe2 and parallel spins in monolayer MoSe2. The spin splitting is determined to be hundreds of meV for the valence <span class="hlt">bands</span> and tens of meV for the conduction <span class="hlt">bands</span>, which are in good agreement with first-principles calculations. These values also suggest that both n- and p-type WSe2 and MoSe2 can be relevant for spin- and valley-based applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SPIE.7504E..0GG','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPIE.7504E..0GG"><span>Ultrafast laser-induced modifications of <span class="hlt">energy</span> <span class="hlt">bands</span> of non-metal crystals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gruzdev, Vitaly</p> <p>2009-10-01</p> <p>Ultrafast laser-induced variations of <span class="hlt">electron</span> <span class="hlt">energy</span> <span class="hlt">bands</span> of transparent solids significantly influence ionization and conduction-<span class="hlt">band</span> <span class="hlt">electron</span> absorption driving the initial stage of laser-induced damage (LID). The mechanisms of the variations are attributed to changing <span class="hlt">electron</span> functions from bonding to anti-bonding configuration via laser-induced ionization; laser-driven <span class="hlt">electron</span> oscillations in quasi-momentum space; and direct distortion of the inter-atomic potential by electric field of laser radiation. The ionization results in the <span class="hlt">band</span>-structure modification via accumulation of broken chemical bonds between atoms and provides significant contribution to the overall modification only when enough excited <span class="hlt">electrons</span> are accumulated in the conduction <span class="hlt">band</span>. The oscillations are associated with modification of <span class="hlt">electron</span> <span class="hlt">energy</span> by pondermotive potential of the oscillations. The direct action of radiation's electric field leads to specific high-frequency Franz-Keldysh effect (FKE) spreading the allowed <span class="hlt">electron</span> states into the <span class="hlt">bands</span> of forbidden <span class="hlt">energy</span>. Those processes determine the effective <span class="hlt">band</span> gap that is a laser-driven <span class="hlt">energy</span> gap between the modified <span class="hlt">electron</span> <span class="hlt">energy</span> <span class="hlt">bands</span>. Among those mechanisms, the latter two provide reversible <span class="hlt">band</span>-structure modification that takes place from the beginning of the ionization and are, therefore, of special interest due to their strong influence on the initial stage of the ionization. The pondermotive potential results either in monotonous increase or oscillatory variations of the effective <span class="hlt">band</span> gap that has been taken into account in some ionization models. The classical FKE provides decrease of the <span class="hlt">band</span> gap. We analyzing the competition between those two opposite trends of the effective-<span class="hlt">band</span>-gap variations and discuss applications of those effects for considerations of the laser-induced damage and its threshold in transparent solids.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991PhRvB..4412197N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991PhRvB..4412197N"><span>Theory of Auger-<span class="hlt">electron</span> and appearance-potential spectroscopy for interacting valence-<span class="hlt">band</span> <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nolting, W.; Geipel, G.; Ertl, K.</p> <p>1991-12-01</p> <p>A theory of Auger-<span class="hlt">electron</span> spectroscopy (AES) and appearance-potential spectroscopy (APS) is presented for interacting <span class="hlt">electrons</span> in a nondegenerate <span class="hlt">energy</span> <span class="hlt">band</span>, described within the framework of the Hubbard model. Both types of spectroscopy are based on the same two-particle spectral density. A diagrammatic vertex-correction method (Matsubara formalism) is used to express this function in terms of the one-particle spectral density. The latter is approximately determined for arbitrary temperature T, arbitrary coupling strength U/W (U, the intra-atomic Coulomb matrix element; W, the width of the ``free'' Bloch <span class="hlt">band</span>), and arbitrary <span class="hlt">band</span> occupations n (0<=n<=2 average number of <span class="hlt">band</span> <span class="hlt">electrons</span> per site) by a self-consistent moment method. In weakly coupled systems the <span class="hlt">electron</span> correlations give rise to certain deformations of the quasiparticle density of states (QDOS) in relation to the Bloch density of states (BDOS), where, however, spontaneous magnetic order is excluded, irrespective of the <span class="hlt">band</span> filling n. The AE (AP) spectra consist of only one structure a few eV wide (``bandlike'') which is strongly n dependent, but only slightly T dependent, being rather well approximated by a simple self-convolution of the occupied (unoccupied) QDOS. For strongly correlated <span class="hlt">electrons</span> the Bloch <span class="hlt">band</span> splits into two quasiparticle subbands. This leads for n<1 to one line in the AE spectrum and three lines in the AP spectrum, and vice versa for n>1. For sufficiently strong correlations U/W additional satellites appear that refer to situations where the two excited quasiparticles (quasiholes) propagate as tightly bound pairs through the lattice without being scattered by other charge carriers. As soon as the satellite splits off from the bandlike part of the spectrum, it takes almost the full spectral weight, conveying the impression of an ``atomiclike'' AE (AP) line shape. The satellite has almost exactly the structure of the free BDOS. If the particle density n as well as the hole</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990068043&hterms=electron+cloud&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Delectron%2Bcloud','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990068043&hterms=electron+cloud&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Delectron%2Bcloud"><span>Global Kinetic Modeling of <span class="hlt">Banded</span> <span class="hlt">Electron</span> Structures in the Plasmasphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Liemohn, M. W.; Khazanov, G. V.</p> <p>1997-01-01</p> <p>Significant fluxes of 10 eV to 30 keV <span class="hlt">electrons</span> have been detected in the plasmasphere, appearing as <span class="hlt">banded</span> structures in <span class="hlt">energy</span> with broad spatial extents and slowly evolving over several days. It is thought that these populations are decaying plasma sheet <span class="hlt">electrons</span> injected into the corotating region of near-Earth space. This capture can occur when the convective electric field drops rapidly and the Alfven boundary suddenly outward, trapping the inner edge of the plasma sheet along closed drift paths. Our bounce-averaged kinetic model of superthermal <span class="hlt">electron</span> transport is able to simulate this capture and the subsequent drift, diffusion, and decay of the plasma cloud. Results of this simulation will be shown and discussed, from the initial injection during the elevated convection to the final loss of the particles. It is thought that not only Coulomb collisions but also wave-particle interactions play a significant role in altering the plasma cloud. Quasilinear diffusion is currently being incorporated into the model and the importance of this mechanism will be examined. Also, the high anisotropy of the trapped population could be unstable and generate plasma waves. These and other processes will be investigated to determine the final fate of the cloud and to quantify where, how, and when the <span class="hlt">energy</span> of the plasma cloud is deposited. Comparisons with CRRES observations of these events are shown to verify the model and explain the data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JPCM...23C5503N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JPCM...23C5503N"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structures of graphene nanoribbons with self-passivating edge reconstructions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nguyen, L. Tung; Pham, C. Huy; Nguyen, V. Lien</p> <p>2011-07-01</p> <p>Using the nearest-neighbor tight-binding approach we study the <span class="hlt">electronic</span> <span class="hlt">band</span> structures of graphene nanoribbons with self-passivating edge reconstructions. For zigzag ribbons the edge reconstruction moves both the Fermi <span class="hlt">energy</span> and the flat <span class="hlt">band</span> down by several hundred meV, and the flat <span class="hlt">band</span> is always found to be below the Fermi <span class="hlt">energy</span>. The states featured by the flat <span class="hlt">band</span> are shown to be mainly localized at the atoms belonging to several lattice lines closest to the edges. For armchair ribbons the edge reconstruction strongly modifies the <span class="hlt">band</span> structure in the region close to the Fermi <span class="hlt">energy</span>, leading to the appearance of a <span class="hlt">band</span> gap even for ribbons which were predicted to be metallic in the model of standard armchair edges. The gap widths are, however, strongly different in magnitude and behave in different ways regarding the ribbon width.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..175a2004P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..175a2004P"><span>Topological Insulators: <span class="hlt">Electronic</span> <span class="hlt">Band</span> Structure and Spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Palaz, S.; Koc, H.; Mamedov, A. M.; Ozbay, E.</p> <p>2017-02-01</p> <p>In this study, we present the results of our ab initio calculation of the elastic constants, density of states, charge density, and Born effective charge tensors for ferroelectric (rhombohedral) and paraelectric phases (cubic) of the narrow <span class="hlt">band</span> ferroelectrics (GeTe, SnTe) pseudopotentials. The related quantities such as bulk modulus and shear modulus using obtained elastic constants have also been estimated in the present work. The total and partial densities of states corresponding to the <span class="hlt">band</span> structure of Sn(Ge)Te(S,Se) were calculated. We also calculated the Born effective charge tensor of an atom (for instance, Ge, Sn, Te, etc.), which is defined as the induced polarization of the solid along the main direction by a unit displacement in the perpendicular direction of the sublattice of an atom at the vanishing electric field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016InJPh..90.1431S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016InJPh..90.1431S"><span><span class="hlt">Electron</span> beam fracturing of ZnO nanostructures and modification in optical <span class="hlt">band</span> gap</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siraj, K.; Kanwal, M.; Saleem, S.; Pedarnig, J. D.; Rafique, M. S.; Naseem, S.</p> <p>2016-12-01</p> <p>In our previous work Siraj et al (J Alloys Comp 563:280, 2013), the <span class="hlt">electron</span> beam irradiation at high <span class="hlt">energies</span> (6-15 MeV) at constant dose of 30 Gy produced Zinc oxide elongated nanostructures and modified the optical <span class="hlt">band</span> gap <span class="hlt">energies</span> accordingly. In present work, those nanostructures are fractured to smaller sizes by increasing the <span class="hlt">electron</span> doses to 100 and 200 Gy. The very high temperature gradient induced stresses are responsible for further fracturing of ZnO nanostructures. The optical properties such as refractive index, extinction coefficient and optical <span class="hlt">band</span> gap <span class="hlt">energy</span> have also modified when higher cumulative <span class="hlt">electron</span> doses are used. The optical <span class="hlt">band</span> gap <span class="hlt">energies</span> are found to decrease by increasing <span class="hlt">electron</span> doses at all used <span class="hlt">electron</span> <span class="hlt">energies</span>, which is attributed to the production of different defects like vacancies, unpaired bonds, nanovoids, nanocavities, nanocracks and high strains. The <span class="hlt">electron</span> beam irradiation of ZnO thin films at used parameters (doses and <span class="hlt">energies</span>) is found to be plausible technique to produce nanostructures of different sizes and accordingly modify the optical <span class="hlt">band</span> gap <span class="hlt">energies</span>. The results can be beneficial for optical and optoelectronic industries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20633853','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20633853"><span><span class="hlt">Energy</span> loss of ions at metal surfaces: <span class="hlt">Band</span>-structure effects</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Alducin, M.; Silkin, V.M.; Juaristi, J.I.; Chulkov, E.V.</p> <p>2003-03-01</p> <p>We study <span class="hlt">band</span>-structure effects on the <span class="hlt">energy</span> loss of protons scattered off the Cu (111) surface. The distance dependent stopping power for a projectile traveling parallel to the surface is calculated within the linear response theory. The self-consistent <span class="hlt">electronic</span> response of the system is evaluated within the random-phase approximation. In order to characterize the surface <span class="hlt">band</span> structure, the <span class="hlt">electronic</span> single-particle wave functions and <span class="hlt">energies</span> are obtained by solving the Schroedinger equation with a realistic one-dimensional model potential. This potential reproduces the main features of the Cu (111) surface: the <span class="hlt">energy</span> <span class="hlt">band</span> gap for <span class="hlt">electron</span> motion along the surface normal, as well as the binding <span class="hlt">energy</span> of the occupied surface state and the first image state. Comparison of our results with those obtained within the jellium model allows us to characterize the <span class="hlt">band</span>-structure effects in the <span class="hlt">energy</span> loss of protons interacting with the Cu (111) surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPCM...29v4004A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPCM...29v4004A"><span>Low <span class="hlt">energy</span> <span class="hlt">bands</span> and transport properties of chromium arsenide</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Autieri, Carmine; Cuono, Giuseppe; Forte, Filomena; Noce, Canio</p> <p>2017-06-01</p> <p>We apply a method that combines the tight-binding approximation and the Löwdin down-folding procedure to evaluate the <span class="hlt">electronic</span> <span class="hlt">band</span> structure of the newly discovered pressure-induced superconductor CrAs. By integrating out all low-lying arsenic degrees of freedom, we derive an effective Hamiltonian model describing the Cr d <span class="hlt">bands</span> near the Fermi level. We calculate and make predictions for the <span class="hlt">energy</span> spectra, the Fermi surface, the density of states and transport and magnetic properties of this compound. Our results are consistent with local-density approximation calculations and they also show good agreement with available experimental data for resistivity and the Cr magnetic moment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAP...121p4902R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAP...121p4902R"><span>V-<span class="hlt">band</span> <span class="hlt">electronically</span> reconfigurable metamaterial</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Radisic, Vesna; Hester, Jimmy G.; Nguyen, Vinh N.; Caira, Nicholas W.; DiMarzio, Donald; Hilgeman, Theodore; Larouche, Stéphane; Kaneshiro, Eric; Gutierrez-Aitken, Augusto</p> <p>2017-04-01</p> <p>In this work, we report on a reconfigurable V-<span class="hlt">band</span> metamaterial fabricated using an InP heterojunction bipolar transistor production process. As designed and fabricated, the implementation uses complementary split ring resonators (cSRRs) and Schottky diodes in both single unit cell and three unit cell monolithic microwave integrated circuits. Each unit cell has two diodes embedded within the gaps of the cSRRs. Reconfigurability is achieved by applying an external bias that turns the diodes on and off, which effectively controls the resonant property of the structure. In order to measure the metamaterial properties, the unit cells are fed and followed by transmission lines. Measured data show good agreement with simulations and demonstrate that the metamaterial structure exhibits resonance at around 65 GHz that can be switched on and off. The three-unit cell transmission line metamaterial shows a deeper resonance and a larger phase change than a single cell, as expected. These are the first reported reconfigurable metamaterials operating at the V-<span class="hlt">band</span> using the InP high speed device fabrication process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000SPIE.4111..297B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000SPIE.4111..297B"><span>Gigahertz-<span class="hlt">band</span> <span class="hlt">electronically</span> scanned antennas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bei, Nikolai A.</p> <p>2000-12-01</p> <p>Foundation and principles of radio lenses construction of centimeter and millimeter wave ranges with controlled refracting index, combining the quality of phased array antennas with optical devices are stated. Possibilities of the <span class="hlt">electronically</span> scanning with wide-angle sector and high gain are maintained. Construction principles of scanning antennas with controlled lenses, combining the quality of phased array antennas with optical devices, are stated. Possibilities of <span class="hlt">electronically</span> scanning with broad angle sector and high gain are maintained. Some examples of construction of antennas millimeter range of waves are listed here.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94g5123T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94g5123T"><span><span class="hlt">Band</span> gaps, ionization potentials, and <span class="hlt">electron</span> affinities of periodic <span class="hlt">electron</span> systems via the adiabatic-connection fluctuation-dissipation theorem</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trushin, Egor; Betzinger, Markus; Blügel, Stefan; Görling, Andreas</p> <p>2016-08-01</p> <p>An approach to calculate fundamental <span class="hlt">band</span> gaps, ionization <span class="hlt">energies</span>, and <span class="hlt">electron</span> affinities of periodic <span class="hlt">electron</span> systems is explored. Starting from total <span class="hlt">energies</span> obtained with the help of the adiabatic-connection fluctuation-dissipation (ACFD) theorem, these physical observables are calculated according to their basic definition by differences of the total <span class="hlt">energies</span> of the N -, (N -1 ) -, and (N +1 ) -<span class="hlt">electron</span> system. The response functions entering the ACFD theorem are approximated here by the direct random phase approximation (dRPA). For a set of prototypical semiconductors and insulators it is shown that even with this quite drastic approximation the resulting <span class="hlt">band</span> gaps are very close to experiment and of a similar quality to those from the computationally more involved G W approximation. By going beyond the dRPA in the future the accuracy of the calculated <span class="hlt">band</span> gaps may be significantly improved further.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18402477','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18402477"><span>Strain-driven <span class="hlt">electronic</span> <span class="hlt">band</span> structure modulation of si nanowires.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hong, Ki-Ha; Kim, Jongseob; Lee, Sung-Hoon; Shin, Jai Kwang</p> <p>2008-05-01</p> <p>One of the major challenges toward Si nanowire (SiNW) based photonic devices is controlling the <span class="hlt">electronic</span> <span class="hlt">band</span> structure of the Si nanowire to obtain a direct <span class="hlt">band</span> gap. Here, we present a new strategy for controlling the <span class="hlt">electronic</span> <span class="hlt">band</span> structure of Si nanowires. Our method is attributed to the <span class="hlt">band</span> structure modulation driven by uniaxial strain. We show that the <span class="hlt">band</span> structure modulation with lattice strain is strongly dependent on the crystal orientation and diameter of SiNWs. In the case of [100] and [111] SiNWs, tensile strain enhances the direct <span class="hlt">band</span> gap characteristic, whereas compressive strain attenuates it. [110] SiNWs have a different strain dependence in that both compressive and tensile strain make SiNWs exhibit an indirect <span class="hlt">band</span> gap. We discuss the origin of this strain dependence based on the <span class="hlt">band</span> features of bulk silicon and the wave functions of SiNWs. These results could be helpful for <span class="hlt">band</span> structure engineering and analysis of SiNWs in nanoscale devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/210006','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/210006"><span>Shape of impurity <span class="hlt">electronic</span> absorption <span class="hlt">bands</span> in nematic liquid crystal</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Aver`yanov, E.M.</p> <p>1994-11-01</p> <p>The impurity-matrix anisotropic static intermolecular interactions, orientation-statistical properties, and <span class="hlt">electronic</span> structure of uniaxial impurity molecules are shown to have a significant influence on spectral moments of the <span class="hlt">electronic</span> absorption <span class="hlt">bands</span> of impurities in the nematic liquid crystal. 14 refs., 3 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20887006','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20887006"><span>Torque detected broad <span class="hlt">band</span> <span class="hlt">electron</span> spin resonance.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>El Hallak, Fadi; van Slageren, Joris; Dressel, Martin</p> <p>2010-09-01</p> <p>We present a novel technique to measure high frequency <span class="hlt">electron</span> spin resonance spectra in a broad frequency range (30-1440 GHz) with high sensitivity. We use a quasioptical setup with tunable frequency sources to induce magnetic resonance transitions. These transitions are detected by measuring the change in the magnetic torque signal by means of cantilever torque magnetometry. The setup allows tuning of the frequency, magnetic field, polarization, and the angle between the sample and the external magnetic field. We demonstrate the capabilities of this technique by showing preliminary results obtained on a single crystal of an Fe(4) molecular nanomagnet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE10000E..1QC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE10000E..1QC"><span>Model development for MODIS thermal <span class="hlt">band</span> <span class="hlt">electronic</span> cross-talk</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Tiejun; Wu, Aisheng; Geng, Xu; Li, Yonghong; Brinkmann, Jake; Keller, Graziela; Xiong, Xiaoxiong (Jack)</p> <p>2016-10-01</p> <p>MODerate-resolution Imaging Spectroradiometer (MODIS) has 36 <span class="hlt">bands</span>. Among them, 16 thermal emissive <span class="hlt">bands</span> covering a wavelength range from 3.8 to 14.4 μm. After 16 years on-orbit operation, the <span class="hlt">electronic</span> crosstalk of a few Terra MODIS thermal emissive <span class="hlt">bands</span> develop substantial issues which cause biases in the EV brightness temperature measurements and surface feature contamination. The crosstalk effects on <span class="hlt">band</span> 27 with center wavelength at 6.7 μm and <span class="hlt">band</span> 29 at 8.5 μm increased significantly in recent years, affecting downstream products such as water vapor and cloud mask. The crosstalk issue can be observed from nearly monthly scheduled lunar measurements, from which the crosstalk coefficients can be derived. Most of MODIS thermal <span class="hlt">bands</span> are saturated at moon surface temperatures and the development of an alternative approach is very helpful for verification. In this work, a physical model was developed to assess the crosstalk impact on calibration as well as in Earth view brightness temperature retrieval. This model was applied to Terra MODIS <span class="hlt">band</span> 29 empirically for correction of Earth brightness temperature measurements. In the model development, the detector nonlinear response is considered. The impacts of the <span class="hlt">electronic</span> crosstalk are assessed in two steps. The first step consists of determining the impact on calibration using the on-board blackbody (BB). Due to the detector nonlinear response and large background signal, both linear and nonlinear coefficients are affected by the crosstalk from sending <span class="hlt">bands</span>. The crosstalk impact on calibration coefficients was calculated. The second step is to calculate the effects on the Earth view brightness temperature retrieval. The effects include those from affected calibration coefficients and the contamination of Earth view measurements. This model links the measurement bias with crosstalk coefficients, detector nonlinearity, and the ratio of Earth measurements between the sending and receiving <span class="hlt">bands</span>. The correction</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120013672','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120013672"><span>Terra MODIS <span class="hlt">Band</span> 27 <span class="hlt">Electronic</span> Crosstalk Effect and Its Removal</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sun, Junqiang; Xiong, Xiaoxiong; Madhavan, Sriharsha; Wenny, Brian</p> <p>2012-01-01</p> <p>The MODerate-resolution Imaging Spectroradiometer (MODIS) is one of the primary instruments in the NASA Earth Observing System (EOS). The first MODIS instrument was launched in December, 1999 on-board the Terra spacecraft. MODIS has 36 <span class="hlt">bands</span>, covering a wavelength range from 0.4 micron to 14.4 micron. MODIS <span class="hlt">band</span> 27 (6.72 micron) is a water vapor <span class="hlt">band</span>, which is designed to be insensitive to Earth surface features. In recent Earth View (EV) images of Terra <span class="hlt">band</span> 27, surface feature contamination is clearly seen and striping has become very pronounced. In this paper, it is shown that <span class="hlt">band</span> 27 is impacted by <span class="hlt">electronic</span> crosstalk from <span class="hlt">bands</span> 28-30. An algorithm using a linear approximation is developed to correct the crosstalk effect. The crosstalk coefficients are derived from Terra MODIS lunar observations. They show that the crosstalk is strongly detector dependent and the crosstalk pattern has changed dramatically since launch. The crosstalk contributions are positive to the instrument response of <span class="hlt">band</span> 27 early in the mission but became negative and much larger in magnitude at later stages of the mission for most detectors of the <span class="hlt">band</span>. The algorithm is applied to both Black Body (BB) calibration and MODIS L1B products. With the crosstalk effect removed, the calibration coefficients of Terra MODIS <span class="hlt">band</span> 27 derived from the BB show that the detector differences become smaller. With the algorithm applied to MODIS L1B products, the Earth surface features are significantly removed and the striping is substantially reduced in the images of the <span class="hlt">band</span>. The approach developed in this report for removal of the <span class="hlt">electronic</span> crosstalk effect can be applied to other MODIS <span class="hlt">bands</span> if similar crosstalk behaviors occur.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27299467','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27299467"><span>Wedge <span class="hlt">energy</span> <span class="hlt">bands</span> of monolayer black phosphorus: a first-principles study.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Minwoo; Bae, Hyeonhu; Lee, Seunghan; Yang, Li; Lee, Hoonkyung</p> <p>2016-08-03</p> <p>On the basis of first-principles calculations, we present intriguing <span class="hlt">electronic</span> properties of halogen-striped functionalized monolayer black phosphorus. The halogen-striped monolayer black phosphorus is found to have a wedge <span class="hlt">energy</span> <span class="hlt">band</span> with the <span class="hlt">energy</span>-momentum relation of [Formula: see text] when the stripe-stripe distance is smaller than ~40 Å. Our tight-binding study shows that the wedge <span class="hlt">energy</span> <span class="hlt">band</span> occurs when 2-atom basis 1D lattices are periodically repeated aligned with each other in a 2D lattice. We also discuss the possible applications of this wedge <span class="hlt">energy</span> <span class="hlt">band</span> in <span class="hlt">electron</span> supercollimation with high mobility or severely anisotropic <span class="hlt">electronic</span> transport, which can be used for the development of optics-like nano-<span class="hlt">electronics</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4444955','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4444955"><span><span class="hlt">Electronic</span> <span class="hlt">Band</span> Structure and Sub-<span class="hlt">band</span>-gap Absorption of Nitrogen Hyperdoped Silicon</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhu, Zhen; Shao, Hezhu; Dong, Xiao; Li, Ning; Ning, Bo-Yuan; Ning, Xi-Jing; Zhao, Li; Zhuang, Jun</p> <p>2015-01-01</p> <p>We investigated the atomic geometry, <span class="hlt">electronic</span> <span class="hlt">band</span> structure, and optical absorption of nitrogen hyperdoped silicon based on first-principles calculations. The results show that all the paired nitrogen defects we studied do not introduce intermediate <span class="hlt">band</span>, while most of single nitrogen defects can introduce intermediate <span class="hlt">band</span> in the gap. Considering the stability of the single defects and the rapid resolidification following the laser melting process in our sample preparation method, we conclude that the substitutional nitrogen defect, whose fraction was tiny and could be neglected before, should have considerable fraction in the hyperdoped silicon and results in the visible sub-<span class="hlt">band</span>-gap absorption as observed in the experiment. Furthermore, our calculations show that the substitutional nitrogen defect has good stability, which could be one of the reasons why the sub-<span class="hlt">band</span>-gap absorptance remains almost unchanged after annealing. PMID:26012369</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26012369','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26012369"><span><span class="hlt">Electronic</span> <span class="hlt">Band</span> Structure and Sub-<span class="hlt">band</span>-gap Absorption of Nitrogen Hyperdoped Silicon.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhu, Zhen; Shao, Hezhu; Dong, Xiao; Li, Ning; Ning, Bo-Yuan; Ning, Xi-Jing; Zhao, Li; Zhuang, Jun</p> <p>2015-05-27</p> <p>We investigated the atomic geometry, <span class="hlt">electronic</span> <span class="hlt">band</span> structure, and optical absorption of nitrogen hyperdoped silicon based on first-principles calculations. The results show that all the paired nitrogen defects we studied do not introduce intermediate <span class="hlt">band</span>, while most of single nitrogen defects can introduce intermediate <span class="hlt">band</span> in the gap. Considering the stability of the single defects and the rapid resolidification following the laser melting process in our sample preparation method, we conclude that the substitutional nitrogen defect, whose fraction was tiny and could be neglected before, should have considerable fraction in the hyperdoped silicon and results in the visible sub-<span class="hlt">band</span>-gap absorption as observed in the experiment. Furthermore, our calculations show that the substitutional nitrogen defect has good stability, which could be one of the reasons why the sub-<span class="hlt">band</span>-gap absorptance remains almost unchanged after annealing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170008487&hterms=thermal&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dthermal','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170008487&hterms=thermal&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dthermal"><span>Model Development for MODIS Thermal <span class="hlt">Band</span> <span class="hlt">Electronic</span> Crosstalk</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chang, Tiejun; Wu, Aisheng; Geng, Xu; Li, Yonghonh; Brinkman, Jake; Keller, Graziela; Xiong, Xiaoxiong</p> <p>2016-01-01</p> <p>MODerate-resolution Imaging Spectroradiometer (MODIS) has 36 <span class="hlt">bands</span>. Among them, 16 thermal emissive <span class="hlt">bands</span> covering a wavelength range from 3.8 to 14.4 m. After 16 years on-orbit operation, the <span class="hlt">electronic</span> crosstalk of a few Terra MODIS thermal emissive <span class="hlt">bands</span> developed substantial issues that cause biases in the EV brightness temperature measurements and surface feature contamination. The crosstalk effects on <span class="hlt">band</span> 27 with center wavelength at 6.7 m and <span class="hlt">band</span> 29 at 8.5 m increased significantly in recent years, affecting downstream products such as water vapor and cloud mask. The crosstalk effect is evident in the near-monthly scheduled lunar measurements, from which the crosstalk coefficients can be derived. The development of an alternative approach is very helpful for independent verification.In this work, a physical model was developed to assess the crosstalk impact on calibration as well as in Earth view brightness temperature retrieval. This model was applied to Terra MODIS <span class="hlt">band</span> 29 empirically to correct the Earth brightness temperature measurements. In the model development, the detectors nonlinear response is considered. The impact of the <span class="hlt">electronic</span> crosstalk is assessed in two steps. The first step consists of determining the impact on calibration using the on-board blackbody (BB). Due to the detectors nonlinear response and large background signal, both linear and nonlinear coefficients are affected by the crosstalk from sending <span class="hlt">bands</span>. The second step is to calculate the effects on the Earth view brightness temperature retrieval. The effects include those from affected calibration coefficients and the contamination of Earth view measurements. This model links the measurement bias with crosstalk coefficients, detector non-linearity, and the ratio of Earth measurements between the sending and receiving <span class="hlt">bands</span>. The correction of the <span class="hlt">electronic</span> cross talk can be implemented empirically from the processed bias at different brightness temperature. The implementation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhRvL.110v6404B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhRvL.110v6404B"><span>Strong Renormalization of the <span class="hlt">Electronic</span> <span class="hlt">Band</span> Gap due to Lattice Polarization in the GW Formalism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Botti, Silvana; Marques, Miguel A. L.</p> <p>2013-05-01</p> <p>The self-consistent GW <span class="hlt">band</span> gaps are known to be significantly overestimated. We show that this overestimation is, to a large extent, due to the neglect of the contribution of the lattice polarization to the screening of the <span class="hlt">electron-electron</span> interaction. To solve this problem, we derive within the GW formalism a generalized plasmon-pole model that accounts for lattice polarization. The resulting GW self-<span class="hlt">energy</span> is used to calculate the <span class="hlt">band</span> structures of a set of binary semiconductors and insulators. The lattice contribution always decreases the <span class="hlt">band</span> gap. The shrinkage increases with the size of the longitudinal-transverse optical splitting and it can represent more than 15% of the <span class="hlt">band</span> gap in highly polar compounds, reducing the <span class="hlt">band</span>-gap percentage error by a factor of 3.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1090..328Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1090..328Z"><span>Correlations of <span class="hlt">Energy</span> Ratios for Collective Nuclear <span class="hlt">Bands</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zamfir, N. V.; Bucurescu, D.; Căta-Danil, G.; Ivaşcu, M.; Mărginean, N.</p> <p>2009-01-01</p> <p>It is shown that the Mallmann's <span class="hlt">energy</span> correlations, introduced a long time ago for the ground state <span class="hlt">bands</span> of the even-even nuclei are, in fact, universal. Various <span class="hlt">bands</span> in all collective nuclei (even-even, odd-even, and odd-odd) obey the same systematics. This unique, universal behaviour indicates the same spin dependence of the <span class="hlt">energy</span> of the levels and, consequently, a common structure of all collective <span class="hlt">bands</span>. Based on the second-order anharmonic vibrator description, parameter-free recurrence relations between <span class="hlt">energy</span> ratios are deduced. These relations can be used to predict levels of higher spins in various <span class="hlt">bands</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AcPPB..40..503Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AcPPB..40..503Z"><span>Correlations of <span class="hlt">Energy</span> Ratios for Collective Nuclear <span class="hlt">Bands</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zamfir, N. V.; Bucurescu, D.; Căta-Danil, G.; Ivaşcu, M.; Mărginean, N.</p> <p>2009-03-01</p> <p>It is shown that the Mallmann's <span class="hlt">energy</span> correlations, introduced a long time ago for the ground state <span class="hlt">bands</span> of the even-even nuclei are, in fact, universal. Various <span class="hlt">bands</span> in all collective nuclei (even-even, odd-even, and odd-odd) obey the same systematics. This unique, universal behaviour indicates the same spin dependence of the <span class="hlt">energy</span> of the levels in all <span class="hlt">bands</span> in all collective nuclei. Based on a second-order anharmonic vibrator description, parameter-free recurrence relations between <span class="hlt">energy</span> ratios are deduced. These relations can be used to predict levels of higher spins in various <span class="hlt">bands</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AdWR...30.2262L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AdWR...30.2262L"><span>Analytical solutions for bacterial <span class="hlt">energy</span> taxis (chemotaxis): Traveling bacterial <span class="hlt">bands</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Long, Wei; Hilpert, Markus</p> <p>2007-11-01</p> <p>Motile bacteria may form <span class="hlt">bands</span> that travel with a constant speed of propagation through a medium containing a dissolved substrate, to which they respond <span class="hlt">energy</span> tactically. We generalize the analytical solution by Keller and Segel for such <span class="hlt">bands</span> by accounting for (1) the presence of a porous medium, (2) substrate consumption described by a Monod kinetics model, and (3) an <span class="hlt">energy</span> tactic response model derived by Rivero et al. Specifically, we determine the concentration profiles of the bacteria and the substrate. We also derive various expressions for the <span class="hlt">band</span> velocity. The <span class="hlt">band</span> velocity is also shown to equal the <span class="hlt">energy</span> tactic velocity at the bacterial peak divided by tortuosity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OptMa..64...18S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OptMa..64...18S"><span>Spectrophotometric method for optical <span class="hlt">band</span> gap and <span class="hlt">electronic</span> transitions determination of semiconductor materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sangiorgi, Nicola; Aversa, Lucrezia; Tatti, Roberta; Verucchi, Roberto; Sanson, Alessandra</p> <p>2017-02-01</p> <p>The optical <span class="hlt">band</span> gap <span class="hlt">energy</span> and the <span class="hlt">electronic</span> processes involved are important parameters of a semiconductor material and it is therefore important to determine their correct values. Among the possible methods, the spectrophotometric is one of the most common. Several methods can be applied to determine the optical <span class="hlt">band</span> gap <span class="hlt">energy</span> and still now a defined consensus on the most suitable one has not been established. A highly diffused and accurate optical method is based on Tauc relationship, however to apply this equation is necessary to know the nature of the <span class="hlt">electronic</span> transitions involved commonly related to the coefficient n. For this purpose, a spectrophotometric technique was used and we developed a graphical method for <span class="hlt">electronic</span> transitions and <span class="hlt">band</span> gap <span class="hlt">energy</span> determination for samples in powder form. In particular, the n coefficient of Tauc equation was determined thorough mathematical elaboration of experimental results on TiO2 (anatase), ZnO, and SnO2. The results were used to calculate the <span class="hlt">band</span> gap <span class="hlt">energy</span> values and then compared with the information obtained by Ultraviolet Photoelectron Spectroscopy (UPS). This approach provides a quick and accurate method for <span class="hlt">band</span> gap determination through n coefficient calculation. Moreover, this simple but reliable method can be used to evaluate the nature of <span class="hlt">electronic</span> transition that occurs in a semiconductor material in powder form.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15..241M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15..241M"><span>Observation of '<span class="hlt">Band</span>' Structures in Spacecraft Observations of Inner Magnetosphere Plasma <span class="hlt">Electrons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mohan Narasimhan, Kirthika; Fazakerley, Andrew; Milhaljcic, Branislav; Grimald, Sandrine; Dandouras, Iannis; Owen, Chris</p> <p>2013-04-01</p> <p>In previous studies, several authors have reported inner magnetosphere observations of proton distributions confined to narrow <span class="hlt">energy</span> <span class="hlt">bands</span> in the range of 1-25 keV. These structures have been known as "nose structures", with reference to their appearance in <span class="hlt">energy</span>-time spectrograms and are known as "<span class="hlt">bands</span>" if they are observed for extended periods of time. These proton structures have been studied quite extensively with multiple mechanisms proposed for their formation, not all of which apply for <span class="hlt">electrons</span>. We examine Double-Star TC1 PEACE <span class="hlt">electron</span> data recorded in the inner magnetosphere (L<15) near the equatorial plane to see if these features are also observed in the <span class="hlt">electron</span> <span class="hlt">energy</span> spectra. These "<span class="hlt">bands</span>" also appear in <span class="hlt">electron</span> spectrograms, spanning an <span class="hlt">energy</span> range of 0.2-30 keV, and are shown to occur predominantly towards the dayside and dusk sectors. We also see multiple <span class="hlt">bands</span> in some instances. We investigate the properties of these multi-<span class="hlt">banded</span> structures and carry out a statistical survey analysing them as a function of geomagnetic activity, looking at both the Kp and Auroral Indices, in an attempt to explain their presence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PhRvB..68j4205T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PhRvB..68j4205T"><span><span class="hlt">Electronic</span> valence <span class="hlt">bands</span> in decagonal Al-Ni-Co</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Theis, W.; Rotenberg, Eli; Franke, K. J.; Gille, P.; Horn, K.</p> <p>2003-09-01</p> <p>Valence-<span class="hlt">band</span> photoemission from the s-p region of the tenfold and the two inequivalent twofold surfaces of quasicrystalline decagonal Al71.8Ni14.8Co13.4 reveals strongly dispersing <span class="hlt">bands</span>. These exhibit a free-<span class="hlt">electron</span>-like dispersion along quasiperiodic and periodic directions of the decagonal quasicrystal. The experimental photoemission maps are reproduced in detail by a model in which parabolic <span class="hlt">bands</span> emanate from a set of reciprocal lattice vectors. A parity rule for the principal zone centers is observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhyB..522...66R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhyB..522...66R"><span><span class="hlt">Band</span> warping, <span class="hlt">band</span> non-parabolicity, and Dirac points in <span class="hlt">electronic</span> and lattice structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Resca, Lorenzo; Mecholsky, Nicholas A.; Pegg, Ian L.</p> <p>2017-10-01</p> <p>We illustrate at a fundamental level the physical and mathematical origins of <span class="hlt">band</span> warping and <span class="hlt">band</span> non-parabolicity in <span class="hlt">electronic</span> and vibrational structures. We point out a robust presence of pairs of topologically induced Dirac points in a primitive-rectangular lattice using a p-type tight-binding approximation. We analyze two-dimensional primitive-rectangular and square Bravais lattices with implications that are expected to generalize to more complex structures. <span class="hlt">Band</span> warping is shown to arise at the onset of a singular transition to a crystal lattice with a larger symmetry group, which allows the possibility of irreducible representations of higher dimensions, hence <span class="hlt">band</span> degeneracy, at special symmetry points in reciprocal space. <span class="hlt">Band</span> warping is incompatible with a multi-dimensional Taylor series expansion, whereas <span class="hlt">band</span> non-parabolicities are associated with multi-dimensional Taylor series expansions to all orders. Still <span class="hlt">band</span> non-parabolicities may merge into <span class="hlt">band</span> warping at the onset of a larger symmetry group. Remarkably, while still maintaining a clear connection with that merging, <span class="hlt">band</span> non-parabolicities may produce pairs of conical intersections at relatively low-symmetry points. Apparently, such conical intersections are robustly maintained by global topology requirements, rather than any local symmetry protection. For two p-type tight-binding <span class="hlt">bands</span>, we find such pairs of conical intersections drifting along the edges of restricted Brillouin zones of primitive-rectangular Bravais lattices as lattice constants vary relatively to each other, until these conical intersections merge into degenerate warped <span class="hlt">bands</span> at high-symmetry points at the onset of a square lattice. The conical intersections that we found appear to have similar topological characteristics as Dirac points extensively studied in graphene and other topological insulators, even though our conical intersections have none of the symmetry complexity and protection afforded by the latter more</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16392585','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16392585"><span>Correlation effects and <span class="hlt">electronic</span> properties of Cr-substituted SZn with an intermediate <span class="hlt">band</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tablero, C</p> <p>2005-09-15</p> <p>A study using first principles of the <span class="hlt">electronic</span> properties of S32Zn31Cr, a material derived from the SZn host semiconductor where a Cr atom has been substituted for each of the 32 Zn atoms, is presented. This material has an intermediate <span class="hlt">band</span> sandwiched between the valence and conduction <span class="hlt">bands</span> of the host semiconductor, which in a formal <span class="hlt">band</span>-theoretic picture is metallic because the Fermi <span class="hlt">energy</span> is located within the impurity <span class="hlt">band</span>. The potential technological application of these materials is that when they are used to absorb photons in solar cells, the efficiency increases significantly with respect to the host semiconductor. An analysis of the gaps, bandwidths, density of states, total and orbital charges, and <span class="hlt">electronic</span> density is carried out. The main effects of the local-density approximation with a Hubbard term corrections are an increase in the bandwidth, a modification of the relative composition of the five d and p transition-metal orbitals, and a splitting of the intermediate <span class="hlt">band</span>. The results demonstrate that the main contribution to the intermediate <span class="hlt">band</span> is the Cr atom. For values of U greater than 6 eV, where U is the empirical Hubbard term U parameter, this <span class="hlt">band</span> is unfolded, thus creating two <span class="hlt">bands</span>, a full one below the Fermi <span class="hlt">energy</span> and an empty one above it, i.e., a metal-insulator transition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25526150','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25526150"><span>Reconstruction of <span class="hlt">band</span> structure induced by <span class="hlt">electronic</span> nematicity in an FeSe superconductor.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nakayama, K; Miyata, Y; Phan, G N; Sato, T; Tanabe, Y; Urata, T; Tanigaki, K; Takahashi, T</p> <p>2014-12-05</p> <p>We have performed high-resolution angle-resolved photoemission spectroscopy on an FeSe superconductor (T_{c}∼8  K), which exhibits a tetragonal-to-orthorhombic structural transition at T_{s}∼90  K. At low temperature, we found splitting of the <span class="hlt">energy</span> <span class="hlt">bands</span> as large as 50 meV at the M point in the Brillouin zone, likely caused by the formation of <span class="hlt">electronically</span> driven nematic states. This <span class="hlt">band</span> splitting persists up to T∼110  K, slightly above T_{s}, suggesting that the structural transition is triggered by the <span class="hlt">electronic</span> nematicity. We have also revealed that at low temperature the <span class="hlt">band</span> splitting gives rise to a van Hove singularity within 5 meV of the Fermi <span class="hlt">energy</span>. The present result strongly suggests that this unusual <span class="hlt">electronic</span> state is responsible for the unconventional superconductivity in FeSe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..APR.T1028S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..APR.T1028S"><span>Achieving Higher <span class="hlt">Energies</span> via Passively Driven X-<span class="hlt">band</span> Structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sipahi, Taylan; Sipahi, Nihan; Milton, Stephen; Biedron, Sandra</p> <p>2014-03-01</p> <p>Due to their higher intrinsic shunt impedance X-<span class="hlt">band</span> accelerating structures significant gradients with relatively modest input powers, and this can lead to more compact particle accelerators. At the Colorado State University Accelerator Laboratory (CSUAL) we would like to adapt this technology to our 1.3 GHz L-<span class="hlt">band</span> accelerator system using a passively driven 11.7 GHz traveling wave X-<span class="hlt">band</span> configuration that capitalizes on the high shunt impedances achievable in X-<span class="hlt">band</span> accelerating structures in order to increase our overall beam <span class="hlt">energy</span> in a manner that does not require investment in an expensive, custom, high-power X-<span class="hlt">band</span> klystron system. Here we provide the design details of the X-<span class="hlt">band</span> structures that will allow us to achieve our goal of reaching the maximum practical net potential across the X-<span class="hlt">band</span> accelerating structure while driven solely by the beam from the L-<span class="hlt">band</span> system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AmJPh..84..924P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AmJPh..84..924P"><span>Calculation of 2D <span class="hlt">electronic</span> <span class="hlt">band</span> structure using matrix mechanics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pavelich, R. L.; Marsiglio, F.</p> <p>2016-12-01</p> <p>We extend previous work, applying elementary matrix mechanics to one-dimensional periodic arrays (to generate <span class="hlt">energy</span> <span class="hlt">bands</span>), to two-dimensional arrays. We generate <span class="hlt">band</span> structures for the square-lattice "2D Kronig-Penney model" (square wells), the "muffin-tin" potential (circular wells), and Gaussian wells. We then apply the method to periodic arrays of more than one atomic site in a unit cell, specifically to the case of materials with hexagonal lattices like graphene. These straightforward extensions of undergraduate-level calculations allow students to readily determine <span class="hlt">band</span> structures of current research interest.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94g5440R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94g5440R"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> gaps and exciton binding <span class="hlt">energies</span> in monolayer M oxW1 -xS2 transition metal dichalcogenide alloys probed by scanning tunneling and optical spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rigosi, Albert F.; Hill, Heather M.; Rim, Kwang Taeg; Flynn, George W.; Heinz, Tony F.</p> <p>2016-08-01</p> <p>Using scanning tunneling spectroscopy (STS) and optical reflectance contrast measurements, we examine <span class="hlt">band</span>-gap properties of single layers of transition metal dichalcogenide (TMDC) alloys: Mo S2 , M o0.5W0.5S2 , M o0.25W0.75S2 , M o0.1W0.9S2 , and W S2 . The quasiparticle <span class="hlt">band</span> gap, spin-orbit separation of the excitonic transitions at the K /K' point in the Brillouin zone, and binding <span class="hlt">energies</span> of the A exciton are extracted from STS and optical data. The exciton binding <span class="hlt">energies</span> change roughly linearly with tungsten concentration. For our samples on an insulating substrate, we report quasiparticle <span class="hlt">band</span> gaps from 2.17 ± 0.04 eV (Mo S2) to 2.38 ± 0.06 eV (W S2) , with A exciton binding <span class="hlt">energies</span> ranging from 310 to 420 meV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SSCom.152.1089M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SSCom.152.1089M"><span>First-principle study of <span class="hlt">energy</span> <span class="hlt">band</span> structure of armchair graphene nanoribbons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Fei; Guo, Zhankui; Xu, Kewei; Chu, Paul K.</p> <p>2012-07-01</p> <p>First-principle calculation is carried out to study the <span class="hlt">energy</span> <span class="hlt">band</span> structure of armchair graphene nanoribbons (AGNRs). Hydrogen passivation is found to be crucial to convert the indirect <span class="hlt">band</span> gaps into direct ones as a result of enhanced interactions between <span class="hlt">electrons</span> and nuclei at the edge boundaries, as evidenced from the shortened bond length as well as the increased differential charge density. Ribbon width usually leads to the oscillatory variation of <span class="hlt">band</span> gaps due to quantum confinement no matter hydrogen passivated or not. Mechanical strain may change the crystal symmetry, reduce the overlapping integral of C-C atoms, and hence modify the <span class="hlt">band</span> gap further, which depends on the specific ribbon width sensitively. In practical applications, those effects will be hybridized to determine the <span class="hlt">energy</span> <span class="hlt">band</span> structure and subsequently the <span class="hlt">electronic</span> properties of graphene. The results can provide insights into the design of carbon-based devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12690192','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12690192"><span><span class="hlt">Band</span> structure and Fermi surface of <span class="hlt">electron</span>-doped C60 monolayers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, W L; Brouet, V; Zhou, X J; Choi, Hyoung J; Louie, Steven G; Cohen, Marvin L; Kellar, S A; Bogdanov, P V; Lanzara, A; Goldoni, A; Parmigiani, F; Hussain, Z; Shen, Z-X</p> <p>2003-04-11</p> <p>C60 fullerides are challenging systems because both the <span class="hlt">electron</span>-phonon and <span class="hlt">electron-electron</span> interactions are large on the <span class="hlt">energy</span> scale of the expected narrow <span class="hlt">band</span> width. We report angle-resolved photoemission data on the <span class="hlt">band</span> dispersion for an alkali-doped C60 monolayer and a detailed comparison with theory. Compared to the maximum bare theoretical <span class="hlt">band</span> width of 170 meV, the observed 100-meV dispersion is within the range of renormalization by <span class="hlt">electron</span>-phonon coupling. This dispersion is only a fraction of the integrated peak width, revealing the importance of many-body effects. Additionally, measurements on the Fermi surface indicate the robustness of the Luttinger theorem even for materials with strong interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT........86C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT........86C"><span>Nanoscale Studies of <span class="hlt">Energy</span> <span class="hlt">Band</span> Gaps and <span class="hlt">Band</span> Offsets in Compound Semiconductor Heterostructures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Alexander S.</p> <p></p> <p>The identification of the precise <span class="hlt">band</span> offsets at semiconductor interfaces is crucially important for the successful development of <span class="hlt">electronic</span> and optoelectronic devices. However, issues at the interfaces, such as strain or defects, needs to be investigated for precise <span class="hlt">band</span> tuning of semiconductor heterostructures. In this dissertation, the nanometer-scale structural and <span class="hlt">electronic</span> properties of InGaAs(Sb)N/GaAs interfaces, InGaN/GaN QDs, and GaSb/GaAs QDs are investigated using a combination of XSTM and STS. The influence of Sb incorporation on the InGaAs(Sb)N/GaAs <span class="hlt">band</span> alignment is investigated. At the InGaAsN/GaAs (InGaAsSbN/GaAs) interfaces, type II (type I) <span class="hlt">band</span> offsets are observed, due to strain-induced splitting of the valence <span class="hlt">band</span> and the incorporation of Sb. <span class="hlt">Band</span> tuning of both conduction and valence <span class="hlt">band</span> edges with the incorporation of Sb can be used to engineer the <span class="hlt">band</span> structure with strong confinement of <span class="hlt">electrons</span> and holes in the InGaAsSbN quantum well layer, which is promising for light emitting applications. The influence of the growth substrate on InGaN/GaN QD formation and properties is examined. The QD density, dimension, and <span class="hlt">band</span> gaps are compared for different InGaN QDs on free-standing GaN or GaN/AlN/sapphire substrates. We present different sources using nucleation on different substrates, and discuss their influences on the <span class="hlt">electronic</span> <span class="hlt">band</span> structure. Our work suggests that a wide variety of InGaN QD dimension, density, and <span class="hlt">band</span> structure can be achieved by using different starting substrate and number of layers of InGaN QD stacks. Furthermore, the influence of strain and dislocation on the GaSb/GaAs QD <span class="hlt">band</span> alignment is investigated using both experimental and computational tools. A combination of cross-sectional transmission <span class="hlt">electron</span> microscopy (XTEM), XSTM, and STS reveals the formation of misfit dislocations and both coherent and semi-coherent clustered QDs, independent of Sb- vs. As-termination of the GaAs surface. Furthermore, finite</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28325035','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28325035"><span>Calculation of <span class="hlt">Energy</span> Diagram of Asymmetric Graded-<span class="hlt">Band</span>-Gap Semiconductor Superlattices.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Monastyrskii, Liubomyr S; Sokolovskii, Bogdan S; Alekseichyk, Mariya P</p> <p>2017-12-01</p> <p>The paper theoretically investigates the peculiarities of <span class="hlt">energy</span> diagram of asymmetric graded-<span class="hlt">band</span>-gap superlattices with linear coordinate dependences of <span class="hlt">band</span> gap and <span class="hlt">electron</span> affinity. For calculating the <span class="hlt">energy</span> diagram of asymmetric graded-<span class="hlt">band</span>-gap superlattices, linearized Poisson's equation has been solved for the two layers forming a period of the superlattice. The obtained coordinate dependences of edges of the conduction and valence <span class="hlt">bands</span> demonstrate substantial transformation of the shape of the <span class="hlt">energy</span> diagram at changing the period of the lattice and the ratio of width of the adjacent layers. The most marked changes in the <span class="hlt">energy</span> diagram take place when the period of lattice is comparable with the Debye screening length. In the case when the lattice period is much smaller that the Debye screening length, the <span class="hlt">energy</span> diagram has the shape of a sawtooth-like pattern.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NRL....12..203M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NRL....12..203M"><span>Calculation of <span class="hlt">Energy</span> Diagram of Asymmetric Graded-<span class="hlt">Band</span>-Gap Semiconductor Superlattices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Monastyrskii, Liubomyr S.; Sokolovskii, Bogdan S.; Alekseichyk, Mariya P.</p> <p>2017-03-01</p> <p>The paper theoretically investigates the peculiarities of <span class="hlt">energy</span> diagram of asymmetric graded-<span class="hlt">band</span>-gap superlattices with linear coordinate dependences of <span class="hlt">band</span> gap and <span class="hlt">electron</span> affinity. For calculating the <span class="hlt">energy</span> diagram of asymmetric graded-<span class="hlt">band</span>-gap superlattices, linearized Poisson's equation has been solved for the two layers forming a period of the superlattice. The obtained coordinate dependences of edges of the conduction and valence <span class="hlt">bands</span> demonstrate substantial transformation of the shape of the <span class="hlt">energy</span> diagram at changing the period of the lattice and the ratio of width of the adjacent layers. The most marked changes in the <span class="hlt">energy</span> diagram take place when the period of lattice is comparable with the Debye screening length. In the case when the lattice period is much smaller that the Debye screening length, the <span class="hlt">energy</span> diagram has the shape of a sawtooth-like pattern.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JIEIB.tmp...38K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JIEIB.tmp...38K"><span><span class="hlt">Electronic</span> Power Conditioner for Ku-<span class="hlt">band</span> Travelling Wave Tube</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kowstubha, Palle; Krishnaveni, K.; Ramesh Reddy, K.</p> <p>2016-07-01</p> <p>A highly sophisticated regulated power supply is known as <span class="hlt">electronic</span> power conditioner (EPC) is required to energise travelling wave tubes (TWTs), which are used as RF signal amplifiers in satellite payloads. The assembly consisting of TWT and EPC together is known as travelling wave tube amplifier (TWTA). EPC is used to provide isolated and conditioned voltage rails with tight regulation to various electrodes of TWT and makes its RF performance independent of solar bus variations which are caused due to varying conditions of eclipse and sunlit. The payload mass and their power consumption is mainly due to the existence of TWTAs that represent about 35 % of total mass and about 70-90 % (based on the type of satellite application) of overall dc power consumption. This situation ensures a continuous improvement in the design of TWTAs and their associated EPCs to realize more efficient and light products. Critical technologies involved in EPCs are design and configuration, closed loop regulation, component and material selection, <span class="hlt">energy</span> limiting of high voltage (HV) outputs and potting of HV card etc. This work addresses some of these critical technologies evolved in realizing and testing the state of art of EPC and it focuses on the design of HV supply with a HV and high power capability, up to 6 kV and 170 WRF, respectively required for a space TWTA. Finally, an experimental prototype of EPC with a dc power of 320 W provides different voltages required by Ku-<span class="hlt">band</span> TWT in open loop configuration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JIEIB..98..213K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JIEIB..98..213K"><span><span class="hlt">Electronic</span> Power Conditioner for Ku-<span class="hlt">band</span> Travelling Wave Tube</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kowstubha, Palle; Krishnaveni, K.; Ramesh Reddy, K.</p> <p>2017-04-01</p> <p>A highly sophisticated regulated power supply is known as <span class="hlt">electronic</span> power conditioner (EPC) is required to energise travelling wave tubes (TWTs), which are used as RF signal amplifiers in satellite payloads. The assembly consisting of TWT and EPC together is known as travelling wave tube amplifier (TWTA). EPC is used to provide isolated and conditioned voltage rails with tight regulation to various electrodes of TWT and makes its RF performance independent of solar bus variations which are caused due to varying conditions of eclipse and sunlit. The payload mass and their power consumption is mainly due to the existence of TWTAs that represent about 35 % of total mass and about 70-90 % (based on the type of satellite application) of overall dc power consumption. This situation ensures a continuous improvement in the design of TWTAs and their associated EPCs to realize more efficient and light products. Critical technologies involved in EPCs are design and configuration, closed loop regulation, component and material selection, <span class="hlt">energy</span> limiting of high voltage (HV) outputs and potting of HV card etc. This work addresses some of these critical technologies evolved in realizing and testing the state of art of EPC and it focuses on the design of HV supply with a HV and high power capability, up to 6 kV and 170 WRF, respectively required for a space TWTA. Finally, an experimental prototype of EPC with a dc power of 320 W provides different voltages required by Ku-<span class="hlt">band</span> TWT in open loop configuration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5511367','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5511367"><span>Auger <span class="hlt">electron</span> emission initiated by the creation of valence-<span class="hlt">band</span> holes in graphene by positron annihilation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chirayath, V. A.; Callewaert, V.; Fairchild, A. J.; Chrysler, M. D.; Gladen, R. W.; Mcdonald, A. D.; Imam, S. K.; Shastry, K.; Koymen, A. R.; Saniz, R.; Barbiellini, B.; Rajeshwar, K.; Partoens, B.; Weiss, A. H.</p> <p>2017-01-01</p> <p>Auger processes involving the filling of holes in the valence <span class="hlt">band</span> are thought to make important contributions to the low-<span class="hlt">energy</span> photoelectron and secondary <span class="hlt">electron</span> spectrum from many solids. However, measurements of the <span class="hlt">energy</span> spectrum and the efficiency with which <span class="hlt">electrons</span> are emitted in this process remain elusive due to a large unrelated background resulting from primary beam-induced secondary <span class="hlt">electrons</span>. Here, we report the direct measurement of the <span class="hlt">energy</span> spectra of <span class="hlt">electrons</span> emitted from single layer graphene as a result of the decay of deep holes in the valence <span class="hlt">band</span>. These measurements were made possible by eliminating competing backgrounds by employing low-<span class="hlt">energy</span> positrons (<1.25 eV) to create valence-<span class="hlt">band</span> holes by annihilation. Our experimental results, supported by theoretical calculations, indicate that between 80 and 100% of the deep valence-<span class="hlt">band</span> holes in graphene are filled via an Auger transition. PMID:28703225</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhD...49R5305S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhD...49R5305S"><span><span class="hlt">Electronic</span> properties of Janus silicene: new direct <span class="hlt">band</span> gap semiconductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Minglei; Ren, Qingqiang; Wang, Sake; Yu, Jin; Tang, Wencheng</p> <p>2016-11-01</p> <p>Using first-principles calculations, we propose a new class of materials, Janus silicene, which is silicene asymmetrically functionalized with hydrogen and halogen atoms. Formation <span class="hlt">energies</span> and phonon dispersion indicated that all the Janus silicene systems exhibit good kinetic stability. As compared to silicane, all Janus silicene systems are direct <span class="hlt">band</span> gap semiconductors. The <span class="hlt">band</span> gap of Janus silicene can take any value between 1.91 and 2.66 eV by carefully tuning the chemical composition of the adatoms. In addition, biaxial elastic strain can further reduce the <span class="hlt">band</span> gap to 1.11 eV (under a biaxial tensile strain up to 10%). According to moderate direct <span class="hlt">band</span> gap, these materials demonstrate potential applications in optoelectronics, exhibiting a very wide spectral range, and they are expected to be highly stable under ambient conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1351137','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1351137"><span><span class="hlt">Electron</span> elevator: Excitations across the <span class="hlt">band</span> gap via a dynamical gap state</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lim, Anthony; Foulkes, W. M. C.; Horsfield, A. P.; Mason, D. R.; Schleife, A.; Draeger, E. W.; Correa, A. A.</p> <p>2016-01-27</p> <p>We use time-dependent density functional theory to study self-irradiated Si. We calculate the <span class="hlt">electronic</span> stopping power of Si in Si by evaluating the <span class="hlt">energy</span> transferred to the <span class="hlt">electrons</span> per unit path length by an ion of kinetic <span class="hlt">energy</span> from 1 eV to 100 keV moving through the host. <span class="hlt">Electronic</span> stopping is found to be significant below the threshold velocity normally identified with transitions across the <span class="hlt">band</span> gap. A structured crossover at low velocity exists in place of a hard threshold. Lastly, an analysis of the time dependence of the transition rates using coupled linear rate equations enables one of the excitation mechanisms to be clearly identified: a defect state induced in the gap by the moving ion acts like an elevator and carries <span class="hlt">electrons</span> across the <span class="hlt">band</span> gap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1351137-electron-elevator-excitations-across-band-gap-via-dynamical-gap-state','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1351137-electron-elevator-excitations-across-band-gap-via-dynamical-gap-state"><span><span class="hlt">Electron</span> elevator: Excitations across the <span class="hlt">band</span> gap via a dynamical gap state</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Lim, Anthony; Foulkes, W. M. C.; Horsfield, A. P.; ...</p> <p>2016-01-27</p> <p>We use time-dependent density functional theory to study self-irradiated Si. We calculate the <span class="hlt">electronic</span> stopping power of Si in Si by evaluating the <span class="hlt">energy</span> transferred to the <span class="hlt">electrons</span> per unit path length by an ion of kinetic <span class="hlt">energy</span> from 1 eV to 100 keV moving through the host. <span class="hlt">Electronic</span> stopping is found to be significant below the threshold velocity normally identified with transitions across the <span class="hlt">band</span> gap. A structured crossover at low velocity exists in place of a hard threshold. Lastly, an analysis of the time dependence of the transition rates using coupled linear rate equations enables one of themore » excitation mechanisms to be clearly identified: a defect state induced in the gap by the moving ion acts like an elevator and carries <span class="hlt">electrons</span> across the <span class="hlt">band</span> gap.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5636342','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5636342"><span><span class="hlt">Electron</span> scattering off the ground-state <span class="hlt">band</span> and the. gamma. <span class="hlt">band</span> in sup 150 Nd</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sandor, R.K.J.; Blok, H.P.; Garg, U.; Girod, M.; Harakeh, M.N.; de Jager, C.W.; de Vries, H. Service de Physique et Techniques Nucleaires, Commissariat a l'Energie Atomique, Bruyeres-le-Chatel, Boite Postale 12, F-91680 Bruyeres-le-Chatel, France Nationaal Instituut voor Kernfysica en Hoge-Energiefysica, sectie K , P.O. Box 4395, 1009AJ Amsterdam, The Netherlands Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556)</p> <p>1991-05-01</p> <p>Inelastic <span class="hlt">electron</span> scattering to levels of the ground-state <span class="hlt">band</span> and the {gamma} <span class="hlt">band</span> in {sup 150}Nd was studied in a momentum transfer range of 0.5 to 2.8 fm{sup {minus}1}. The extracted transition charge densities were compared to microscopic Hartree-Fock-Boguliubov calculations. The overall agreement between the data and the calculations is good, indicating that the dynamic properties of the rotational collective degrees of freedom in statically deformed nuclei can be well described in this microscopic model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010CoTPh..54..167X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010CoTPh..54..167X"><span>CONDENSED MATTER: <span class="hlt">ELECTRONIC</span> STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES: Suppression of Anti-resonant Effect in Presence of <span class="hlt">Band</span> Overlap</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xiong, Gang</p> <p>2010-07-01</p> <p>By exact resolution of coupled ideal chains connecting an extra side site, we show that the so-called "anti-resonant effect" is suppressed when the <span class="hlt">electron</span> <span class="hlt">energy</span> is inside the overlap region of extended <span class="hlt">bands</span> of the ideal tight-binding chains. When the <span class="hlt">electronic</span> <span class="hlt">energy</span> is outside the <span class="hlt">band</span> overlap region, the existence of "anti-resonant effect" is tuned by details of local connectivity around the extra side site and can be suppressed by introduction of magnetic flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22304278','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22304278"><span><span class="hlt">Electronic</span> transitions in GdN <span class="hlt">band</span> structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vidyasagar, R. Kita, T.; Sakurai, T.; Ohta, H.</p> <p>2014-05-28</p> <p>Using the near-infrared (NIR) absorbance spectroscopy, <span class="hlt">electronic</span> transitions and spin polarization of the GdN epitaxial film have been investigated; and the GdN epitaxial film was grown by a reactive rf sputtering technique. The GdN film exhibited three broad <span class="hlt">bands</span> in the NIR frequency regimes; and those <span class="hlt">bands</span> are attributable primarily to the minority and majority spin transitions at the X-point and an indirect transition along the Γ-X symmetric direction of GdN Brillouin zone. We experimentally observe a pronounced red-shift of the indirect <span class="hlt">band</span> gap when cooling down below the Curie temperature which is ascribed to the orbital-dependent coulomb interactions of Gd-5dxy <span class="hlt">electrons</span>, which tend to push-up the N-2p <span class="hlt">bands</span>. On the other hand, we have evaluated the spin polarization of 0.17 (±0.005), which indicates that the GdN epitaxial film has almost 100% spin-polarized carriers. Furthermore, the experimental result of GdN <span class="hlt">electronic</span> transitions are consistent with the previous reports and are thus well-reproduced. The Arrott plots evidenced that the Curie temperature of GdN film is 36 K and the large spin moment is explained by the nitrogen vacancies and the intra-atomic exchange interaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..MAR.T8014B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..MAR.T8014B"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structure and phonons in V2O5</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bhandari, Churna; Lambrecht, Walter R. L.</p> <p>2013-03-01</p> <p>Among the vanadium oxides, V2O5 presents special interest as a layered material. As for other layered materials, it is of interest to search for changes in its <span class="hlt">electronic</span> structure and phonon spectrum in the monolayer modification of this material. For example, reduced screening may modify phonon modes affected by long-range Coulomb interactions. As a preliminary we here present a first-principles study of the bulk <span class="hlt">electronic</span> <span class="hlt">band</span> structure and the phonons at the Γ-point. Density functional calculations in the local density approximation were carried out for the <span class="hlt">electronic</span> <span class="hlt">band</span> structure and the density functional perturbation method was used for the phonon calculations. We used LDA and norm-conserving pseudopotentials in the abinit code. A group theoretical analysis is used to label the phonon modes. Non-analyticity is included for the LO modes. The <span class="hlt">band</span> structures are in good agreement with previous work and yield an indirect <span class="hlt">band</span> gap. Relaxed structural properties are also in good agreement with experiment. Simulated infrared and Raman spectra will be presented. Our results will be compared with experimental and previous theoretical work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720011057','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720011057"><span>Excitation of the Werner <span class="hlt">bands</span> of H2 by <span class="hlt">electron</span> impact</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stone, E. J.; Zipf, E. C.</p> <p>1972-01-01</p> <p>Absolute cross sections for the excitation of the H2 Werner <span class="hlt">band</span> system were measured from <span class="hlt">energy</span> threshold to 300 eV for <span class="hlt">electron</span> impact on H2. The <span class="hlt">bands</span> were observed in emission in the wavelength region 1100A to 1250A. The measured cross sections were compared with published transition probabilities, leading to the conclusion that the Werner <span class="hlt">bands</span> are suitable as the basis for a relative spectral response calibration only when the <span class="hlt">bands</span> are observed under sufficiently high resolution. The effect of the perturbation between the C 1Pi u and B 1 Sigma-u states of the hydrogen molecule was clearly observed in anomalies in the rotational intensity distribution in <span class="hlt">bands</span> of the (3 v '') progression.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005IJMPB..19.2798T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005IJMPB..19.2798T"><span><span class="hlt">Band</span> like <span class="hlt">Electronic</span> Structures in Square Hollow Quantum Dots by 3D-MHFKS Calculation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takizawa, Tokihiro; Okada, Hoshihito; Matsuse, Takehiro</p> <p></p> <p>To find novel aspects of the <span class="hlt">electronic</span> structures in quantum dots (QD) from a view point of spatial broken symmetry, 3-dimensional-mesh Hartree-Fock-Kohn-Sham (3D-MHFKS) calculations1 are applied to the interacting <span class="hlt">electron</span> system of <span class="hlt">electron</span> number N in a symmetry broken hollow QD. For the case of a square hollow quantum dot confined in square hard wall (HW) potential (SSHQD), the magnetic (B) field dependence of the obtained single particle <span class="hlt">energy</span> levels and chemical potentials in B-N diagram are shown to have a <span class="hlt">band</span> like <span class="hlt">electronic</span> structures over the wide B-field range up to 20T. To clarify the origin of the <span class="hlt">band</span> like <span class="hlt">electronic</span> structures in SSHQD, 3D-MHFKS calculations are also applied for the mixed symmetry QD's with a circular hollow in square HW potential (SCHQD) and with a square hollow in circular HW potential (CSHQD).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..95h1106W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..95h1106W"><span>Formation of Hubbard-like <span class="hlt">bands</span> as a fingerprint of strong <span class="hlt">electron-electron</span> interactions in FeSe</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Watson, Matthew D.; Backes, Steffen; Haghighirad, Amir A.; Hoesch, Moritz; Kim, Timur K.; Coldea, Amalia I.; Valentí, Roser</p> <p>2017-02-01</p> <p>We use angle-resolved photoemission spectroscopy (ARPES) to explore the <span class="hlt">electronic</span> structure of single crystals of FeSe over a wide range of binding <span class="hlt">energies</span> and study the effects of strong <span class="hlt">electron-electron</span> correlations. We provide evidence for the existence of "Hubbard-like <span class="hlt">bands</span>" at high binding <span class="hlt">energies</span> consisting of incoherent many-body excitations originating from Fe 3 d states in addition to the renormalized quasiparticle <span class="hlt">bands</span> near the Fermi level. Many high-<span class="hlt">energy</span> features of the observed ARPES data can be accounted for when incorporating the effects of strong local Coulomb interactions in calculations of the spectral function via dynamical mean-field theory, including the formation of a Hubbard-like <span class="hlt">band</span>. This shows that over the <span class="hlt">energy</span> scale of several eV, local correlations arising from the on-site Coulomb repulsion and Hund's coupling are essential for a proper understanding of the <span class="hlt">electronic</span> structure of FeSe and other related iron-based superconductors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5141287','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5141287"><span>Quantifying <span class="hlt">electronic</span> <span class="hlt">band</span> interactions in van der Waals materials using angle-resolved reflected-<span class="hlt">electron</span> spectroscopy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jobst, Johannes; van der Torren, Alexander J. H.; Krasovskii, Eugene E.; Balgley, Jesse; Dean, Cory R.; Tromp, Rudolf M.; van der Molen, Sense Jan</p> <p>2016-01-01</p> <p>High <span class="hlt">electron</span> mobility is one of graphene's key properties, exploited for applications and fundamental research alike. Highest mobility values are found in heterostructures of graphene and hexagonal boron nitride, which consequently are widely used. However, surprisingly little is known about the interaction between the <span class="hlt">electronic</span> states of these layered systems. Rather pragmatically, it is assumed that these do not couple significantly. Here we study the unoccupied <span class="hlt">band</span> structure of graphite, boron nitride and their heterostructures using angle-resolved reflected-<span class="hlt">electron</span> spectroscopy. We demonstrate that graphene and boron nitride <span class="hlt">bands</span> do not interact over a wide <span class="hlt">energy</span> range, despite their very similar dispersions. The method we use can be generally applied to study interactions in van der Waals systems, that is, artificial stacks of layered materials. With this we can quantitatively understand the ‘chemistry of layers' by which novel materials are created via <span class="hlt">electronic</span> coupling between the layers they are composed of. PMID:27897180</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatCo...713621J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatCo...713621J"><span>Quantifying <span class="hlt">electronic</span> <span class="hlt">band</span> interactions in van der Waals materials using angle-resolved reflected-<span class="hlt">electron</span> spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jobst, Johannes; van der Torren, Alexander J. H.; Krasovskii, Eugene E.; Balgley, Jesse; Dean, Cory R.; Tromp, Rudolf M.; van der Molen, Sense Jan</p> <p>2016-11-01</p> <p>High <span class="hlt">electron</span> mobility is one of graphene's key properties, exploited for applications and fundamental research alike. Highest mobility values are found in heterostructures of graphene and hexagonal boron nitride, which consequently are widely used. However, surprisingly little is known about the interaction between the <span class="hlt">electronic</span> states of these layered systems. Rather pragmatically, it is assumed that these do not couple significantly. Here we study the unoccupied <span class="hlt">band</span> structure of graphite, boron nitride and their heterostructures using angle-resolved reflected-<span class="hlt">electron</span> spectroscopy. We demonstrate that graphene and boron nitride <span class="hlt">bands</span> do not interact over a wide <span class="hlt">energy</span> range, despite their very similar dispersions. The method we use can be generally applied to study interactions in van der Waals systems, that is, artificial stacks of layered materials. With this we can quantitatively understand the `chemistry of layers' by which novel materials are created via <span class="hlt">electronic</span> coupling between the layers they are composed of.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27228462','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27228462"><span>Correlation between morphology, <span class="hlt">electron</span> <span class="hlt">band</span> structure, and resistivity of Pb atomic chains on the Si(5 5 3)-Au surface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jałochowski, M; Kwapiński, T; Łukasik, P; Nita, P; Kopciuszyński, M</p> <p>2016-07-20</p> <p>Structural and <span class="hlt">electron</span> transport properties of multiple Pb atomic chains fabricated on the Si(5 5 3)-Au surface are investigated using scanning tunneling spectroscopy, reflection high <span class="hlt">electron</span> <span class="hlt">energy</span> diffraction, angular resolved photoemission <span class="hlt">electron</span> spectroscopy and in situ electrical resistance. The study shows that Pb atomic chains growth modulates the <span class="hlt">electron</span> <span class="hlt">band</span> structure of pristine Si(5 5 3)-Au surface and hence changes its sheet resistivity. Strong correlation between chains morphology, <span class="hlt">electron</span> <span class="hlt">band</span> structure and <span class="hlt">electron</span> transport properties is found. To explain experimental findings a theoretical tight-binding model of multiple atomic chains interacting on effective substrate is proposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPCM...28B4003J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPCM...28B4003J"><span>Correlation between morphology, <span class="hlt">electron</span> <span class="hlt">band</span> structure, and resistivity of Pb atomic chains on the Si(5 5 3)-Au surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jałochowski, M.; Kwapiński, T.; Łukasik, P.; Nita, P.; Kopciuszyński, M.</p> <p>2016-07-01</p> <p>Structural and <span class="hlt">electron</span> transport properties of multiple Pb atomic chains fabricated on the Si(5 5 3)-Au surface are investigated using scanning tunneling spectroscopy, reflection high <span class="hlt">electron</span> <span class="hlt">energy</span> diffraction, angular resolved photoemission <span class="hlt">electron</span> spectroscopy and in situ electrical resistance. The study shows that Pb atomic chains growth modulates the <span class="hlt">electron</span> <span class="hlt">band</span> structure of pristine Si(5 5 3)-Au surface and hence changes its sheet resistivity. Strong correlation between chains morphology, <span class="hlt">electron</span> <span class="hlt">band</span> structure and <span class="hlt">electron</span> transport properties is found. To explain experimental findings a theoretical tight-binding model of multiple atomic chains interacting on effective substrate is proposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MPLB...3050402W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MPLB...3050402W"><span>The <span class="hlt">energy</span> <span class="hlt">band</span> structure of Si and Ge nanolayers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Xueke; Huang, Weiqi; Huang, Zhongmei; Qin, Chaojie; Tang, Yanlin</p> <p>2016-12-01</p> <p>First-principles calculation based on density functional theory (DFT) with the generalized gradient approximation (GGA) were carried out to investigate the <span class="hlt">energy</span> <span class="hlt">band</span> gap structure of Si and Ge nanofilms. Calculation results show that the <span class="hlt">band</span> gaps of Si(111) and Ge(110) nanofilms are indirect structures and independent of film thickness, the <span class="hlt">band</span> gaps of Si(110) and Ge(100) nanofilms could be transfered into the direct structure for nanofilm thickness of less than a certain value, and the <span class="hlt">band</span> gaps of Si(100) and Ge(111) nanofilms are the direct structures in the present model thickness range (about 7 nm). Moreover, the changes of the <span class="hlt">band</span> gaps on the Si and Ge nanofilms follow the quantum confinement effects. It will be a good way to obtain direct <span class="hlt">band</span> gap emission in Si and Ge materials, and to develop Si and Ge laser on Si chip.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5068113','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5068113"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structure and optical properties of the cubic, Sc, Y and La hydride systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Peterman, D.J.</p> <p>1980-01-01</p> <p><span class="hlt">Electronic</span> <span class="hlt">band</span> structure calculations are used to interpret the optical spectra of the cubic Sc, Y and La hydride systems. Self-consistent <span class="hlt">band</span> calculations of ScH/sub 2/ and YH/sub 2/ were carried out. The respective joint densities of states are computed and compared to the dielectric functions determined from the optical measurements. Additional calculations were performed in which the Fermi level or <span class="hlt">band</span> gap <span class="hlt">energies</span> are rigidly shifted by a small <span class="hlt">energy</span> increment. These calculations are then used to simulate the derivative structure in thermomodulation spectra and relate the origin of experimental interband features to the calculated <span class="hlt">energy</span> <span class="hlt">bands</span>. While good systematic agreement is obtained for several spectral features, the origin of low-<span class="hlt">energy</span> interband transitions in YH/sub 2/ cannot be explained by these calculated <span class="hlt">bands</span>. A lattice-size-dependent premature occupation of octahedral sites by hydrogen atoms in the fcc metal lattice is suggested to account for this discrepancy. Various non-self-consistent calculations are used to examine the effect of such a premature occupation. Measurements of the optical absorptivity of LaH/sub x/ with 1.6 < x < 2.9 are presented which, as expected, indicate a more premature occupation of the octahedral sites in the larger LaH/sub 2/ lattice. These experimental results also suggest that, in contrast to recent calculations, LaH/sub 3/ is a small-<span class="hlt">band</span>-gap semiconductor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JAP...113u3509C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JAP...113u3509C"><span>Fe-substituted indium thiospinels: New intermediate <span class="hlt">band</span> semiconductors with better absorption of solar <span class="hlt">energy</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Ping; Chen, Haijie; Qin, Mingsheng; Yang, Chongyin; Zhao, Wei; Liu, Yufeng; Zhang, Wenqing; Huang, Fuqiang</p> <p>2013-06-01</p> <p>The indium thiospinels In2S3 and MgIn2S4 are promising host for the intermediated <span class="hlt">band</span> (IB) photovoltaic materials due to their ideal <span class="hlt">band</span> gap value. Here, the optical properties and <span class="hlt">electronic</span> structure of Fe-doped In2S3 and MgIn2S4 have been investigated. All the Fe-substituted semiconductors exhibit two additional absorption <span class="hlt">bands</span> at about 0.7 and 1.25 eV, respectively. The results of first-principles calculations revealed that the Fe substituted at the octahedral In site would introduce a partially filled IB into the <span class="hlt">band</span> gap. Thanks to the formation of IB, the Fe-substituted semiconductors have the ability to absorb the photons with <span class="hlt">energies</span> below the <span class="hlt">band</span> gap. With the wide-spectrum absorption of solar <span class="hlt">energy</span>, these materials possess potential applications in photovoltaic domain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD0739310','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD0739310"><span>Concerning the Optical Absorption <span class="hlt">Band</span> of the Hydrated <span class="hlt">Electron</span>,</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p></p> <p>methylene blue ) showed marked nonlinear absorption due to saturation of optical transitions, no such change was observed for hydrated <span class="hlt">electrons</span> even though the light intensity was varied by > 10 to the 7th power up to 200 photons per hydrated <span class="hlt">electron</span> per sq cm. Consequently the photoexcited state lifetime is estimated to be than 6 x 10 to the -12th power sec. This finding is discussed briefly in terms of three possible origins for the absorption <span class="hlt">band</span>, namely that involving excitation to a bound excited state, as a photoionization efficiency profile or as a distribution</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4174871','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4174871"><span><span class="hlt">Electronic</span> materials with a wide <span class="hlt">band</span> gap: recent developments</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Klimm, Detlef</p> <p>2014-01-01</p> <p>The development of semiconductor <span class="hlt">electronics</span> is reviewed briefly, beginning with the development of germanium devices (<span class="hlt">band</span> gap E g = 0.66 eV) after World War II. A tendency towards alternative materials with wider <span class="hlt">band</span> gaps quickly became apparent, starting with silicon (E g = 1.12 eV). This improved the signal-to-noise ratio for classical <span class="hlt">electronic</span> applications. Both semiconductors have a tetrahedral coordination, and by isoelectronic alternative replacement of Ge or Si with carbon or various anions and cations, other semiconductors with wider E g were obtained. These are transparent to visible light and belong to the group of wide <span class="hlt">band</span> gap semiconductors. Nowadays, some nitrides, especially GaN and AlN, are the most important materials for optical emission in the ultraviolet and blue regions. Oxide crystals, such as ZnO and β-Ga2O3, offer similarly good <span class="hlt">electronic</span> properties but still suffer from significant difficulties in obtaining stable and technologically adequate p-type conductivity. PMID:25295170</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6285670','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6285670"><span><span class="hlt">Electron</span> charge densities at conduction-<span class="hlt">band</span> edges of semiconductors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Richardson, S.L.; Cohen, M.L.; Louie, S.G.; Chelikowsky, J.R.</p> <p>1986-01-15</p> <p>We demonstrate that both the empirical pseudopotential method (EPM) and the linear combination of atomiclike orbitals (LCAO) approach are capable of producing consistent <span class="hlt">electronic</span> charge distributions in a compound semiconductor. Since the EPM approach is known to produce total valence <span class="hlt">electron</span> charge densities which compare well with experimental x-ray data (e.g., Si), this work serves as a further test for the LCAO method. In particular, the EPM scheme, which uses an extended plane-wave basis, and the LCAO scheme, which employs a localized Gaussian basis, are used, with the same empirical potential as input, to analyze both the total valence <span class="hlt">electron</span> charge density and the charge density of the first conduction <span class="hlt">band</span> at the GAMMA, L, and X k points of the Brillouin zone. These charge densities are decomposed into their s-, p-, and d-orbital contributions, and this information is used to interpret the differences in the topologies of the conduction <span class="hlt">bands</span> at GAMMA, L, and X. Such differences are crucial for a comprehensive understanding of interstitial impurities and the response of specific <span class="hlt">band</span> states to perturbations in compound semiconductors.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800005174','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800005174"><span>A low <span class="hlt">energy</span> <span class="hlt">electron</span> magnetometer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Singh, J. J.; Wood, G. M., Jr.; Rayborn, G. H.; White, F. A.</p> <p>1979-01-01</p> <p>The concept of a highly sensitive magnetometer based on the deflection of low <span class="hlt">energy</span> <span class="hlt">electron</span> beams in magnetic fields is analyzed. Because of its extremely low mass and consequently high e/m ratio, a low <span class="hlt">energy</span> <span class="hlt">electron</span> is easily deflected in a magnetic field, thus providing a basis for very low field measurement. Calculations for a specific instrument design indicate that a low <span class="hlt">energy</span> <span class="hlt">electron</span> magnetometer (LEEM) can measure magnetic fields as low as 1000 nT. The anticipated performance of LEEM is compared with that of the existing high resolution magnetometers in selected applications. The fast response time of LEEM makes it especially attractive as a potential instrument for magnetic signature analysis in large engineering systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22218247','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22218247"><span><span class="hlt">Electronic</span>- and <span class="hlt">band</span>-structure evolution in low-doped (Ga,Mn)As</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yastrubchak, O.; Gluba, L.; Żuk, J.; Sadowski, J.; Krzyżanowska, H.; Domagala, J. Z.; Andrearczyk, T.; Wosinski, T.</p> <p>2013-08-07</p> <p>Modulation photoreflectance spectroscopy and Raman spectroscopy have been applied to study the <span class="hlt">electronic</span>- and <span class="hlt">band</span>-structure evolution in (Ga,Mn)As epitaxial layers with increasing Mn doping in the range of low Mn content, up to 1.2%. Structural and magnetic properties of the layers were characterized with high-resolution X-ray diffractometry and SQUID magnetometery, respectively. The revealed results of decrease in the <span class="hlt">band</span>-gap-transition <span class="hlt">energy</span> with increasing Mn content in very low-doped (Ga,Mn)As layers with n-type conductivity are interpreted as a result of merging the Mn-related impurity <span class="hlt">band</span> with the host GaAs valence <span class="hlt">band</span>. On the other hand, an increase in the <span class="hlt">band</span>-gap-transition <span class="hlt">energy</span> with increasing Mn content in (Ga,Mn)As layers with higher Mn content and p-type conductivity indicates the Moss-Burstein shift of the absorption edge due to the Fermi level location within the valence <span class="hlt">band</span>, determined by the free-hole concentration. The experimental results are consistent with the valence-<span class="hlt">band</span> origin of mobile holes mediating ferromagnetic ordering in the (Ga,Mn)As diluted ferromagnetic semiconductor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/554429','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/554429"><span>Effects of <span class="hlt">electron</span> <span class="hlt">band</span> structure on neutrino pair bremsstrahlung in neutron star crusts</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pethick, C.J. |</p> <p>1997-12-01</p> <p>We calculate the rate of <span class="hlt">energy</span> emission by bremsstrahlung of neutrino pairs by <span class="hlt">electrons</span> moving in the crystalline lattice of ions in dense matter in the crust of a neutron star. Since the periodic potential in the solid gives rise to <span class="hlt">electronic</span> <span class="hlt">band</span> gaps which can be as large as about 1 MeV, it is necessary in estimating the bremsstrahlung rate at low temperatures to take into account <span class="hlt">band</span> structure in detail. We find that, in the densest parts of the inner crust of a neutron star, neutrino emission at temperatures of about 2{times}10{sup 9}K or less is much suppressed compared with earlier estimates that treated the <span class="hlt">electron</span>-lattice interaction perturbatively, and conclude that neutrino pair bremsstrahlung by <span class="hlt">electrons</span> in the crusts of neutron stars is much less important for neutron star thermal evolution than was previously thought. {copyright} {ital 1997} {ital The American Physical Society}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvB..89w5124P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvB..89w5124P"><span>Determination of the first satellite valley <span class="hlt">energy</span> in the conduction <span class="hlt">band</span> of wurtzite GaN by near-<span class="hlt">band</span>-gap photoemission spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Piccardo, Marco; Martinelli, Lucio; Iveland, Justin; Young, Nathan; DenBaars, Steven P.; Nakamura, Shuji; Speck, James S.; Weisbuch, Claude; Peretti, Jacques</p> <p>2014-06-01</p> <p>The position of the first satellite valley in wurtzite GaN is directly determined by near-<span class="hlt">band</span>-gap photoemission spectroscopy of p-doped GaN activated to negative <span class="hlt">electron</span> affinity. The photoemission spectra exhibit two structures, with fixed <span class="hlt">energy</span> position, which originate from <span class="hlt">electrons</span> accumulated in the conduction <span class="hlt">band</span> valleys of the bulk material. We assigned the two observed features respectively to Γ and L valleys and obtain an intervalley <span class="hlt">energy</span> separation of 0.90±0.08 eV, well below the theoretical values of the lowest subsidiary valley <span class="hlt">energy</span> provided by ab initio calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..12111737M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..12111737M"><span>Characteristic <span class="hlt">energy</span> range of <span class="hlt">electron</span> scattering due to plasmaspheric hiss</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Q.; Li, W.; Thorne, R. M.; Bortnik, J.; Reeves, G. D.; Kletzing, C. A.; Kurth, W. S.; Hospodarsky, G. B.; Spence, H. E.; Baker, D. N.; Blake, J. B.; Fennell, J. F.; Claudepierre, S. G.; Angelopoulos, V.</p> <p>2016-12-01</p> <p>We investigate the characteristic <span class="hlt">energy</span> range of <span class="hlt">electron</span> flux decay due to the interaction with plasmaspheric hiss in the Earth's inner magnetosphere. The Van Allen Probes have measured the energetic <span class="hlt">electron</span> flux decay profiles in the Earth's outer radiation belt during a quiet period following the geomagnetic storm that occurred on 7 November 2015. The observed <span class="hlt">energy</span> of significant <span class="hlt">electron</span> decay increases with decreasing L shell and is well correlated with the <span class="hlt">energy</span> <span class="hlt">band</span> corresponding to the first adiabatic invariant μ = 4-200 MeV/G. The <span class="hlt">electron</span> diffusion coefficients due to hiss scattering are calculated at L = 2-6, and the modeled <span class="hlt">energy</span> <span class="hlt">band</span> of effective pitch angle scattering is also well correlated with the constant μ lines and is consistent with the observed <span class="hlt">energy</span> range of <span class="hlt">electron</span> decay. Using the previously developed statistical plasmaspheric hiss model during modestly disturbed periods, we perform a 2-D Fokker-Planck simulation of the <span class="hlt">electron</span> phase space density evolution at L = 3.5 and demonstrate that plasmaspheric hiss causes the significant decay of 100 keV-1 MeV <span class="hlt">electrons</span> with the largest decay rate occurring at around 340 keV, forming anisotropic pitch angle distributions at lower <span class="hlt">energies</span> and more flattened distributions at higher <span class="hlt">energies</span>. Our study provides reasonable estimates of the <span class="hlt">electron</span> populations that can be most significantly affected by plasmaspheric hiss and the consequent <span class="hlt">electron</span> decay profiles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvL.119h6401M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvL.119h6401M"><span>Ultrafast <span class="hlt">Electronic</span> <span class="hlt">Band</span> Gap Control in an Excitonic Insulator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mor, Selene; Herzog, Marc; Golež, Denis; Werner, Philipp; Eckstein, Martin; Katayama, Naoyuki; Nohara, Minoru; Takagi, Hide; Mizokawa, Takashi; Monney, Claude; Stähler, Julia</p> <p>2017-08-01</p> <p>We report on the nonequilibrium dynamics of the <span class="hlt">electronic</span> structure of the layered semiconductor Ta2NiSe5 investigated by time- and angle-resolved photoelectron spectroscopy. We show that below the critical excitation density of FC=0.2 mJ cm-2 , the <span class="hlt">band</span> gap narrows transiently, while it is enhanced above FC . Hartree-Fock calculations reveal that this effect can be explained by the presence of the low-temperature excitonic insulator phase of Ta2 NiSe5 , whose order parameter is connected to the gap size. This work demonstrates the ability to manipulate the <span class="hlt">band</span> gap of Ta2 NiSe5 with light on the femtosecond time scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvP...3e4005S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvP...3e4005S"><span>Discrete <span class="hlt">Electronic</span> <span class="hlt">Bands</span> in Semiconductors and Insulators: Potential High-Light-Yield Scintillators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Hongliang; Du, Mao-Hua</p> <p>2015-05-01</p> <p>Bulk semiconductors and insulators typically have continuous valence and conduction <span class="hlt">bands</span>. Here, we show that valence and conduction <span class="hlt">bands</span> of a multinary semiconductor or insulator can be split to narrow discrete <span class="hlt">bands</span> separated by large <span class="hlt">energy</span> gaps. This unique <span class="hlt">electronic</span> structure is demonstrated by first-principles calculations in several quaternary elpasolite compounds, i.e., Cs2NaInBr6 , Cs2NaBiCl6 , and Tl2NaBiCl6 . The narrow discrete <span class="hlt">band</span> structure in these quaternary elpasolites is due to the large electronegativity difference among cations and the large nearest-neighbor distances in cation sublattices. We further use Cs2NaInBr6 as an example to show that the narrow <span class="hlt">bands</span> can stabilize self-trapped and dopant-bound excitons (in which both the <span class="hlt">electron</span> and the hole are strongly localized in static positions on adjacent sites) and promote strong exciton emission at room temperature. The discrete <span class="hlt">band</span> structure should further suppress thermalization of hot carriers and may lead to enhanced impact ionization, which is usually considered inefficient in bulk semiconductors and insulators. These characteristics can enable efficient room-temperature light emission in low-gap scintillators and may overcome the light-yield bottleneck in current scintillator research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1185880-discrete-electronic-bands-semiconductors-insulators-potential-high-light-yield-scintillators','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1185880-discrete-electronic-bands-semiconductors-insulators-potential-high-light-yield-scintillators"><span>Discrete <span class="hlt">Electronic</span> <span class="hlt">Bands</span> in Semiconductors and Insulators: Potential High-Light-Yield Scintillators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Shi, Hongliang; Du, Mao-Hua</p> <p>2015-05-12</p> <p>Bulk semiconductors and insulators typically have continuous valence and conduction <span class="hlt">bands</span>. In this paper, we show that valence and conduction <span class="hlt">bands</span> of a multinary semiconductor or insulator can be split to narrow discrete <span class="hlt">bands</span> separated by large <span class="hlt">energy</span> gaps. This unique <span class="hlt">electronic</span> structure is demonstrated by first-principles calculations in several quaternary elpasolite compounds, i.e., Cs2NaInBr6, Cs2NaBiCl6, and Tl2NaBiCl6. The narrow discrete <span class="hlt">band</span> structure in these quaternary elpasolites is due to the large electronegativity difference among cations and the large nearest-neighbor distances in cation sublattices. We further use Cs2NaInBr6 as an example to show that the narrow <span class="hlt">bands</span> can stabilize self-trappedmore » and dopant-bound excitons (in which both the <span class="hlt">electron</span> and the hole are strongly localized in static positions on adjacent sites) and promote strong exciton emission at room temperature. The discrete <span class="hlt">band</span> structure should further suppress thermalization of hot carriers and may lead to enhanced impact ionization, which is usually considered inefficient in bulk semiconductors and insulators. Finally, these characteristics can enable efficient room-temperature light emission in low-gap scintillators and may overcome the light-yield bottleneck in current scintillator research.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1185880','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1185880"><span>Discrete <span class="hlt">Electronic</span> <span class="hlt">Bands</span> in Semiconductors and Insulators: Potential High-Light-Yield Scintillators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shi, Hongliang; Du, Mao-Hua</p> <p>2015-05-12</p> <p>Bulk semiconductors and insulators typically have continuous valence and conduction <span class="hlt">bands</span>. In this paper, we show that valence and conduction <span class="hlt">bands</span> of a multinary semiconductor or insulator can be split to narrow discrete <span class="hlt">bands</span> separated by large <span class="hlt">energy</span> gaps. This unique <span class="hlt">electronic</span> structure is demonstrated by first-principles calculations in several quaternary elpasolite compounds, i.e., Cs<sub>2</sub>NaInBr<sub>6</sub>, Cs<sub>2</sub>NaBiCl<sub>6</sub>, and Tl<sub>2</sub>NaBiCl<sub>6</sub>. The narrow discrete <span class="hlt">band</span> structure in these quaternary elpasolites is due to the large electronegativity difference among cations and the large nearest-neighbor distances in cation sublattices. We further use Cs<sub>2</sub>NaInBr<sub>6</sub> as an example to show that the narrow <span class="hlt">bands</span> can stabilize self-trapped and dopant-bound excitons (in which both the <span class="hlt">electron</span> and the hole are strongly localized in static positions on adjacent sites) and promote strong exciton emission at room temperature. The discrete <span class="hlt">band</span> structure should further suppress thermalization of hot carriers and may lead to enhanced impact ionization, which is usually considered inefficient in bulk semiconductors and insulators. Finally, these characteristics can enable efficient room-temperature light emission in low-gap scintillators and may overcome the light-yield bottleneck in current scintillator research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JEMat..45.5040J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JEMat..45.5040J"><span>Strain-Induced <span class="hlt">Energy</span> <span class="hlt">Band</span> Gap Opening in Two-Dimensional Bilayered Silicon Film</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ji, Z.; Zhou, R.; Lew Yan Voon, L. C.; Zhuang, Y.</p> <p>2016-10-01</p> <p>This work presents a theoretical study of the structural and <span class="hlt">electronic</span> properties of bilayered silicon film (BiSF) under in-plane biaxial strain/stress using density functional theory (DFT). Atomic structures of the two-dimensional (2-D) silicon films are optimized by using both the local-density approximation (LDA) and generalized gradient approximation (GGA). In the absence of strain/stress, five buckled hexagonal honeycomb structures of the BiSF with triangular lattice have been obtained as local <span class="hlt">energy</span> minima, and their structural stability has been verified. These structures present a Dirac-cone shaped <span class="hlt">energy</span> <span class="hlt">band</span> diagram with zero <span class="hlt">energy</span> <span class="hlt">band</span> gaps. Applying a tensile biaxial strain leads to a reduction of the buckling height. Atomically flat structures with zero buckling height have been observed when the AA-stacking structures are under a critical biaxial strain. Increase of the strain between 10.7% and 15.4% results in a <span class="hlt">band</span>-gap opening with a maximum <span class="hlt">energy</span> <span class="hlt">band</span> gap opening of ˜0.17 eV, obtained when a 14.3% strain is applied. <span class="hlt">Energy</span> <span class="hlt">band</span> diagrams, <span class="hlt">electron</span> transmission efficiency, and the charge transport property are calculated. Additionally, an asymmetric energetically favorable atomic structure of BiSF shows a non-zero <span class="hlt">band</span> gap in the absence of strain/stress and a maximum <span class="hlt">band</span> gap of 0.15 eV as a -1.71% compressive strain is applied. Both tensile and compressive strain/stress can lead to a <span class="hlt">band</span> gap opening in the asymmetric structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22392075','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22392075"><span><span class="hlt">Electron</span> and hole photoemission detection for <span class="hlt">band</span> offset determination of tunnel field-effect transistor heterojunctions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Li, Wei; Zhang, Qin; Kirillov, Oleg A.; Levin, Igor; Richter, Curt A.; Gundlach, David J.; Nguyen, N. V. E-mail: liangxl@pku.edu.cn; Bijesh, R.; Datta, S.; Liang, Yiran; Peng, Lian-Mao; Liang, Xuelei E-mail: liangxl@pku.edu.cn</p> <p>2014-11-24</p> <p>We report experimental methods to ascertain a complete <span class="hlt">energy</span> <span class="hlt">band</span> alignment of a broken-gap tunnel field-effect transistor based on an InAs/GaSb hetero-junction. By using graphene as an optically transparent electrode, both the <span class="hlt">electron</span> and hole barrier heights at the InAs/GaSb interface can be quantified. For a Al{sub 2}O{sub 3}/InAs/GaSb layer structure, the barrier height from the top of the InAs and GaSb valence <span class="hlt">bands</span> to the bottom of the Al{sub 2}O{sub 3} conduction <span class="hlt">band</span> is inferred from <span class="hlt">electron</span> emission whereas hole emissions reveal the barrier height from the top of the Al{sub 2}O{sub 3} valence <span class="hlt">band</span> to the bottom of the InAs and GaSb conduction <span class="hlt">bands</span>. Subsequently, the offset parameter at the broken gap InAs/GaSb interface is extracted and thus can be used to facilitate the development of predicted models of <span class="hlt">electron</span> quantum tunneling efficiency and transistor performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..MARB23013K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..MARB23013K"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structure, doping, and defects in the semiconducting Half Heusler compound CoTiSb</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kawasaki, Jason; Johansson, Linda; Hjort, Martin; Timm, Rainer; Schultz, Brian; Balasubramanian, Thiagarajan; Mikkelsen, Anders; Palmstrom, Chris</p> <p>2013-03-01</p> <p>We report transport and <span class="hlt">electronic</span> <span class="hlt">band</span> structure measurements on epitaxial films of the Half Heusler compound CoTiSb. CoTiSb belongs to the family of Half Heuslers with 18 valence <span class="hlt">electrons</span> per formula unit that are predicted to be semiconducting despite being composed of all metallic components. Here the CoTiSb films were grown by molecular beam epitaxy on a lattice matched InAlAs buffer. The films are epitaxial and single crystalline, as measured by reflection high-<span class="hlt">energy</span> <span class="hlt">electron</span> diffraction and X-ray diffraction. Scanning tunnelling spectroscopy and temperature-dependent transport measurements reveal that the films are semiconducting, with unintentionally doped carrier concentrations comparable to that of highly doped conventional compound semiconductors. These carrier concentrations can be modulated by doping with Sn. The <span class="hlt">band</span> structure of the films was measured by angle resolved photoemission spectroscopy at the MAX-Lab Synchrotron facility. The bulk <span class="hlt">bands</span> are in general agreement with density functional theory calculations, with a valence <span class="hlt">band</span> maximum at Γ and surface states within the bulk <span class="hlt">band</span> gap. The effects of defects are explored in order to explain the ARPES results. This work was supported by the ARO, AFOSR, ONR, and NSF.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvL.115q6405S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvL.115q6405S"><span>Detecting <span class="hlt">Band</span> Inversions by Measuring the Environment: Fingerprints of <span class="hlt">Electronic</span> <span class="hlt">Band</span> Topology in Bulk Phonon Linewidths</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saha, Kush; Légaré, Katherine; Garate, Ion</p> <p>2015-10-01</p> <p>The interplay between topological phases of matter and dissipative baths constitutes an emergent research topic with links to condensed matter, photonic crystals, cold atomic gases, and quantum information. While recent studies suggest that dissipative baths can induce topological phases in intrinsically trivial quantum materials, the backaction of topological invariants on dissipative baths is overlooked. By exploring this backaction for a centrosymmetric Dirac insulator coupled to phonons, we show that the linewidths of bulk optical phonons can reveal <span class="hlt">electronic</span> <span class="hlt">band</span> inversions. This result is the first known example where topological phases of an open quantum system may be detected by measuring the bulk properties of the surrounding environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28527312','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28527312"><span>Low-<span class="hlt">energy</span> <span class="hlt">electron</span> potentiometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jobst, Johannes; Kautz, Jaap; Mytiliniou, Maria; Tromp, Rudolf M; van der Molen, Sense Jan</p> <p>2017-10-01</p> <p>In a lot of systems, charge transport is governed by local features rather than being a global property as suggested by extracting a single resistance value. Consequently, techniques that resolve local structure in the <span class="hlt">electronic</span> potential are crucial for a detailed understanding of <span class="hlt">electronic</span> transport in realistic devices. Recently, we have introduced a new potentiometry method based on low-<span class="hlt">energy</span> <span class="hlt">electron</span> microscopy (LEEM) that utilizes characteristic features in the reflectivity spectra of layered materials [1]. Performing potentiometry experiments in LEEM has the advantage of being fast, offering a large field of view and the option to zoom in and out easily, and of being non-invasive compared to scanning-probe methods. However, not all materials show clear features in their reflectivity spectra. Here we, therefore, focus on a different version of low-<span class="hlt">energy</span> <span class="hlt">electron</span> potentiometry (LEEP) that uses the mirror mode transition, i.e. the drop in <span class="hlt">electron</span> reflectivity around zero <span class="hlt">electron</span> landing <span class="hlt">energy</span> when they start to interact with the sample rather than being reflected in front of it. This transition is universal and sensitive to the local electrostatic surface potential (either workfunction or applied potential). It can consequently be used to perform LEEP experiments on a broader range of material compared to the method described in Ref[1]. We provide a detailed description of the experimental setup and demonstrate LEEP on workfunction-related intrinsic potential variations on the Si(111) surface and for a metal-semiconductor-metal junction with external bias applied. In the latter, we visualize the Schottky effect at the metal-semiconductor interface. Finally, we compare how robust the two LEEP techniques discussed above are against image distortions due to sample inhomogeneities or contamination. Copyright © 2017 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997PhRvB..56.3664B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997PhRvB..56.3664B"><span>Exchange-correlation <span class="hlt">energy</span> of a hole gas including valence <span class="hlt">band</span> coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bobbert, P. A.; Wieldraaijer, H.; van der Weide, R.; Kemerink, M.; Koenraad, P. M.; Wolter, J. H.</p> <p>1997-08-01</p> <p>We have calculated an accurate exchange-correlation <span class="hlt">energy</span> of a hole gas, including the complexities related to the valence <span class="hlt">band</span> coupling as occurring in semiconductors like GaAs, but excluding the <span class="hlt">band</span> warping. A parametrization for the dependence on the density and the ratio between light- and heavy-hole masses is given. We apply our results to a hole gas in an AlxGa1-xAs/GaAs/AlxGa1-xAs quantum well and calculate the two-dimensional <span class="hlt">band</span> structure and the <span class="hlt">band</span>-gap renormalization. The inclusion of the valence <span class="hlt">band</span> coupling in the calculation of the exchange-correlation potentials for holes and <span class="hlt">electrons</span> leads to a much better agreement between theoretical and experimental data than when it is omitted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..95x5309M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..95x5309M"><span>Modeling the <span class="hlt">electronic</span> properties of GaAs polytype nanostructures: Impact of strain on the conduction <span class="hlt">band</span> character</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marquardt, Oliver; Ramsteiner, Manfred; Corfdir, Pierre; Geelhaar, Lutz; Brandt, Oliver</p> <p>2017-06-01</p> <p>We study the <span class="hlt">electronic</span> properties of GaAs nanowires composed of both the zinc-blende and wurtzite modifications using a ten-<span class="hlt">band</span> k .p model. In the wurtzite phase, two energetically close conduction <span class="hlt">bands</span> are of importance for the confinement and the <span class="hlt">energy</span> levels of the <span class="hlt">electron</span> ground state. These <span class="hlt">bands</span> form two intersecting potential landscapes for <span class="hlt">electrons</span> in zinc-blende/wurtzite nanostructures. The <span class="hlt">energy</span> difference between the two <span class="hlt">bands</span> depends sensitively on strain, such that even small strains can reverse the <span class="hlt">energy</span> ordering of the two <span class="hlt">bands</span>. This reversal may already be induced by the non-negligible lattice mismatch between the two crystal phases in polytype GaAs nanostructures, a fact that was ignored in previous studies of these structures. We present a systematic study of the influence of intrinsic and extrinsic strain on the <span class="hlt">electron</span> ground state for both purely zinc-blende and wurtzite nanowires as well as for polytype superlattices. The coexistence of the two conduction <span class="hlt">bands</span> and their opposite strain dependence results in complex <span class="hlt">electronic</span> and optical properties of GaAs polytype nanostructures. In particular, both the <span class="hlt">energy</span> and the polarization of the lowest intersubband transition depends on the relative fraction of the two crystal phases in the nanowire.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MAR.G1033M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MAR.G1033M"><span>Tuning the <span class="hlt">electronic</span> <span class="hlt">band</span>-gap of fluorinated 3C-silicon carbide nanowires</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miranda Durán, Álvaro; Trejo Baños, Alejandro; Pérez, Luis Antonio; Cruz Irisson, Miguel</p> <p></p> <p>The possibility of control and modulation of the <span class="hlt">electronic</span> properties of silicon carbide nanowires (SiCNWs) by varying the wire diameter is well known. SiCNWs are particularly interesting and technologically important, due to its electrical and mechanical properties, allowing the development of materials with specific <span class="hlt">electronic</span> features for the design of stable and robust <span class="hlt">electronic</span> devices. Tuning the <span class="hlt">band</span> gap by chemical surface passivation constitutes a way for the modification of the <span class="hlt">electronic</span> <span class="hlt">band</span> gap of these nanowires. We present, the structural and <span class="hlt">electronic</span> properties of fluorinated SiCNWs, grown along the [111] crystallographic direction, which are investigated by first principles. We consider nanowires with six diameters, varying from 0.35 nm to 2.13 nm, and eight random covering schemes including fully hydrogen- and fluorine terminated ones. Gibbs free <span class="hlt">energy</span> of formation and <span class="hlt">electronic</span> properties were calculated for the different surface functionalization schemes and diameters considered. The results indicate that the stability and <span class="hlt">band</span> gap of SiCNWs can be tuned by surface passivation with fluorine atoms This work was supported by CONACYT infrastructure project 252749 and UNAM-DGAPA-PAPIIT IN106714. A.M. would like to thank for financial support from CONACyT-Retención. Computing resources from proyect SC15-1-IR-27 of DGTIC-UNAM are acknowledged.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAP...122h5104W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAP...122h5104W"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structures and excitonic properties of delafossites: A GW-BSE study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Xiaoming; Meng, Weiwei; Yan, Yanfa</p> <p>2017-08-01</p> <p>We report the <span class="hlt">band</span> structures and excitonic properties of delafossites CuMO2 (M=Al, Ga, In, Sc, Y, Cr) calculated using the state-of-the-art GW-BSE approach. We evaluate different levels of self-consistency of the GW approximations, namely G0W0, GW0, GW, and QSGW, on the <span class="hlt">band</span> structures and find that GW0, in general, predicts the <span class="hlt">band</span> gaps in better agreement with experiments considering the <span class="hlt">electron</span>-hole effect. For CuCrO2, the HSE wave function is used as the starting point for the perturbative GW0 calculations, since it corrects the <span class="hlt">band</span> orders wrongly predicted by PBE. The discrepancy about the valence <span class="hlt">band</span> characters of CuCrO2 is classified based on both HSE and QSGW calculations. The PBE wave functions, already good, are used for other delafossites. All the delafossites are shown to be indirect <span class="hlt">band</span> gap semiconductors with large exciton binding <span class="hlt">energies</span>, varying from 0.24 to 0.44 eV, in consistent with experimental findings. The excitation mechanisms are explained by examining the exciton amplitude projections on the <span class="hlt">band</span> structures. Discrepancies compared with experiments are also addressed. The lowest and strongest exciton, mainly contributed from either Cu 3d → Cu 3p (Al, Ga, In) or Cu 3d → M 3d (M = Sc, Y, Cr) transitions, is always located at the L point of the rhombohedral Brillouin zone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6513538','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6513538"><span><span class="hlt">Electron</span>-impact excitation of the 31. 4-eV <span class="hlt">band</span> in N sub 2</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>de Souza, G.G.B.; Bielschowsky, C.E.; Lucas, C.A.; Souza, A.C.A. )</p> <p>1990-08-01</p> <p>Generalized oscillator strengths (GOS) for the dipole-forbidden 31.4-eV <span class="hlt">band</span> in N{sub 2} have been determined both experimentally and theoretically. The experimental values for the GOS were obtained using a crossed-beam <span class="hlt">electron</span> spectrometer at 1-keV impact <span class="hlt">energy</span>. The theoretical results were determined using the first Born approximation with {ital ab} {ital initio} configuration-interaction target wave functions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4555038','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4555038"><span>Quantitative analysis on electric dipole <span class="hlt">energy</span> in Rashba <span class="hlt">band</span> splitting</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hong, Jisook; Rhim, Jun-Won; Kim, Changyoung; Ryong Park, Seung; Hoon Shim, Ji</p> <p>2015-01-01</p> <p>We report on quantitative comparison between the electric dipole <span class="hlt">energy</span> and the Rashba <span class="hlt">band</span> splitting in model systems of Bi and Sb triangular monolayers under a perpendicular electric field. We used both first-principles and tight binding calculations on p-orbitals with spin-orbit coupling. First-principles calculation shows Rashba <span class="hlt">band</span> splitting in both systems. It also shows asymmetric charge distributions in the Rashba split <span class="hlt">bands</span> which are induced by the orbital angular momentum. We calculated the electric dipole <span class="hlt">energies</span> from coupling of the asymmetric charge distribution and external electric field, and compared it to the Rashba splitting. Remarkably, the total split <span class="hlt">energy</span> is found to come mostly from the difference in the electric dipole <span class="hlt">energy</span> for both Bi and Sb systems. A perturbative approach for long wave length limit starting from tight binding calculation also supports that the Rashba <span class="hlt">band</span> splitting originates mostly from the electric dipole <span class="hlt">energy</span> difference in the strong atomic spin-orbit coupling regime. PMID:26323493</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvS..20h0706T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvS..20h0706T"><span>High gain harmonic generation free <span class="hlt">electron</span> lasers enhanced by pseudoenergy <span class="hlt">bands</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanaka, Takashi; Kinjo, Ryota</p> <p>2017-08-01</p> <p>We propose a new scheme for high gain harmonic generation free <span class="hlt">electron</span> lasers (HGHG FELs), which is seeded by a pair of intersecting laser beams to interact with an <span class="hlt">electron</span> beam in a modulator undulator located in a dispersive section. The interference of the laser beams gives rise to a two-dimensional modulation in the <span class="hlt">energy</span>-time phase space because of a strong correlation between the <span class="hlt">electron</span> <span class="hlt">energy</span> and the position in the direction of dispersion. This eventually forms pseudoenergy <span class="hlt">bands</span> in the <span class="hlt">electron</span> beam, which result in efficient harmonic generation in HGHG FELs in a similar manner to the well-known scheme using the echo effects. The advantage of the proposed scheme is that the beam quality is less deteriorated than in other existing schemes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760014431','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760014431"><span>Thermo <span class="hlt">electronic</span> laser <span class="hlt">energy</span> conversion</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hansen, L. K.; Rasor, N. S.</p> <p>1976-01-01</p> <p>The thermo <span class="hlt">electronic</span> laser <span class="hlt">energy</span> converter (TELEC) is described and compared to the Waymouth converter and the conventional thermionic converter. The electrical output characteristics and efficiency of TELEC operation are calculated for a variety of design variables. Calculations and results are briefly outlined. It is shown that the TELEC concept can potentially convert 25 to 50 percent of incident laser radiation into electric power at high power densities and high waste heat rejection temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1180097-design-application-multimegawatt-band-deflectors-femtosecond-electron-beam-diagnostics','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1180097-design-application-multimegawatt-band-deflectors-femtosecond-electron-beam-diagnostics"><span>Design and application of multimegawatt X-<span class="hlt">band</span> deflectors for femtosecond <span class="hlt">electron</span> beam diagnostics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Dolgashev, Valery A.; Bowden, Gordon; Ding, Yuantao; ...</p> <p>2014-10-02</p> <p>Performance of the x-ray free <span class="hlt">electron</span> laser Linac Coherent Light Source (LCLS) and the Facility for Advanced Accelerator Experimental Tests (FACET) is determined by the properties of their extremely short <span class="hlt">electron</span> bunches. Multi-GeV <span class="hlt">electron</span> bunches in both LCLS and FACET are less than 100 fs long. Optimization of beam properties and understanding of free-<span class="hlt">electron</span> laser operation require <span class="hlt">electron</span> beam diagnostics with time resolution of about 10 fs. We designed, built and commissioned a set of high frequency X-<span class="hlt">band</span> deflectors which can measure the beam longitudinal space charge distribution and slice <span class="hlt">energy</span> spread to better than 10 fs resolution at fullmore » LCLS <span class="hlt">energy</span> (14 GeV), and with 70 fs resolution at full FACET <span class="hlt">energy</span> (20 GeV). Use of high frequency and high gradient in these devices allows them to reach unprecedented performance. We report on the physics motivation, design considerations, operational configuration, cold tests, and typical results of the X-<span class="hlt">band</span> deflector systems currently in use at SLAC.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.T33C2433S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.T33C2433S"><span>Propagation <span class="hlt">Energies</span> Inferred from Deformation <span class="hlt">Bands</span> in Sandstone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schultz, R. A.; Soliva, R.</p> <p>2011-12-01</p> <p>The J-integral is used to calculate the <span class="hlt">band</span> propagation <span class="hlt">energies</span> Jband for pure and shear-enhanced compaction <span class="hlt">bands</span> from four sandstones from around the world. The value obtained previously for the Valley of Fire (Utah) site assumed compactional offsets only across the <span class="hlt">bands</span>; shearing offsets along these and shear-enhanced compaction <span class="hlt">bands</span> (SECBs) from the Buckskin Gulch (Utah) and the recently reported Boncavaï quarry near Mornas (France) are consistent with trigonometrically obtained estimates calculated from <span class="hlt">band</span> thickness and angle to the maximum compressive principal stress. Compactional offsets were calculated from porosity reductions from host rock to <span class="hlt">band</span>. Cataclastic deformation <span class="hlt">bands</span> from the Quartier de l'Etang quarry near Orange (France) were also analyzed for comparison with <span class="hlt">bands</span> having smaller ratios of shear/compaction. Normal and shear stresses resolved across the <span class="hlt">bands</span> at the time of their formation were estimated from stratigraphic overburden and friction coefficients for porous sandstones measured in the laboratory. Assuming that the SECBs may be characterized by small-scale yielding, so that Jband is equivalent to the strain <span class="hlt">energy</span> release rate G, the values of Jband can be compared to the previous values. SECBs having strike-slip offsets from Valley of Fire have Jband = 11.1 kJ/m2, consistent with the previously reported range of GIc = 10-60 kJ/m2 calculated by using the J-integral approach by Rudnicki and Sternlof [2005]. Pure compaction <span class="hlt">bands</span> (PCBs) from the same site have Jband = 5.5 kJ/m2, implying that less work is required to propagate PCBs than SECBs. The value of Jband for the Buckskin Gulch site, 60.5 kJ/m2, is consistent with the lower range of values for strain <span class="hlt">energy</span> release rate obtained previously, GIc = 55-120 kJ/m2. <span class="hlt">Band</span> propagation <span class="hlt">energy</span> for SECBs from the Boncavaï quarry site, Jband = 16.4 kJ/m2, is comparable to that for similar structures from the Valley of Fire site. Cataclastic deformation <span class="hlt">bands</span> at the Orange quarry</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840004376','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840004376"><span>Low <span class="hlt">energy</span> <span class="hlt">electron</span> magnetometer using a monoenergetic <span class="hlt">electron</span> beam</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Singh, J. J.; Wood, G. M.; Rayborn, G. H.; White, F. A. (Inventor)</p> <p>1983-01-01</p> <p>A low <span class="hlt">energy</span> <span class="hlt">electron</span> beam magnetometer utilizes near-monoenergetic <span class="hlt">electrons</span> thereby reducing errors due to <span class="hlt">electron</span> <span class="hlt">energy</span> spread and <span class="hlt">electron</span> nonuniform angular distribution. In a first embodiment, atoms in an atomic beam of an inert gas are excited to a Rydberg state and then <span class="hlt">electrons</span> of near zero <span class="hlt">energy</span> are detached from the Rydberg atoms. The near zero <span class="hlt">energy</span> <span class="hlt">electrons</span> are then accelerated by an electric field V(acc) to form the <span class="hlt">electron</span> beam. In a second embodiment, a filament emits <span class="hlt">electrons</span> into an electrostatic analyzer which selects <span class="hlt">electrons</span> at a predetermined <span class="hlt">energy</span> level within a very narrow range. These selected <span class="hlt">electrons</span> make up the <span class="hlt">electron</span> beam that is subjected to the magnetic field being measured.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..95l5105X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..95l5105X"><span>Unified <span class="hlt">band</span>-theoretic description of structural, <span class="hlt">electronic</span>, and magnetic properties of vanadium dioxide phases</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Sheng; Shen, Xiao; Hallman, Kent A.; Haglund, Richard F.; Pantelides, Sokrates T.</p> <p>2017-03-01</p> <p>The debate about whether the insulating phases of vanadium dioxide (V O2 ) can be described by <span class="hlt">band</span> theory or whether it requires a theory of strong <span class="hlt">electron</span> correlations remains unresolved even after decades of research. <span class="hlt">Energy-band</span> calculations using hybrid exchange functionals or including self-<span class="hlt">energy</span> corrections account for the insulating or metallic nature of different phases but have not yet successfully accounted for the observed magnetic orderings. Strongly correlated theories have had limited quantitative success. Here we report that by using hard pseudopotentials and an optimized hybrid exchange functional, the <span class="hlt">energy</span> gaps and magnetic orderings of both monoclinic V O2 phases and the metallic nature of the high-temperature rutile phase are consistent with available experimental data, obviating an explicit role for strong correlations. We also identify a potential candidate for the newly found metallic monoclinic phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94g5424W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94g5424W"><span>Mapping unoccupied <span class="hlt">electronic</span> states of freestanding graphene by angle-resolved low-<span class="hlt">energy</span> <span class="hlt">electron</span> transmission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wicki, Flavio; Longchamp, Jean-Nicolas; Latychevskaia, Tatiana; Escher, Conrad; Fink, Hans-Werner</p> <p>2016-08-01</p> <p>We report angle-resolved <span class="hlt">electron</span> transmission measurements through freestanding graphene sheets in the <span class="hlt">energy</span> range of 18 to 30 eV above the Fermi level. The measurements are carried out in a low-<span class="hlt">energy</span> <span class="hlt">electron</span> point source microscope, which allows simultaneously probing the transmission for a large angular range. The characteristics of low-<span class="hlt">energy</span> <span class="hlt">electron</span> transmission through graphene depend on its <span class="hlt">electronic</span> structure above the vacuum level. The experimental technique described here allows mapping of the unoccupied <span class="hlt">band</span> structure of freestanding two-dimensional materials as a function of the <span class="hlt">energy</span> and probing angle, respectively, in-plane momentum. Our experimental findings are consistent with theoretical predictions of a resonance in the <span class="hlt">band</span> structure of graphene above the vacuum level [V. U. Nazarov, E. E. Krasovskii, and V. M. Silkin, Phys. Rev. B 87, 041405 (2013), 10.1103/PhysRevB.87.041405].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JSemi..36a3001A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JSemi..36a3001A"><span>The calculation of <span class="hlt">band</span> gap <span class="hlt">energy</span> in zinc oxide films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arif, Ali; Belahssen, Okba; Gareh, Salim; Benramache, Said</p> <p>2015-01-01</p> <p>We investigated the optical properties of undoped zinc oxide thin films as the n-type semiconductor; the thin films were deposited at different precursor molarities by ultrasonic spray and spray pyrolysis techniques. The thin films were deposited at different substrate temperatures ranging between 200 and 500 °C. In this paper, we present a new approach to control the optical gap <span class="hlt">energy</span> of ZnO thin films by concentration of the ZnO solution and substrate temperatures from experimental data, which were published in international journals. The model proposed to calculate the <span class="hlt">band</span> gap <span class="hlt">energy</span> with the Urbach <span class="hlt">energy</span> was investigated. The relation between the experimental data and theoretical calculation suggests that the <span class="hlt">band</span> gap <span class="hlt">energies</span> are predominantly estimated by the Urbach <span class="hlt">energies</span>, film transparency, and concentration of the ZnO solution and substrate temperatures. The measurements by these proposal models are in qualitative agreements with the experimental data; the correlation coefficient values were varied in the range 0.96-0.99999, indicating high quality representation of data based on Equation (2), so that the relative errors of all calculation are smaller than 4%. Thus, one can suppose that the undoped ZnO thin films are chemically purer and have many fewer defects and less disorder owing to an almost complete chemical decomposition and contained higher optical <span class="hlt">band</span> gap <span class="hlt">energy</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARL14011X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARL14011X"><span>Doping and strain dependence of the <span class="hlt">electronic</span> <span class="hlt">band</span> structure in Ge and GeSn alloys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Chi; Gallagher, James; Senaratne, Charutha; Brown, Christopher; Fernando, Nalin; Zollner, Stefan; Kouvetakis, John; Menendez, Jose</p> <p>2015-03-01</p> <p>A systematic study of the effect of dopants and strain on the <span class="hlt">electronic</span> structure of Ge and GeSn alloys is presented. Samples were grown by UHV-CVD on Ge-buffered Si using Ge3H8 and SnD4 as the sources of Ge and Sn, and B2H6/P(GeH3)3 as dopants. High-<span class="hlt">energy</span> critical points in the joint-density of <span class="hlt">electronic</span> states were studied using spectroscopic ellipsometry, which yields detailed information on the strain and doping dependence of the so-called E1, E1 +Δ1 , E0' and E2 transitions. The corresponding dependencies of the lowest direct <span class="hlt">band</span> gap E0 and the fundamental indirect <span class="hlt">band</span> gap Eindwere studied via room-T photoluminescence spectroscopy. Of particular interest for this work were the determination of deformation potentials, <span class="hlt">band</span> gap renormalization effects, Burstein-Moss shifts due to the presence of carriers at <span class="hlt">band</span> minima, and the dependence of other critical point parameters, such as amplitudes and phase angles, on the doping concentration. The selective blocking of transitions due to high doping makes it possible to investigate the precise k-space location of critical points. These studies are complemented with detailed <span class="hlt">band</span>-structure calculations within a full-zone k-dot- p approach. Supported by AFOSR under DOD AFOSR FA9550-12-1-0208 and DOD AFOSR FA9550-13-1-0022.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20951430','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20951430"><span><span class="hlt">Band</span>-gap measurements of direct and indirect semiconductors using monochromated <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gu Lin; Srot, Vesna; Sigle, Wilfried; Koch, Christoph; Aken, Peter van; Ruehle, Manfred; Scholz, Ferdinand; Thapa, Sarad B.; Kirchner, Christoph; Jetter, Michael</p> <p>2007-05-15</p> <p>With the development of monochromators for transmission <span class="hlt">electron</span> microscopes, valence <span class="hlt">electron-energy</span>-loss spectroscopy (VEELS) has become a powerful technique to study the <span class="hlt">band</span> structure of materials with high spatial resolution. However, artifacts such as Cerenkov radiation pose a limit for interpretation of the low-loss spectra. In order to reveal the exact <span class="hlt">band</span>-gap onset using the VEELS method, semiconductors with direct and indirect <span class="hlt">band</span>-gap transitions have to be treated differently. For direct semiconductors, spectra acquired at thin regions can efficiently minimize the Cerenkov effects. Examples of hexagonal GaN (h-GaN) spectra acquired at different thickness showed that a correct <span class="hlt">band</span>-gap onset value can be obtained for sample thicknesses up to 0.5 t/{lambda}. In addition, {omega}-q maps acquired at different specimen thicknesses confirm the thickness dependency of Cerenkov losses. For indirect semiconductors, the correct <span class="hlt">band</span>-gap onset can be obtained in the dark-field mode when the required momentum transfer for indirect transition is satisfied. Dark-field VEEL spectroscopy using a star-shaped entrance aperture provides a way of removing Cerenkov effects in diffraction mode. Examples of Si spectra acquired by displacing the objective aperture revealed the exact indirect transition gap E{sub g} of 1.1 eV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27045790','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27045790"><span>Monoclinic Tungsten Oxide with {100} Facet Orientation and Tuned <span class="hlt">Electronic</span> <span class="hlt">Band</span> Structure for Enhanced Photocatalytic Oxidations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Ning; Chen, Chen; Mei, Zongwei; Liu, Xiaohe; Qu, Xiaolei; Li, Yunxiang; Li, Siqi; Qi, Weihong; Zhang, Yuanjian; Ye, Jinhua; Roy, Vellaisamy A L; Ma, Renzhi</p> <p>2016-04-27</p> <p>Exploring surface-exposed highly active crystal facets for photocatalytic oxidations is promising in utilizing monoclinic WO3 semiconductor. However, the previously reported highly active facets for monoclinic WO3 were mainly toward enhancing photocatalytic reductions. Here we report that the WO3 with {100} facet orientation and tuned surface <span class="hlt">electronic</span> <span class="hlt">band</span> structure can effectively enhance photocatalytic oxidation properties. The {100} faceted WO3 single crystals are synthesized via a facile hydrothermal method. The UV-visible diffuse reflectance, X-ray photoelectron spectroscopy valence <span class="hlt">band</span> spectra, and photoelectrochemical measurements suggest that the {100} faceted WO3 has a much higher <span class="hlt">energy</span> level of valence <span class="hlt">band</span> maximum compared with the normal WO3 crystals without preferred orientation of the crystal face. The density functional theory calculations reveal that the shift of O 2p and W 5d states in {100} face induce a unique <span class="hlt">band</span> structure. In comparison with the normal WO3, the {100} faceted WO3 exhibits an O2 evolution rate about 5.1 times in water splitting, and also shows an acetone evolution rate of 4.2 times as well as CO2 evolution rate of 3.8 times in gaseous degradation of 2-propanol. This study demonstrates an efficient crystal face engineering route to tune the surface <span class="hlt">electronic</span> <span class="hlt">band</span> structure for enhanced photocatalytic oxidations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22591505','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22591505"><span>A class of monolayer metal halogenides MX{sub 2}: <span class="hlt">Electronic</span> structures and <span class="hlt">band</span> alignments</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lu, Feng; Wang, Weichao; Luo, Xiaoguang; Cheng, Yahui; Dong, Hong; Liu, Hui; Wang, Wei-Hua; Xie, Xinjian</p> <p>2016-03-28</p> <p>With systematic first principles calculations, a class of monolayer metal halogenides MX{sub 2} (M = Mg, Ca, Zn, Cd, Ge, Pb; M = Cl, Br, I) has been proposed. Our study indicates that these monolayer materials are semiconductors with the <span class="hlt">band</span> gaps ranging from 2.03 eV of ZnI{sub 2} to 6.08 eV of MgCl{sub 2}. Overall, the <span class="hlt">band</span> gap increases with the increase of the electronegativity of the X atom or the atomic number of the metal M. Meanwhile, the <span class="hlt">band</span> gaps of monolayer MgX{sub 2} (X = Cl, Br) are direct while those of other monolayers are indirect. Based on the <span class="hlt">band</span> edge curvatures, the derived <span class="hlt">electron</span> (m{sub e}) and hole (m{sub h}) effective masses of MX{sub 2} monolayers are close to their corresponding bulk values except that the m{sub e} of CdI{sub 2} is three times larger and the m{sub h} for PbI{sub 2} is twice larger. Finally, the <span class="hlt">band</span> alignments of all the studied MX{sub 2} monolayers are provided using the vacuum level as <span class="hlt">energy</span> reference. These theoretical results may not only introduce the monolayer metal halogenides family MX{sub 2} into the emerging two-dimensional materials, but also provide insights into the applications of MX{sub 2} in future <span class="hlt">electronic</span>, visible and ultraviolet optoelectronic devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122.1702C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122.1702C"><span>Bounce resonance scattering of radiation belt <span class="hlt">electrons</span> by H+ <span class="hlt">band</span> EMIC waves</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cao, Xing; Ni, Binbin; Summers, Danny; Bortnik, Jacob; Tao, Xin; Shprits, Yuri Y.; Lou, Yuequn; Gu, Xudong; Fu, Song; Shi, Run; Xiang, Zheng; Wang, Qi</p> <p>2017-02-01</p> <p>We perform a detailed analysis of bounce-resonant pitch angle scattering of radiation belt <span class="hlt">electrons</span> due to electromagnetic ion cyclotron (EMIC) waves. It is found that EMIC waves can resonate with near-equatorially mirroring <span class="hlt">electrons</span> over a wide range of L shells and <span class="hlt">energies</span>. H+ <span class="hlt">band</span> EMIC waves efficiently scatter radiation belt <span class="hlt">electrons</span> of <span class="hlt">energy</span> >100 keV from near 90° pitch angles to lower pitch angles where the cyclotron resonance mechanism can take over to further diffuse <span class="hlt">electrons</span> into the loss cone. Bounce-resonant <span class="hlt">electron</span> pitch angle scattering rates show a strong dependence on L shell, wave normal angle distribution, and wave spectral properties. We find distinct quantitative differences between EMIC wave-induced bounce-resonant and cyclotron-resonant diffusion coefficients. Cyclotron-resonant <span class="hlt">electron</span> scattering by EMIC waves has been well studied and found to be a potentially crucial <span class="hlt">electron</span> scattering mechanism. The new investigation here demonstrates that bounce-resonant <span class="hlt">electron</span> scattering may also be very important. We conclude that bounce resonance scattering by EMIC waves should be incorporated into future modeling efforts of radiation belt <span class="hlt">electron</span> dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22269429','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22269429"><span>Size effect on the <span class="hlt">electronic</span> and optical <span class="hlt">band</span> gap of CdSe QD</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sisodia, Namita</p> <p>2014-04-24</p> <p>Present paper deals with a critical and comprehensive analysis of the dependence of photo emission (PE) <span class="hlt">electronic</span> <span class="hlt">band</span> gap and optical absorption (OA) excitonic <span class="hlt">band</span> gap on the size of CdSe QD, via connecting it with excitonic absorbance wavelength. Excitonic absorbance wavelength is determined through an empirical fit of established experimental evidences. Effective excitonic charge and Bohr radius is determined as a function of size. Increase in size of the CdSe QD results in greater Bohr radius and smaller effective excitonic charge. Excitonic binding <span class="hlt">energy</span> as a degree of size of QD is also calculated which further relates with the difference in PE <span class="hlt">electronic</span> and OA optical <span class="hlt">band</span> gaps. It is also shown that with increase in size of CdSe QD, the excitonic binding <span class="hlt">energy</span> decreases which consequently increases differences in two <span class="hlt">band</span> gaps. Our results are very well comparable with the established results. Explanation for the origin of the unusual optical properties of CdSe QD has been also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EL....11448001S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EL....11448001S"><span><span class="hlt">Energy</span> <span class="hlt">band</span> gaps in graphene nanoribbons with corners</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Szczȩśniak, Dominik; Durajski, Artur P.; Khater, Antoine; Ghader, Doried</p> <p>2016-05-01</p> <p>In the present paper, we study the relation between the <span class="hlt">band</span> gap size and the corner-corner length in representative chevron-shaped graphene nanoribbons (CGNRs) with 120° and 150° corner edges. The direct physical insight into the <span class="hlt">electronic</span> properties of CGNRs is provided within the tight-binding model with phenomenological edge parameters, developed against recent first-principle results. We show that the analyzed CGNRs exhibit inverse relation between their <span class="hlt">band</span> gaps and corner-corner lengths, and that they do not present a metal-insulator transition when the chemical edge modifications are introduced. Our results also suggest that the <span class="hlt">band</span> gap width for the CGNRs is predominantly governed by the armchair edge effects, and is tunable through edge modifications with foreign atoms dressing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EPJB...86..350O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EPJB...86..350O"><span>Ab initio <span class="hlt">electronic</span> <span class="hlt">band</span> structure study of III-VI layered semiconductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Olguín, Daniel; Rubio-Ponce, Alberto; Cantarero, Andrés</p> <p>2013-08-01</p> <p>We present a total <span class="hlt">energy</span> study of the <span class="hlt">electronic</span> properties of the rhombohedral γ-InSe, hexagonal ɛ-GaSe, and monoclinic GaTe layered compounds. The calculations have been done using the full potential linear augmented plane wave method, including spin-orbit interaction. The calculated valence <span class="hlt">bands</span> of the three compounds compare well with angle resolved photoemission measurements and a discussion of the small discrepancies found has been given. The present calculations are also compared with recent and previous <span class="hlt">band</span> structure calculations available in the literature for the three compounds. Finally, in order to improve the calculated <span class="hlt">band</span> gap value we have used the recently proposed modified Becke-Johnson correction for the exchange-correlation potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JPhCS.377a2093S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPhCS.377a2093S"><span><span class="hlt">Electron</span> <span class="hlt">band</span> structure of the high pressure cubic phase of AlH3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Hongliang; Zarifi, Niliffar; Yim, Wai-Leung; Tse, J. S.</p> <p>2012-07-01</p> <p>The <span class="hlt">electronic</span> <span class="hlt">band</span> structure of the cubic Pm3n phase of AlH3 stable above 100 GPa is examined with semi-local, Tran-Blaha modified Becke-Johnson local density approximation (TB-mBJLDA), screened hybrid density functionals and GW methods. The shift of the conduction <span class="hlt">band</span> to higher <span class="hlt">energy</span> with increasing pressure is predicted by all methods. However, there are significant differences in detail <span class="hlt">band</span> structure. In the pressure range from 90 to160 GPa, semi-local, hybrid functional and TB-mBJLDA calculations predicted that AlH3 is a poor metal. In comparison, GW calculations show a gap opening at 160 GPa and AlH3 becomes a small gap semi-conductor. From the trends of the calculated <span class="hlt">band</span> shifts, it can be concluded that the favourable conditions leading to the nesting of Fermi surfaces predicted by semi-local calculation have disappeared if the exchange term is included. The results highlight the importance of the correction to the exchange <span class="hlt">energy</span> on the <span class="hlt">band</span> structure of hydrogen dominant dense metal hydrides at high pressure hydrides and may help to rationalize the absence of superconductivity in AlH3 from experimental measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94w5205M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94w5205M"><span>Intervalley <span class="hlt">energy</span> of GaN conduction <span class="hlt">band</span> measured by femtosecond pump-probe spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marcinkevičius, Saulius; Uždavinys, Tomas K.; Foronda, Humberto M.; Cohen, Daniel A.; Weisbuch, Claude; Speck, James S.</p> <p>2016-12-01</p> <p>Time-resolved transmission and reflection measurements were performed for bulk GaN at room temperature to evaluate the <span class="hlt">energy</span> of the first conduction <span class="hlt">band</span> satellite valley. The measurements showed clear threshold-like spectra for transmission decay and reflection rise times. The thresholds were associated with the onset of the intervalley <span class="hlt">electron</span> scattering. Transmission measurements with pump and probe pulses in the near infrared produced an intervalley <span class="hlt">energy</span> of 0.97 ±0.02 eV. Ultraviolet pump and infrared probe reflection provided a similar value. Comparison of the threshold <span class="hlt">energies</span> obtained in these experiments allowed estimating the hole effective mass in the upper valence <span class="hlt">band</span> to be 1.4 m0 . Modeling of the reflection transients with rate equations has allowed estimating <span class="hlt">electron</span>-LO (longitudinal optical) phonon scattering rates and the satellite valley effective mass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170000982&hterms=Particles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DParticles','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170000982&hterms=Particles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DParticles"><span><span class="hlt">Banded</span> Structures in <span class="hlt">Electron</span> Pitch Angle Diffusion Coefficients from Resonant Wave Particle Interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tripathi, A. K.; Singhal, R. P.; Khazanov, G. V.; Avanov, L. A.</p> <p>2016-01-01</p> <p><span class="hlt">Electron</span> pitch angle (D (alpha)) and momentum (D(pp)) diffusion coefficients have been calculated due to resonant interactions with electrostatic <span class="hlt">electron</span> cyclotron harmonic (ECH) and whistler mode chorus waves. Calculations have been performed at two spatial locations L = 4.6 and 6.8 for <span class="hlt">electron</span> <span class="hlt">energies</span> 10 keV. Landau (n = 0) resonance and cyclotron harmonic resonances n = +/-1, +/-2,...+/-5 have been included in the calculations. It is found that diffusion coefficient versus pitch angle (alpha) profiles show large dips and oscillations or <span class="hlt">banded</span> structures. The structures are more pronounced for ECH and lower <span class="hlt">band</span> chorus (LBC) and particularly at location 4.6. Calculations of diffusion coefficients have also been performed for individual resonances. It is noticed that the main contribution of ECH waves in pitch angle diffusion coefficient is due to resonances n = +1 and n = +2. A major contribution to momentum diffusion coefficients appears from n = +2. However, the <span class="hlt">banded</span> structures in D alpha and Dpp coefficients appear only in the profile of diffusion coefficients for n = +2. The contribution of other resonances to diffusion coefficients is found to be, in general, quite small or even negligible. For LBC and upper <span class="hlt">band</span> chorus waves, the <span class="hlt">banded</span> structures appear only in Landau resonance. The Dpp diffusion coefficient for ECH waves is one to two orders smaller than D alpha coefficients. For chorus waves, Dpp coefficients are about an order of magnitude smaller than D alpha coefficients for the case n does not = 0. In case of Landau resonance, the values of Dpp coefficient are generally larger than the values of D alpha coefficients particularly at lower <span class="hlt">energies</span>. As an aid to the interpretation of results, we have also determined the resonant frequencies. For ECH waves, resonant frequencies have been estimated for wave normal angle 89 deg and harmonic resonances n = +1, +2, and +3, whereas for whistler mode waves, the frequencies have been calculated for angle</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170003516&hterms=Particles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DParticles','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170003516&hterms=Particles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DParticles"><span><span class="hlt">Banded</span> Structures in <span class="hlt">Electron</span> Pitch Angle Diffusion Coefficients from Resonant Wave-Particle Interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tripathi, A. K.; Singhal, R. P.; Khazanov, G. V.; Avanov, L. A.</p> <p>2016-01-01</p> <p><span class="hlt">Electron</span> pitch angle (D(sub (alpha alpha))) and momentum (D(sub pp)) diffusion coefficients have been calculated due to resonant interactions with electrostatic <span class="hlt">electron</span> cyclotron harmonic (ECH) and whistler mode chorus waves. Calculations have been performed at two spatial locations L=4.6 and 6.8 for <span class="hlt">electron</span> <span class="hlt">energies</span> less than or equal to 10 keV. Landau (n=0) resonance and cyclotron harmonic resonances n= +/- 1, +/-2, ... +/-5 have been included in the calculations. It is found that diffusion coefficient versus pitch angle (alpha) profiles show large dips and oscillations or <span class="hlt">banded</span> structures. The structures are more pronounced for ECH and lower <span class="hlt">band</span> chorus (LBC) and particularly at location 4.6. Calculations of diffusion coefficients have also been performed for individual resonances. It is noticed that the main contribution of ECH waves in pitch angle diffusion coefficient is due to resonances n=+1 and n=+2. A major contribution to momentum diffusion coefficients appears from n=+2. However, the <span class="hlt">banded</span> structures in D(sub alpha alpha) and D(sub pp) coefficients appear only in the profile of diffusion coefficients for n=+2. The contribution of other resonances to diffusion coefficients is found to be, in general, quite small or even negligible. For LBC and upper <span class="hlt">band</span> chorus waves, the <span class="hlt">banded</span> structures appear only in Landau resonance. The D(sub pp) diffusion coefficient for ECH waves is one to two orders smaller than D(sub alpha alpha) coefficients. For chorus waves, D(sub pp) coefficients are about an order of magnitude smaller than D(sub alpha alpha) coefficients for the case n does not equal 0. In case of Landau resonance, the values of D(sub pp) coefficient are generally larger than the values of D(sub alpha alpha) coefficients particularly at lower <span class="hlt">energies</span>. As an aid to the interpretation of results, we have also determined the resonant frequencies. For ECH waves, resonant frequencies have been estimated for wave normal angle 89 deg and harmonic resonances</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170000982&hterms=1089&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231089','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170000982&hterms=1089&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231089"><span><span class="hlt">Banded</span> Structures in <span class="hlt">Electron</span> Pitch Angle Diffusion Coefficients from Resonant Wave Particle Interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tripathi, A. K.; Singhal, R. P.; Khazanov, G. V.; Avanov, L. A.</p> <p>2016-01-01</p> <p><span class="hlt">Electron</span> pitch angle (D (alpha)) and momentum (D(pp)) diffusion coefficients have been calculated due to resonant interactions with electrostatic <span class="hlt">electron</span> cyclotron harmonic (ECH) and whistler mode chorus waves. Calculations have been performed at two spatial locations L = 4.6 and 6.8 for <span class="hlt">electron</span> <span class="hlt">energies</span> 10 keV. Landau (n = 0) resonance and cyclotron harmonic resonances n = +/-1, +/-2,...+/-5 have been included in the calculations. It is found that diffusion coefficient versus pitch angle (alpha) profiles show large dips and oscillations or <span class="hlt">banded</span> structures. The structures are more pronounced for ECH and lower <span class="hlt">band</span> chorus (LBC) and particularly at location 4.6. Calculations of diffusion coefficients have also been performed for individual resonances. It is noticed that the main contribution of ECH waves in pitch angle diffusion coefficient is due to resonances n = +1 and n = +2. A major contribution to momentum diffusion coefficients appears from n = +2. However, the <span class="hlt">banded</span> structures in D alpha and Dpp coefficients appear only in the profile of diffusion coefficients for n = +2. The contribution of other resonances to diffusion coefficients is found to be, in general, quite small or even negligible. For LBC and upper <span class="hlt">band</span> chorus waves, the <span class="hlt">banded</span> structures appear only in Landau resonance. The Dpp diffusion coefficient for ECH waves is one to two orders smaller than D alpha coefficients. For chorus waves, Dpp coefficients are about an order of magnitude smaller than D alpha coefficients for the case n does not = 0. In case of Landau resonance, the values of Dpp coefficient are generally larger than the values of D alpha coefficients particularly at lower <span class="hlt">energies</span>. As an aid to the interpretation of results, we have also determined the resonant frequencies. For ECH waves, resonant frequencies have been estimated for wave normal angle 89 deg and harmonic resonances n = +1, +2, and +3, whereas for whistler mode waves, the frequencies have been calculated for angle</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRD..120.9944S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRD..120.9944S"><span>Long-term drift induced by the <span class="hlt">electronic</span> crosstalk in Terra MODIS <span class="hlt">Band</span> 29</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Junqiang; Madhavan, Sriharsha; Xiong, Xiaoxiong; Wang, Menghua</p> <p>2015-10-01</p> <p>Terra MODerate Resolution Imaging Spectroradiometer (MODIS) is one of the key sensors in the NASA's Earth Observing System, which has successfully completed 15 years of on-orbit operation. Terra MODIS continues to collect valuable information of the Earth's <span class="hlt">energy</span> radiation from visible to thermal infrared wavelengths. The instrument has been well characterized over its lifetime using onboard calibrators whose calibration references are traceable to the National Institute of Standards and Technology standards. In this paper, we focus on the <span class="hlt">electronic</span> crosstalk effect of Terra MODIS <span class="hlt">band</span> 29, a thermal emissive <span class="hlt">band</span> (TEB) whose center wavelength is 8.55 µm. Previous works have established the mechanism to describe the effect of the <span class="hlt">electronic</span> crosstalk in the TEB channels of Terra MODIS. This work utilizes the established methodology to apply to <span class="hlt">band</span> 29. The <span class="hlt">electronic</span> crosstalk is identified and characterized using the regularly scheduled lunar observations. The moon being a near-pulse-like source allowed easy detection of extraneous signals around the actual Moon surface. First, the crosstalk-transmitting <span class="hlt">bands</span> are identified along with their amplitudes. The crosstalk effect then is characterized using a moving average mechanism that allows a high fidelity of the magnitude to be corrected. The lunar-based analysis unambiguously shows that the crosstalk contamination is becoming more severe in recent years and should be corrected in order to maintain calibration quality for the affected spectral <span class="hlt">bands</span>. Finally, two radiometrically well-characterized sites, Pacific Ocean and Libya 1 desert, are used to assess the impact of crosstalk effect. It is shown that the crosstalk contamination induces a long-term upward drift of 1.5 K in <span class="hlt">band</span> 29 brightness temperature of MODIS Collection 6 L1B, which could significantly impact the science products. The crosstalk effect also induces strong detector-to-detector differences, which result in severe stripping in the Earth view</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21544143','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21544143"><span>Convergence of <span class="hlt">electronic</span> <span class="hlt">bands</span> for high performance bulk thermoelectrics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pei, Yanzhong; Shi, Xiaoya; LaLonde, Aaron; Wang, Heng; Chen, Lidong; Snyder, G Jeffrey</p> <p>2011-05-05</p> <p>Thermoelectric generators, which directly convert heat into electricity, have long been relegated to use in space-based or other niche applications, but are now being actively considered for a variety of practical waste heat recovery systems-such as the conversion of car exhaust heat into electricity. Although these devices can be very reliable and compact, the thermoelectric materials themselves are relatively inefficient: to facilitate widespread application, it will be desirable to identify or develop materials that have an intensive thermoelectric materials figure of merit, zT, above 1.5 (ref. 1). Many different concepts have been used in the search for new materials with high thermoelectric efficiency, such as the use of nanostructuring to reduce phonon thermal conductivity, which has led to the investigation of a variety of complex material systems. In this vein, it is well known that a high valley degeneracy (typically ≤6 for known thermoelectrics) in the <span class="hlt">electronic</span> <span class="hlt">bands</span> is conducive to high zT, and this in turn has stimulated attempts to engineer such degeneracy by adopting low-dimensional nanostructures. Here we demonstrate that it is possible to direct the convergence of many valleys in a bulk material by tuning the doping and composition. By this route, we achieve a convergence of at least 12 valleys in doped PbTe(1-x)Se(x) alloys, leading to an extraordinary zT value of 1.8 at about 850 kelvin. <span class="hlt">Band</span> engineering to converge the valence (or conduction) <span class="hlt">bands</span> to achieve high valley degeneracy should be a general strategy in the search for and improvement of bulk thermoelectric materials, because it simultaneously leads to a high Seebeck coefficient and high electrical conductivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22055896','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22055896"><span>Characterization of a 2D soft x-ray tomography camera with discrimination in <span class="hlt">energy</span> <span class="hlt">bands</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Romano, A.; Pacella, D.; Gabellieri, L.; Tilia, B.; Piergotti, V.; Mazon, D.; Malard, P.</p> <p>2010-10-15</p> <p>A gas detector with a 2D pixel readout is proposed for a future soft x-ray (SXR) tomography with discrimination in <span class="hlt">energy</span> <span class="hlt">bands</span> separately per pixel. The detector has three gas <span class="hlt">electron</span> multiplier foils for the <span class="hlt">electron</span> amplification and it offers the advantage, compared with the single stage, to be less sensitive to neutrons and gammas. The <span class="hlt">energy</span> resolution and the detection efficiency of the detector have been accurately studied in the laboratory with continuous SXR spectra produced by an <span class="hlt">electronic</span> tube and line emissions produced by fluorescence (K, Fe, and Mo) in the range of 3-17 keV. The front-end <span class="hlt">electronics</span>, working in photon counting mode with a selectable threshold for pulse discrimination, is optimized for high rates. The distribution of the pulse amplitude has been indirectly derived by means of scans of the threshold. Scans in detector gain have also been performed to assess the capability of selecting different <span class="hlt">energy</span> ranges.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvL.118h7403T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvL.118h7403T"><span>Impact of the <span class="hlt">Electronic</span> <span class="hlt">Band</span> Structure in High-Harmonic Generation Spectra of Solids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tancogne-Dejean, Nicolas; Mücke, Oliver D.; Kärtner, Franz X.; Rubio, Angel</p> <p>2017-02-01</p> <p>An accurate analytic model describing the microscopic mechanism of high-harmonic generation (HHG) in solids is derived. Extensive first-principles simulations within a time-dependent density-functional framework corroborate the conclusions of the model. Our results reveal that (i) the emitted HHG spectra are highly anisotropic and laser-polarization dependent even for cubic crystals; (ii) the harmonic emission is enhanced by the inhomogeneity of the <span class="hlt">electron</span>-nuclei potential; the yield is increased for heavier atoms; and (iii) the cutoff photon <span class="hlt">energy</span> is driver-wavelength independent. Moreover, we show that it is possible to predict the laser polarization for optimal HHG in bulk crystals solely from the knowledge of their <span class="hlt">electronic</span> <span class="hlt">band</span> structure. Our results pave the way to better control and optimize HHG in solids by engineering their <span class="hlt">band</span> structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28282201','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28282201"><span>Impact of the <span class="hlt">Electronic</span> <span class="hlt">Band</span> Structure in High-Harmonic Generation Spectra of Solids.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tancogne-Dejean, Nicolas; Mücke, Oliver D; Kärtner, Franz X; Rubio, Angel</p> <p>2017-02-24</p> <p>An accurate analytic model describing the microscopic mechanism of high-harmonic generation (HHG) in solids is derived. Extensive first-principles simulations within a time-dependent density-functional framework corroborate the conclusions of the model. Our results reveal that (i) the emitted HHG spectra are highly anisotropic and laser-polarization dependent even for cubic crystals; (ii) the harmonic emission is enhanced by the inhomogeneity of the <span class="hlt">electron</span>-nuclei potential; the yield is increased for heavier atoms; and (iii) the cutoff photon <span class="hlt">energy</span> is driver-wavelength independent. Moreover, we show that it is possible to predict the laser polarization for optimal HHG in bulk crystals solely from the knowledge of their <span class="hlt">electronic</span> <span class="hlt">band</span> structure. Our results pave the way to better control and optimize HHG in solids by engineering their <span class="hlt">band</span> structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MS%26E...73a2100V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MS%26E...73a2100V"><span>Effect of Γ-X <span class="hlt">band</span> mixing on the donor binding <span class="hlt">energy</span> in a Quantum Wire</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vijaya Shanthi, R.; Jayakumar, K.; Nithiananthi, P.</p> <p>2015-02-01</p> <p>To invoke the technological applications of heterostructure semiconductors like Quantum Well (QW), Quantum Well Wire (QWW) and Quantum Dot (QD), it is important to understand the property of impurity <span class="hlt">energy</span> which is responsible for the peculiar <span class="hlt">electronic</span> & optical behavior of the Low Dimensional Semiconductor Systems (LDSS). Application of hydrostatic pressure P>35kbar drastically alters the <span class="hlt">band</span> offsets leading to the crossover of Γ <span class="hlt">band</span> of the well & X <span class="hlt">band</span> of the barrier resulting in an indirect transition of the carrier and this effect has been studied experimentally and theoretically in a QW structure. In this paper, we have investigated the effect of Γ-X <span class="hlt">band</span> mixing due to the application of hydrostatic pressure in a GaAs/AlxGa1-xAs QWW system. The results are presented and discussed for various widths of the wire.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/530950','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/530950"><span>Including the relativistic kinetic <span class="hlt">energy</span> in a spline-augmented plane-wave <span class="hlt">band</span> calculation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fehrenbach, G.M.; Schmidt, G.</p> <p>1997-03-01</p> <p>The first-order relativistic correction to the kinetic <span class="hlt">energy</span> of an <span class="hlt">electron</span>, the mass-velocity term, is not bounded from below. It can, therefore, not be used within a variational framework. To overcome this deficiency we developed a method to include the entire relativistic kinetic <span class="hlt">energy</span> {radical}(p{sup 2}c{sup 2}+m{sub 0}{sup 2}c{sup 4}){minus}m{sub 0}c{sup 2} in a spline-augmented plane-wave <span class="hlt">band</span> calculation. The first results for silver are quite promising, especially for d and p states: The analysis of the <span class="hlt">energies</span> of the core states as well as of the valence <span class="hlt">band</span> structure suggests that the <span class="hlt">energies</span> of d <span class="hlt">bands</span> are reproduced within 1 mRy. However, the combination of the relativistic kinetic <span class="hlt">energy</span> with the Darwin term leads to <span class="hlt">energies</span> which are too low for s-like valence states by 10 mRy. Therefore, the s and d valence <span class="hlt">band</span> complex is spread out and the Fermi level is lowered by the same amount as the s states. We expect to overcome these deficiencies in future investigations by using a alternative form of the relativistic potential correction along the lines proposed by Douglas and Kroll. {copyright} {ital 1997} {ital The American Physical Society}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1035024','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1035024"><span><span class="hlt">Energy</span> Efficient <span class="hlt">Electronics</span> Cooling Project</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Steve O'Shaughnessey; Tim Louvar; Mike Trumbower; Jessica Hunnicutt; Neil Myers</p> <p>2012-02-17</p> <p>Parker Precision Cooling Business Unit was awarded a Department of <span class="hlt">Energy</span> grant (DE-EE0000412) to support the DOE-ITP goal of reducing industrial <span class="hlt">energy</span> intensity and GHG emissions. The project proposed by Precision Cooling was to accelerate the development of a cooling technology for high heat generating <span class="hlt">electronics</span> components. These components are specifically related to power <span class="hlt">electronics</span> found in power drives focused on the inverter, converter and transformer modules. The proposed cooling system was expected to simultaneously remove heat from all three of the major modules listed above, while remaining dielectric under all operating conditions. Development of the cooling system to meet specific customer's requirements and constraints not only required a robust system design, but also new components to support long system functionality. Components requiring further development and testing during this project included pumps, fluid couplings, cold plates and condensers. All four of these major categories of components are required in every Precision Cooling system. Not only was design a key area of focus, but the process for manufacturing these components had to be determined and proven through the system development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPSJ...86e4702M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPSJ...86e4702M"><span>Comprehensive Study on <span class="hlt">Band</span>-Gap Variations in sp3-Bonded Semiconductors: Roles of <span class="hlt">Electronic</span> States Floating in Internal Space</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matsushita, Yu-ichiro; Oshiyama, Atsushi</p> <p>2017-05-01</p> <p>We have performed <span class="hlt">electronic</span> structure calculations to explore the <span class="hlt">band</span>-gap dependence on the polytype for sp3-bonded semiconducting materials, i.e., SiC, AlN, BN, GaN, Si, and diamond. In this comprehensive study, we have found that the dependence of the <span class="hlt">band</span> gap on the polytype is common in sp3-bonded semiconductors; SiC, AlN, and BN exhibit the smallest <span class="hlt">band</span> gaps in the 3C structure, whereas diamond does in the 2H structure. We have also clarified that the microscopic mechanism of the <span class="hlt">band</span>-gap variations is due to peculiar <span class="hlt">electron</span> states floating in the internal channel space at the conduction <span class="hlt">band</span> minimum (CBM), and that the internal channel length and the electrostatic potential in the channel affect the <span class="hlt">energy</span> level of the CBM.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ITPS...44..918O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ITPS...44..918O"><span>Low Starting <span class="hlt">Electron</span> Beam Current in Degenerate <span class="hlt">Band</span> Edge Oscillators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Othman, Mohamed A. K.; Veysi, Mehdi; Figotin, Alexander; Capolino, Filippo</p> <p>2016-06-01</p> <p>We propose a new principle of operation in vacuum <span class="hlt">electron</span>-beam-based oscillators that leads to a low beam current for starting oscillations. The principle is based on super synchronous operation of an <span class="hlt">electron</span> beam interacting with four degenerate electromagnetic modes in a slow-wave structure (SWS). The four mode super synchronous regime is associated with a very special degeneracy condition in the dispersion diagram of a cold periodic SWS called degenerate <span class="hlt">band</span> edge (DBE). This regime features a giant group delay in the finitelength SWS and low starting-oscillation beam current. The starting beam current is at least an order of magnitude smaller compared to a conventional backward wave oscillator (BWO) of the same length. As a representative example we consider a SWS conceived by a periodically-loaded metallic waveguide supporting a DBE, and investigate starting-oscillation conditions using Pierce theory generalized to coupled transmission lines (CTL). The proposed super synchronism regime can be straightforwardly adapted to waveguide geometries others than the periodically-loaded waveguide considered here since DBE is a general property that can be realized in a variety of structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5445773','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5445773"><span>Transparent Conducting Oxides for Photovoltaics: Manipulation of Fermi Level, Work Function and <span class="hlt">Energy</span> <span class="hlt">Band</span> Alignment</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Klein, Andreas; Körber, Christoph; Wachau, André; Säuberlich, Frank; Gassenbauer, Yvonne; Harvey, Steven P.; Proffit, Diana E.; Mason, Thomas O.</p> <p>2010-01-01</p> <p>Doping limits, <span class="hlt">band</span> gaps, work functions and <span class="hlt">energy</span> <span class="hlt">band</span> alignments of undoped and donor-doped transparent conducting oxides ZnO, In2O3, and SnO2 as accessed by X-ray and ultraviolet photoelectron spectroscopy (XPS/UPS) are summarized and compared. The presented collection provides an extensive data set of technologically relevant <span class="hlt">electronic</span> properties of photovoltaic transparent electrode materials and illustrates how these relate to the underlying defect chemistry, the dependence of surface dipoles on crystallographic orientation and/or surface termination, and Fermi level pinning. PMID:28883359</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10134320','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10134320"><span>Photonic <span class="hlt">Band</span> Gap resonators for high <span class="hlt">energy</span> accelerators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schultz, S.; Smith, D.R.; Kroll, N. |</p> <p>1993-12-31</p> <p>We have proposed that a new type of microwave resonator, based on Photonic <span class="hlt">Band</span> Gap (PBG) structures, may be particularly useful for high <span class="hlt">energy</span> accelerators. We provide an explanation of the PBG concept and present data which illustrate some of the special properties associated with such structures. Further evaluation of the utility of PBG resonators requires laboratory testing of model structures at cryogenic temperatures, and at high fields. We provide a brief discussion of our test program, which is currently in progress.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18764346','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18764346"><span>Transition-metal-substituted indium thiospinels as novel intermediate-<span class="hlt">band</span> materials: prediction and understanding of their <span class="hlt">electronic</span> properties.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Palacios, P; Aguilera, I; Sánchez, K; Conesa, J C; Wahnón, P</p> <p>2008-07-25</p> <p>Results of density-functional calculations for indium thiospinel semiconductors substituted at octahedral sites with isolated transition metals (M=Ti,V) show an isolated partially filled narrow <span class="hlt">band</span> containing three t2g-type states per M atom inside the usual semiconductor <span class="hlt">band</span> gap. Thanks to this <span class="hlt">electronic</span> structure feature, these materials will allow the absorption of photons with <span class="hlt">energy</span> below the <span class="hlt">band</span> gap, in addition to the normal light absorption of a semiconductor. To our knowledge, we demonstrate for the first time the formation of an isolated intermediate <span class="hlt">electronic</span> <span class="hlt">band</span> structure through M substitution at octahedral sites in a semiconductor, leading to an enhancement of the absorption coefficient in both infrared and visible ranges of the solar spectrum. This <span class="hlt">electronic</span> structure feature could be applied for developing a new third-generation photovoltaic cell.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22089496','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22089496"><span>Evidence of Eu{sup 2+} 4f <span class="hlt">electrons</span> in the valence <span class="hlt">band</span> spectra of EuTiO{sub 3} and EuZrO{sub 3}</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kolodiazhnyi, T.; Valant, M.; Williams, J. R.; Bugnet, M.; Botton, G. A.; Ohashi, N.; Sakka, Y.</p> <p>2012-10-15</p> <p>We report on optical <span class="hlt">band</span> gap and valence <span class="hlt">electronic</span> structure of two Eu{sup 2+}-based perovskites, EuTiO{sub 3} and EuZrO{sub 3} as revealed by diffuse optical scattering, <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectroscopy, and valence-<span class="hlt">band</span> x-ray photoelectron spectroscopy. The data show good agreement with the first-principles studies in which the top of the valence <span class="hlt">band</span> structure is formed by the narrow Eu 4f{sup 7} <span class="hlt">electron</span> <span class="hlt">band</span>. The O 2p <span class="hlt">band</span> shows the features similar to those of the Ba(Sr)TiO{sub 3} perovskites except that it is shifted to higher binding <span class="hlt">energies</span>. Appearance of the Eu{sup 2+} 4f{sup 7} <span class="hlt">band</span> is a reason for narrowing of the optical <span class="hlt">band</span> gap in the title compounds as compared to their Sr-based analogues.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JAP...112h3719K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JAP...112h3719K"><span>Evidence of Eu2+ 4f <span class="hlt">electrons</span> in the valence <span class="hlt">band</span> spectra of EuTiO3 and EuZrO3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kolodiazhnyi, T.; Valant, M.; Williams, J. R.; Bugnet, M.; Botton, G. A.; Ohashi, N.; Sakka, Y.</p> <p>2012-10-01</p> <p>We report on optical <span class="hlt">band</span> gap and valence <span class="hlt">electronic</span> structure of two Eu2+-based perovskites, EuTiO3 and EuZrO3 as revealed by diffuse optical scattering, <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectroscopy, and valence-<span class="hlt">band</span> x-ray photoelectron spectroscopy. The data show good agreement with the first-principles studies in which the top of the valence <span class="hlt">band</span> structure is formed by the narrow Eu 4f7 <span class="hlt">electron</span> <span class="hlt">band</span>. The O 2p <span class="hlt">band</span> shows the features similar to those of the Ba(Sr)TiO3 perovskites except that it is shifted to higher binding <span class="hlt">energies</span>. Appearance of the Eu2+ 4f7 <span class="hlt">band</span> is a reason for narrowing of the optical <span class="hlt">band</span> gap in the title compounds as compared to their Sr-based analogues.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApSS..406..122M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApSS..406..122M"><span>Adsorbate-induced modification of <span class="hlt">electronic</span> <span class="hlt">band</span> structure of epitaxial Bi(111) films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matetskiy, A. V.; Bondarenko, L. V.; Tupchaya, A. Y.; Gruznev, D. V.; Eremeev, S. V.; Zotov, A. V.; Saranin, A. A.</p> <p>2017-06-01</p> <p>Changes of the <span class="hlt">electronic</span> <span class="hlt">band</span> structure of Bi(111) films on Si(111) induced by Cs and Sn adsorption have been studied using angle-resolved photoemission spectroscopy and density functional theory calculations. It has been found that small amounts of Cs when it presents at the surface in a form of the adatom gas leads to shifting of the surface and quantum well states to the higher binding <span class="hlt">energies</span> due to the <span class="hlt">electron</span> donation from adsorbate to the Bi film. In contrast, adsorbed Sn dissolves into the Bi film bulk upon heating and acts as an acceptor dopant, that results in shifting of the surface and quantum well states upward to the lower binding <span class="hlt">energies</span>. These results pave the way to manipulate with the Bi thin film <span class="hlt">electron</span> <span class="hlt">band</span> structure allowing to achieve a certain type of conductivity (<span class="hlt">electron</span> or hole) with a single spin channel at the Fermi level making the adsorbate-modified Bi a reliable base for prospective spintronics applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..96c5310M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..96c5310M"><span>Valence <span class="hlt">band</span> <span class="hlt">energy</span> spectrum of HgTe quantum wells with an inverted <span class="hlt">band</span> structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Minkov, G. M.; Aleshkin, V. Ya.; Rut, O. E.; Sherstobitov, A. A.; Germanenko, A. V.; Dvoretski, S. A.; Mikhailov, N. N.</p> <p>2017-07-01</p> <p>The <span class="hlt">energy</span> spectrum of the valence <span class="hlt">band</span> in HgTe /CdxHg1 -xTe quantum wells of a width (8 -20 ) nm has been studied experimentally by magnetotransport effects and theoretically in the framework of a four-<span class="hlt">band</span> k P method. Comparison of the Hall density with the density found from a period of the Shubnikov-de Haas (SdH) oscillations clearly shows that the degeneracy of states of the top of the valence <span class="hlt">band</span> is equal to 2 at the hole density p <5.5 ×1011cm-2 . Such degeneracy does not agree with the calculations of the spectrum performed within the framework of the four-<span class="hlt">band</span> k P method for symmetric quantum wells. These calculations show that the top of the valence <span class="hlt">band</span> consists of four spin-degenerate extremes located at k ≠0 (valleys) which gives the total degeneracy K =8 . It is shown that taking into account the "mixing of states" at the interfaces leads to the removal of the spin degeneracy that reduces the degeneracy to K =4 . Accounting for any additional asymmetry, for example, due to the difference in the mixing parameters at the interfaces, the different broadening of the boundaries of the well, etc., leads to reduction of the valleys degeneracy, making K =2 . It is noteworthy that for our case twofold degeneracy occurs due to degeneracy of two single-spin valleys. The hole effective mass (mh) determined from analysis of the temperature dependence of the amplitude of the SdH oscillations shows that mh is equal to (0.25 ±0.02 ) m0 and weakly increases with the hole density. Such a value of mh and its dependence on the hole density are in a good agreement with the calculated effective mass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Prama..89...34G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Prama..89...34G"><span>A new perspective of ground <span class="hlt">band</span> <span class="hlt">energy</span> formulae</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gupta, J. B.</p> <p>2017-09-01</p> <p>A host of alternative <span class="hlt">energy</span> formulae for the ground <span class="hlt">bands</span> of even Z even N nuclei are available in the literature. The usual approach is to compare the relative numerical accuracy of the predictions of the level <span class="hlt">energies</span> by these formulae, for varying deformations of the nuclear core and for high spins. The soft rotor formula and variable moment of inertia model, the ab and pq formulae, the rotation vibration interaction and power index formulae are illustrated. Here, a new perspective is presented, with emphasis on the limitation of the region of their physical validity and on deriving useful meaning of their parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150007369&hterms=nanotube&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dnanotube','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150007369&hterms=nanotube&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dnanotube"><span><span class="hlt">Energy</span> <span class="hlt">Band</span> Gap Study of Semiconducting Single Walled Carbon Nanotube Bundle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Elkadi, Asmaa; Decrossas, Emmanuel; El-Ghazaly, Samir</p> <p>2013-01-01</p> <p>The <span class="hlt">electronic</span> properties of multiple semiconducting single walled carbon nanotubes (s-SWCNTs) considering various distribution inside a bundle are studied. The model derived from the proposed analytical potential function of <span class="hlt">electron</span> density for na individual s-SWCNT is general and can be easily applied to multiple nanotubes. This work demonstrates that regardless the number of carbon nanotubes, the strong coupling occurring between the closet neighbors reduces the <span class="hlt">energy</span> <span class="hlt">band</span> gap of the bundle by 10%. As expected, the coupling is strongly dependent on the distance separating the s-SWCNTs. In addition, based on the developed model, it is proposed to enhance this coupling effect by applying an electric field across the bundle to significantly reduce the <span class="hlt">energy</span> <span class="hlt">band</span> gap of the bundle by 20%.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150007367&hterms=nanotube&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dnanotube','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150007367&hterms=nanotube&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dnanotube"><span><span class="hlt">Energy</span> <span class="hlt">Band</span> Gap Study of Semiconducting Single Walled Carbon Nanotube Bundle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Elkadi, Asmaa; Decrossas, Emmanuel; El-Ghazaly, Samir</p> <p>2013-01-01</p> <p>The <span class="hlt">electronic</span> properties of multiple semiconducting single walled carbon nanotubes (s-SWCNTs) considering various distribution inside a bundle are studied. The model derived from the proposed analytical potential function of the <span class="hlt">electron</span> density for an individual s-SWCNT is general and can be easily applied to multiple nanotubes. This work demonstrates that regardless the number of carbon nanotubes, the strong coupling occurring between the closest neighbours reduces the <span class="hlt">energy</span> <span class="hlt">band</span> gap of the bundle by 10%. As expected, the coupling is strongly dependent on the distance separating the s-SWCNTs. In addition, based on the developed model, it is proposed to enhance this coupling effect by applying an electric field across the bundle to significantly reduce the <span class="hlt">energy</span> <span class="hlt">band</span> gap of the bundle by 20%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/970664','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/970664"><span>STABILITY IN BCC TRANSITION METALS: MADELUNG AND <span class="hlt">BAND-ENERGY</span> EFFECTS DUE TO ALLOYING</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Landa, A; Soderlind, P; Ruban, A; Peil, O; Vitos, L</p> <p>2009-08-28</p> <p>The phase stability of the bcc Group VB (V, Nb, and Ta) transition metals is explored by first-principles <span class="hlt">electronic</span>-structure calculations. Alloying with a small amount of a neighboring metal can either stabilize or destabilize the bcc phase. This counterintuitive behavior is explained by competing mechanisms that dominate depending on particular dopand. We show that <span class="hlt">band</span>-structure effects dictate stability when a particular Group VB metal is alloyed with its nearest neighbors within the same d-transition series. In this case, the neighbor with less (to the left) and more (to the right) d <span class="hlt">electrons</span>, destabilize and stabilize bcc, respectively. When alloying with neighbors of different d-transition series, electrostatic Madelung <span class="hlt">energy</span> dominates over the <span class="hlt">band</span> <span class="hlt">energy</span> and always stabilizes the bcc phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150007367&hterms=carbon+nanotube&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcarbon%2Bnanotube','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150007367&hterms=carbon+nanotube&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcarbon%2Bnanotube"><span><span class="hlt">Energy</span> <span class="hlt">Band</span> Gap Study of Semiconducting Single Walled Carbon Nanotube Bundle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Elkadi, Asmaa; Decrossas, Emmanuel; El-Ghazaly, Samir</p> <p>2013-01-01</p> <p>The <span class="hlt">electronic</span> properties of multiple semiconducting single walled carbon nanotubes (s-SWCNTs) considering various distribution inside a bundle are studied. The model derived from the proposed analytical potential function of the <span class="hlt">electron</span> density for an individual s-SWCNT is general and can be easily applied to multiple nanotubes. This work demonstrates that regardless the number of carbon nanotubes, the strong coupling occurring between the closest neighbours reduces the <span class="hlt">energy</span> <span class="hlt">band</span> gap of the bundle by 10%. As expected, the coupling is strongly dependent on the distance separating the s-SWCNTs. In addition, based on the developed model, it is proposed to enhance this coupling effect by applying an electric field across the bundle to significantly reduce the <span class="hlt">energy</span> <span class="hlt">band</span> gap of the bundle by 20%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150007369&hterms=carbon+nanotube&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcarbon%2Bnanotube','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150007369&hterms=carbon+nanotube&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcarbon%2Bnanotube"><span><span class="hlt">Energy</span> <span class="hlt">Band</span> Gap Study of Semiconducting Single Walled Carbon Nanotube Bundle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Elkadi, Asmaa; Decrossas, Emmanuel; El-Ghazaly, Samir</p> <p>2013-01-01</p> <p>The <span class="hlt">electronic</span> properties of multiple semiconducting single walled carbon nanotubes (s-SWCNTs) considering various distribution inside a bundle are studied. The model derived from the proposed analytical potential function of <span class="hlt">electron</span> density for na individual s-SWCNT is general and can be easily applied to multiple nanotubes. This work demonstrates that regardless the number of carbon nanotubes, the strong coupling occurring between the closet neighbors reduces the <span class="hlt">energy</span> <span class="hlt">band</span> gap of the bundle by 10%. As expected, the coupling is strongly dependent on the distance separating the s-SWCNTs. In addition, based on the developed model, it is proposed to enhance this coupling effect by applying an electric field across the bundle to significantly reduce the <span class="hlt">energy</span> <span class="hlt">band</span> gap of the bundle by 20%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JAP...118h4305M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JAP...118h4305M"><span>Near <span class="hlt">band</span>-gap <span class="hlt">electronics</span> properties and luminescence mechanisms of boron nitride nanotubes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Museur, L.; Kanaev, A.</p> <p>2015-08-01</p> <p>The deep ultraviolet luminescence (hν ≥ 5 eV) of multiwall boron nitride nanotubes (BNNTs) is studied with time- and <span class="hlt">energy</span>-resolved photoluminescence spectroscopy. Two luminescence <span class="hlt">bands</span> are observed at 5.35 and 5.54 eV. Both emissions undergo a large blue shift of several tens of meV with a linear slope Δ E l u m / Δ E e x c < 1 as the excitation <span class="hlt">energy</span> Eexc increases. When E e x c ≥ 5.8 eV, the spectral <span class="hlt">band</span> positions become fixed, which marks the transition between the excitation of donor-acceptor pairs and creation of free charge carriers. We assign the 5.35 eV <span class="hlt">band</span> to quasi donor-acceptor pair transitions and the <span class="hlt">band</span> at 5.54 eV to free-bound transitions. Boron and nitrogen atoms distributed along characteristic defect lines in BNNTs should be involved in the luminescence process. The presented results permit a revision of previous assignments of <span class="hlt">electronic</span> transitions in BNNTs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20718377','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20718377"><span><span class="hlt">Band</span>-structure-based collisional model for <span class="hlt">electronic</span> excitations in ion-surface collisions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Faraggi, M.N.; Gravielle, M.S.; Alducin, M.; Silkin, V.M.; Juaristi, J.I.</p> <p>2005-07-15</p> <p><span class="hlt">Energy</span> loss per unit path in grazing collisions with metal surfaces is studied by using the collisional and dielectric formalisms. Within both theories we make use of the <span class="hlt">band</span>-structure-based (BSB) model to represent the surface interaction. The BSB approach is based on a model potential and provides a precise description of the one-<span class="hlt">electron</span> states and the surface-induced potential. The method is applied to evaluate the <span class="hlt">energy</span> lost by 100 keV protons impinging on aluminum surfaces at glancing angles. We found that when the realistic BSB description of the surface is used, the <span class="hlt">energy</span> loss obtained from the collisional formalism agrees with the dielectric one, which includes not only binary but also plasmon excitations. The distance-dependent stopping power derived from the BSB model is in good agreement with available experimental data. We have also investigated the influence of the surface <span class="hlt">band</span> structure in collisions with the Al(100) surface. Surface-state contributions to the <span class="hlt">energy</span> loss and <span class="hlt">electron</span> emission probability are analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JApSp..82..303T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JApSp..82..303T"><span>The Effect of Carbon Nanotube on <span class="hlt">Band</span> Gap <span class="hlt">Energy</span> of TiO2 Nanoparticles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Taleshi, F.</p> <p>2015-05-01</p> <p>A composite of TiO2-carbon nanotubes (CNTs) was synthesized via a sol-gel method. The structure and morphology of the nanocomposite samples were characterized by X-ray diffraction (XRD) and scanning <span class="hlt">electron</span> microscopy (SEM). The optical properties of the samples were studied using UV-Vis spectroscopy. The results show that CNTs can decrease the value of <span class="hlt">band</span> gap <span class="hlt">energy</span> of TiO2 nanoparticles considerably.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SSCom.258...11M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SSCom.258...11M"><span>Designing and engineering <span class="hlt">electronic</span> <span class="hlt">band</span> gap of graphene nanosheet by P dopants</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mohammed, Mohammed H.</p> <p>2017-05-01</p> <p>Chemical doping is promising route to modify and control the <span class="hlt">electronic</span> properties of graphene Nanosheet (GNS). The <span class="hlt">electronic</span> properties of the GNS are investigated with and without various concentrations of phosphorus impurities in the various sites by using the first-principles of the density functional theory (DFT) method, which realized in Quantum Espresso packages. My founding results show that the <span class="hlt">electronic</span> <span class="hlt">band</span> structure of the GNS is not only depending on the concentrations of phosphorus impurities, but also depending on the geometrical pattern of phosphorus impurities in the GNS. Furthermore, I found out that there is an <span class="hlt">electronic</span> <span class="hlt">band</span> gap with a single phosphorus impurities and it is increased with increasing the concentrations of phosphorus impurities. Also, total <span class="hlt">energy</span> is affected and decreased with increasing the concentrations of phosphorus impurities, which is led to make all structures are unstable and more reactive. Then, phosphorus impurities are significantly contributing to engineering, control and alter the <span class="hlt">electronic</span> properties of the GNS, which is very important in various applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820017210','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820017210"><span>A broad-<span class="hlt">band</span> VLF-burst associated with ring-current <span class="hlt">electrons</span>. [geomagnetic storms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Maeda, K.</p> <p>1982-01-01</p> <p>Frequency <span class="hlt">band</span> broadening takes place just outside of the nighttime plasmasphere, where the density of cold plasma is known to be very low during the later phase of a geomagnetic storm. Instead of the gradual broadening of several hours duration, a burst type broadening of VLF emission lasting less than ten minutes was observed by Explorer 45 in a similar location. The magnetic field component of this emission is very weak and the frequency spreads below the local half <span class="hlt">electron</span> cyclotron frequency. Corresponding enhancement of the anisotropic ring current <span class="hlt">electrons</span> is also very sudden and limited below the order of 10 keV without significant velocity dispersion, in contrast to the gradual broadening events. The cause of this type of emission <span class="hlt">band</span> spreading can be attributed to the generation of the quasielectrostatic whistler mode emission of short wavelength by hot bimaxwellian <span class="hlt">electrons</span> surging into the domain of relatively low density magnetized cold plasma. The lack of <span class="hlt">energy</span> dispersion in the enhanced <span class="hlt">electrons</span> indicates that the inner edge of the plasma sheet, the source of these hot <span class="hlt">electrons</span>, is not far from the location of this event.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22494717','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22494717"><span>Surface-plasmon enhanced photodetection at communication <span class="hlt">band</span> based on hot <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wu, Kai; Zhan, Yaohui E-mail: xfli@suda.edu.cn; Wu, Shaolong; Deng, Jiajia; Li, Xiaofeng E-mail: xfli@suda.edu.cn</p> <p>2015-08-14</p> <p>Surface plasmons can squeeze light into a deep-subwavelength space and generate abundant hot <span class="hlt">electrons</span> in the nearby metallic regions, enabling a new paradigm of photoconversion by the way of hot <span class="hlt">electron</span> collection. Unlike the visible spectral range concerned in previous literatures, we focus on the communication <span class="hlt">band</span> and design the infrared hot-<span class="hlt">electron</span> photodetectors with plasmonic metal-insulator-metal configuration by using full-wave finite-element method. Titanium dioxide-silver Schottky interface is employed to boost the low-<span class="hlt">energy</span> infrared photodetection. The photodetection sensitivity is strongly improved by enhancing the plasmonic excitation from a rationally engineered metallic grating, which enables a strong unidirectional photocurrent. With a five-step electrical simulation, the optimized device exhibits an unbiased responsivity of ∼0.1 mA/W and an ultra-narrow response <span class="hlt">band</span> (FWHM = 4.66 meV), which promises to be a candidate as the compact photodetector operating in communication <span class="hlt">band</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20845972','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20845972"><span>Mass, <span class="hlt">energy</span>, and the <span class="hlt">electron</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mulligan, Bernard . E-mail: mulligan.3@osu.edu</p> <p>2006-08-15</p> <p>The two-component solutions of the Dirac equation currently in use are not separately a particle equation or an antiparticle equation. We present a unitary transformation that uncouples the four-component, force-free Dirac equation to yield a two-component spinor equation for the force-free motion of a relativistic particle and a corresponding two-component, time-reversed equation for an antiparticle. The particle-antiparticle nature of the two equations is established by applying to the solutions of these two-component equations criteria analogous to those applied for establishing the four-component particle and antiparticle solutions of the four-component Dirac equation. Wave function solutions of our two-component particle equation describe both a right and a left circularly polarized particle. Interesting characteristics of our solutions include spatial distributions that are confined in extent along directions perpendicular to the motion, without the artifice of wave packets, and an intrinsic chirality (handedness) that replaces the usual definition of chirality for particles without mass. Our solutions demonstrate that both the rest mass and the relativistic increase in mass with velocity of the force-free <span class="hlt">electron</span> are due to an increase in the rate of Zitterbewegung with velocity. We extend this result to a bound <span class="hlt">electron</span>, in which case the loss of <span class="hlt">energy</span> due to binding is shown to decrease the rate of Zitterbewegung.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=foam&pg=5&id=EJ546509','ERIC'); return false;" href="http://eric.ed.gov/?q=foam&pg=5&id=EJ546509"><span>Housing <span class="hlt">Electrons</span>: Relating Quantum Numbers, <span class="hlt">Energy</span> Levels, and <span class="hlt">Electron</span> Configurations.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Garofalo, Anthony</p> <p>1997-01-01</p> <p>Presents an activity that combines the concepts of quantum numbers and probability locations, <span class="hlt">energy</span> levels, and <span class="hlt">electron</span> configurations in a concrete, hands-on way. Uses model houses constructed out of foam board and colored beads to represent <span class="hlt">electrons</span>. (JRH)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004SSCom.129..205B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004SSCom.129..205B"><span><span class="hlt">Energy-band</span> structure of CdTe and Si: a sp 3(s ∗) 2k.p model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boujdaria, Kais; Zitouni, Omar</p> <p>2004-01-01</p> <p>The <span class="hlt">energy</span> <span class="hlt">bands</span> of the direct-<span class="hlt">band</span>-gap semiconductor (CdTe) as well as the indirect-<span class="hlt">band</span>-gap semiconductor (Si), throughout the entire Brillouin zone, have been obtained by diagonalizing a 24×24 k.p Hamiltonian referred to basis states at k=0. We extend the sp 3s ∗ basis functions by the inclusion of sV∗ orbitals. We find that the sp 3'd'(s ∗) 2k.p model is fairly sufficient to describe the <span class="hlt">electronic</span> structure of these systems over a wide <span class="hlt">energy</span> range, obviating the use of any d orbitals. Finally, the comparison with available theoretical results shows that the present model reproduces known results for bulk CdTe and Si, that is, their <span class="hlt">band</span> structure, including s and p valence <span class="hlt">bands</span> and the lowest two conduction <span class="hlt">bands</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994PhRvB..4916480G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994PhRvB..4916480G"><span>Density of states of the one-dimensional <span class="hlt">electron</span> gas: Impurity levels, impurity <span class="hlt">bands</span>, and the <span class="hlt">band</span> tail</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gold, A.; Ghazali, A.</p> <p>1994-06-01</p> <p>The density of states of cylindrical quantum wires is calculated in the presence of charged impurities located in the center of the wire. A multiple-scattering approach (Klauder's fifth approximation), which represents a self-consistent t-matrix approximation, is used. For small impurity densities and in the weak screening limit the ground-state impurity <span class="hlt">band</span> and four excited-state impurity <span class="hlt">bands</span> are obtained within our approach. We find good agreement between the numerically obtained spectral densities with the corresponding analytical spectral densities calculated with the single-impurity wave functions. The merging of impurity <span class="hlt">bands</span> is studied. For large impurity densities we obtain a <span class="hlt">band</span> tail. We present an analytical expression for the disorder-induced renormalized <span class="hlt">band</span>-edge <span class="hlt">energy</span> in the <span class="hlt">band</span>-tail regime.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22493679','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22493679"><span>Exact two-component relativistic <span class="hlt">energy</span> <span class="hlt">band</span> theory and application</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhao, Rundong; Zhang, Yong; Xiao, Yunlong; Liu, Wenjian</p> <p>2016-01-28</p> <p>An exact two-component (X2C) relativistic density functional theory in terms of atom-centered basis functions is proposed for relativistic calculations of <span class="hlt">band</span> structures and structural properties of periodic systems containing heavy elements. Due to finite radial extensions of the local basis functions, the periodic calculation is very much the same as a molecular calculation, except only for an Ewald summation for the Coulomb potential of fluctuating periodic monopoles. For comparison, the nonrelativistic and spin-free X2C counterparts are also implemented in parallel. As a first and pilot application, the <span class="hlt">band</span> gaps, lattice constants, cohesive <span class="hlt">energies</span>, and bulk moduli of AgX (X = Cl, Br, I) are calculated to compare with other theoretical results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9607E..0VS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9607E..0VS"><span><span class="hlt">Electronic</span> crosstalk in Terra MODIS thermal emissive <span class="hlt">bands</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Junqiang; Madhavan, Sriharsha; Xiong, Xiaoxiong; Wang, Menghua</p> <p>2015-09-01</p> <p>The MODerate-resolution Imaging Spectroradiometer (MODIS) is a legacy Earth remote sensing instrument in the National Aeronautics and Space Administration (NASA) Earth Observing System (EOS). The first MODIS instrument was launched in December 1999 on board the Terra spacecraft. MODIS has 36 <span class="hlt">bands</span>, among which <span class="hlt">bands</span> 20-25 and <span class="hlt">bands</span> 27-36 are thermal emissive <span class="hlt">bands</span> covering a wavelength range from 3.7μm to 14.2μm. It has been found that there are severe contaminations in Terra <span class="hlt">bands</span> 27-30 (6.7 μm - 9.73 μm) due to crosstalk of signals among themselves. The crosstalk effect induces strong striping artifacts in the Earth View (EV) images and causes large long-term drifts in the EV brightness temperature (BT) in these <span class="hlt">bands</span>. An algorithm using a linear approximation derived from on-orbit lunar observations has been developed to correct the crosstalk effect for them. It was demonstrated that the crosstalk correction can substantially reduce the striping noise in the EV images and significantly remove the long-term drifts in the EV BT in the Long Wave InfraRed (LWIR) water vapor channels (<span class="hlt">bands</span> 27-28). In this paper, the crosstalk correction algorithm previously developed is applied to correct the crosstalk effect in the remaining LWIR <span class="hlt">bands</span> 29 and 30. The crosstalk correction successfully reduces the striping artifact in the EV images and removes long-term drifts in the EV BT in <span class="hlt">bands</span> 29-30 as was done similarly for <span class="hlt">bands</span> 27-28. The crosstalk correction algorithm can thus substantially improve both the image quality and the radiometric accuracy of the Level 1B (L1B) products of the LWIR PV <span class="hlt">bands</span>, <span class="hlt">bands</span> 27-30. From this study it is also understood that other Terra MODIS thermal emissive <span class="hlt">bands</span> are contaminated by the crosstalk effect and that the algorithm can be applied to these <span class="hlt">bands</span> for crosstalk correction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22591250','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22591250"><span>Flat <span class="hlt">electronic</span> <span class="hlt">bands</span> in fractal-kagomé network and the effect of perturbation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nandy, Atanu Chakrabarti, Arunava</p> <p>2016-05-06</p> <p>We demonstrate an analytical prescription of demonstrating the flat <span class="hlt">band</span> [FB] states in a fractal incorporated kagomé type network that can give rise to a countable infinity of flat non-dispersive eigenstates with a multitude of localization area. The onset of localization can, in principle, be delayed in space by an appropriate choice of <span class="hlt">energy</span> regime. The length scale, at which the onset of localization for each mode occurs, can be tuned at will following the formalism developed within the framework of real space renormalization group. This scheme leads to an exact determination of <span class="hlt">energy</span> eigenvalue for which one can have dispersionless flat <span class="hlt">electronic</span> <span class="hlt">bands</span>. Furthermore, we have shown the effect ofuniform magnetic field for the same non-translationally invariant network model that has ultimately led to an‘apparent invisibility’ of such staggered localized states and to generate absolutely continuous sub-<span class="hlt">bands</span> in the <span class="hlt">energy</span> spectrum and again an interesting re-entrant behavior of those FB states.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JPhCS.417a2012O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JPhCS.417a2012O"><span>Determination of <span class="hlt">Energy</span> <span class="hlt">Band</span> Alignment in Ultrathin Hf-based Oxide/Pt System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ohta, A.; Murakami, H.; Higashi, S.; Miyazaki, S.</p> <p>2013-03-01</p> <p>Effect of incorporating a third element into HfO2 on the <span class="hlt">electronic</span> structures has been studied by high resolution x-ray photoelectron spectroscopy (XPS). Hf-IIIa (La, Y, Gd, and Dy) oxide and Hf-Ti oxide films were deposited on a Pt layer by metal organic chemical vapor deposition (MOCVD) and co-sputtering and followed by post-deposition annealing in O2 ambience at 500°C. The <span class="hlt">energy</span> bandgap (Eg) of these Hf-based oxide films was determined by analyzing the <span class="hlt">energy</span> loss spectra of O 1s photoelectrons in consideration of the overlap with Hf 4s core-line signals. From analyses of the valence <span class="hlt">band</span> signals and the cut-off <span class="hlt">energy</span> for photoelectrons, the valence <span class="hlt">band</span> offset between the Hf based-oxide, and the Pt electrode and the work function value of the Pt layer were evaluated. By combining the oxide bandgap values, the valence <span class="hlt">band</span> line-ups, and the Pt work function value, the <span class="hlt">energy</span> <span class="hlt">band</span> profile of the Hf-based oxide/Pt has been determined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JaJAP..56dCK06K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JaJAP..56dCK06K"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structure of TiN/MgO nanostructures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kobayashi, Kazuaki; Takaki, Hirokazu; Shimono, Masato; Kobayashi, Nobuhiko; Hirose, Kenji</p> <p>2017-04-01</p> <p>Various nanostructured TiN(001)/MgO(001) superlattices based on a repeated slab model with a vacuum region have been investigated by the total <span class="hlt">energy</span> pseudopotential method. They are rectangular and rectangular parallelepiped TiN(001) dot structures on MgO(001)-2×2 and 3×3 substrates. A rectangular TiN(001) structure on a MgO(001)-2×1 substrate has also been calculated. Their detailed <span class="hlt">electronic</span> and internal lattice properties were investigated systematically. The internal atomic coordinates in a unit cell were fully relaxed. The rectangular TiN(001) structure on the MgO(001)-2×1 superlattice, which is not a dot owing to its periodicity, corresponds to metallicity. The <span class="hlt">electronic</span> states of relaxed rectangular TiN(001) dot/MgO(001)-2×2 and MgO(001)-3×3 superlattices are semiconducting. All relaxed rectangular parallelepiped TiN(001) dot/MgO(001)-2×2 and MgO(001)-3×3 superlattices correspond to metallicity. The <span class="hlt">electronic</span> properties depend on the shape of the TiN dot and the size of the MgO substrate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5919399','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5919399"><span><span class="hlt">Electrons</span> and grain boundary <span class="hlt">energies</span> in metals</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ferrante, J.; Smith, J.R.; Balluffi, R.W.; Brokman, A.</p> <p>1985-03-01</p> <p>It was found that differences between <span class="hlt">electron</span> density profiles in grain boundaries and those in the crystal yield relatively large <span class="hlt">electronic</span> contributions to grain boundary <span class="hlt">energies</span>. These <span class="hlt">electronic</span> effects can be combined self-consistently with pair-wise interactions in a practical method for computing grain boundary structures and <span class="hlt">energies</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatSR...517490L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatSR...517490L"><span>Extreme sensitivity of the electric-field-induced <span class="hlt">band</span> gap to the <span class="hlt">electronic</span> topological transition in sliding bilayer graphene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Kyu Won; Lee, Cheol Eui</p> <p>2015-12-01</p> <p>We have investigated the effect of <span class="hlt">electronic</span> topological transition on the electric field-induced <span class="hlt">band</span> gap in sliding bilayer graphene by using the density functional theory calculations. The electric field-induced <span class="hlt">band</span> gap was found to be extremely sensitive to the <span class="hlt">electronic</span> topological transition. At the <span class="hlt">electronic</span> topological transition induced by layer sliding, four Dirac cones in the Bernal-stacked bilayer graphene reduces to two Dirac cones with equal or unequal Dirac <span class="hlt">energies</span> depending on the sliding direction. While the critical electric field required for the <span class="hlt">band</span> gap opening increases with increasing lateral shift for the two Dirac cones with unequal Dirac <span class="hlt">energies</span>, the critical field is essentially zero with or without a lateral shift for the two Dirac cones with equal Dirac <span class="hlt">energies</span>. The critical field is determined by the Dirac <span class="hlt">energy</span> difference and the <span class="hlt">electronic</span> screening effect. The <span class="hlt">electronic</span> screening effect was also found to be enhanced with increasing lateral shift, apparently indicating that the massless helical and massive chiral fermions are responsible for the perfect and imperfect <span class="hlt">electronic</span> screening, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JChPh.144b4107V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JChPh.144b4107V"><span>Photoconductivities from <span class="hlt">band</span> states and a dissipative <span class="hlt">electron</span> dynamics: Si(111) without and with adsorbed Ag clusters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vazhappilly, Tijo; Hembree, Robert H.; Micha, David A.</p> <p>2016-01-01</p> <p>A new general computational procedure is presented to obtain photoconductivities starting from atomic structures, combining ab initio <span class="hlt">electronic</span> <span class="hlt">energy</span> <span class="hlt">band</span> states with populations from density matrix theory, and implemented for a specific set of materials based on Si crystalline slabs and their nanostructured surfaces without and with adsorbed Ag clusters. The procedure accounts for charge mobility in semiconductors in photoexcited states, and specifically <span class="hlt">electron</span> and hole photomobilities at Si(111) surfaces with and without adsorbed Ag clusters using ab initio <span class="hlt">energy</span> <span class="hlt">bands</span> and orbitals generated from a generalized gradient functional, however with excited <span class="hlt">energy</span> levels modified to provide correct bandgaps. Photoexcited state populations for each <span class="hlt">band</span> and carrier type were generated using steady state solution of a reduced density matrix which includes dissipative medium effects. The present calculations provide photoexcited <span class="hlt">electronic</span> populations and photoinduced mobilities resulting from applied electric fields and obtained from the change of driven <span class="hlt">electron</span> <span class="hlt">energies</span> with their <span class="hlt">electronic</span> momentum. Extensive results for Si slabs with 8 layers, without and with adsorbed Ag clusters, show that the metal adsorbates lead to substantial increases in the photomobility and photoconductivity of <span class="hlt">electrons</span> and holes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26772554','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26772554"><span>Photoconductivities from <span class="hlt">band</span> states and a dissipative <span class="hlt">electron</span> dynamics: Si(111) without and with adsorbed Ag clusters.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vazhappilly, Tijo; Hembree, Robert H; Micha, David A</p> <p>2016-01-14</p> <p>A new general computational procedure is presented to obtain photoconductivities starting from atomic structures, combining ab initio <span class="hlt">electronic</span> <span class="hlt">energy</span> <span class="hlt">band</span> states with populations from density matrix theory, and implemented for a specific set of materials based on Si crystalline slabs and their nanostructured surfaces without and with adsorbed Ag clusters. The procedure accounts for charge mobility in semiconductors in photoexcited states, and specifically <span class="hlt">electron</span> and hole photomobilities at Si(111) surfaces with and without adsorbed Ag clusters using ab initio <span class="hlt">energy</span> <span class="hlt">bands</span> and orbitals generated from a generalized gradient functional, however with excited <span class="hlt">energy</span> levels modified to provide correct bandgaps. Photoexcited state populations for each <span class="hlt">band</span> and carrier type were generated using steady state solution of a reduced density matrix which includes dissipative medium effects. The present calculations provide photoexcited <span class="hlt">electronic</span> populations and photoinduced mobilities resulting from applied electric fields and obtained from the change of driven <span class="hlt">electron</span> <span class="hlt">energies</span> with their <span class="hlt">electronic</span> momentum. Extensive results for Si slabs with 8 layers, without and with adsorbed Ag clusters, show that the metal adsorbates lead to substantial increases in the photomobility and photoconductivity of <span class="hlt">electrons</span> and holes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22493630','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22493630"><span>Photoconductivities from <span class="hlt">band</span> states and a dissipative <span class="hlt">electron</span> dynamics: Si(111) without and with adsorbed Ag clusters</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vazhappilly, Tijo; Hembree, Robert H.; Micha, David A.</p> <p>2016-01-14</p> <p>A new general computational procedure is presented to obtain photoconductivities starting from atomic structures, combining ab initio <span class="hlt">electronic</span> <span class="hlt">energy</span> <span class="hlt">band</span> states with populations from density matrix theory, and implemented for a specific set of materials based on Si crystalline slabs and their nanostructured surfaces without and with adsorbed Ag clusters. The procedure accounts for charge mobility in semiconductors in photoexcited states, and specifically <span class="hlt">electron</span> and hole photomobilities at Si(111) surfaces with and without adsorbed Ag clusters using ab initio <span class="hlt">energy</span> <span class="hlt">bands</span> and orbitals generated from a generalized gradient functional, however with excited <span class="hlt">energy</span> levels modified to provide correct bandgaps. Photoexcited state populations for each <span class="hlt">band</span> and carrier type were generated using steady state solution of a reduced density matrix which includes dissipative medium effects. The present calculations provide photoexcited <span class="hlt">electronic</span> populations and photoinduced mobilities resulting from applied electric fields and obtained from the change of driven <span class="hlt">electron</span> <span class="hlt">energies</span> with their <span class="hlt">electronic</span> momentum. Extensive results for Si slabs with 8 layers, without and with adsorbed Ag clusters, show that the metal adsorbates lead to substantial increases in the photomobility and photoconductivity of <span class="hlt">electrons</span> and holes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhDT.......183P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhDT.......183P"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structure effects in monolayer, bilayer, and hybrid graphene structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Puls, Conor</p> <p></p> <p>Since its discovery in 2005, graphene has been the focus of intense theoretical and experimental study owing to its unique two-dimensional <span class="hlt">band</span> structure and related <span class="hlt">electronic</span> properties. In this thesis, we explore the <span class="hlt">electronic</span> properties of graphene structures from several perspectives including the magnetoelectrical transport properties of monolayer graphene, gap engineering and measurements in bilayer graphene, and anomalous quantum oscillation in the monolayer-bilayer graphene hybrids. We also explored the device implications of our findings, and the application of some experimental techniques developed for the graphene work to the study of a complex oxide, Ca3Ru2O7, exhibiting properties of strongly correlated <span class="hlt">electrons</span>. Graphene's high mobility and ballistic transport over device length scales, make it suitable for numerous applications. However, two big challenges remain in the way: maintaining high mobility in fabricated devices, and engineering a <span class="hlt">band</span> gap to make graphene compatible with logical <span class="hlt">electronics</span> and various optical devices. We address the first challenge by experimentally evaluating mobilities in scalable monolayer graphene-based field effect transistors (FETs) and dielectric-covered Hall bars. We find that the mobility is limited in these devices, and is roughly inversely proportional to doping. By considering interaction of graphene's Dirac fermions with local charged impurities at the interface between graphene and the top-gate dielectric, we find that Coulomb scattering is responsible for degraded mobility. Even in the cleanest devices, a <span class="hlt">band</span> gap is still desirable for <span class="hlt">electronic</span> applications of graphene. We address this challenge by probing the <span class="hlt">band</span> structure of bilayer graphene, in which a field-tunable <span class="hlt">energy</span> <span class="hlt">band</span> gap has been theoretically proposed. We use planar tunneling spectroscopy of exfoliated bilayer graphene flakes demonstrate both measurement and control of the <span class="hlt">energy</span> <span class="hlt">band</span> gap. We find that both the Fermi level and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27285145','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27285145"><span>Simulations and measurements in scanning <span class="hlt">electron</span> microscopes at low <span class="hlt">electron</span> <span class="hlt">energy</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Walker, Christopher G H; Frank, Luděk; Müllerová, Ilona</p> <p>2016-11-01</p> <p>The advent of new imaging technologies in Scanning <span class="hlt">Electron</span> Microscopy (SEM) using low <span class="hlt">energy</span> (0-2 keV) <span class="hlt">electrons</span> has brought about new ways to study materials at the nanoscale. It also brings new challenges in terms of understanding <span class="hlt">electron</span> transport at these <span class="hlt">energies</span>. In addition, reduction in <span class="hlt">energy</span> has brought new contrast mechanisms producing images that are sometimes difficult to interpret. This is increasing the push for simulation tools, in particular for low impact <span class="hlt">energies</span> of <span class="hlt">electrons</span>. The use of Monte Carlo calculations to simulate the transport of <span class="hlt">electrons</span> in materials has been undertaken by many authors for several decades. However, inaccuracies associated with the Monte Carlo technique start to grow as the <span class="hlt">energy</span> is reduced. This is not simply associated with inaccuracies in the knowledge of the scattering cross-sections, but is fundamental to the Monte Carlo technique itself. This is because effects due to the wave nature of the <span class="hlt">electron</span> and the <span class="hlt">energy</span> <span class="hlt">band</span> structure of the target above the vacuum <span class="hlt">energy</span> level become important and these are properties which are difficult to handle using the Monte Carlo method. In this review we briefly describe the new techniques of scanning low <span class="hlt">energy</span> <span class="hlt">electron</span> microscopy and then outline the problems and challenges of trying to understand and quantify the signals that are obtained. The effects of charging and spin polarised measurement are also briefly explored. SCANNING 38:802-818, 2016. © 2016 Wiley Periodicals, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22038773','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22038773"><span>Microstructure, optical property, and <span class="hlt">electronic</span> <span class="hlt">band</span> structure of cuprous oxide thin films</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Park, Jun-Woo; Jang, Hyungkeun; Kim, Sung; Choi, Suk-Ho; Lee, Hosun; Kang, Joongoo; Wei, Su-Huai</p> <p>2011-11-15</p> <p>Cuprous oxide (Cu{sub 2}O) thin films were grown via radio frequency sputtering deposition at various temperatures. The dielectric functions and luminescence properties of the Cu{sub 2}O thin films were measured using spectroscopic ellipsometry and photoluminescence, respectively. High-<span class="hlt">energy</span> peaks were observed in the photoluminescence spectra. Several critical points (CPs) were found using second derivative spectra of the dielectric functions and the standard critical point model. The <span class="hlt">electronic</span> <span class="hlt">band</span> structure and the dielectric functions were calculated using density functional theory, and the CP <span class="hlt">energies</span> were estimated to compare with the experimental data. We identified the high-<span class="hlt">energy</span> photoluminescence peaks to quasi-direct transitions which arose from the granular structures of the Cu{sub 2}O thin films.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21448499','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21448499"><span>Excitation of Meinel and the first negative <span class="hlt">band</span> system at the collision of <span class="hlt">electrons</span> and protons with the nitrogen molecule</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gochitashvili, Malkhaz R.; Lomsadze, Ramaz A.; Kezerashvili, Roman Ya.</p> <p>2010-08-15</p> <p>The absolute cross sections for the e-N{sub 2} and p-N{sub 2} collisions for the first negative B{sup 2{Sigma}}{sub u}{sup +}-X{sup 2{Sigma}}{sub g}{sup +} and Meinel A{sup 2{Pi}}{sub u}-X{sup 2{Sigma}}{sub g}{sup +} <span class="hlt">bands</span> have been measured in the <span class="hlt">energy</span> region of 400-1500 eV for <span class="hlt">electrons</span> and 0.4-10 keV for protons, respectively. Measurements are performed in the visible spectral region of 400-800 nm by an optical spectroscopy method. The ratio of the cross sections of the Meinel <span class="hlt">band</span> system to the cross section of the first negative <span class="hlt">band</span> system (0,0) does not depend on the incident <span class="hlt">electron</span> <span class="hlt">energy</span>. The populations of vibrational levels corresponding to A{sup 2{Pi}}{sub u} states are consistent with the Franck-Condon principle. The ratios of the cross sections of (4,1) to (3,0) <span class="hlt">bands</span> and (5,2) to (3,0) <span class="hlt">bands</span> exhibit slight dependence on the proton <span class="hlt">energy</span>. A theoretical estimation within the quasimolecular approximation provides a reasonable description of the total cross section for the first negative <span class="hlt">band</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JAP...118g5101W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JAP...118g5101W"><span><span class="hlt">Electronic</span> and thermoelectric properties of van der Waals materials with ring-shaped valence <span class="hlt">bands</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wickramaratne, Darshana; Zahid, Ferdows; Lake, Roger K.</p> <p>2015-08-01</p> <p>The valence <span class="hlt">band</span> of a variety of few-layer, two-dimensional materials consist of a ring of states in the Brillouin zone. The <span class="hlt">energy</span>-momentum relation has the form of a "Mexican hat" or a Rashba dispersion. The two-dimensional density of states is singular at or near the <span class="hlt">band</span> edge, and the <span class="hlt">band</span>-edge density of modes turns on nearly abruptly as a step function. The large <span class="hlt">band</span>-edge density of modes enhances the Seebeck coefficient, the power factor, and the thermoelectric figure of merit ZT. <span class="hlt">Electronic</span> and thermoelectric properties are determined from ab initio calculations for few-layer III-VI materials GaS, GaSe, InS, InSe, for Bi2Se3, for monolayer Bi, and for bilayer graphene as a function of vertical field. The effect of interlayer coupling on these properties in few-layer III-VI materials and Bi2Se3 is described. Analytical models provide insight into the layer dependent trends that are relatively consistent for all of these few-layer materials. Vertically biased bilayer graphene could serve as an experimental test-bed for measuring these effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991JAP....69.5003S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991JAP....69.5003S"><span>Spin-resolved <span class="hlt">electronic</span> <span class="hlt">band</span> structure of fct-cobalt (100) (abstract)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schneider, C. M.; Schuster, P.; Hammond, M.; Ebert, H.; Noffke, J.; Kirschner, J.</p> <p>1991-04-01</p> <p>The spin-polarized <span class="hlt">electronic</span> structure of the fcc high-temperature modification of cobalt has not been investigated yet, because of the experimental difficulties of photoemission at high temperature. We stabilized fcc Co by molecular-beam epitaxy on a Cu(100) substrate with large, atomically flat terasses (0.5-1 μm wide) as revealed by STM. The structure of the layers was studied by LEED and MEED, showing a tetragonal distortion of the fcc lattice perpendicular to the (100) surface plane. The dispersion of the exchange split <span class="hlt">bands</span> perpendicular to the surface was determined for a 5-monolayer-thick sample (tetragonal distortion on average 4%-5%) by spin- and momentum-resolved photoemission. The results are compared to two relativistic spin-polarized <span class="hlt">band</span>-structure calculations for fcc cobalt. Somewhat surprisingly, even a 5-ML-thick sample shows three-dimensional dispersion in good agreement with the calculations, as far as the average exchange splitting (1.2±0.2 eV), and the symmetry character of the <span class="hlt">bands</span> is concerned. There are, however, some systematic deviations of minority <span class="hlt">bands</span> near the Fermi <span class="hlt">energy</span> which are attributed to the tetragonal compression.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22494769','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22494769"><span><span class="hlt">Electronic</span> and thermoelectric properties of van der Waals materials with ring-shaped valence <span class="hlt">bands</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wickramaratne, Darshana E-mail: rlake@ece.ucr.edu; Lake, Roger K. E-mail: rlake@ece.ucr.edu; Zahid, Ferdows</p> <p>2015-08-21</p> <p>The valence <span class="hlt">band</span> of a variety of few-layer, two-dimensional materials consist of a ring of states in the Brillouin zone. The <span class="hlt">energy</span>-momentum relation has the form of a “Mexican hat” or a Rashba dispersion. The two-dimensional density of states is singular at or near the <span class="hlt">band</span> edge, and the <span class="hlt">band</span>-edge density of modes turns on nearly abruptly as a step function. The large <span class="hlt">band</span>-edge density of modes enhances the Seebeck coefficient, the power factor, and the thermoelectric figure of merit ZT. <span class="hlt">Electronic</span> and thermoelectric properties are determined from ab initio calculations for few-layer III–VI materials GaS, GaSe, InS, InSe, for Bi{sub 2}Se{sub 3}, for monolayer Bi, and for bilayer graphene as a function of vertical field. The effect of interlayer coupling on these properties in few-layer III–VI materials and Bi{sub 2}Se{sub 3} is described. Analytical models provide insight into the layer dependent trends that are relatively consistent for all of these few-layer materials. Vertically biased bilayer graphene could serve as an experimental test-bed for measuring these effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SPIE.8176E..0ZS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8176E..0ZS"><span>Terra MODIS <span class="hlt">band</span> 27 <span class="hlt">electronic</span> crosstalk: cause, impact, and mitigation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, J.; Madhavan, S.; Wenny, B. N.; Xiong, X.</p> <p>2011-11-01</p> <p>MODIS-Terra is one of the key sensors in the suite of remote sensing instruments in the Earth Observing System (EOS). MODIS on the Terra platform was launched into orbit in December of 1999 and has successfully completed eleven plus years of operation. MODIS has 36 spectral channels with wavelengths varying from 0.4 μm to 14.4 μm. The native spatial resolutions for the reflective channels are 2 <span class="hlt">bands</span> at 0.25 km, 5 <span class="hlt">bands</span> at 0.5 km and 29 <span class="hlt">bands</span> at 1km. However, the MODIS L1B product allows the high spatial resolution <span class="hlt">bands</span> to be aggregated into 1km resolution. All the thermal channels in MODIS (i.e. 3.75μm - 14.24μm) have a native spatial resolution of 1 km. Over the eleven plus years of mission lifetime, the sensor degradation has been carefully monitored using various On-Board Calibrators (OBC). In particular, the thermal channels are monitored using the on-board Black-Body (BB) which is traceable to NIST standards. MODIS also has a unique feature for calibration reference in terms of lunar irradiance. The lunar observations are scheduled for MODIS periodically (at least 9 observations in a calendar year). Based on the lunar observations, it was found that there was a possible signal leak for <span class="hlt">band</span> 27 from its neighboring <span class="hlt">bands</span> located on the Long-Wave Infrared (LWIR) focal plane. Further investigations revealed a possible leak from <span class="hlt">bands</span> 28, 29 and 30. The magnitude of the leak was trended and correction coefficients were derived. In this paper, we demonstrate the across-<span class="hlt">band</span> signal leak in MODIS <span class="hlt">band</span> 27, its potential impact on the retrieved Brightness temperature (B.T.). Also, the paper explores a correction methodology to relieve the artifacts due to the across-<span class="hlt">band</span> signal leak. Finally, the improvement in the <span class="hlt">band</span> 27 image quality is quantified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27120582','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27120582"><span>Physical properties and <span class="hlt">electronic</span> <span class="hlt">band</span> structure of noncentrosymmetric Th7Co3 superconductor.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sahakyan, M; Tran, V H</p> <p>2016-05-25</p> <p>The physical properties of the noncentrosymmetric superconductor Th7Co3 have been investigated by means of ac-magnetic susceptibility, magnetization, specific heat, electrical resistivity, magnetoresistance and Hall effect measurements. From these data it is established that Th7Co3 is a dirty type-II superconductor with [Formula: see text] K, [Formula: see text] and moderate <span class="hlt">electron</span>-phonon coupling [Formula: see text]. Some evidences for anisotropic superconducting gap are found, including e.g. reduced specific heat jump ([Formula: see text]) at T c, diminished superconducting <span class="hlt">energy</span> gap ([Formula: see text]) as compared to the BCS values, power law field dependence of the Sommerfeld coefficient at 0.4 K ([Formula: see text]), and a concave curvature of the [Formula: see text] line. The magnitudes of the thermodynamic critical field and the <span class="hlt">energy</span> gap are consistent with mean-squared anisotropy parameter [Formula: see text]. The <span class="hlt">electronic</span> specific heat in the superconducting state is reasonably fitted to an oblate spheroidal gap model. Calculations of scalar relativistic and fully relativistic <span class="hlt">electronic</span> <span class="hlt">band</span> structures reveal considerable differences in the degenerate structure, resulting from asymmetric spin-orbit coupling (ASOC). A large splitting <span class="hlt">energy</span> of spin-up spin-down <span class="hlt">bands</span> at the Fermi level E F, [Formula: see text] meV is observed and a sizeable ratio [Formula: see text] could classify the studied compound into the class of noncentrosymmetric superconductors with strong ASOC. The noncentrosymmetry of the crystal structure and the atomic relativistic effects are both responsible for an importance of ASOC in Th7Co3. The calculated results for the density of states show a Van Hove singularity just below E F and dominant role of the 6d <span class="hlt">electrons</span> of Th to the superconductivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060042261&hterms=polyatomic+ions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dpolyatomic%2Bions','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060042261&hterms=polyatomic+ions&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dpolyatomic%2Bions"><span><span class="hlt">Electron</span> Attachment to Molecules at Low <span class="hlt">Electron</span> <span class="hlt">Energies</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chutjian, A.; Garscadden, A.; Wadehra, J. M.</p> <p>1994-01-01</p> <p>One of the most efficient ways of producing negative ions is by the process of dissociative <span class="hlt">electron</span> attachment to molecules. Here, a diatomic or polyatomic molecule dissociates, by the impact of a low <span class="hlt">energy</span> <span class="hlt">electron</span>, into component atoms (or smaller molecular species) while the incident <span class="hlt">electron</span> attaches itself to one of the dissociating fragments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28319838','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28319838"><span>Graphene oxide quantum dot-sensitized porous titanium dioxide microsphere: Visible-light-driven photocatalyst based on <span class="hlt">energy</span> <span class="hlt">band</span> engineering.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Yu; Qi, Fuyuan; Li, Ying; Zhou, Xin; Sun, Hongfeng; Zhang, Wei; Liu, Daliang; Song, Xi-Ming</p> <p>2017-07-15</p> <p>We report a novel graphene oxide quantum dot (GOQD)-sensitized porous TiO2 microsphere for efficient photoelectric conversion. Electro-chemical analysis along with the Mott-Schottky equation reveals conductivity type and <span class="hlt">energy</span> <span class="hlt">band</span> structure of the two semiconductors. Based on their <span class="hlt">energy</span> <span class="hlt">band</span> structures, visible light-induced <span class="hlt">electrons</span> can transfer from the p-type GOQD to the n-type TiO2. Enhanced photocurrent and photocatalytic activity in visible light further confirm the enhanced separation of <span class="hlt">electrons</span> and holes in the nanocomposite. Copyright © 2017 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009NIMPA.599..270B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009NIMPA.599..270B"><span>Single track nanodosimetry of low <span class="hlt">energy</span> <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bantsar, A.; Grosswendt, B.; Pszona, S.; Kula, J.</p> <p>2009-02-01</p> <p>Auger-<span class="hlt">electron</span>-emitting radionuclides (for instance, 125I) with a predominant <span class="hlt">energy</span> spectrum below 3 keV are an active area of research towards the clinical application of radiopharmaceuticals. Hence, the necessity for an adequate description of the effects of radiation by low-<span class="hlt">energy</span> <span class="hlt">electrons</span> on nanometric biological targets seems to be unquestionable. Experimental nanodosimetry for low-<span class="hlt">energy</span> <span class="hlt">electrons</span> has been accomplished with a device named JET COUNTER. The present paper describes, for the first time, nanodosimetric experiments in nanometer-sized cavities of nitrogen using low <span class="hlt">energy</span> <span class="hlt">electrons</span> ranging from 100 eV to 2 keV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..96c5422G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..96c5422G"><span>Anisotropic plasmons, excitons, and <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectroscopy of phosphorene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghosh, Barun; Kumar, Piyush; Thakur, Anmol; Chauhan, Yogesh Singh; Bhowmick, Somnath; Agarwal, Amit</p> <p>2017-07-01</p> <p>In this article, we explore the anisotropic <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectrum (EELS) in monolayer phosphorene based on ab initio time-dependent density-functional-theory calculations. Similarly to black phosphorus, the EELS of undoped monolayer phosphorene is characterized by anisotropic excitonic peaks for <span class="hlt">energies</span> in the vicinity of the <span class="hlt">band</span> gap and by interband plasmon peaks for higher <span class="hlt">energies</span>. On doping, an additional intraband plasmon peak also appears for <span class="hlt">energies</span> within the <span class="hlt">band</span> gap. Similarly to other two-dimensional systems, the intraband plasmon peak disperses as ωpl∝√{q } in both the zigzag and armchair directions in the long-wavelength limit and deviates for larger wave vectors. The anisotropy of the long-wavelength plasmon intraband dispersion is found to be inversely proportional to the square root of the ratio of the effective masses: ωpl(q y ̂) /ωpl(q x ̂) =√{mx/my } .</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JChPh.145d4703E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JChPh.145d4703E"><span>Vibrational effects on surface <span class="hlt">energies</span> and <span class="hlt">band</span> gaps in hexagonal and cubic ice</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Engel, Edgar A.; Monserrat, Bartomeu; Needs, Richard J.</p> <p>2016-07-01</p> <p>Surface <span class="hlt">energies</span> of hexagonal and cubic water ice are calculated using first-principles quantum mechanical methods, including an accurate description of anharmonic nuclear vibrations. We consider two proton-orderings of the hexagonal and cubic ice basal surfaces and three proton-orderings of hexagonal ice prism surfaces, finding that vibrations reduce the surface <span class="hlt">energies</span> by more than 10%. We compare our vibrational densities of states to recent sum frequency generation absorption measurements and identify surface proton-orderings of experimental ice samples and the origins of characteristic absorption peaks. We also calculate zero point quantum vibrational corrections to the surface <span class="hlt">electronic</span> <span class="hlt">band</span> gaps, which range from -1.2 eV for the cubic ice basal surface up to -1.4 eV for the hexagonal ice prism surface. The vibrational corrections to the surface <span class="hlt">band</span> gaps are up to 12% smaller than for bulk ice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JChPh.144l4309J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JChPh.144l4309J"><span>Theoretical and experimental differential cross sections for <span class="hlt">electron</span> impact excitation of the <span class="hlt">electronic</span> <span class="hlt">bands</span> of furfural</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jones, D. B.; Neves, R. F. C.; Lopes, M. C. A.; da Costa, R. F.; do N. Varella, M. T.; Bettega, M. H. F.; Lima, M. A. P.; García, G.; Limão-Vieira, P.; Brunger, M. J.</p> <p>2016-03-01</p> <p>We report results from a joint experimental and theoretical investigation into <span class="hlt">electron</span> scattering from the important industrial species furfural (C5H4O2). Specifically, differential cross sections (DCSs) have been measured and calculated for the <span class="hlt">electron</span>-impact excitation of the <span class="hlt">electronic</span> states of C5H4O2. The measurements were carried out at <span class="hlt">energies</span> in the range 20-40 eV, and for scattered-<span class="hlt">electron</span> angles between 10° and 90°. The <span class="hlt">energy</span> resolution of those experiments was typically ˜80 meV. Corresponding Schwinger multichannel method with pseudo-potential calculations, for <span class="hlt">energies</span> between 6-50 eV and with and without Born-closure, were also performed for a sub-set of the excited <span class="hlt">electronic</span>-states that were accessed in the measurements. Those calculations were undertaken at the static exchange plus polarisation-level using a minimum orbital basis for single configuration interaction (MOB-SCI) approach. Agreement between the measured and calculated DCSs was qualitatively quite good, although to obtain quantitative accord, the theory would need to incorporate even more channels into the MOB-SCI. The role of multichannel coupling on the computed <span class="hlt">electronic</span>-state DCSs is also explored in some detail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..93h5202G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..93h5202G"><span>Quasiparticle <span class="hlt">band</span> gap of organic-inorganic hybrid perovskites: Crystal structure, spin-orbit coupling, and self-<span class="hlt">energy</span> effects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, Weiwei; Gao, Xiang; Abtew, Tesfaye A.; Sun, Yi-Yang; Zhang, Shengbai; Zhang, Peihong</p> <p>2016-02-01</p> <p>The quasiparticle <span class="hlt">band</span> gap is one of the most important materials properties for photovoltaic applications. Often the <span class="hlt">band</span> gap of a photovoltaic material is determined (and can be controlled) by various factors, complicating predictive materials optimization. An in-depth understanding of how these factors affect the size of the gap will provide valuable guidance for new materials discovery. Here we report a comprehensive investigation on the <span class="hlt">band</span> gap formation mechanism in organic-inorganic hybrid perovskites by decoupling various contributing factors which ultimately determine their <span class="hlt">electronic</span> structure and quasiparticle <span class="hlt">band</span> gap. Major factors, namely, quasiparticle self-<span class="hlt">energy</span>, spin-orbit coupling, and structural distortions due to the presence of organic molecules, and their influences on the quasiparticle <span class="hlt">band</span> structure of organic-inorganic hybrid perovskites are illustrated. We find that although methylammonium cations do not contribute directly to the <span class="hlt">electronic</span> states near <span class="hlt">band</span> edges, they play an important role in defining the <span class="hlt">band</span> gap by introducing structural distortions and controlling the overall lattice constants. The spin-orbit coupling effects drastically reduce the <span class="hlt">electron</span> and hole effective masses in these systems, which is beneficial for high carrier mobilities and small exciton binding <span class="hlt">energies</span>.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..96f4505L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..96f4505L"><span>Universal phase diagrams with superconducting domes for <span class="hlt">electronic</span> flat <span class="hlt">bands</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Löthman, Tomas; Black-Schaffer, Annica M.</p> <p>2017-08-01</p> <p>Condensed matter systems with flat <span class="hlt">bands</span> close to the Fermi level generally exhibit, due to their very large density of states, extraordinarily high critical ordering temperatures of symmetry-breaking orders, such as superconductivity and magnetism. Here we show that the critical temperatures follow one of two universal curves with doping away from a flat <span class="hlt">band</span> depending on the ordering channel, which completely dictates both the general order competition and the phase diagram. Notably, we find that orders in the particle-particle channel (superconducting orders) survive decisively farther than orders in the particle-hole channel (magnetic or charge orders) because the channels have fundamentally different polarizabilities. Thus, even if a magnetic or charge order initially dominates, superconducting domes are still likely to exist on the flanks of flat <span class="hlt">bands</span>. We apply these general results to both the topological surface flat <span class="hlt">bands</span> of rhombohedral ABC-stacked graphite and to the Van Hove singularity of graphene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27711601','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27711601"><span>Low <span class="hlt">energy</span> <span class="hlt">electron</span> catalyst: the <span class="hlt">electronic</span> origin of catalytic strategies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Davis, Daly; Sajeev, Y</p> <p>2016-10-12</p> <p>Using a low <span class="hlt">energy</span> <span class="hlt">electron</span> (LEE) as a catalyst, the <span class="hlt">electronic</span> origin of the catalytic strategies corresponding to substrate selectivity, reaction specificity and reaction rate enhancement is investigated for a reversible unimolecular elementary reaction. An <span class="hlt">electronic</span> <span class="hlt">energy</span> complementarity between the catalyst and the substrate molecule is the origin of substrate selectivity and reaction specificity. The <span class="hlt">electronic</span> <span class="hlt">energy</span> complementarity is induced by tuning the <span class="hlt">electronic</span> <span class="hlt">energy</span> of the catalyst. The <span class="hlt">energy</span> complementarity maximizes the binding forces between the catalyst and the molecule. Consequently, a new <span class="hlt">electronically</span> metastable high-<span class="hlt">energy</span> reactant state and a corresponding new low barrier reaction path are resonantly created for a specific reaction of the substrate through the formation of a catalyst-substrate transient adduct. The LEE catalysis also reveals a fundamental structure-<span class="hlt">energy</span> correspondence in the formation of the catalyst-substrate transient adduct. Since the <span class="hlt">energy</span> complementarities corresponding to the substrate molecules of the forward and the backward steps of the reversible reactions are not the same due to their structural differences, the LEE catalyst exhibits a unique one-way catalytic strategy, i.e., the LEE catalyst favors the reversible reaction more effectively in one direction. A characteristic stronger binding of the catalyst to the transition state of the reaction than in the initial reactant state and the final product state is the molecular origin of barrier lowering.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARB15001A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARB15001A"><span>Dynamical and anharmonic effects on the <span class="hlt">electron</span>-phonon coupling and the zero-point renormalization of the <span class="hlt">band</span> structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antonius, Gabriel; Poncé, Samuel; Lantagne-Hurtubise, Étienne; Auclair, Gabriel; Côté, Michel; Gonze, Xavier</p> <p>2015-03-01</p> <p>The <span class="hlt">electron</span>-phonon coupling in solids renormalizes the <span class="hlt">band</span> structure, reducing the <span class="hlt">band</span> gap by several tenths of an eV in light-atoms semiconductors. Using the Allen-Heine-Cardona theory (AHC), we compute the zero-point renormalization (ZPR) as well as the quasiparticle lifetimes of the full <span class="hlt">band</span> structure in diamond, BN, LiF and MgO. We show how dynamical effects can be included in the AHC theory, and still allow for the use of a Sternheimer equation to avoid the summation over unoccupied <span class="hlt">bands</span>. The convergence properties of the <span class="hlt">electron</span>-phonon coupling self-<span class="hlt">energy</span> with respect to the Brillouin zone sampling prove to be strongly affected by dynamical effects. We complement our study with a frozen-phonon approach, which reproduces the static AHC theory, but also allows to probe the phonon wavefunctions at finite displacements and include anharmonic effects in the self-<span class="hlt">energy</span>. We show that these high-order components tend to reduce the strongest <span class="hlt">electron</span>-phonon coupling elements, which affects significantly the <span class="hlt">band</span> gap ZPR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22599108','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22599108"><span><span class="hlt">Banded</span> structures in <span class="hlt">electron</span> pitch angle diffusion coefficients from resonant wave-particle interactions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tripathi, A. K. Singhal, R. P.; Khazanov, G. V.; Avanov, L. A.</p> <p>2016-04-15</p> <p><span class="hlt">Electron</span> pitch angle (D{sub αα}) and momentum (D{sub pp}) diffusion coefficients have been calculated due to resonant interactions with electrostatic <span class="hlt">electron</span> cyclotron harmonic (ECH) and whistler mode chorus waves. Calculations have been performed at two spatial locations L = 4.6 and 6.8 for <span class="hlt">electron</span> <span class="hlt">energies</span> ≤10 keV. Landau (n = 0) resonance and cyclotron harmonic resonances n = ±1, ±2, … ±5 have been included in the calculations. It is found that diffusion coefficient versus pitch angle (α) profiles show large dips and oscillations or <span class="hlt">banded</span> structures. The structures are more pronounced for ECH and lower <span class="hlt">band</span> chorus (LBC) and particularly at location 4.6. Calculations of diffusion coefficients have also been performed for individual resonances. It is noticed that the main contribution of ECH waves in pitch angle diffusion coefficient is due to resonances n = +1 and n = +2. A major contribution to momentum diffusion coefficients appears from n = +2. However, the <span class="hlt">banded</span> structures in D{sub αα} and D{sub pp} coefficients appear only in the profile of diffusion coefficients for n = +2. The contribution of other resonances to diffusion coefficients is found to be, in general, quite small or even negligible. For LBC and upper <span class="hlt">band</span> chorus waves, the <span class="hlt">banded</span> structures appear only in Landau resonance. The D{sub pp} diffusion coefficient for ECH waves is one to two orders smaller than D{sub αα} coefficients. For chorus waves, D{sub pp} coefficients are about an order of magnitude smaller than D{sub αα} coefficients for the case n ≠ 0. In case of Landau resonance, the values of D{sub pp} coefficient are generally larger than the values of D{sub αα} coefficients particularly at lower <span class="hlt">energies</span>. As an aid to the interpretation of results, we have also determined the resonant frequencies. For ECH waves, resonant frequencies have been estimated for wave normal angle 89° and harmonic resonances n = +1, +2, and +3</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..MARQ33011L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..MARQ33011L"><span>Spectroscopic investigation on the <span class="hlt">electronic</span> structure of a 5 d <span class="hlt">band</span> insulator SrHfO3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Yunsang; Seo, Y. K.; Lee, D. J.; Noh, H. J.</p> <p>2011-03-01</p> <p>We investigated the high-<span class="hlt">energy</span> <span class="hlt">electronic</span> structure of a 5d perovskite SrHf O3 . By using optical spectroscopy and O 1 s x-ray absorption spectroscopy, the values of <span class="hlt">electronic</span> structure parameters are estimated properly. In particular, the crystal field splitting <span class="hlt">energy</span>, which is closely associated with the p - d hybridization strength, is as high as 5 eV, and the Sr 4 d <span class="hlt">bands</span> appear to be strongly mixed with the Hf 5 d <span class="hlt">bands</span>. Moreover, the emission spectra with a 325 nm light excitation exhibit a sizable strength near 500 nm at low temperatures due to oxygen defects. These findings in SrHf O3 are compared with <span class="hlt">electronic</span> properties of similar compounds, 3 d SrTi O3 and 4 d SrZr O3 .</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARG24002H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARG24002H"><span><span class="hlt">Electronic</span> correlation contributions to structural <span class="hlt">energies</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haydock, Roger</p> <p>2015-03-01</p> <p>The recursion method is used to calculate <span class="hlt">electronic</span> excitation spectra including <span class="hlt">electron-electron</span> interactions within the Hubbard model. The effects of correlation on structural <span class="hlt">energies</span> are then obtained from these spectra and applied to stacking faults. http://arxiv.org/abs/1405.2288 Supported by the Richmond F. Snyder Fund and Gifts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000CP....261..289L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000CP....261..289L"><span><span class="hlt">Electron</span> momentum spectroscopy study of amantadine: binding <span class="hlt">energy</span> spectra and valence orbital <span class="hlt">electron</span> density distributions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Litvinyuk, I. V.; Zheng, Y.; Brion, C. E.</p> <p>2000-11-01</p> <p>The <span class="hlt">electron</span> binding <span class="hlt">energy</span> spectrum and valence orbital <span class="hlt">electron</span> momentum density distributions of amantadine (1-aminoadamantane), an important anti-viral and anti-Parkinsonian drug, have been measured by <span class="hlt">electron</span> momentum spectroscopy. Theoretical momentum distributions, calculated at the 6-311++G** and AUG-CC-PVTZ levels within the target Hartree-Fock and also the target Kohn-Sham density functional theory approximations, show good agreement with the experimental results. The results for amantadine are also compared with those for the parent molecule, adamantane, reported earlier (Chem. Phys. 253 (2000) 41). Based on the comparison tentative assignments of the valence region ionization <span class="hlt">bands</span> of amantadine have been made.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22047453','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22047453"><span><span class="hlt">Energy</span> efficiency of <span class="hlt">electron</span> plasma emitters</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zalesski, V. G.</p> <p>2011-12-15</p> <p><span class="hlt">Electron</span> emission influence from gas-discharge plasma on plasma emitter <span class="hlt">energy</span> parameters is considered. It is shown, that <span class="hlt">electron</span> emission from plasma is accompanied by <span class="hlt">energy</span> contribution redistribution in the gas-discharge from plasma emitter supplies sources-the gas-discharge power supply and the accelerating voltage power supply. Some modes of <span class="hlt">electron</span> emission as a result can be realized: 'a probe measurements mode,' 'a transitive mode,' and 'a full switching mode.'.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22271091','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22271091"><span>Effect of low-temperature annealing on the <span class="hlt">electronic</span>- and <span class="hlt">band</span>-structures of (Ga,Mn)As epitaxial layers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yastrubchak, O. Gluba, L.; Żuk, J.; Wosinski, T. Andrearczyk, T.; Domagala, J. Z.; Sadowski, J.</p> <p>2014-01-07</p> <p>The effect of outdiffusion of Mn interstitials from (Ga,Mn)As epitaxial layers, caused by post-growth low-temperature annealing, on their <span class="hlt">electronic</span>- and <span class="hlt">band</span>-structure properties has been investigated by modulation photoreflectance (PR) spectroscopy. The annealing-induced changes in structural and magnetic properties of the layers were examined with high-resolution X-ray diffractometry and superconducting quantum interference device magnetometry, respectively. They confirmed an outdiffusion of Mn interstitials from the layers and an enhancement in their hole concentration, which were more efficient for the layer covered with a Sb cap acting as a sink for diffusing Mn interstitials. The PR results demonstrating a decrease in the <span class="hlt">band</span>-gap-transition <span class="hlt">energy</span> in the as-grown (Ga,Mn)As layers, with respect to that in the reference GaAs one, are interpreted by assuming a merging of the Mn-related impurity <span class="hlt">band</span> with the GaAs valence <span class="hlt">band</span>. Whereas an increase in the <span class="hlt">band</span>-gap-transition <span class="hlt">energy</span> caused by the annealing treatment of the (Ga,Mn)As layers is interpreted as a result of annealing-induced enhancement of the free-hole concentration and the Fermi level location within the valence <span class="hlt">band</span>. The experimental results are consistent with the valence-<span class="hlt">band</span> origin of itinerant holes mediating ferromagnetic ordering in (Ga,Mn)As, in agreement with the Zener model for ferromagnetic semiconductors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JAP...115a2009Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JAP...115a2009Y"><span>Effect of low-temperature annealing on the <span class="hlt">electronic</span>- and <span class="hlt">band</span>-structures of (Ga,Mn)As epitaxial layers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yastrubchak, O.; Wosinski, T.; Gluba, L.; Andrearczyk, T.; Domagala, J. Z.; Żuk, J.; Sadowski, J.</p> <p>2014-01-01</p> <p>The effect of outdiffusion of Mn interstitials from (Ga,Mn)As epitaxial layers, caused by post-growth low-temperature annealing, on their <span class="hlt">electronic</span>- and <span class="hlt">band</span>-structure properties has been investigated by modulation photoreflectance (PR) spectroscopy. The annealing-induced changes in structural and magnetic properties of the layers were examined with high-resolution X-ray diffractometry and superconducting quantum interference device magnetometry, respectively. They confirmed an outdiffusion of Mn interstitials from the layers and an enhancement in their hole concentration, which were more efficient for the layer covered with a Sb cap acting as a sink for diffusing Mn interstitials. The PR results demonstrating a decrease in the <span class="hlt">band</span>-gap-transition <span class="hlt">energy</span> in the as-grown (Ga,Mn)As layers, with respect to that in the reference GaAs one, are interpreted by assuming a merging of the Mn-related impurity <span class="hlt">band</span> with the GaAs valence <span class="hlt">band</span>. Whereas an increase in the <span class="hlt">band</span>-gap-transition <span class="hlt">energy</span> caused by the annealing treatment of the (Ga,Mn)As layers is interpreted as a result of annealing-induced enhancement of the free-hole concentration and the Fermi level location within the valence <span class="hlt">band</span>. The experimental results are consistent with the valence-<span class="hlt">band</span> origin of itinerant holes mediating ferromagnetic ordering in (Ga,Mn)As, in agreement with the Zener model for ferromagnetic semiconductors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/878935','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/878935"><span>Attainment of <span class="hlt">Electron</span> Beam Suitable for Medium <span class="hlt">Energy</span> <span class="hlt">Electron</span> Cooling</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Seletskiy, Sergei M.</p> <p>2005-01-01</p> <p><span class="hlt">Electron</span> cooling of charged particle beams is a well-established technique at <span class="hlt">electron</span> <span class="hlt">energies</span> of up to 300 keV. However, up to the present time the advance of <span class="hlt">electron</span> cooling to the MeV-range <span class="hlt">energies</span> has remained a purely theoretical possibility. The <span class="hlt">electron</span> cooling project at Fermilab has recently demonstrated the ¯rst cooling of 8.9 GeV/c antiprotons in the Recycler ring, and therefore, has proved the validity of the idea of relativistic <span class="hlt">electron</span> cool- ing. The Recycler <span class="hlt">Electron</span> Cooler (REC) is the key component of the Teva- tron Run II luminosity upgrade project. Its performance depends critically on the quality of <span class="hlt">electron</span> beam. A stable <span class="hlt">electron</span> beam of 4.3 MeV car- rying 0.5 A of DC current is required. The beam suitable for the Recycler <span class="hlt">Electron</span> Cooler must have an angular spread not exceeding 200 ¹rad. The full-scale prototype of the REC was designed, built and tested at Fermilab in the Wideband laboratory to study the feasibility of attaining the high-quality <span class="hlt">electron</span> beam. In this thesis I describe various aspects of development of the Fermilab <span class="hlt">electron</span> cooling system, and the techniques used to obtain the <span class="hlt">electron</span> beam suitable for the cooling process. In particular I emphasize those aspects of the work for which I was principally responsible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002APS..MARS12014L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002APS..MARS12014L"><span>Magnetic excitations versus <span class="hlt">electronic</span> <span class="hlt">bands</span> on twinned YBa_2Cu_3O_7-δ superconductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Jun; Tam, Ka Ming; Lin, Hai-Qing</p> <p>2002-03-01</p> <p>Connection between the magnetic excitations detected by the inelastic neutron-scattering (INS) [1,2,3] and the angle-resolved photoemission (ARPES) measured <span class="hlt">electronic</span> structures [4] on the high temperature YBa_2Cu_3O_7-δ superconductors is still an open question. Direct use of the ARPES derived bonding and antibonding quasiparticle <span class="hlt">bands</span> will produce an unphysical incommensurability (ICM) of δ =0.5π in the INS measured ICM peak positions Q^*=(π ,π ± δ ). We point out that the slave-boson approach [5] provides a systematic way of relating these two kinds of experiments. At nearly optimal doping of x=15%, the ARPES derived <span class="hlt">bands</span> on untwinned YBa_2Cu_3O_7-δ are taken as a starting point. The slave-boson renormalized fermion <span class="hlt">bands</span> are less curved around the Brillouin zone diagonals so that they are able to induce an incommensurability of δ =0.2π in the odd spin excitation channel with neutron <span class="hlt">energy</span> ω =37.5meV as well as resonance peak with neutron frequency ω =47.3 meV . These magnetic spectra are in good agreement with the INS experiments on nearly optimally doped twinned YBa_2twinning is averaged out due to the equal populations of the two twin domains. New factor should be taken into account to explain the INS spectra of untwinned samples [3]. In the underdoped region (x=10%), no ARPES derived <span class="hlt">band</span> is presently available. A rigid <span class="hlt">band</span> approximations by using the same ARPES <span class="hlt">bands</span> cannot give consistent INS spectra [1] for less doped YBaslave-boson approach is used. This is due to the sensitive doping dependence of <span class="hlt">electronic</span> structures of high-Tc cuprates. References [1] H. A. Mook et al. , Nature 395, 580 (1998). [2] P. Bourges et al. , Science 288, 1234 (2000). [3] H. A. Mook et al. , Nature 404, 729 (2000). [4] M.C.Schabel et al., Phys. Rev. B 57, 6090 (1998). [5] J. Brinckmann and P. A. Lee, Phys. Rev. Lett. 82, 2915(1999).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JChPh.141d4709C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JChPh.141d4709C"><span>All-<span class="hlt">electron</span> GW quasiparticle <span class="hlt">band</span> structures of group 14 nitride compounds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chu, Iek-Heng; Kozhevnikov, Anton; Schulthess, Thomas C.; Cheng, Hai-Ping</p> <p>2014-07-01</p> <p>We have investigated the group 14 nitrides (M3N4) in the spinel phase (γ-M3N4 with M = C, Si, Ge, and Sn) and β phase (β-M3N4 with M = Si, Ge, and Sn) using density functional theory with the local density approximation and the GW approximation. The Kohn-Sham <span class="hlt">energies</span> of these systems have been first calculated within the framework of full-potential linearized augmented plane waves (LAPW) and then corrected using single-shot G0W0 calculations, which we have implemented in the modified version of the Elk full-potential LAPW code. Direct <span class="hlt">band</span> gaps at the Γ point have been found for spinel-type nitrides γ-M3N4 with M = Si, Ge, and Sn. The corresponding GW-corrected <span class="hlt">band</span> gaps agree with experiment. We have also found that the GW calculations with and without the plasmon-pole approximation give very similar results, even when the system contains semi-core d <span class="hlt">electrons</span>. These spinel-type nitrides are novel materials for potential optoelectronic applications because of their direct and tunable <span class="hlt">band</span> gaps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22419957','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22419957"><span>All-<span class="hlt">electron</span> GW quasiparticle <span class="hlt">band</span> structures of group 14 nitride compounds</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chu, Iek-Heng; Cheng, Hai-Ping; Kozhevnikov, Anton; Schulthess, Thomas C.</p> <p>2014-07-28</p> <p>We have investigated the group 14 nitrides (M{sub 3}N{sub 4}) in the spinel phase (γ-M{sub 3}N{sub 4} with M = C, Si, Ge, and Sn) and β phase (β-M{sub 3}N{sub 4} with M = Si, Ge, and Sn) using density functional theory with the local density approximation and the GW approximation. The Kohn-Sham <span class="hlt">energies</span> of these systems have been first calculated within the framework of full-potential linearized augmented plane waves (LAPW) and then corrected using single-shot G{sub 0}W{sub 0} calculations, which we have implemented in the modified version of the Elk full-potential LAPW code. Direct <span class="hlt">band</span> gaps at the Γ point have been found for spinel-type nitrides γ-M{sub 3}N{sub 4} with M = Si, Ge, and Sn. The corresponding GW-corrected <span class="hlt">band</span> gaps agree with experiment. We have also found that the GW calculations with and without the plasmon-pole approximation give very similar results, even when the system contains semi-core d <span class="hlt">electrons</span>. These spinel-type nitrides are novel materials for potential optoelectronic applications because of their direct and tunable <span class="hlt">band</span> gaps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22494713','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22494713"><span>8-<span class="hlt">band</span> and 14-<span class="hlt">band</span> kp modeling of <span class="hlt">electronic</span> <span class="hlt">band</span> structure and material gain in Ga(In)AsBi quantum wells grown on GaAs and InP substrates</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gladysiewicz, M.; Wartak, M. S.; Kudrawiec, R.</p> <p>2015-08-07</p> <p>The <span class="hlt">electronic</span> <span class="hlt">band</span> structure and material gain have been calculated for GaAsBi/GaAs quantum wells (QWs) with various bismuth concentrations (Bi ≤ 15%) within the 8-<span class="hlt">band</span> and 14-<span class="hlt">band</span> kp models. The 14-<span class="hlt">band</span> kp model was obtained by extending the standard 8-<span class="hlt">band</span> kp Hamiltonian by the valence <span class="hlt">band</span> anticrossing (VBAC) Hamiltonian, which is widely used to describe Bi-related changes in the <span class="hlt">electronic</span> <span class="hlt">band</span> structure of dilute bismides. It has been shown that in the range of low carrier concentrations n < 5 × 10{sup 18 }cm{sup −3}, material gain spectra calculated within 8- and 14-<span class="hlt">band</span> kp Hamiltonians are similar. It means that the 8-<span class="hlt">band</span> kp model can be used to calculate material gain in dilute bismides QWs. Therefore, it can be applied to analyze QWs containing new dilute bismides for which the VBAC parameters are unknown. Thus, the <span class="hlt">energy</span> gap and <span class="hlt">electron</span> effective mass for Bi-containing materials are used instead of VBAC parameters. The <span class="hlt">electronic</span> <span class="hlt">band</span> structure and material gain have been calculated for 8 nm wide GaInAsBi QWs on GaAs and InP substrates with various compositions. In these QWs, Bi concentration was varied from 0% to 5% and indium concentration was tuned in order to keep the same compressive strain (ε = 2%) in QW region. For GaInAsBi/GaAs QW with 5% Bi, gain peak was determined to be at about 1.5 μm. It means that it can be possible to achieve emission at telecommunication windows (i.e., 1.3 μm and 1.55 μm) for GaAs-based lasers containing GaInAsBi/GaAs QWs. For GaInAsBi/Ga{sub 0.47}In{sub 0.53}As/InP QWs with 5% Bi, gain peak is predicted to be at about 4.0 μm, i.e., at the wavelengths that are not available in current InP-based lasers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JAP...118e5702G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JAP...118e5702G"><span>8-<span class="hlt">band</span> and 14-<span class="hlt">band</span> kp modeling of <span class="hlt">electronic</span> <span class="hlt">band</span> structure and material gain in Ga(In)AsBi quantum wells grown on GaAs and InP substrates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gladysiewicz, M.; Kudrawiec, R.; Wartak, M. S.</p> <p>2015-08-01</p> <p>The <span class="hlt">electronic</span> <span class="hlt">band</span> structure and material gain have been calculated for GaAsBi/GaAs quantum wells (QWs) with various bismuth concentrations (Bi ≤ 15%) within the 8-<span class="hlt">band</span> and 14-<span class="hlt">band</span> kp models. The 14-<span class="hlt">band</span> kp model was obtained by extending the standard 8-<span class="hlt">band</span> kp Hamiltonian by the valence <span class="hlt">band</span> anticrossing (VBAC) Hamiltonian, which is widely used to describe Bi-related changes in the <span class="hlt">electronic</span> <span class="hlt">band</span> structure of dilute bismides. It has been shown that in the range of low carrier concentrations n < 5 × 1018 cm-3, material gain spectra calculated within 8- and 14-<span class="hlt">band</span> kp Hamiltonians are similar. It means that the 8-<span class="hlt">band</span> kp model can be used to calculate material gain in dilute bismides QWs. Therefore, it can be applied to analyze QWs containing new dilute bismides for which the VBAC parameters are unknown. Thus, the <span class="hlt">energy</span> gap and <span class="hlt">electron</span> effective mass for Bi-containing materials are used instead of VBAC parameters. The <span class="hlt">electronic</span> <span class="hlt">band</span> structure and material gain have been calculated for 8 nm wide GaInAsBi QWs on GaAs and InP substrates with various compositions. In these QWs, Bi concentration was varied from 0% to 5% and indium concentration was tuned in order to keep the same compressive strain (ɛ = 2%) in QW region. For GaInAsBi/GaAs QW with 5% Bi, gain peak was determined to be at about 1.5 μm. It means that it can be possible to achieve emission at telecommunication windows (i.e., 1.3 μm and 1.55 μm) for GaAs-based lasers containing GaInAsBi/GaAs QWs. For GaInAsBi/Ga0.47In0.53As/InP QWs with 5% Bi, gain peak is predicted to be at about 4.0 μm, i.e., at the wavelengths that are not available in current InP-based lasers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000058155','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000058155"><span>High Resolution Emission Spectroscopy of the Alpha Pi-1 - Chi Sigma-1(+) Fourth Positive <span class="hlt">Band</span> System of CO from <span class="hlt">Electron</span> Impact</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Beegle, Luther W.; Ajello, Joseph M.; James, Geoffrey K.; Alvarez, Marcos; Dziczek, Dariusz</p> <p>2000-01-01</p> <p>We report <span class="hlt">electron</span>-impact induced fluorescence spectra [300 mA full width at half maximum (FWHM)] of CO for 20 and 100 eV impact <span class="hlt">energies</span> of the spectral region of 1300 to 2050 A and high resolution spectra (FWHM) of the v'=5 to v"=l and the v'=3 to v"=O <span class="hlt">bands</span> showing that the rotational structure of the <span class="hlt">band</span> system are modeled accurately. The excitation function of the (0,1) <span class="hlt">band</span> (1597 A) was measured from <span class="hlt">electron</span> impact in the <span class="hlt">energy</span> range from threshold to 750 eV and placed on an absolute scale from modem calibration standards.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21828568','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21828568"><span>A simple <span class="hlt">energy</span> filter for low <span class="hlt">energy</span> <span class="hlt">electron</span> microscopy/photoelectron emission microscopy instruments.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tromp, R M; Fujikawa, Y; Hannon, J B; Ellis, A W; Berghaus, A; Schaff, O</p> <p>2009-08-05</p> <p>Addition of an <span class="hlt">electron</span> <span class="hlt">energy</span> filter to low <span class="hlt">energy</span> <span class="hlt">electron</span> microscopy (LEEM) and photoelectron emission microscopy (PEEM) instruments greatly improves their analytical capabilities. However, such filters tend to be quite complex, both <span class="hlt">electron</span> optically and mechanically. Here we describe a simple <span class="hlt">energy</span> filter for the existing IBM LEEM/PEEM instrument, which is realized by adding a single scanning aperture slit to the objective transfer optics, without any further modifications to the microscope. This <span class="hlt">energy</span> filter displays a very high <span class="hlt">energy</span> resolution ΔE/E = 2 × 10(-5), and a non-isochromaticity of ∼0.5 eV/10 µm. The setup is capable of recording selected area <span class="hlt">electron</span> <span class="hlt">energy</span> spectra and angular distributions at 0.15 eV <span class="hlt">energy</span> resolution, as well as <span class="hlt">energy</span> filtered images with a 1.5 eV <span class="hlt">energy</span> pass <span class="hlt">band</span> at an estimated spatial resolution of ∼10 nm. We demonstrate the use of this <span class="hlt">energy</span> filter in imaging and spectroscopy of surfaces using a laboratory-based He I (21.2 eV) light source, as well as imaging of Ag nanowires on Si(001) using the 4 eV <span class="hlt">energy</span> loss Ag plasmon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20366157','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20366157"><span>Stability in bcc transition metals: Madelung and <span class="hlt">band-energy</span> effects due to alloying.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Landa, A; Söderlind, P; Ruban, A V; Peil, O E; Vitos, L</p> <p>2009-12-04</p> <p>The phase stability of group VB (V, Nb, and Ta) transition metals is explored by first-principles <span class="hlt">electronic</span>-structure calculations. Alloying with a small amount of a neighboring metal can either stabilize or destabilize the body-centered-cubic phase relative to low-symmetry rhombohedral phases. We show that <span class="hlt">band</span>-structure effects determine phase stability when a particular group VB metal is alloyed with its nearest neighbors within the same d-transition series. In this case, the neighbor with less (to the left) and more (to the right) d <span class="hlt">electrons</span> destabilize and stabilize bcc, respectively. When alloying with neighbors of higher d-transition series, electrostatic Madelung <span class="hlt">energy</span> dominates and stabilizes the body-centered-cubic phase. This surprising prediction invalidates current understanding of simple d-<span class="hlt">electron</span> bonding that dictates high-symmetry cubic and hexagonal phases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28805062','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28805062"><span>Ultrafast <span class="hlt">Electron</span> Dynamics in Solar <span class="hlt">Energy</span> Conversion.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ponseca, Carlito S; Chábera, Pavel; Uhlig, Jens; Persson, Petter; Sundström, Villy</p> <p>2017-08-23</p> <p><span class="hlt">Electrons</span> are the workhorses of solar <span class="hlt">energy</span> conversion. Conversion of the <span class="hlt">energy</span> of light to electricity in photovoltaics, or to <span class="hlt">energy</span>-rich molecules (solar fuel) through photocatalytic processes, invariably starts with photoinduced generation of <span class="hlt">energy</span>-rich <span class="hlt">electrons</span>. The harvesting of these <span class="hlt">electrons</span> in practical devices rests on a series of <span class="hlt">electron</span> transfer processes whose dynamics and efficiencies determine the function of materials and devices. To capture the <span class="hlt">energy</span> of a photogenerated <span class="hlt">electron</span>-hole pair in a solar cell material, charges of opposite sign have to be separated against electrostatic attractions, prevented from recombining and being transported through the active material to electrodes where they can be extracted. In photocatalytic solar fuel production, these <span class="hlt">electron</span> processes are coupled to chemical reactions leading to storage of the <span class="hlt">energy</span> of light in chemical bonds. With the focus on the ultrafast time scale, we here discuss the light-induced <span class="hlt">electron</span> processes underlying the function of several molecular and hybrid materials currently under development for solar <span class="hlt">energy</span> applications in dye or quantum dot-sensitized solar cells, polymer-fullerene polymer solar cells, organometal halide perovskite solar cells, and finally some photocatalytic systems.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22806244','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22806244"><span>Alignment of <span class="hlt">electronic</span> <span class="hlt">energy</span> levels at electrochemical interfaces.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cheng, Jun; Sprik, Michiel</p> <p>2012-08-28</p> <p>The position of <span class="hlt">electronic</span> <span class="hlt">energy</span> levels in a phase depends on the surface potentials at its boundaries. Bringing two phases in contact at an interface will alter the surface potentials shifting the <span class="hlt">energy</span> levels relative to each other. Calculating such shifts for electrochemical interfaces requires a combination of methods from computational surface science and physical chemistry. The problem is closely related to the computation of potentials of electrochemically inactive electrodes. These so-called ideally polarizable interfaces are impossible to cross for <span class="hlt">electrons</span>. In this perspective we review two density functional theory based methods that have been developed for this purpose, the workfunction method and the hydrogen insertion method. The key expressions of the two methods are derived from the formal theory of absolute electrode potentials. As an illustration of the workfunction method we review the computation of the potential of zero charge of the Pt(111)-water interface as recently published by a number of groups. The example of the hydrogen insertion method is from our own work on the rutile TiO(2)(110)-water interface at the point of zero proton charge. The calculations are summarized in level diagrams aligning the <span class="hlt">electronic</span> <span class="hlt">energy</span> levels of the solid electrode (Fermi level of the metal, valence <span class="hlt">band</span> maximum and conduction <span class="hlt">band</span> minimum of the semiconductor) to the <span class="hlt">band</span> edges of liquid water and the standard potential for the reduction of the hydroxyl radical. All potentials are calculated at the same level of density functional theory using the standard hydrogen electrode as common <span class="hlt">energy</span> reference. Comparison to experiment identifies the treatment of the valence <span class="hlt">band</span> of water as a potentially dangerous source of error for application to electrocatalysis and photocatalysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22415503','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22415503"><span>Differential cross sections for <span class="hlt">electron</span> impact excitation of the <span class="hlt">electronic</span> <span class="hlt">bands</span> of phenol</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Neves, R. F. C.; Jones, D. B.; Lopes, M. C. A.; Nixon, K. L.; Silva, G. B. da; Duque, H. V.; Oliveira, E. M. de; Lima, M. A. P.; Costa, R. F. da; Varella, M. T. do N.; Bettega, M. H. F.; and others</p> <p>2015-03-14</p> <p>We report results from a joint theoretical and experimental investigation into <span class="hlt">electron</span> scattering from the important organic species phenol (C{sub 6}H{sub 5}OH). Specifically, differential cross sections (DCSs) have been measured and calculated for the <span class="hlt">electron</span>-impact excitation of the <span class="hlt">electronic</span> states of C{sub 6}H{sub 5}OH. The measurements were carried out at <span class="hlt">energies</span> in the range 15–40 eV, and for scattered-<span class="hlt">electron</span> angles between 10{sup ∘} and 90{sup ∘}. The <span class="hlt">energy</span> resolution of those experiments was typically ∼80 meV. Corresponding Schwinger multichannel method with pseudo-potentials calculations, with and without Born-closure, were also performed for a sub-set of the excited <span class="hlt">electronic</span>-states that were accessed in the measurements. Those calculations were conducted at the static exchange plus polarisation (SEP)-level using a minimum orbital basis for single configuration interaction (MOBSCI) approach. Agreement between the measured and calculated DCSs was typically fair, although to obtain quantitative accord, the theory would need to incorporate even more channels into the MOBSCI.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MAR.G1179S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MAR.G1179S"><span>The <span class="hlt">electronic</span> and transport properties of monolayer transition metal dichalcogenides: a complex <span class="hlt">band</span> structure analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Szczesniak, Dominik</p> <p></p> <p>Recently, monolayer transition metal dichalcogenides have attracted much attention due to their potential use in both nano- and opto-<span class="hlt">electronics</span>. In such applications, the <span class="hlt">electronic</span> and transport properties of group-VIB transition metal dichalcogenides (MX2 , where M=Mo, W; X=S, Se, Te) are particularly important. Herein, new insight into these properties is presented by studying the complex <span class="hlt">band</span> structures (CBS's) of MX2 monolayers while accounting for spin-orbit coupling effects. By using the symmetry-based tight-binding model a nonlinear generalized eigenvalue problem for CBS's is obtained. An efficient method for solving such class of problems is presented and gives a complete set of physically relevant solutions. Next, these solutions are characterized and classified into propagating and evanescent states, where the latter states present not only monotonic but also oscillatory decay character. It is observed that some of the oscillatory evanescent states create characteristic complex loops at the direct <span class="hlt">band</span> gaps, which describe the tunneling currents in the MX2 materials. The importance of CBS's and tunneling currents is demonstrated by the analysis of the quantum transport across MX2 monolayers within phase field matching theory. Present work has been prepared within the Qatar <span class="hlt">Energy</span> and Environment Research Institute (QEERI) grand challenge ATHLOC project (Project No. QEERI- GC-3008).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JAP...107l3110L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JAP...107l3110L"><span>Quantum well infrared photodetectors hardiness to the nonideality of the <span class="hlt">energy</span> <span class="hlt">band</span> profile</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lhuillier, Emmanuel; Péré-Laperne, Nicolas; Ribet-Mohamed, Isabelle; Rosencher, Emmanuel; Patriarche, Gilles; Buffaz, Amandine; Berger, Vincent; Nedelcu, Alexandru; Carras, Mathieu</p> <p>2010-06-01</p> <p>We report results on the effect of a nonsharp and disordered potential in quantum well infrared photodetectors (QWIP). Scanning <span class="hlt">electronic</span> transmission microscopy is used to measure the alloy profile of the structure which is shown to present a gradient of composition along the growth axis. Those measurements are used as inputs to quantify the effect on the detector performance (peak wavelength, spectral broadening, and dark current). The influence of the random positioning of the doping is also studied. Finally we demonstrate that QWIP properties are quite robust with regard to the nonideality of the <span class="hlt">energy</span> <span class="hlt">band</span> profile.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/972690','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/972690"><span><span class="hlt">Band</span>- and momentum-dependent <span class="hlt">electron</span> dynamics in superconducting Ba(Fe1-xCox)2As2 as seen via <span class="hlt">electronic</span> Raman scattering</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Muschler, B.</p> <p>2010-02-24</p> <p>We present details of carrier properties in high quality Ba(Fe{sub 1-x}Co{sub x}){sub 2}As{sub 2} single crystals obtained from <span class="hlt">electronic</span> Raman scattering. The experiments indicate a strong <span class="hlt">band</span> and momentum anisotropy of the <span class="hlt">electron</span> dynamics above and below the superconducting transition highlighting the importance of complex <span class="hlt">band</span>-dependent interactions. The presence of low <span class="hlt">energy</span> spectral weight deep in the superconducting state suggests a gap with accidental nodes which may be lifted by doping and/or impurity scattering. When combined with other measurements, our observation of <span class="hlt">band</span> and momentum dependent carrier dynamics indicate that the iron arsenides may have several competing superconducting ground states.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.4446H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.4446H"><span>Combined scattering loss of radiation belt relativistic <span class="hlt">electrons</span> by simultaneous three-<span class="hlt">band</span> EMIC waves: A case study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>He, Fengming; Cao, Xing; Ni, Binbin; Xiang, Zheng; Zhou, Chen; Gu, Xudong; Zhao, Zhengyu; Shi, Run; Wang, Qi</p> <p>2016-05-01</p> <p>Multiband electromagnetic ion cyclotron (EMIC) waves can drive efficient scattering loss of radiation belt relativistic <span class="hlt">electrons</span>. However, it is statistically uncommon to capture the three <span class="hlt">bands</span> of EMIC waves concurrently. Utilizing data from the Electric and Magnetic Field Instrument Suite and Integrated Science magnetometer onboard Van Allen Probe A, we report the simultaneous presence of three (H+, He+, and O+) emission <span class="hlt">bands</span> in an EMIC wave event, which provides an opportunity to look into the combined scattering effect of all EMIC emissions and the relative roles of each <span class="hlt">band</span> in diffusing radiation belt relativistic <span class="hlt">electrons</span> under realistic circumstances. Our quantitative results, obtained by quasi-linear diffusion rate computations and 1-D pure pitch angle diffusion simulations, demonstrate that the combined resonant scattering by the simultaneous three-<span class="hlt">band</span> EMIC waves is overall dominated by He+ <span class="hlt">band</span> wave diffusion, mainly due to its dominance over the wave power (the mean wave amplitudes are approximately 0.4 nT, 1.6 nT, and 0.15 nT for H+, He+, and O+ <span class="hlt">bands</span>, respectively). Near the loss cone, while 2-3 MeV <span class="hlt">electrons</span> undergo pitch angle scattering at a rate of the order of 10-6-10-5 s-1, 5-10 MeV <span class="hlt">electrons</span> can be diffused more efficiently at a rate of the order of 10-3-10-2 s-1, which approaches the strong diffusion level and results in a moderately or heavily filled loss cone for the atmospheric loss. The corresponding <span class="hlt">electron</span> loss timescales (i.e., lifetimes) vary from several days at the <span class="hlt">energies</span> of ~2 MeV to less than 1 h at ~10 MeV. This case study indicates the leading contribution of He+ <span class="hlt">band</span> waves to radiation belt relativistic <span class="hlt">electron</span> losses during the coexistence of three EMIC wave <span class="hlt">bands</span> and suggests that the roles of different EMIC wave <span class="hlt">bands</span> in the relativistic <span class="hlt">electron</span> dynamics should be carefully incorporated in future modeling efforts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1342054-electronic-band-structure-effects-stopping-protons-copper-electronic-band-structure-non-linear-effects-stopping-protons-copper','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1342054-electronic-band-structure-effects-stopping-protons-copper-electronic-band-structure-non-linear-effects-stopping-protons-copper"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structure effects in the stopping of protons in copper [<span class="hlt">Electronic</span> <span class="hlt">band</span> structure non-linear effects in the stopping of protons in copper</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Quashie, Edwin E.; Saha, Bidhan C.; Correa, Alfredo A.</p> <p>2016-10-05</p> <p>Here, we present an ab initio study of the <span class="hlt">electronic</span> stopping power of protons in copper over a wide range of proton velocities v = 0.02–10a.u. where we take into account nonlinear effects. Time-dependent density functional theory coupled with molecular dynamics is used to study <span class="hlt">electronic</span> excitations produced by energetic protons. A plane-wave pseudopotential scheme is employed to solve the time-dependent Kohn-Sham equations for a moving ion in a periodic crystal. The <span class="hlt">electronic</span> excitations and the <span class="hlt">band</span> structure determine the stopping power of the material and alter the interatomic forces for both channeling and off-channeling trajectories. Our off-channeling results aremore » in quantitative agreement with experiments, and at low velocity they unveil a crossover region of superlinear velocity dependence (with a power of ~1.5) in the velocity range v = 0.07–0.3a.u., which we associate to the copper crystalline <span class="hlt">electronic</span> <span class="hlt">band</span> structure. The results are rationalized by simple <span class="hlt">band</span> models connecting two separate regimes. We find that the limit of <span class="hlt">electronic</span> stopping v → 0 is not as simple as phenomenological models suggest and it is plagued by <span class="hlt">band</span>-structure effects.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1342054','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1342054"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structure effects in the stopping of protons in copper [<span class="hlt">Electronic</span> <span class="hlt">band</span> structure non-linear effects in the stopping of protons in copper</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Quashie, Edwin E.; Saha, Bidhan C.; Correa, Alfredo A.</p> <p>2016-10-05</p> <p>Here, we present an <i>ab initio</i> study of the <span class="hlt">electronic</span> stopping power of protons in copper over a wide range of proton velocities v = 0.02–10a.u. where we take into account nonlinear effects. Time-dependent density functional theory coupled with molecular dynamics is used to study <span class="hlt">electronic</span> excitations produced by energetic protons. A plane-wave pseudopotential scheme is employed to solve the time-dependent Kohn-Sham equations for a moving ion in a periodic crystal. The <span class="hlt">electronic</span> excitations and the <span class="hlt">band</span> structure determine the stopping power of the material and alter the interatomic forces for both channeling and off-channeling trajectories. Our off-channeling results are in quantitative agreement with experiments, and at low velocity they unveil a crossover region of superlinear velocity dependence (with a power of ~1.5) in the velocity range v = 0.07–0.3a.u., which we associate to the copper crystalline <span class="hlt">electronic</span> <span class="hlt">band</span> structure. The results are rationalized by simple <span class="hlt">band</span> models connecting two separate regimes. We find that the limit of <span class="hlt">electronic</span> stopping v → 0 is not as simple as phenomenological models suggest and it is plagued by <span class="hlt">band</span>-structure effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1342054','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1342054"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structure effects in the stopping of protons in copper [<span class="hlt">Electronic</span> <span class="hlt">band</span> structure non-linear effects in the stopping of protons in copper</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Quashie, Edwin E.; Saha, Bidhan C.; Correa, Alfredo A.</p> <p>2016-10-05</p> <p>Here, we present an <i>ab initio</i> study of the <span class="hlt">electronic</span> stopping power of protons in copper over a wide range of proton velocities v = 0.02–10a.u. where we take into account nonlinear effects. Time-dependent density functional theory coupled with molecular dynamics is used to study <span class="hlt">electronic</span> excitations produced by energetic protons. A plane-wave pseudopotential scheme is employed to solve the time-dependent Kohn-Sham equations for a moving ion in a periodic crystal. The <span class="hlt">electronic</span> excitations and the <span class="hlt">band</span> structure determine the stopping power of the material and alter the interatomic forces for both channeling and off-channeling trajectories. Our off-channeling results are in quantitative agreement with experiments, and at low velocity they unveil a crossover region of superlinear velocity dependence (with a power of ~1.5) in the velocity range v = 0.07–0.3a.u., which we associate to the copper crystalline <span class="hlt">electronic</span> <span class="hlt">band</span> structure. The results are rationalized by simple <span class="hlt">band</span> models connecting two separate regimes. We find that the limit of <span class="hlt">electronic</span> stopping v → 0 is not as simple as phenomenological models suggest and it is plagued by <span class="hlt">band</span>-structure effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NatSR...4E5983J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NatSR...4E5983J"><span><span class="hlt">Energy</span> level control: toward an efficient hot <span class="hlt">electron</span> transport</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jin, Xiao; Li, Qinghua; Li, Yue; Chen, Zihan; Wei, Tai-Huei; He, Xingdao; Sun, Weifu</p> <p>2014-08-01</p> <p>Highly efficient hot <span class="hlt">electron</span> transport represents one of the most important properties required for applications in photovoltaic devices. Whereas the fabrication of efficient hot <span class="hlt">electron</span> capture and lost-cost devices remains a technological challenge, regulating the <span class="hlt">energy</span> level of acceptor-donor system through the incorporation of foreign ions using the solution-processed technique is one of the most promising strategies to overcome this obstacle. Here we present a versatile acceptor-donor system by incorporating MoO3:Eu nanophosphors, which reduces both the `excess' <span class="hlt">energy</span> offset between the conduction <span class="hlt">band</span> of acceptor and the lowest unoccupied molecular orbital of donor, and that between the valence <span class="hlt">band</span> and highest occupied molecular orbital. Strikingly, the hot <span class="hlt">electron</span> transfer time has been shortened. This work demonstrates that suitable <span class="hlt">energy</span> level alignment can be tuned to gain the higher hot <span class="hlt">electron</span>/hole transport efficiency in a simple approach without the need for complicated architectures. This work builds up the foundation of engineering building blocks for third-generation solar cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4124467','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4124467"><span><span class="hlt">Energy</span> level control: toward an efficient hot <span class="hlt">electron</span> transport</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jin, Xiao; Li, Qinghua; Li, Yue; Chen, Zihan; Wei, Tai-Huei; He, Xingdao; Sun, Weifu</p> <p>2014-01-01</p> <p>Highly efficient hot <span class="hlt">electron</span> transport represents one of the most important properties required for applications in photovoltaic devices. Whereas the fabrication of efficient hot <span class="hlt">electron</span> capture and lost-cost devices remains a technological challenge, regulating the <span class="hlt">energy</span> level of acceptor-donor system through the incorporation of foreign ions using the solution-processed technique is one of the most promising strategies to overcome this obstacle. Here we present a versatile acceptor-donor system by incorporating MoO3:Eu nanophosphors, which reduces both the ‘excess' <span class="hlt">energy</span> offset between the conduction <span class="hlt">band</span> of acceptor and the lowest unoccupied molecular orbital of donor, and that between the valence <span class="hlt">band</span> and highest occupied molecular orbital. Strikingly, the hot <span class="hlt">electron</span> transfer time has been shortened. This work demonstrates that suitable <span class="hlt">energy</span> level alignment can be tuned to gain the higher hot <span class="hlt">electron</span>/hole transport efficiency in a simple approach without the need for complicated architectures. This work builds up the foundation of engineering building blocks for third-generation solar cells. PMID:25099864</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25099864','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25099864"><span><span class="hlt">Energy</span> level control: toward an efficient hot <span class="hlt">electron</span> transport.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jin, Xiao; Li, Qinghua; Li, Yue; Chen, Zihan; Wei, Tai-Huei; He, Xingdao; Sun, Weifu</p> <p>2014-08-07</p> <p>Highly efficient hot <span class="hlt">electron</span> transport represents one of the most important properties required for applications in photovoltaic devices. Whereas the fabrication of efficient hot <span class="hlt">electron</span> capture and lost-cost devices remains a technological challenge, regulating the <span class="hlt">energy</span> level of acceptor-donor system through the incorporation of foreign ions using the solution-processed technique is one of the most promising strategies to overcome this obstacle. Here we present a versatile acceptor-donor system by incorporating MoO3:Eu nanophosphors, which reduces both the 'excess' <span class="hlt">energy</span> offset between the conduction <span class="hlt">band</span> of acceptor and the lowest unoccupied molecular orbital of donor, and that between the valence <span class="hlt">band</span> and highest occupied molecular orbital. Strikingly, the hot <span class="hlt">electron</span> transfer time has been shortened. This work demonstrates that suitable <span class="hlt">energy</span> level alignment can be tuned to gain the higher hot <span class="hlt">electron</span>/hole transport efficiency in a simple approach without the need for complicated architectures. This work builds up the foundation of engineering building blocks for third-generation solar cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21813979','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21813979"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structures of AV(2) (A = Ta, Ti, Hf and Nb) Laves phase compounds.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Charifi, Z; Reshak, Ali Hussain; Baaziz, H</p> <p>2009-01-14</p> <p>First-principles density functional calculations, using the all-<span class="hlt">electron</span> full potential linearized augmented plane wave method, have been performed in order to investigate the structural and <span class="hlt">electronic</span> properties for Laves phase AV(2) (A = Ta, Ti, Hf and Nb) compounds. The generalized gradient approximation and the Engel-Vosko-generalized gradient approximation were used. Our calculations show that these compounds are metallic with more <span class="hlt">bands</span> cutting the Fermi <span class="hlt">energy</span> (E(F)) as we move from Nb to Ta, Hf and Ti, consistent with the increase in the values of the density of states at the Fermi level N(E(F)). N(E(F)) is controlled by the overlapping of V-p/d, A-d and A-p states around the Fermi <span class="hlt">energy</span>. The ground state properties of these compounds, such as equilibrium lattice constant, are calculated and compared with the available literature. There is a strong/weak hybridization between the states, V-s states are strongly hybridized with A-s states below and above E(F). Around the Fermi <span class="hlt">energy</span> we notice that V-p shows strong hybridization with A-p states.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAP...121x4303Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAP...121x4303Y"><span>Conductance modulation in Weyl semimetals with tilted <span class="hlt">energy</span> dispersion without a <span class="hlt">band</span> gap</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yesilyurt, Can; Siu, Zhuo Bin; Tan, Seng Ghee; Liang, Gengchiau; Jalil, Mansoor B. A.</p> <p>2017-06-01</p> <p>We investigate the tunneling conductance of Weyl semimetal with tilted <span class="hlt">energy</span> dispersion by considering <span class="hlt">electron</span> transmission through a p-n-p junction with one-dimensional electric and magnetic barriers. In the presence of both electric and magnetic barriers, we found that a large conductance gap can be produced with the aid of tilted <span class="hlt">energy</span> dispersion without a <span class="hlt">band</span> gap. The origin of this effect is the shift of the <span class="hlt">electron</span> wave-vector at barrier boundaries caused by (i) the pseudo-magnetic field induced by electrical potential, i.e., a newly discovered feature that is only possible in the materials possessing tilted <span class="hlt">energy</span> dispersion, (ii) the real magnetic field induced by a ferromagnetic layer deposited on the top of the system. We use a realistic barrier structure applicable in current nanotechnology and analyze the temperature dependence of the tunneling conductance. The new approach presented here may resolve a major problem of possible transistor applications in topological semimetals, i.e., the absence of normal backscattering and gapless <span class="hlt">band</span> structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4635360','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4635360"><span>Micro-metric <span class="hlt">electronic</span> patterning of a topological <span class="hlt">band</span> structure using a photon beam</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Frantzeskakis, E.; De Jong, N.; Zwartsenberg, B.; Huang, Y. K.; Bay, T. V.; Pronk, P.; Van Heumen, E.; Wu, D.; Pan, Y.; Radovic, M.; Plumb, N. C.; Xu, N.; Shi, M.; De Visser, A.; Golden, M. S.</p> <p>2015-01-01</p> <p>In an ideal 3D topological insulator (TI), the bulk is insulating and the surface conducting due to the existence of metallic states that are localized on the surface; these are the topological surface states. Quaternary Bi-based compounds of Bi2−xSbxTe3−ySey with finely-tuned bulk stoichiometries are good candidates for realizing ideal 3D TI behavior due to their bulk insulating character. However, despite its insulating bulk in transport experiments, the surface region of Bi2−xSbxTe3−ySey crystals cleaved in ultrahigh vacuum also exhibits occupied states originating from the bulk conduction <span class="hlt">band</span>. This is due to adsorbate-induced downward <span class="hlt">band</span>-bending, a phenomenon known from other Bi-based 3D TIs. Here we show, using angle-resolved photoemission, how an EUV light beam of moderate flux can be used to exclude these topologically trivial states from the Fermi level of Bi1.46Sb0.54Te1.7Se1.3 single crystals, thereby re-establishing the purely topological character of the low lying <span class="hlt">electronic</span> states of the system. We furthermore prove that this process is highly local in nature in this bulk-insulating TI, and are thus able to imprint structures in the spatial <span class="hlt">energy</span> landscape at the surface. We illustrate this by ‘writing’ micron-sized letters in the Dirac point <span class="hlt">energy</span> of the system. PMID:26543011</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15885909','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15885909"><span>Valence <span class="hlt">electron</span> <span class="hlt">energy</span>-loss spectroscopy in monochromated scanning transmission <span class="hlt">electron</span> microscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Erni, Rolf; Browning, Nigel D</p> <p>2005-10-01</p> <p>With the development of monochromators for (scanning) transmission <span class="hlt">electron</span> microscopes, valence <span class="hlt">electron</span> <span class="hlt">energy</span>-loss spectroscopy (VEELS) is developing into a unique technique to study the <span class="hlt">band</span> structure and optical properties of nanoscale materials. This article discusses practical aspects of spatially resolved VEELS performed in scanning transmission mode and the alignments necessary to achieve the current optimum performance of approximately 0.15 eV <span class="hlt">energy</span> resolution with an <span class="hlt">electron</span> probe size of approximately 1 nm. In particular, a collection of basic concepts concerning the acquisition process, the optimization of the <span class="hlt">energy</span> resolution, the spatial resolution and the data processing are provided. A brief study of planar defects in a Y(1)Ba(2)Cu(3)O(7-)(delta) high-temperature superconductor illustrates these concepts and shows what kind of information can be accessed by VEELS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987PhDT........14Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987PhDT........14Y"><span>Hot <span class="hlt">Electron</span> <span class="hlt">Energy</span> Relaxation in Quantum Wells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Chia-Hung</p> <p></p> <p>We present experimental results on hot <span class="hlt">electron</span> relaxation in doped bulk GaAs and quantum wells. Using steady state photoluminescence we measured the <span class="hlt">electron</span> -LO phonon scattering time for thermalized hot <span class="hlt">electrons</span> in quantum wells. The results are in good agreement with our theoretical calculation of <span class="hlt">electron</span>-LO phonon interaction in two dimensional systems. Within random phase approximation, the emitted LO phonons may couple to two dimensional plasmons. Both the screening and phonon reabsorption properties can be drastically changed as a function of <span class="hlt">electron</span> density, temperature and phonon lifetime. Theoretical <span class="hlt">energy</span> relaxation rates, including dynamical screening and phonon reabsorption effects, will be presented. For hot <span class="hlt">electrons</span> with <span class="hlt">energies</span> well above the LO phonon <span class="hlt">energy</span>, we developed a two-beam, lock-in technique to measure the <span class="hlt">energy</span>-resolved cooling rate. In the case of quantum wells, hot <span class="hlt">electrons</span> relax at a constant rate. For heavily doped bulk GaAs, the relaxation rate is inversely proportional to <span class="hlt">electron</span> kinetic <span class="hlt">energy</span>. The new method demonstrates itself as a valuable way to study the fast initial relaxation which would otherwise need femtosecond pulse laser techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PhRvL..92i7205S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PhRvL..92i7205S"><span><span class="hlt">Electronic</span> Quasiparticle Renormalization on the Spin Wave <span class="hlt">Energy</span> Scale</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schäfer, J.; Schrupp, D.; Rotenberg, Eli; Rossnagel, K.; Koh, H.; Blaha, P.; Claessen, R.</p> <p>2004-03-01</p> <p>High-resolution photoemission data of the (110) iron surface reveal the existence of well-defined metallic surface resonances in good correspondence to <span class="hlt">band</span> calculations. Close to the Fermi level, their dispersion and momentum broadening display anomalies characteristic of quasiparticle renormalization due to coupling to bosonic excitations. Its <span class="hlt">energy</span> scale exceeds that of phonons by far, and is in striking coincidence with that of the spin wave spectrum in iron. The self-<span class="hlt">energy</span> behavior thus gives spectroscopic evidence of a quasiparticle mass enhancement due to <span class="hlt">electron</span>-magnon coupling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006APS..DPPVO1010H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006APS..DPPVO1010H"><span>Magnetic <span class="hlt">Energy</span> Release from <span class="hlt">Electron</span> Scale Reconnection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Horton, Wendell; Kim, Juhyung; Militello, Fulvio; Ottaviani, Maurizio</p> <p>2006-10-01</p> <p>Magnetic reconnection may occur as bursts of nonlinear plasma dynamics on the <span class="hlt">electron</span> collisionless skin length scale de= c/φpe during which a large fraction of the magnetic <span class="hlt">energy</span> is converted to <span class="hlt">electron</span> thermal <span class="hlt">energy</span> and plasma flow <span class="hlt">energy</span>. The energization mechanism is the crossfield compression of the <span class="hlt">electron</span> gas between interacting magnetic islands and the parallel electric fields accelerating the small pitch angle <span class="hlt">electrons</span>. Solutions of the reduced Hall-MHD equations show the heating pulses in nearly collisionless, <span class="hlt">energy</span> conserving simulations. The <span class="hlt">electron</span> energization appears to be measured in the 4s, 200km resolution data from Cluster crossing thin, multipeaked current sheets in the geotail at -17 RE (JGR, Nakamura et al (2006)). The <span class="hlt">electron</span> PAD and <span class="hlt">energy</span> fluxes change rapidly consistent with the magnetic fluctuations. In short time (10 ion cyclotron periods or 30s) from 0.5-0.8 keV up to 5 keV in ninety degree pitch angle flux and weak parallel <span class="hlt">electron</span> beams formed at small pitch angles. Work partially supported by US Dept of <span class="hlt">Energy</span>, NSF 0539099, and CEA Cadarache.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24108361','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24108361"><span>Hydrogen production by tuning the photonic <span class="hlt">band</span> gap with the <span class="hlt">electronic</span> <span class="hlt">band</span> gap of TiO₂.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Waterhouse, G I N; Wahab, A K; Al-Oufi, M; Jovic, V; Anjum, D H; Sun-Waterhouse, D; Llorca, J; Idriss, H</p> <p>2013-10-10</p> <p>Tuning the photonic <span class="hlt">band</span> gap (PBG) to the <span class="hlt">electronic</span> <span class="hlt">band</span> gap (EBG) of Au/TiO2 catalysts resulted in considerable enhancement of the photocatalytic water splitting to hydrogen under direct sunlight. Au/TiO2 (PBG-357 nm) photocatalyst exhibited superior photocatalytic performance under both UV and sunlight compared to the Au/TiO2 (PBG-585 nm) photocatalyst and both are higher than Au/TiO2 without the 3 dimensionally ordered macro-porous structure materials. The very high photocatalytic activity is attributed to suppression of a fraction of <span class="hlt">electron</span>-hole recombination route due to the co-incidence of the PBG with the EBG of TiO2 These materials that maintain their activity with very small amount of sacrificial agents (down to 0.5 vol.% of ethanol) are poised to find direct applications because of their high activity, low cost of the process, simplicity and stability.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25233436','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25233436"><span>Hydration Effect on Amide I Infrared <span class="hlt">Bands</span> in Water: An Interpretation Based on an Interaction <span class="hlt">Energy</span> Decomposition Scheme.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Farag, Marwa H; Ruiz-López, Manuel F; Bastida, Adolfo; Monard, Gérald; Ingrosso, Francesca</p> <p>2015-07-23</p> <p>The sensitivity of some infrared <span class="hlt">bands</span> to the local environment can be exploited to shed light on the structure and the dynamics of biological systems. In particular, the amide I <span class="hlt">band</span>, which is specifically related to vibrations within the peptide bonds, can give information on the ternary structure of proteins, and can be used as a probe of <span class="hlt">energy</span> transfer. In this work, we propose a model to quantitatively interpret the frequency shift on the amide I <span class="hlt">band</span> of a model peptide induced by the formation of hydrogen bonds in the first solvation shell. This method allows us to analyze to what extent the electrostatic interaction, <span class="hlt">electronic</span> polarization and charge transfer affect the position of the amide I <span class="hlt">band</span>. The impact of the anharmoniticy of the pontential <span class="hlt">energy</span> surface on the hydration induced shift is elucidated as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94p5203G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94p5203G"><span>Pressure dependence of the <span class="hlt">band</span>-gap <span class="hlt">energy</span> in BiTeI</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Güler-Kılıç, Sümeyra; Kılıç, ćetin</p> <p>2016-10-01</p> <p>The evolution of the <span class="hlt">electronic</span> structure of BiTeI, a layered semiconductor with a van der Waals gap, under compression is studied by employing semilocal and dispersion-corrected density-functional calculations. Comparative analysis of the results of these calculations shows that the <span class="hlt">band</span>-gap <span class="hlt">energy</span> of BiTeI decreases till it attains a minimum value of zero at a critical pressure, after which it increases again. The critical pressure corresponding to the closure of the <span class="hlt">band</span> gap is calculated, at which BiTeI becomes a topological insulator. Comparison of the critical pressure to the pressure at which BiTeI undergoes a structural phase transition indicates that the closure of the <span class="hlt">band</span> gap would not be hindered by a structural transformation. Moreover, the <span class="hlt">band</span>-gap pressure coefficients of BiTeI are computed, and an expression of the critical pressure is devised in terms of these coefficients. Our findings indicate that the semilocal and dispersion-corrected approaches are in conflict about the compressibility of BiTeI, which result in overestimation and underestimation, respectively. Nevertheless, the effect of pressure on the atomic structure of BiTeI is found to be manifested primarily as the reduction of the width of the van der Waals gap according to both approaches, which also yield consistent predictions concerning the interlayer metallic bonding in BiTeI under compression. It is consequently shown that the calculated <span class="hlt">band</span>-gap <span class="hlt">energies</span> follow qualitatively and quantitatively the same trend within the two approximations employed here, and the transition to the zero-gap state occurs at the same critical width of the van der Waals gap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.574a2118R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.574a2118R"><span>Ab initio <span class="hlt">electronic</span> <span class="hlt">band</span> structure study of the valence <span class="hlt">bands</span> of II-VI C(2 × 2) reconstructed surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rubio-Ponce, A.; Olguín, D.</p> <p>2015-01-01</p> <p>The structural and <span class="hlt">electronic</span> properties of CdTe(001), CdSe(001), and ZnSe(001) C(2 x 2) reconstructed surfaces have been investigated through the use of first-principles calculations. To simulate the surface, we employed the slab model. Using the experimentally determined lattice parameters as inputs, we relaxed the internal atomic positions of the outer atomic layers. We demonstrate that our model appropriately reproduces both the surface structural parameters and the known <span class="hlt">electronic</span> properties found for these semiconductor compounds in bulk. Finally, we discuss our results of the projected bulk <span class="hlt">bands</span> and the surface and resonance states found for these surfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992PhRvB..46.4899A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992PhRvB..46.4899A"><span>Diffraction of <span class="hlt">electrons</span> at intermediate <span class="hlt">energies</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ascolani, H.; Barrachina, R. O.; Guraya, M. M.; Zampieri, G.</p> <p>1992-08-01</p> <p>We present a theory of the elastic scattering of <span class="hlt">electrons</span> from crystalline surfaces that contains both low-<span class="hlt">energy-electron</span>-diffraction (LEED) effects at low <span class="hlt">energies</span> and x-ray-photoelectron- and Auger-<span class="hlt">electron</span>-diffraction (XPD/AED) effects at intermediate <span class="hlt">energies</span>. The theory is based on a cluster-type approach to the scattering problem and includes temperature effects. The transition from one regime to the other may be explained as follows: At low <span class="hlt">energies</span> all the scattered waves add coherently, and the intensity is dominated by LEED effects. At intermediate <span class="hlt">energies</span> the thermal vibration of the atoms destroys the long-range coherency responsible for the LEED peaks, but affects little the interference of those waves that share parts of their paths inside the solid. Thus, the interference of these waves comes to dominate the intensity, giving rise to structures similar to those observed in XPD/AED experiments. We perform a calculation of the elastic reflection of <span class="hlt">electrons</span> from Cu(001) that is in good agreement with the experiment in the range 200-1500 eV. At low <span class="hlt">energies</span> the intensity is dominated by LEED peaks; at 400 eV LEED peaks and XPD/AED structures coexist; and above this <span class="hlt">energy</span> the intensity is dominated by the latter. We analyze the contributions to the intensity at intermediate <span class="hlt">energies</span> of the interferences in the incoming and outgoing parts of the <span class="hlt">electron</span> path.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=solar+AND+cell&pg=3&id=EJ226424','ERIC'); return false;" href="https://eric.ed.gov/?q=solar+AND+cell&pg=3&id=EJ226424"><span>Applications in <span class="hlt">Energy</span>, Optics and <span class="hlt">Electronics</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Rosenberg, Robert; And Others</p> <p>1980-01-01</p> <p>Discusses the applications of thin films in <span class="hlt">energy</span>, optics and <span class="hlt">electronics</span>. The use of thin-film technologies for heat mirrors, anti-reflection coatings, interference filters, solar cells, and metal contacts is included. (HM)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=thin+AND+film&pg=3&id=EJ226424','ERIC'); return false;" href="http://eric.ed.gov/?q=thin+AND+film&pg=3&id=EJ226424"><span>Applications in <span class="hlt">Energy</span>, Optics and <span class="hlt">Electronics</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Rosenberg, Robert; And Others</p> <p>1980-01-01</p> <p>Discusses the applications of thin films in <span class="hlt">energy</span>, optics and <span class="hlt">electronics</span>. The use of thin-film technologies for heat mirrors, anti-reflection coatings, interference filters, solar cells, and metal contacts is included. (HM)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11015956','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11015956"><span>Formation of <span class="hlt">electron</span> strings in narrow <span class="hlt">band</span> polar semiconductors</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kusmartsev</p> <p>2000-01-17</p> <p>We show that linear <span class="hlt">electron</span> strings may arise in polar semiconductors. A single string consists of M spinless fermions trapped by an extended polarization well of a cigar shape. Inside the string the particles are free although they interact with each other via Coulomb forces. The strings arise as a result of an <span class="hlt">electronic</span> phase separation associated with an instability of small adiabatic polarons. We have found the length of the string which depends on dielectric constants of semiconductors. The appearance of these <span class="hlt">electron</span> strings may have an impact on the effect of stripe formation observed in a variety of high- T(c) experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=%22light-emitting+diode%22+OR+lighting&pg=3&id=EJ829407','ERIC'); return false;" href="https://eric.ed.gov/?q=%22light-emitting+diode%22+OR+lighting&pg=3&id=EJ829407"><span>Simple Experimental Verification of the Relation between the <span class="hlt">Band</span>-Gap <span class="hlt">Energy</span> and the <span class="hlt">Energy</span> of Photons Emitted by LEDs</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Precker, Jurgen W.</p> <p>2007-01-01</p> <p>The wavelength of the light emitted by a light-emitting diode (LED) is intimately related to the <span class="hlt">band</span>-gap <span class="hlt">energy</span> of the semiconductor from which the LED is made. We experimentally estimate the <span class="hlt">band</span>-gap <span class="hlt">energies</span> of several types of LEDs, and compare them with the <span class="hlt">energies</span> of the emitted light, which ranges from infrared to white. In spite of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=%22light-emitting+diode%22+OR+lighting&pg=3&id=EJ829407','ERIC'); return false;" href="http://eric.ed.gov/?q=%22light-emitting+diode%22+OR+lighting&pg=3&id=EJ829407"><span>Simple Experimental Verification of the Relation between the <span class="hlt">Band</span>-Gap <span class="hlt">Energy</span> and the <span class="hlt">Energy</span> of Photons Emitted by LEDs</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Precker, Jurgen W.</p> <p>2007-01-01</p> <p>The wavelength of the light emitted by a light-emitting diode (LED) is intimately related to the <span class="hlt">band</span>-gap <span class="hlt">energy</span> of the semiconductor from which the LED is made. We experimentally estimate the <span class="hlt">band</span>-gap <span class="hlt">energies</span> of several types of LEDs, and compare them with the <span class="hlt">energies</span> of the emitted light, which ranges from infrared to white. In spite of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JAP...114s4501J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JAP...114s4501J"><span>Feasibility study of <span class="hlt">electron</span> transfer quantum well infrared photodetectors for spectral tuning in the long-wave infrared <span class="hlt">band</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jolley, Greg; Dehdashti Akhavan, Nima; Umana-Membreno, Gilberto; Antoszewski, Jarek; Faraone, Lorenzo</p> <p>2013-11-01</p> <p>An <span class="hlt">electron</span> transfer quantum well infrared photodetector (QWIP) consisting of repeating units of two coupled quantum wells (QWs) is capable of exhibiting a two color voltage dependent spectral response. However, significant <span class="hlt">electron</span> transfer between the coupled QWs is required for spectral tuning, which may require the application of relatively high electric fields. Also, the <span class="hlt">band</span> structure of coupled quantum wells is more complicated in comparison to a regular quantum well and, therefore, it is not always obvious if an <span class="hlt">electron</span> transfer QWIP can be designed such that it meets specific performance characteristics. This paper presents a feasibility study of the <span class="hlt">electron</span> transfer QWIP and its suitability for spectral tuning. Self consistent calculations have been performed of the bandstructure and the electric field that results from <span class="hlt">electron</span> population within the quantum wells, from which the optical characteristics have been obtained. The <span class="hlt">band</span> structure, spectral response, and the resonant final state <span class="hlt">energy</span> locations have been compared with standard QWIPs. It is shown that spectral tuning in the long-wave infrared <span class="hlt">band</span> can be achieved over a wide wavelength range of several microns while maintaining a relatively narrow spectral response FWHM. However, the total absorption strength is more limited in comparison to a standard QWIP, since the higher QW doping densities require much higher electric fields for <span class="hlt">electron</span> transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22258790','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22258790"><span>Feasibility study of <span class="hlt">electron</span> transfer quantum well infrared photodetectors for spectral tuning in the long-wave infrared <span class="hlt">band</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jolley, Greg; Dehdashti Akhavan, Nima; Umana-Membreno, Gilberto; Antoszewski, Jarek; Faraone, Lorenzo</p> <p>2013-11-21</p> <p>An <span class="hlt">electron</span> transfer quantum well infrared photodetector (QWIP) consisting of repeating units of two coupled quantum wells (QWs) is capable of exhibiting a two color voltage dependent spectral response. However, significant <span class="hlt">electron</span> transfer between the coupled QWs is required for spectral tuning, which may require the application of relatively high electric fields. Also, the <span class="hlt">band</span> structure of coupled quantum wells is more complicated in comparison to a regular quantum well and, therefore, it is not always obvious if an <span class="hlt">electron</span> transfer QWIP can be designed such that it meets specific performance characteristics. This paper presents a feasibility study of the <span class="hlt">electron</span> transfer QWIP and its suitability for spectral tuning. Self consistent calculations have been performed of the bandstructure and the electric field that results from <span class="hlt">electron</span> population within the quantum wells, from which the optical characteristics have been obtained. The <span class="hlt">band</span> structure, spectral response, and the resonant final state <span class="hlt">energy</span> locations have been compared with standard QWIPs. It is shown that spectral tuning in the long-wave infrared <span class="hlt">band</span> can be achieved over a wide wavelength range of several microns while maintaining a relatively narrow spectral response FWHM. However, the total absorption strength is more limited in comparison to a standard QWIP, since the higher QW doping densities require much higher electric fields for <span class="hlt">electron</span> transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6676644','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6676644"><span>Atomic <span class="hlt">electron</span> binding <span class="hlt">energies</span> in fermium</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Das, M.P.</p> <p>1981-02-01</p> <p>Calculations of the binding <span class="hlt">energies</span> of <span class="hlt">electrons</span> in fermium by using a relativistic local-density functional theory are reported. It is found that relaxation effects are nonnegligible for inner core orbitals. Calculated orbital binding <span class="hlt">energies</span> are compared with those due to nonlocal Dirac-Fock calculations and also with those determined experimentally from conversion <span class="hlt">electron</span> spectroscopy. Finally the usefulness of the local-density approximation for the study of heavy atomic and condensed systems is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22668077','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22668077"><span>Microdosimetry of low-<span class="hlt">energy</span> <span class="hlt">electrons</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liamsuwan, Thiansin; Emfietzoglou, Dimitris; Uehara, Shuzo; Nikjoo, Hooshang</p> <p>2012-12-01</p> <p>To investigate differences in <span class="hlt">energy</span> depositions and microdosimetric parameters of low-<span class="hlt">energy</span> <span class="hlt">electrons</span> in liquid and gaseous water using Monte Carlo track structure simulations. KURBUC-liq (Kyushu University and Radiobiology Unit Code for liquid water) was used for simulating <span class="hlt">electron</span> tracks in liquid water. The inelastic scattering cross sections of liquid water were obtained from the dielectric response model of Emfietzoglou et al. (Radiation Research 2005;164:202-211). Frequencies of <span class="hlt">energy</span> deposited in nanometre-size cylindrical targets per unit absorbed dose and associated lineal <span class="hlt">energies</span> were calculated for 100-5000 eV monoenergetic <span class="hlt">electrons</span> and the <span class="hlt">electron</span> spectrum of carbon K edge X-rays. The results for liquid water were compared with those for water vapour. Regardless of <span class="hlt">electron</span> <span class="hlt">energy</span>, there is a limit how much <span class="hlt">energy</span> <span class="hlt">electron</span> tracks can deposit in a target. Phase effects on the frequencies of <span class="hlt">energy</span> depositions are largely visible for the targets with diameters and heights smaller than 30 nm. For the target of 2.3 nm by 2.3 nm (similar to dimension of DNA segments), the calculated frequency- and dose-mean lineal <span class="hlt">energies</span> for liquid water are up to 40% smaller than those for water vapour. The corresponding difference is less than 12% for the targets with diameters ≥ 30 nm. Condensed-phase effects are non-negligible for microdosimetry of low-<span class="hlt">energy</span> <span class="hlt">electrons</span> for targets with sizes smaller than a few tens of nanometres, similar to dimensions of DNA molecular structures and nucleosomes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6360474','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6360474"><span><span class="hlt">Electron</span> <span class="hlt">energy</span>-distribution functions in gases</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pitchford, L.C.</p> <p>1981-01-01</p> <p>Numerical calculation of the <span class="hlt">electron</span> <span class="hlt">energy</span> distribution functions in the regime of drift tube experiments is discussed. The discussion is limited to constant applied fields and values of E/N (ratio of electric field strength to neutral density) low enough that <span class="hlt">electron</span> growth due to ionization can be neglected. (GHT)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JInst..12P3020S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JInst..12P3020S"><span>Observation of <span class="hlt">electron</span> excitation into silicon conduction <span class="hlt">band</span> by slow-ion surface neutralization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shchemelinin, S.; Breskin, A.</p> <p>2017-03-01</p> <p>Bare reverse biased silicon photodiodes were exposed to 3 eV He+, Ne+, Ar+, N2+, N+ and H2O+ ions. In all cases an increase of the reverse current through the diode was observed. This effect and its dependence on the ionization <span class="hlt">energy</span> of the incident ions and on other factors are qualitatively explained in the framework of Auger-type surface neutralization theory. Amplification of the ion-induced charge was observed with an avalanche photodiode under high applied bias. The observed effect can be considered as ion-induced internal potential <span class="hlt">electron</span> emission into the conduction <span class="hlt">band</span> of silicon. To the best of our knowledge, no experimental evidence of such effect was previously reported. Possible applications are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001JChPh.115.4292X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001JChPh.115.4292X"><span>Charge transfer and ``<span class="hlt">band</span> lineup'' in molecular <span class="hlt">electronic</span> devices: A chemical and numerical interpretation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xue, Yongqiang; Datta, Supriyo; Ratner, Mark A.</p> <p>2001-09-01</p> <p>We present first-principles based calculation of charge transfer and "<span class="hlt">band</span> lineup" in molecular <span class="hlt">electronic</span> devices using as an example the device formed by a phenyldithiolate molecule bridging two gold electrodes and local-spin-density-functional theory with a Gaussian-type orbital basis. We show that significant charge transfer from the metal to the molecule occurs, reflecting the partially ionic character of the sulfur-gold bond and localized in the interfacial region. Such charge transfer increases the electrostatic potential in the molecule which changes the molecular <span class="hlt">energy</span> level structures. The interaction between the molecular orbitals under the self-consistent potential and the surface metal states determines the lineup of molecular levels relative to the metal Fermi level. We also discuss the implications of our work on device engineering at the molecular scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/136076','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/136076"><span>Conformational statistics of molecules with inner rotation and shapes of their <span class="hlt">electronic</span> absorption <span class="hlt">bands</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Aver`yanov, E.M.</p> <p>1994-10-01</p> <p>The effect of conformational statistics of molecules with inner rotation of {pi}-conjugated fragments on the position, intensity, and <span class="hlt">electronic</span> absorption <span class="hlt">band</span> shapes is studied in isotropic molecular media. It is shown that the conformational disorder of molecules with one inner rotation degree of freedom exerts an appreciable effect on the shift, inhomogeneous broadening, and asymmetry of the <span class="hlt">electronic</span> absorption <span class="hlt">bands</span>. An interpretation of the available experimental data is give. 19 refs., 1 fig.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPCM...28t5701S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPCM...28t5701S"><span>Physical properties and <span class="hlt">electronic</span> <span class="hlt">band</span> structure of noncentrosymmetric Th7Co3 superconductor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sahakyan, M.; Tran, V. H.</p> <p>2016-05-01</p> <p>The physical properties of the noncentrosymmetric superconductor Th7Co3 have been investigated by means of ac-magnetic susceptibility, magnetization, specific heat, electrical resistivity, magnetoresistance and Hall effect measurements. From these data it is established that Th7Co3 is a dirty type-II superconductor with {{T}\\text{c}}=1.8+/- 0.02 K, Hc2\\text{orb}<{{H}c2}(0)˜ 10~\\text{kOe}c2p and moderate <span class="hlt">electron</span>-phonon coupling {λ\\text{el-\\text{ph}}}=0.56 . Some evidences for anisotropic superconducting gap are found, including e.g. reduced specific heat jump (Δ {{C}p}/γ {{T}\\text{c}}=1.01 ) at T c, diminished superconducting <span class="hlt">energy</span> gap ({{Δ }0}/{{k}\\text{B}}{{T}\\text{c}}=2.17 ) as compared to the BCS values, power law field dependence of the Sommerfeld coefficient at 0.4 K ({{C}p}/T\\propto {{H}0.6} ), and a concave curvature of the {{H}c2}≤ft({{T}\\text{c}}\\right) line. The magnitudes of the thermodynamic critical field and the <span class="hlt">energy</span> gap are consistent with mean-squared anisotropy parameter < {{a}2}> ˜ 0.23 . The <span class="hlt">electronic</span> specific heat in the superconducting state is reasonably fitted to an oblate spheroidal gap model. Calculations of scalar relativistic and fully relativistic <span class="hlt">electronic</span> <span class="hlt">band</span> structures reveal considerable differences in the degenerate structure, resulting from asymmetric spin-orbit coupling (ASOC). A large splitting <span class="hlt">energy</span> of spin-up spin-down <span class="hlt">bands</span> at the Fermi level E F, Δ {{E}\\text{ASOC}}˜ 100 meV is observed and a sizeable ratio Δ {{E}\\text{ASOC}}/{{k}\\text{B}}{{T}\\text{c}}˜ 640 could classify the studied compound into the class of noncentrosymmetric superconductors with strong ASOC. The noncentrosymmetry of the crystal structure and the atomic relativistic effects are both responsible for an importance of ASOC in Th7Co3. The calculated results for the density of states show a Van Hove singularity just below E F and dominant role of the 6d <span class="hlt">electrons</span> of Th to the superconductivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94g5310T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94g5310T"><span><span class="hlt">Band</span> offset formation at semiconductor heterojunctions through density-based minimization of interface <span class="hlt">energy</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tung, Raymond T.; Kronik, Leeor</p> <p>2016-08-01</p> <p>It is well known that the magnitude of <span class="hlt">band</span> offset (BO) at any semiconductor heterojunction is directly derivable from the distribution of charge at that interface and that the latter is decided by a minimization of total <span class="hlt">energy</span>. However, the fact that BO formation is governed by <span class="hlt">energy</span> minimization has not been explicitly used in theoretical BO models, likely because the equilibrium charge densities at heterojunction interfaces appear difficult to predict, except via explicit calculation. In this paper, <span class="hlt">electron</span> densities at a large number of (100), (110), and (111) oriented heterojunctions between lattice-matched, isovalent semiconductors with the zinc blende (ZB) structure have been calculated by first-principles methods and analyzed in detail for possible common characteristics among <span class="hlt">energy</span>-minimized densities. Remarkably, the heterojunction <span class="hlt">electron</span> density was found to largely depend only on the immediate, local atomic arrangement. In fact, it is so much so that a juxtaposition of local <span class="hlt">electron</span>-densities generated in oligo-cells (LEGOs) accurately reproduced the charge densities that minimize the <span class="hlt">energy</span> for the heterojunctions. Furthermore, the charge distribution for each bulk semiconductor was found to display a striking separability of its electrostatic effect into two neutral parts, associated with the cation and the anion, which are approximately transferrable among semiconductors. These discoveries form the basis of a neutral polyhedra theory (NPT) that approximately predicts the equilibrium charge density and BO of relaxed heterojunctions from the <span class="hlt">energy</span> minimization requirement. Well-known experimentally observed characteristics of heterojunctions, such as the insensitivity of BO to heterojunction orientation and the identity of interface bonds, the transitivity rule, etc., are all in good agreement with the NPT. Therefore, <span class="hlt">energy</span> minimization, which essentially decides the <span class="hlt">electronic</span> properties of all other solid and molecular systems, also governs</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27157509','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27157509"><span>Control of valence and conduction <span class="hlt">band</span> <span class="hlt">energies</span> in layered transition metal phosphates via surface functionalization.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lentz, Levi C; Kolb, Brian; Kolpak, Alexie M</p> <p>2016-05-18</p> <p>Layered transition metal phosphates and phosphites (TMPs) are a class of materials composed of layers of 2D sheets bound together via van der Waals interactions and/or hydrogen bonds. Explored primarily for use in proton transfer, their unique chemical tunability also makes TMPs of interest for forming large-scale hybrid materials. Further, unlike many layered materials, TMPs can readily be solution exfoliated to form single 2D sheets or bilayers, making them exciting candidates for a variety of applications. However, the <span class="hlt">electronic</span> properties of TMPs have largely been unstudied to date. In this work, we use first-principles computations to investigate the atomic and <span class="hlt">electronic</span> structure of TMPs with a variety of stoichiometries. We demonstrate that there exists a strong linear relationship between the <span class="hlt">band</span> gap and the ionic radius of the transition metal cation in these materials, and show that this relationship, which opens opportunities for engineering new compositions with a wide range of <span class="hlt">band</span> gaps, arises from constraints imposed by the phosphorus-oxygen bond geometry. In addition, we find that the <span class="hlt">energies</span> of the valence and conduction <span class="hlt">band</span> edges can be systematically tuned over a range of ∼3 eV via modification of the functional group extending from the phosphorus. Based on the Hammett constant of this functional group, we identify a simple, predictive relationship for the ionization potential and <span class="hlt">electron</span> affinity of layered TMPs. Our results thus provide guidelines for systematic design of TMP-derived functional materials, which may enable new approaches for optimizing charge transfer in <span class="hlt">electronics</span>, photovoltaics, electrocatalysts, and other applications.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED210511.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED210511.pdf"><span><span class="hlt">Electronic</span> Devices and Systems. <span class="hlt">Energy</span> Technology Series.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Technical Education Research Centre-Southwest, Waco, TX.</p> <p></p> <p>This course in <span class="hlt">electronic</span> devices and systems is one of 16 courses in the <span class="hlt">Energy</span> Technology Series developed for an <span class="hlt">Energy</span> Conservation-and-Use Technology curriculum. Intended for use in two-year postsecondary technical institutions to prepare technicians for employment, the courses are also useful in industry for updating employees in…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23431560','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23431560"><span>Transient mid-IR study of <span class="hlt">electron</span> dynamics in TiO2 conduction <span class="hlt">band</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sá, Jacinto; Friedli, Peter; Geiger, Richard; Lerch, Philippe; Rittmann-Frank, Mercedes H; Milne, Christopher J; Szlachetko, Jakub; Santomauro, Fabio G; van Bokhoven, Jeroen A; Chergui, Majed; Rossi, Michel J; Sigg, Hans</p> <p>2013-04-07</p> <p>The dynamics of TiO2 conduction <span class="hlt">band</span> <span class="hlt">electrons</span> were followed with a novel broadband synchrotron-based transient mid-IR spectroscopy setup. The lifetime of conduction <span class="hlt">band</span> <span class="hlt">electrons</span> was found to be dependent on the injection method used. Direct <span class="hlt">band</span> gap excitation results in a lifetime of 2.5 ns, whereas indirect excitation at 532 nm via Ru-N719 dye followed by injection from the dye into TiO2 results in a lifetime of 5.9 ns.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26226296','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26226296"><span>Esaki Diodes in van der Waals Heterojunctions with Broken-Gap <span class="hlt">Energy</span> <span class="hlt">Band</span> Alignment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yan, Rusen; Fathipour, Sara; Han, Yimo; Song, Bo; Xiao, Shudong; Li, Mingda; Ma, Nan; Protasenko, Vladimir; Muller, David A; Jena, Debdeep; Xing, Huili Grace</p> <p>2015-09-09</p> <p>van der Waals (vdW) heterojunctions composed of two-dimensional (2D) layered materials are emerging as a solid-state materials family that exhibits novel physics phenomena that can power a range of <span class="hlt">electronic</span> and photonic applications. Here, we present the first demonstration of an important building block in vdW solids: room temperature Esaki tunnel diodes. The Esaki diodes were realized in vdW heterostructures made of black phosphorus (BP) and tin diselenide (SnSe2), two layered semiconductors that possess a broken-gap <span class="hlt">energy</span> <span class="hlt">band</span> offset. The presence of a thin insulating barrier between BP and SnSe2 enabled the observation of a prominent negative differential resistance (NDR) region in the forward-bias current-voltage characteristics, with a peak to valley ratio of 1.8 at 300 K and 2.8 at 80 K. A weak temperature dependence of the NDR indicates <span class="hlt">electron</span> tunneling being the dominant transport mechanism, and a theoretical model shows excellent agreement with the experimental results. Furthermore, the broken-gap <span class="hlt">band</span> alignment is confirmed by the junction photoresponse, and the phosphorus double planes in a single layer of BP are resolved in transmission <span class="hlt">electron</span> microscopy (TEM) for the first time. Our results represent a significant advance in the fundamental understanding of vdW heterojunctions and broaden the potential applications of 2D layered materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..96h5205B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..96h5205B"><span>Narrow-<span class="hlt">band</span> anisotropic <span class="hlt">electronic</span> structure of ReS2</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Biswas, D.; Ganose, Alex M.; Yano, R.; Riley, J. M.; Bawden, L.; Clark, O. J.; Feng, J.; Collins-Mcintyre, L.; Sajjad, M. T.; Meevasana, W.; Kim, T. K.; Hoesch, M.; Rault, J. E.; Sasagawa, T.; Scanlon, David O.; King, P. D. C.</p> <p>2017-08-01</p> <p>We have used angle-resolved photoemission spectroscopy to investigate the <span class="hlt">band</span> structure of ReS2, a transition-metal dichalcogenide semiconductor with a distorted 1T crystal structure. We find a large number of narrow valence <span class="hlt">bands</span>, which we attribute to the combined influence of structural distortion and spin-orbit coupling. We further show how this leads to a strong in-plane anisotropy of the <span class="hlt">electronic</span> structure, with quasi-one-dimensional <span class="hlt">bands</span> reflecting predominant hopping along zigzag Re chains. We find that this does not persist up to the top of the valence <span class="hlt">band</span>, where a more three-dimensional character is recovered with the fundamental <span class="hlt">band</span> gap located away from the Brillouin zone center along kz. These experiments are in good agreement with our density-functional theory calculations, shedding light on the bulk <span class="hlt">electronic</span> structure of ReS2, and how it can be expected to evolve when thinned to a single layer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020024134&hterms=CERN&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCERN','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020024134&hterms=CERN&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCERN"><span>High <span class="hlt">Energy</span> <span class="hlt">Electron</span> Detection with ATIC</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chang, J.; Schmidt, W. K. H.; Adams, James H., Jr.; Ahn, H.; Ampe, J.; Whitaker, Ann F. (Technical Monitor)</p> <p>2001-01-01</p> <p>The ATIC (Advanced Thin Ionization Calorimeter) balloon-borne ionization calorimeter is well suited to record and identify high <span class="hlt">energy</span> cosmic ray <span class="hlt">electrons</span>. The instrument was exposed to high-<span class="hlt">energy</span> beams at CERN H2 bean-dine in September of 1999. We have simulated the performance of the instrument, and compare the simulations with actual high <span class="hlt">energy</span> <span class="hlt">electron</span> exposures at the CERN accelerator. Simulations and measurements do not compare exactly, in detail, but overall the simulations have predicted actual measured behavior quite well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..96k5301K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..96k5301K"><span><span class="hlt">Electronic</span> structure of the surface unoccupied <span class="hlt">band</span> of Ge(001)-c (4 ×2 ) : Direct imaging of surface <span class="hlt">electron</span> relaxation pathways</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kanasaki, J.; Yamamoto, I.; Azuma, J.; Fukatsu, S.</p> <p>2017-09-01</p> <p>We have studied the <span class="hlt">electronic</span> structure of the surface unoccupied <span class="hlt">band</span> (SUB) of clean Ge(001)-c (4 ×2 ) , with high <span class="hlt">energy</span> and momentum resolution, by means of time- and angle-resolved two-photon photoelectron spectroscopy. The time evolution of photoelectron intensity images, measured as functions of <span class="hlt">energy</span> and emission angle after photoexcitation with laser pulses (1.5 eV, 200 fs), provides a momentum space view of the relaxation pathways of surface excited <span class="hlt">electrons</span> toward the bottom of the SUB. Surface excited <span class="hlt">electrons</span> relax in several picoseconds along the strongly dispersive directions (Γ ¯J'¯ and Γ ¯J2 '¯ ) and then accumulate near the <span class="hlt">band</span> bottom. Taking into account the ultrafast change of surface potential, possibly due to the spatial redistribution of nonthermal carriers generated by photoexcitation, an <span class="hlt">energy</span> width of 0.22 eV was determined as the surface <span class="hlt">band</span> gap, as well as the surface dispersion properties along three high-symmetry directions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16575550','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16575550"><span>Theory of directed <span class="hlt">electronic</span> <span class="hlt">energy</span> transfer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Andrews, David L; Crisp, Richard G</p> <p>2006-03-01</p> <p>The migration of <span class="hlt">electronic</span> <span class="hlt">energy</span> between molecules or chromophores in molecular solids is a well-studied phenomenon. The ability to exert control over the directionality of this transfer, by a variety of methods involving applied electrical or optical fields, holds promise for advances in fields including nanoelectronics and <span class="hlt">energy</span> harvesting materials. In this paper, we review in detail a number of methods for directing <span class="hlt">energy</span> transfer, also identifying potential applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SurSc.664..241B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SurSc.664..241B"><span><span class="hlt">Electron</span> <span class="hlt">band</span> bending and surface sensitivity: X-ray photoelectron spectroscopy of polar GaN surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bartoš, I.; Romanyuk, O.; Paskova, T.; Jiříček, P.</p> <p>2017-10-01</p> <p>The role of <span class="hlt">electron</span> <span class="hlt">band</span> bending and surface sensitivity in determining the core level binding <span class="hlt">energies</span> by X-ray photoelectron spectroscopy is investigated. A dominating contribution of surface atomic layers to photoemission intensity is confirmed for normal photoemission. The <span class="hlt">energy</span> of the photoelectron core level peak does not deviate from core level peak <span class="hlt">energies</span> of <span class="hlt">electrons</span> photoemitted from the surface atomic layers of the crystal. The higher surface sensitivity regime, achieved e.g. at off-normal photoelectron detection angle, can be used to study the surface potential barrier in just a few topmost atomic layers. In addition, it is demonstrated that core level binding <span class="hlt">energy</span> measured by angle-resolved X-ray photoelectron spectroscopy reflect the <span class="hlt">electron</span> attenuation anisotropy. In particular, core level binding <span class="hlt">energy</span> changes with emission angle and correlates with the forward focusing directions in a crystal. This effect is demonstrated by measuring the polar angle dependence of Ga 3d core levels on clean GaN(0001) and GaN(000 1 bar) surfaces with a higher and a lower <span class="hlt">band</span> bending, respectively. The effect is explained by variation of emission depth in a crystal for normal and off-normal photoelectron emission angles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017OptMa..66..149L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017OptMa..66..149L"><span><span class="hlt">Electronic</span> structure and optical properties of noncentrosymmetric LiGaSe2: Experimental measurements and DFT <span class="hlt">band</span> structure calculations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lavrentyev, A. A.; Gabrelian, B. V.; Vu, V. T.; Ananchenko, L. N.; Isaenko, L. I.; Yelisseyev, A. P.; Khyzhun, O. Y.</p> <p>2017-04-01</p> <p>We report on measurements of X-ray photoelectron (XP) spectra for pristine and Ar+ ion-irradiated surfaces of LiGaSe2 single crystal grown by Bridgman-Stockbarger method. <span class="hlt">Electronic</span> structure of the LiGaSe2 compound is studied from a theoretical and experimental viewpoint. In particular, total and partial densities of states of LiGaSe2 are investigated by density functional theory (DFT) calculations employing the augmented plane wave + local orbitals (APW + lo) method and they are verified by data of X-ray spectroscopy measurements. The DFT calculations indicate that the main contributors to the valence <span class="hlt">band</span> of LiGaSe2 are the Se 4p states, which contribute mainly at the top and in the upper portion of the valence <span class="hlt">band</span>, with also essential contributions of these states in the lower portion of the <span class="hlt">band</span>. Other substantial contributions to the valence <span class="hlt">band</span> of LiGaSe2 emerge from the Ga 4s and Ga 4p states contributing mainly at the lower ant upper portions of the valence <span class="hlt">band</span>, respectively. With respect to the conduction <span class="hlt">band</span>, the calculations indicate that its bottom is composed mainly from contributions of the unoccupied Ga s and Se p states. The present calculations are confirmed experimentally when comparing the XP valence-<span class="hlt">band</span> spectrum of the LiGaS2 single crystal on a common <span class="hlt">energy</span> scale with the X-ray emission <span class="hlt">bands</span> representing the <span class="hlt">energy</span> distribution of the Ga 4p and Se 4p states. Measurements of the fundamental absorption edges at room temperature reveal that bandgap value, Eg, of LiGaSe2 is equal to 3.47 eV and the Eg value increases up to 3.66 eV when decreasing temperature to 80 K. The main optical characteristics of the LiGaSe2 compound are clarified by the DFT calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26651872','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26651872"><span><span class="hlt">Band</span> Gap Engineering in a 2D Material for Solar-to-Chemical <span class="hlt">Energy</span> Conversion.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hu, Jun; Guo, Zhenkun; Mcwilliams, Peter E; Darges, John E; Druffel, Daniel L; Moran, Andrew M; Warren, Scott C</p> <p>2016-01-13</p> <p>The <span class="hlt">electronic</span> structure of 2D semiconductors depends on their thickness, providing new opportunities to engineer semiconductors for <span class="hlt">energy</span> conversion, <span class="hlt">electronics</span>, and catalysis. Here we show how a 3D semiconductor, black phosphorus, becomes active for solar-to-chemical <span class="hlt">energy</span> conversion when it is thinned to a 2D material. The increase in its <span class="hlt">band</span> gap, from 0.3 eV (3D) to 2.1 eV (2D monolayer), is accompanied by a 40-fold enhancement in the formation of chemical products. Despite this enhancement, smaller flakes also have shorter excited state lifetimes. We deduce a mechanism in which recombination occurs at flake edges, while the "van der Waals" surface of black phosphorus bonds to chemical intermediates and facilitates <span class="hlt">electron</span> transfer. The unique properties of black phosphorus highlight its potential as a customizable material for solar <span class="hlt">energy</span> conversion and catalysis, while also allowing us to identify design rules for 2D photocatalysts that will enable further improvements in these materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22493431','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22493431"><span>Vibrational renormalisation of the <span class="hlt">electronic</span> <span class="hlt">band</span> gap in hexagonal and cubic ice</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Engel, Edgar A. Needs, Richard J.; Monserrat, Bartomeu</p> <p>2015-12-28</p> <p><span class="hlt">Electron</span>-phonon coupling in hexagonal and cubic water ice is studied using first-principles quantum mechanical methods. We consider 29 distinct hexagonal and cubic ice proton-orderings with up to 192 molecules in the simulation cell to account for proton-disorder. We find quantum zero-point vibrational corrections to the minimum <span class="hlt">electronic</span> <span class="hlt">band</span> gaps ranging from −1.5 to −1.7 eV, which leads to improved agreement between calculated and experimental <span class="hlt">band</span> gaps. Anharmonic nuclear vibrations play a negligible role in determining the gaps. Deuterated ice has a smaller <span class="hlt">band</span>-gap correction at zero-temperature of −1.2 to −1.4 eV. Vibrations reduce the differences between the <span class="hlt">electronic</span> <span class="hlt">band</span> gaps of different proton-orderings from around 0.17 eV to less than 0.05 eV, so that the <span class="hlt">electronic</span> <span class="hlt">band</span> gaps of hexagonal and cubic ice are almost independent of the proton-ordering when quantum nuclear vibrations are taken into account. The comparatively small reduction in the <span class="hlt">band</span> gap over the temperature range 0 − 240 K of around 0.1 eV does not depend on the proton ordering, or whether the ice is protiated or deuterated, or hexagonal, or cubic. We explain this in terms of the atomistic origin of the strong <span class="hlt">electron</span>-phonon coupling in ice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JChPh.143x4708E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JChPh.143x4708E"><span>Vibrational renormalisation of the <span class="hlt">electronic</span> <span class="hlt">band</span> gap in hexagonal and cubic ice</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Engel, Edgar A.; Monserrat, Bartomeu; Needs, Richard J.</p> <p>2015-12-01</p> <p><span class="hlt">Electron</span>-phonon coupling in hexagonal and cubic water ice is studied using first-principles quantum mechanical methods. We consider 29 distinct hexagonal and cubic ice proton-orderings with up to 192 molecules in the simulation cell to account for proton-disorder. We find quantum zero-point vibrational corrections to the minimum <span class="hlt">electronic</span> <span class="hlt">band</span> gaps ranging from -1.5 to -1.7 eV, which leads to improved agreement between calculated and experimental <span class="hlt">band</span> gaps. Anharmonic nuclear vibrations play a negligible role in determining the gaps. Deuterated ice has a smaller <span class="hlt">band</span>-gap correction at zero-temperature of -1.2 to -1.4 eV. Vibrations reduce the differences between the <span class="hlt">electronic</span> <span class="hlt">band</span> gaps of different proton-orderings from around 0.17 eV to less than 0.05 eV, so that the <span class="hlt">electronic</span> <span class="hlt">band</span> gaps of hexagonal and cubic ice are almost independent of the proton-ordering when quantum nuclear vibrations are taken into account. The comparatively small reduction in the <span class="hlt">band</span> gap over the temperature range 0 - 240 K of around 0.1 eV does not depend on the proton ordering, or whether the ice is protiated or deuterated, or hexagonal, or cubic. We explain this in terms of the atomistic origin of the strong <span class="hlt">electron</span>-phonon coupling in ice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27189431','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27189431"><span>Correlating structure and <span class="hlt">electronic</span> <span class="hlt">band</span>-edge properties in organolead halide perovskites nanoparticles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhu, Qiushi; Zheng, Kaibo; Abdellah, Mohamed; Generalov, Alexander; Haase, Dörthe; Carlson, Stefan; Niu, Yuran; Heimdal, Jimmy; Engdahl, Anders; Messing, Maria E; Pullerits, Tonu; Canton, Sophie E</p> <p>2016-06-01</p> <p>After having emerged as primary contenders in the race for highly efficient optoelectronics materials, organolead halide perovskites (OHLP) are now being investigated in the nanoscale regime as promising building blocks with unique properties. For example, unlike their bulk counterpart, quantum dots of OHLP are brightly luminescent, owing to large exciton binding <span class="hlt">energies</span> that cannot be rationalized solely on the basis of quantum confinement. Here, we establish the direct correlation between the structure and the <span class="hlt">electronic</span> <span class="hlt">band</span>-edge properties of CH3NH3PbBr3 nanoparticles. Complementary structural and spectroscopic measurements probing long-range and local order reveal that lattice strain influences the nature of the valence <span class="hlt">band</span> and modifies the subtle stereochemical activity of the Pb(2+) lone-pair. More generally, this work demonstrates that the stereochemical activity of the lone-pair at the metal site is a specific physicochemical parameter coupled to composition, size and strain, which can be employed to engineer novel functionalities in OHLP nanomaterials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19525066','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19525066"><span>Mapping of valence <span class="hlt">energy</span> losses via <span class="hlt">energy</span>-filtered annular dark-field scanning transmission <span class="hlt">electron</span> microscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gu, Lin; Sigle, Wilfried; Koch, Christoph T; Nelayah, Jaysen; Srot, Vesna; van Aken, Peter A</p> <p>2009-08-01</p> <p>The advent of <span class="hlt">electron</span> monochromators has opened new perspectives on <span class="hlt">electron</span> <span class="hlt">energy</span>-loss spectroscopy at low <span class="hlt">energy</span> losses, including phenomena such as surface plasmon resonances or <span class="hlt">electron</span> transitions from the valence to the conduction <span class="hlt">band</span>. In this paper, we report first results making use of the combination of an <span class="hlt">energy</span> filter and a post-filter annular dark-field detector. This instrumental design allows us to obtain <span class="hlt">energy</span>-filtered (i.e. inelastic) annular dark-field images in scanning transmission <span class="hlt">electron</span> microscopy of the 2-dimensional semiconductor <span class="hlt">band</span>-gap distribution of a GaN/Al(45)Ga(55)N structure and of surface plasmon resonances of silver nanoprisms. In comparison to other approaches, the technique is less prone to inelastic delocalization and relativistic artefacts. The mixed contribution of elastic and inelastic contrast is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985JGR....90.6587S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985JGR....90.6587S"><span>Optimization of energetic <span class="hlt">electron</span> <span class="hlt">energy</span> degradation calculations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Swartz, W. E.</p> <p>1985-07-01</p> <p>It is pointed out that, in the past two decades, much progress has been made in the theoretical computation of energetic <span class="hlt">electron</span> transport and thermalization in the ionosphere. The present investigation is concerned with an optimized scheme which uses the same discrete formalism at all <span class="hlt">energies</span>, and guarantees numerical <span class="hlt">energy</span> conservation independently of the <span class="hlt">energy</span> grid size or configuration. The considered method was employed by Kelley et al. (1977) and by Swartz et al. (1979). Attention is given to <span class="hlt">energy</span> degradation and reapportionment with <span class="hlt">energy</span> conservation following inelastic collisions, <span class="hlt">energy</span> reapportionment with <span class="hlt">energy</span> conservation of emergent primaries following ionizing collisions, the establishment of consistent sources for numerical comparisons, and an example of an <span class="hlt">energy</span> grid with the minimum number of cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1301251','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1301251"><span><span class="hlt">Energy</span> selection is not correlated in the Qx and Qy <span class="hlt">bands</span> of a Mg-porphyrin embedded in a protein.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Suisalu, A; Mauring, K; Kikas, J; Herenyi, L; Fidy, J</p> <p>2001-01-01</p> <p>The Qx-Qy splitting observed in the fluorescence excitation spectra of Mg-mesoporphyrin-IX substituted horseradish peroxidase (MgMP-HRP) and of its complex with naphthohydroxamic acid (NHA) was studied by spectral hole burning techniques. The width of a hole directly burnt in the Qy <span class="hlt">band</span> and that of a satellite hole indirectly produced in Qy as a result of hole burning in Qx was compared. We also studied the dependence of the satellite hole in the Qy <span class="hlt">band</span> on the burning frequency used in the Qx <span class="hlt">band</span>. Both the directly and indirectly burnt holes were very broad in the (higher <span class="hlt">energy</span>) Qy <span class="hlt">band</span>. The width of the satellite hole in the Qy <span class="hlt">band</span> was equal to the entire width of the inhomogeneously broadened <span class="hlt">band</span>, independently from the position of hole burning in Qx. This is indicative of a clear lack of correlation between the <span class="hlt">electronic</span> transition <span class="hlt">energies</span> of the Qx and Qy <span class="hlt">bands</span>. A photoproduct was produced by laser irradiation of the MgMP-HRP/NHA complex and was identified as a species with lowered Q-splitting. Conversion of the photoproduct could be achieved by thermal activation measured in temperature-cycling experiments, with a characteristic temperature of 25 K. We attribute the phototransformation to a conformational change of MgMP. PMID:11159420</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhA...50K5203G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhA...50K5203G"><span>Topology of time-reversal invariant <span class="hlt">energy</span> <span class="hlt">bands</span> with adiabatic structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gat, Omri; Robbins, J. M.</p> <p>2017-09-01</p> <p>We classify the topology of <span class="hlt">bands</span> defined by the <span class="hlt">energy</span> states of quantum systems with scale separation between slow and fast degrees of freedom, invariant under fermionic time reversal. Classical phase space transforms differently from momentum space under time reversal, and as a consequence the topology of adiabatic <span class="hlt">bands</span> is different from that of Bloch <span class="hlt">bands</span>. We show that <span class="hlt">bands</span> defined over a two-dimensional phase space are classified by the Chern number, whose parity must be equal to the parity of the <span class="hlt">band</span> rank. Even-rank <span class="hlt">bands</span> are equivalently classified by the Kane-Mele index, an integer equal to one half the Chern number.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5686304','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5686304"><span><span class="hlt">Electronic</span> structure of metal hydrides. VI. Photoemission studies and <span class="hlt">band</span> theory of VH, NbH, and TaH</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Peterman, D.J.; Misemer, D.K.; Weaver, J.H.; Peterson, D.T.</p> <p>1983-01-15</p> <p>The <span class="hlt">electronic</span> structures of VH/sub x/, NbH/sub x/, and TaH/sub x/ (0.6< or =x< or =1.0) have been studied with the use of photoemission spectroscopy with synchrotron radiation (10< or =h..nu..< or =100 eV). Two hydrogen-derived features are observed at approx.5.5- and 7.5-eV binding <span class="hlt">energies</span>, and the metal d <span class="hlt">bands</span> are shown to be modified by the hydrogen interaction. These results show no agreement with rigid-<span class="hlt">band</span> models based on the density of states of the pure metals and relatively poor agreement with previous <span class="hlt">band</span>-structure calculations for monohydrides. We have calculated the <span class="hlt">energy</span> <span class="hlt">bands</span> of ..gamma..-phase NbH (self-consistently) and of NbH/sub 0/ and NbH/sub 2/ (non-self-consistently). Together, the calculations and experiments show how the metal-hydrogen interaction alters the <span class="hlt">electronic</span> properties of the bcc metals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4701338','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4701338"><span>Molecular <span class="hlt">Electronic</span> Angular Motion Transducer Broad <span class="hlt">Band</span> Self-Noise</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zaitsev, Dmitry; Agafonov, Vadim; Egorov, Egor; Antonov, Alexander; Shabalina, Anna</p> <p>2015-01-01</p> <p>Modern molecular <span class="hlt">electronic</span> transfer (MET) angular motion sensors combine high technical characteristics with low cost. Self-noise is one of the key characteristics which determine applications for MET sensors. However, until the present there has not been a model describing the sensor noise in the complete operating frequency range. The present work reports the results of an experimental study of the self-noise level of such sensors in the frequency range of 0.01–200 Hz. Based on the experimental data, a theoretical model is developed. According to the model, self-noise is conditioned by thermal hydrodynamic fluctuations of the operating fluid flow in the frequency range of 0.01–2 Hz. At the frequency range of 2–100 Hz, the noise power spectral density has a specific inversely proportional dependence of the power spectral density on the frequency that could be attributed to convective processes. In the high frequency range of 100–200 Hz, the noise is conditioned by the voltage noise of the <span class="hlt">electronics</span> module input stage operational amplifiers and is heavily reliant to the sensor electrical impedance. The presented results allow a deeper understanding of the molecular <span class="hlt">electronic</span> sensor noise nature to suggest the ways to reduce it. PMID:26610502</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPCS..101...45S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPCS..101...45S"><span>k - dependent Jeff=1/2 <span class="hlt">band</span> splitting and the <span class="hlt">electron</span>-hole asymmetry in SrIrO3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Vijeta; Pulikkotil, J. J.</p> <p>2017-02-01</p> <p>The Ir ion in Srn+1 IrnO 3 n + 1 series of compounds is octahedrally coordinated. However, unlike Sr2IrO4 (n=1) and Sr3Ir2O7 (n=2) which are insulating due to spin-orbit induced Jeff splitting of the t2g <span class="hlt">bands</span>, SrIrO3 (n= ∞) is conducting. To explore whether such a splitting is relevant in SrIrO3, and if so to what extent, we investigate the <span class="hlt">electronic</span> structure of orthorhombic SrIrO3 using density functional theory. Calculations reveal that the crystal field split Ir t2 g <span class="hlt">bands</span> in SrIrO3 are indeed split into Jeff=3/2 and and Jeff=1/2 states. However, the splitting is found to be strongly k - dependent with its magnitude determined by the Ir - O orbital hybridization. Besides, we find that the spin-orbit induced pseudo-gap, into which the Fermi <span class="hlt">energy</span> is positioned, is composed of both light <span class="hlt">electron</span>-like and heavy hole-like <span class="hlt">bands</span>. These features in the <span class="hlt">band</span> structure of SrIrO3 suggest that variations in the carrier concentration control the <span class="hlt">electronic</span> transport properties in SrIrO3, which is consistent with the experiments.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24576851','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24576851"><span>Superconductivity in an <span class="hlt">electron</span> <span class="hlt">band</span> just above the Fermi level: possible route to BCS-BEC superconductivity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Okazaki, K; Ito, Y; Ota, Y; Kotani, Y; Shimojima, T; Kiss, T; Watanabe, S; Chen, C-T; Niitaka, S; Hanaguri, T; Takagi, H; Chainani, A; Shin, S</p> <p>2014-02-28</p> <p>Conventional superconductivity follows Bardeen-Cooper-Schrieffer(BCS) theory of <span class="hlt">electrons</span>-pairing in momentum-space, while superfluidity is the Bose-Einstein condensation(BEC) of atoms paired in real-space. These properties of solid metals and ultra-cold gases, respectively, are connected by the BCS-BEC crossover. Here we investigate the <span class="hlt">band</span> dispersions in FeTe(0.6)Se(0.4)(Tc = 14.5 K ~ 1.2 meV) in an accessible range below and above the Fermi level(EF) using ultra-high resolution laser angle-resolved photoemission spectroscopy. We uncover an <span class="hlt">electron</span> <span class="hlt">band</span> lying just 0.7 meV (~8 K) above EF at the Γ-point, which shows a sharp superconducting coherence peak with gap formation below Tc. The estimated superconducting gap Δ and Fermi <span class="hlt">energy</span> [Symbol: see text]F indicate composite superconductivity in an iron-based superconductor, consisting of strong-coupling BEC in the <span class="hlt">electron</span> <span class="hlt">band</span> and weak-coupling BCS-like superconductivity in the hole <span class="hlt">band</span>. The study identifies the possible route to BCS-BEC superconductivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/133184','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/133184"><span>Shape of impurity <span class="hlt">electronic</span> absorption <span class="hlt">bands</span> in a nematic liquid crystal</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Aver`yanov, E.M.</p> <p>1995-02-01</p> <p>It is shown that the anisotropic intermolecular impurity-matrix interactions, statistical orientation properties, and the <span class="hlt">electronic</span> structure of the uniaxial impurity molecules considerably affect the spectral moments of the impurity <span class="hlt">electronic</span> adsorption <span class="hlt">bands</span> in a nematic liquid crystal. 15 refs., 3 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhDT.......133T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhDT.......133T"><span>Valence <span class="hlt">electronic</span> structure of semiconductor quantum dot and wide <span class="hlt">band</span> gap oxide interfaces by ultraviolet photoelectron spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Timp, Brooke Andrea</p> <p></p> <p><span class="hlt">Energy</span> level alignment is an important factor in efficient charge transfer at an interface between two semiconductors. This topic is explored in model systems that are relevant to quantum dot-sensitized solar cells, inorganic semiconductor nanoparticles adsorbed on single crystal wide <span class="hlt">band</span> gap oxide substrates, using ultraviolet photoelectron spectroscopy. Cadmium selenide quantum dots are assembled on a ZnO (10 1¯ 0) surface using 3-mercaptopropionic acid linkers. The valence <span class="hlt">band</span> maximum of the CdSe quantum dots is found to be located at 1.1 +/- 0.1 eV above the valence <span class="hlt">band</span> maximum of ZnO, nearly independent of the size of the quantum dots (2.1-4.2 nm). This finding suggests that, upon adsorption, there is strong <span class="hlt">electronic</span> interaction between CdSe quantum dots and the ZnO surface. As a result, varying the quantum dot size mainly tunes the alignment of the conduction <span class="hlt">band</span> minimum of CdSe with respect to that of the ZnO surface. Sub-monolayer films of PbSe quantum dots are prepared on single crystal substrates, ZnO (10 1 0 ) and TiO2 (110), and exposed to ligand solutions, either hydrazine or 1,2-ethanedithiol (EDT) in acetonitrile. Interfacial <span class="hlt">energy</span> alignment is measured as a function of quantum dot size, substrate and ligand treatment. The affect of the ligand treatments on the <span class="hlt">energy</span> alignment is substrate-dependent. The valence <span class="hlt">band</span> maximum of the dots is size-independent on ZnO due to strong <span class="hlt">electronic</span> interactions with the substrate; in particular, EDT-treated films show significant enhancement of quantum dot valence <span class="hlt">band</span> intensity due to <span class="hlt">electronic</span> coupling with the ZnO surface. In contrast, the quantum dot valence <span class="hlt">band</span> maximum is size-dependent and shows a smaller shift between ligand treatments for films on TiO2, suggesting weaker quantum dot-substrate interactions. In most cases the measured alignment predicts that <span class="hlt">electron</span> injection from a photoexcited PbSe quantum dot to either ZnO or TiO2 will necessitate the involvement of higher-lying levels</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18315272','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18315272"><span>Extreme ultraviolet narrow <span class="hlt">band</span> emission from <span class="hlt">electron</span> cyclotron resonance plasmas.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhao, H Y; Zhao, H W; Sun, L T; Zhang, X Z; Wang, H; Ma, B H; Li, X X; Zhu, Y H; Sheng, L S; Zhang, G B; Tian, Y C</p> <p>2008-02-01</p> <p>Extreme ultraviolet lithography (EUVL) is considered as the most promising solution at and below dynamic random access memory 32 nm half pitch among the next generation lithography, and EUV light sources with high output power and sufficient lifetime are crucial for the realization of EUVL. However, there is no EUV light source completely meeting the requirements for the commercial application in lithography yet. Therefore, ECR plasma is proposed as a novel concept EUV light source. In order to investigate the feasibility of ECR plasma as a EUV light source, the narrow <span class="hlt">band</span> EUV power around 13.5 nm emitted by two highly charged ECR ion sources -- LECR2M and SECRAL -- was measured with a calibrated EUV power measurement tool. Since the emission lines around 13.5 nm can be attributed to the 4d-5p transitions of Xe XI or the 4d-4f unresolved transition array of Sn VIII-XIII, xenon plasma was investigated. The dependence of the EUV throughput and the corresponding conversion efficiency on the parameters of the ion source, such as the rf power and the magnetic confinement configurations, were preliminarily studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/948877','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/948877"><span>Stability of <span class="hlt">electron</span> <span class="hlt">energy</span> in the Fermilab <span class="hlt">electron</span> cooler</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Shemyakin, A.; Carlson, K.; Prost, L.R.; Saewert, G.; /Fermilab</p> <p>2009-02-01</p> <p>A powerful <span class="hlt">electron</span> beam (4.3 MeV, 0.1 A DC) generated by an electrostatic accelerator has been used at Fermilab for three years to cool antiprotons in the Recycler ring. For <span class="hlt">electron</span> cooling to be effective, the <span class="hlt">electron</span> <span class="hlt">energy</span> should not deviate from its optimum value by more than 500V. The main tool for studying the <span class="hlt">energy</span> stability is the <span class="hlt">electron</span> beam position in a high-dispersion area. The <span class="hlt">energy</span> ripple (frequencies above 0.2 Hz) was found to be less than 150 eV rms; the main cause of the ripple is the fluctuations of the chain current. In addition, the <span class="hlt">energy</span> can drift to up to several keV that is traced to two main sources. One of them is a drift of the charging current, and another is a temperature dependence of generating voltmeter readings. The paper describes the efforts to reach the required level of stability as well as the setup, diagnostics, results of measurements, and operational experience.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MPLB...3050159N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MPLB...3050159N"><span>Topological <span class="hlt">band</span> order, structural, <span class="hlt">electronic</span> and optical properties of XPdBi (X = Lu, Sc) compounds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Narimani, M.; Nourbakhsh, Z.</p> <p>2016-05-01</p> <p>In this paper, the structural, <span class="hlt">electronic</span> and optical properties of LuPdBi and ScPdBi compounds are investigated using the density functional theory by WIEN2K package within the generalized gradient approximation, local density approximation, Engel-Vosco generalized gradient approximations and modified Becke-Johnson potential approaches. The topological phases and <span class="hlt">band</span> orders of these compounds are studied. The effect of pressure on <span class="hlt">band</span> inversion strength, <span class="hlt">electron</span> density of states and the linear coefficient of the <span class="hlt">electronic</span> specific heat of these compounds is investigated. Furthermore, the effect of pressure on real and imaginary parts of dielectric function, absorption and reflectivity coefficients of these compounds is studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27462927','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27462927"><span>Exploring the <span class="hlt">Electronic</span> <span class="hlt">Band</span> Structure of Organometal Halide Perovskite via Photoluminescence Anisotropy of Individual Nanocrystals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Täuber, Daniela; Dobrovolsky, Alexander; Camacho, Rafael; Scheblykin, Ivan G</p> <p>2016-08-10</p> <p>Understanding <span class="hlt">electronic</span> processes in organometal halide perovskites, flourishing photovoltaic, and emitting materials requires unraveling the origin of their <span class="hlt">electronic</span> transitions. Light polarization studies can provide important information regarding transition dipole moment orientations. Investigating individual methylammonium lead triiodide perovskite nanocrystals enabled us to detect the polarization of photoluminescence intensity and photoluminescence excitation, hidden in bulk samples by ensemble averaging. Polarization properties of the crystals were correlated with their photoluminescence spectra and <span class="hlt">electron</span> microscopy images. We propose that distortion of PbI6 octahedra leads to peculiarities of the <span class="hlt">electronic</span> <span class="hlt">band</span> structure close to the <span class="hlt">band</span>-edge. Namely, the lowest <span class="hlt">band</span> transition possesses a transition dipole moment along the apical Pb-I-Pb bond resulting in polarized photoluminescence. Excitation of photoluminescence above the bandgap is unpolarized because it involves molecular orbitals delocalized both in the apical and equatorial directions of the perovskite octahedron. Trap-assisted emission at 77 K, rather surprisingly, was polarized similar to the bandgap emission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22494809','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22494809"><span>Spatially resolved <span class="hlt">band</span> alignments at Au-hexadecanethiol monolayer-GaAs(001) interfaces by ballistic <span class="hlt">electron</span> emission microscopy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Junay, A.; Guézo, S. Turban, P.; Delhaye, G.; Lépine, B.; Tricot, S.; Ababou-Girard, S.; Solal, F.</p> <p>2015-08-28</p> <p>We study structural and <span class="hlt">electronic</span> inhomogeneities in Metal—Organic Molecular monoLayer (OML)—semiconductor interfaces at the sub-nanometer scale by means of in situ Ballistic <span class="hlt">Electron</span> Emission Microscopy (BEEM). BEEM imaging of Au/1-hexadecanethiols/GaAs(001) heterostructures reveals the evolution of pinholes density as a function of the thickness of the metallic top-contact. Using BEEM in spectroscopic mode in non-short-circuited areas, local <span class="hlt">electronic</span> fingerprints (barrier height values and corresponding spectral weights) reveal a low-<span class="hlt">energy</span> tunneling regime through the insulating organic monolayer. At higher <span class="hlt">energies</span>, BEEM evidences new conduction channels, associated with hot-<span class="hlt">electron</span> injection in the empty molecular orbitals of the OML. Corresponding <span class="hlt">band</span> diagrams at buried interfaces can be thus locally described. The <span class="hlt">energy</span> position of GaAs conduction <span class="hlt">band</span> minimum in the heterostructure is observed to evolve as a function of the thickness of the deposited metal, and coherently with size-dependent electrostatic effects under the molecular patches. Such BEEM analysis provides a quantitative diagnosis on metallic top-contact formation on organic molecular monolayer and appears as a relevant characterization for its optimization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1286676','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1286676"><span>Image simulation for <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectroscopy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Oxley, Mark P.; Pennycook, Stephen J.</p> <p>2007-10-22</p> <p>In this paper, aberration correction of the probe forming optics of the scanning transmission <span class="hlt">electron</span> microscope has allowed the probe-forming aperture to be increased in size, resulting in probes of the order of 1 Å in diameter. The next generation of correctors promise even smaller probes. Improved spectrometer optics also offers the possibility of larger <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectrometry detectors. The localization of images based on core-loss <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectroscopy is examined as function of both probe-forming aperture and detector size. The effective ionization is nonlocal in nature, and two common local approximations are compared to full nonlocal calculations. Finally, the affect of the channelling of the <span class="hlt">electron</span> probe within the sample is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1286676-image-simulation-electron-energy-loss-spectroscopy','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1286676-image-simulation-electron-energy-loss-spectroscopy"><span>Image simulation for <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectroscopy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Oxley, Mark P.; Pennycook, Stephen J.</p> <p>2007-10-22</p> <p>In this paper, aberration correction of the probe forming optics of the scanning transmission <span class="hlt">electron</span> microscope has allowed the probe-forming aperture to be increased in size, resulting in probes of the order of 1 Å in diameter. The next generation of correctors promise even smaller probes. Improved spectrometer optics also offers the possibility of larger <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectrometry detectors. The localization of images based on core-loss <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectroscopy is examined as function of both probe-forming aperture and detector size. The effective ionization is nonlocal in nature, and two common local approximations are compared to full nonlocal calculations.more » Finally, the affect of the channelling of the <span class="hlt">electron</span> probe within the sample is also discussed.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JaJAP..48e6002O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JaJAP..48e6002O"><span>Collective <span class="hlt">Energy</span> Loss of Attosecond <span class="hlt">Electron</span> Bunches</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ogata, Atsushi; Kondoh, Takafumi; Norizawa, Kimihiro; Yang, Jinfeng; Yoshida, Yoichi</p> <p>2009-05-01</p> <p>The formalism of the stopping power for cluster beams was adapted to the stopping power for short <span class="hlt">electron</span> bunches using the wake field of a medium characterized by plasma frequency. It was shown that, if the bunch length is in the 100 as range, the <span class="hlt">energy</span> loss of the bunch is proportional to the square of the number of <span class="hlt">electrons</span> in the bunch. If the number of <span class="hlt">electrons</span> is large, the collective loss is able to excite a high-<span class="hlt">energy</span> density state in the target. The target medium and beam parameters were examined to demonstrate the collective effect, and an accelerator system consisting of an accumulation ring and an inverse free-<span class="hlt">electron</span> laser (IFEL) was considered to produce attosecond bunches.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/212778','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/212778"><span><span class="hlt">Electron</span> <span class="hlt">energy</span> relaxation of <span class="hlt">electron</span> swarms in RF fields</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bzenic, S.A.; Petrovic, Z.Lj.; Maeda, K.; Makabe, T.</p> <p>1995-12-31</p> <p>Efficient modeling of RF discharges requires approximate treatment of non-local transport of <span class="hlt">electrons</span> both in time and space. Exact solution of space and time dependent Boltzmann equation is both very difficult and time consuming when taken in conjunction with self consistent calculation of the development of electric field and so are the Monte Carlo simulations. Therefore approximate methods have been developed based on fluid models which make modeling of one dimensional RF plasmas tractable and modeling of two dimensional plasmas becomes possible. The crucial problem in such numerical models is the non local <span class="hlt">electron</span> transport and it is treated by different approximate schemes, one of the most successful being the Relaxation Continuum Theory (RCT). Critical part of the RCT scheme is application of relaxation times for various processes. The most important is the <span class="hlt">energy</span> relaxation lifetime but it is of limited value when high <span class="hlt">energy</span> <span class="hlt">electrons</span> are important component of the <span class="hlt">energy</span> distribution function. In addition behavior of different inelastic processes will depend not on the threshold <span class="hlt">energy</span> and <span class="hlt">energy</span> distribution time dependence above that threshold. In this paper we follow the relaxation of the mean <span class="hlt">energy</span> and other properties of <span class="hlt">electron</span> swarms in the high frequency RF field. We use both the specially developed Monte Carlo simulation technique-(MCS) and the direct numeric procedure for solving the Boltzmann equation. As the basis for calculations we use the cross section set for the Reid`s ramp model which has been used extensively in tests of numerical techniques and thus the accurate values of the transport coefficients are very well known.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900056925&hterms=gibbons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dgibbons','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900056925&hterms=gibbons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dgibbons"><span><span class="hlt">Electron</span> <span class="hlt">energy</span> loss spectrometry of interstellar diamonds</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bernatowicz, Thomas J.; Gibbons, Patrick C.; Lewis, Roy S.</p> <p>1990-01-01</p> <p>The results are reported of <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectra (EELS) measurements on diamond residues from carbonaceous meteorites designed to elucidate the structure and composition of interstellar diamonds. Dynamic effective medium theory is used to model the dielectric properties of the diamonds and in particular to synthesize the observed spectra as mixtures of diamond and various pi-bonded carbons. The results are shown to be quantitatively consistent with the idea that diamonds and their surfaces are the only contributors to the <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectra of the diamond residues and that these peculiar spectra are the result of the exceptionally small grain size and large specific surface area of the interstellar diamonds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJTP...55.5233P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJTP...55.5233P"><span>On Puthoff's Semiclassical <span class="hlt">Electron</span> and Vacuum <span class="hlt">Energy</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pereira, N. R.</p> <p>2016-12-01</p> <p>A possible connection between a point <span class="hlt">electron</span> and vacuum <span class="hlt">energy</span> was recently claimed by Puthoff (Int. J. Theor. Phys. 46, 3005 (2007)). He envisions a point <span class="hlt">electron</span> as an ideally conducting spherical shell with a distributed charge on the surface, in equilibrium with the radiation pressure from electromagnetic vacuum fluctuations on the outside, and claims that his analysis demonstrates the reality of high-<span class="hlt">energy</span>-density vacuum fluctuation fields. The present paper finds, instead, that the analysis is meaningless without specific knowledge on the cutoff frequency that is a free parameter in the model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900056925&hterms=gibbon&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dgibbon','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900056925&hterms=gibbon&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dgibbon"><span><span class="hlt">Electron</span> <span class="hlt">energy</span> loss spectrometry of interstellar diamonds</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bernatowicz, Thomas J.; Gibbons, Patrick C.; Lewis, Roy S.</p> <p>1990-01-01</p> <p>The results are reported of <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectra (EELS) measurements on diamond residues from carbonaceous meteorites designed to elucidate the structure and composition of interstellar diamonds. Dynamic effective medium theory is used to model the dielectric properties of the diamonds and in particular to synthesize the observed spectra as mixtures of diamond and various pi-bonded carbons. The results are shown to be quantitatively consistent with the idea that diamonds and their surfaces are the only contributors to the <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectra of the diamond residues and that these peculiar spectra are the result of the exceptionally small grain size and large specific surface area of the interstellar diamonds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1731e0026M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1731e0026M"><span><span class="hlt">Electronic</span> <span class="hlt">energy</span> loss spectra from mono-layer to few layers of phosphorene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mohan, Brij; Thakur, Rajesh; Ahluwalia, P. K.</p> <p>2016-05-01</p> <p>Using first principles calculations, <span class="hlt">electronic</span> and optical properties of few-layers phosphorene has been investigated. <span class="hlt">Electronic</span> <span class="hlt">band</span> structure show a moderate <span class="hlt">band</span> gap of 0.9 eV in monolayer phosphorene which decreases with increasing number of layers. Optical properties of few-layers of phosphorene in infrared and visible region shows tunability with number of layers. <span class="hlt">Electron</span> <span class="hlt">energy</span> loss function has been plotted and huge red shift in plasmonic behaviours is found. These tunable <span class="hlt">electronic</span> and optical properties of few-layers of phosphorene can be useful for the applications of optoelectronic devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22606277','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22606277"><span><span class="hlt">Electronic</span> <span class="hlt">energy</span> loss spectra from mono-layer to few layers of phosphorene</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mohan, Brij Thakur, Rajesh; Ahluwalia, P. K.</p> <p>2016-05-23</p> <p>Using first principles calculations, <span class="hlt">electronic</span> and optical properties of few-layers phosphorene has been investigated. <span class="hlt">Electronic</span> <span class="hlt">band</span> structure show a moderate <span class="hlt">band</span> gap of 0.9 eV in monolayer phosphorene which decreases with increasing number of layers. Optical properties of few-layers of phosphorene in infrared and visible region shows tunability with number of layers. <span class="hlt">Electron</span> <span class="hlt">energy</span> loss function has been plotted and huge red shift in plasmonic behaviours is found. These tunable <span class="hlt">electronic</span> and optical properties of few-layers of phosphorene can be useful for the applications of optoelectronic devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4792950','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4792950"><span>Stable topological insulators achieved using high <span class="hlt">energy</span> <span class="hlt">electron</span> beams</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhao, Lukas; Konczykowski, Marcin; Deng, Haiming; Korzhovska, Inna; Begliarbekov, Milan; Chen, Zhiyi; Papalazarou, Evangelos; Marsi, Marino; Perfetti, Luca; Hruban, Andrzej; Wołoś, Agnieszka; Krusin-Elbaum, Lia</p> <p>2016-01-01</p> <p>Topological insulators are potentially transformative quantum solids with metallic surface states which have Dirac <span class="hlt">band</span> structure and are immune to disorder. Ubiquitous charged bulk defects, however, pull the Fermi <span class="hlt">energy</span> into the bulk <span class="hlt">bands</span>, denying access to surface charge transport. Here we demonstrate that irradiation with swift (∼2.5 MeV <span class="hlt">energy</span>) <span class="hlt">electron</span> beams allows to compensate these defects, bring the Fermi level back into the bulk gap and reach the charge neutrality point (CNP). Controlling the beam fluence, we tune bulk conductivity from p- (hole-like) to n-type (<span class="hlt">electron</span>-like), crossing the Dirac point and back, while preserving the Dirac <span class="hlt">energy</span> dispersion. The CNP conductance has a two-dimensional character on the order of ten conductance quanta and reveals, both in Bi2Te3 and Bi2Se3, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size. PMID:26961901</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26961901','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26961901"><span>Stable topological insulators achieved using high <span class="hlt">energy</span> <span class="hlt">electron</span> beams.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhao, Lukas; Konczykowski, Marcin; Deng, Haiming; Korzhovska, Inna; Begliarbekov, Milan; Chen, Zhiyi; Papalazarou, Evangelos; Marsi, Marino; Perfetti, Luca; Hruban, Andrzej; Wołoś, Agnieszka; Krusin-Elbaum, Lia</p> <p>2016-03-10</p> <p>Topological insulators are potentially transformative quantum solids with metallic surface states which have Dirac <span class="hlt">band</span> structure and are immune to disorder. Ubiquitous charged bulk defects, however, pull the Fermi <span class="hlt">energy</span> into the bulk <span class="hlt">bands</span>, denying access to surface charge transport. Here we demonstrate that irradiation with swift (∼2.5 MeV <span class="hlt">energy</span>) <span class="hlt">electron</span> beams allows to compensate these defects, bring the Fermi level back into the bulk gap and reach the charge neutrality point (CNP). Controlling the beam fluence, we tune bulk conductivity from p- (hole-like) to n-type (<span class="hlt">electron</span>-like), crossing the Dirac point and back, while preserving the Dirac <span class="hlt">energy</span> dispersion. The CNP conductance has a two-dimensional character on the order of ten conductance quanta and reveals, both in Bi2Te3 and Bi2Se3, the presence of only two quantum channels corresponding to two topological surfaces. The intrinsic quantum transport of the topological states is accessible disregarding the bulk size.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SurSc.660...47R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SurSc.660...47R"><span>Effect of the d <span class="hlt">electrons</span> on the <span class="hlt">electronic</span> <span class="hlt">band</span> structure of the valence <span class="hlt">bands</span> of IIb-VIa C (2 × 2) reconstructed surfaces: GGA+U calculation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rubio-Ponce, A.; Olguín, D.</p> <p>2017-06-01</p> <p>The structural and <span class="hlt">electronic</span> properties of the ZnSe(001), ZnTe(001), CdSe(001), and CdTe(001) C (2 × 2) reconstructed surfaces have been studied using first principles calculations. To study the influence of the cation d states on the surface and resonance states of the valence <span class="hlt">bands</span>, we have used the GGA+U approach. From a relaxation procedure of the reconstructed surface, we show that our model properly reproduces the <span class="hlt">electronic</span> properties found in the bulk for these semiconductor compounds, as well as the known surface structural parameters.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986JMMM...58..145A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986JMMM...58..145A"><span>Mixed-valence effects and metamagnetism in a two-<span class="hlt">band</span> model of correlated <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Acquarone, M.; SpaŁek, J.; Ray, D. K.</p> <p>1986-03-01</p> <p>We discuss both continuous and discontinuous transitions form para- to ferromagnetism within a model of <span class="hlt">electrons</span> in double degenerate and hybridized <span class="hlt">band</span>. We transform out rigorously the hybridization and obtain a two-<span class="hlt">band</span> model with the component <span class="hlt">bands</span> of substantially different width. This <span class="hlt">band</span> structure is approximated by a <span class="hlt">band</span> and a level placed in the center of the <span class="hlt">band</span>. The model is solved both with and without applied magnetic field, within the Hartree-Fock approximation for the intraband and the interband interactions, and treating the Coulomb interactions on the level exactly. The self-consistent solutions for the magnetic moment and the <span class="hlt">band</span> filling are given allowing for a redistribution of particles between the <span class="hlt">band</span> and the level. A number of ferromagnetic and mixed-valent-type of configurations is possible, leading to a possibility of appearance of ferromagnetism in a discontinuous way and without the Stoner condition being fulfilled at the transition. Such transition cannot be described within the standard Ginzburg-Landau theory obtained from the Stoner-Wohlfarth model for a single <span class="hlt">band</span>. The obtained result are used to give a qualitative explanation of the main results observed for the systems Co(S 1 - xSe x) 2 and CoTi 1 - xAl x.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NIMPB.360..103C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NIMPB.360..103C"><span><span class="hlt">Band</span> structure effects in the <span class="hlt">energy</span> loss of low-<span class="hlt">energy</span> protons and deuterons in thin films of Pt</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Celedón, C. E.; Sánchez, E. A.; Salazar Alarcón, L.; Guimpel, J.; Cortés, A.; Vargas, P.; Arista, N. R.</p> <p>2015-10-01</p> <p>We have investigated experimentally and by computer simulations the <span class="hlt">energy</span>-loss and angular distribution of low <span class="hlt">energy</span> (E < 10 keV) protons and deuterons transmitted through thin polycrystalline platinum films. The experimental results show significant deviations from the expected velocity dependence of the stopping power in the range of very low <span class="hlt">energies</span> with respect to the predictions of the Density Functional Theory for a jellium model. This behavior is similar to those observed in other transition metals such as Cu, Ag and Au, but different from the linear dependence recently observed in another transition metal, Pd, which belongs to the same Group of Pt in the Periodic Table. These differences are analyzed in term of the properties of the <span class="hlt">electronic</span> <span class="hlt">bands</span> corresponding to Pt and Pd, represented in terms of the corresponding density of states. The present experiments include also a detailed study of the angular dependence of the <span class="hlt">energy</span> loss and the angular distributions of transmitted protons and deuterons. The results are compared with computer simulations based on the Monte Carlo method and with a theoretical model that evaluates the contributions of elastic collisions, path length effects in the inelastic <span class="hlt">energy</span> losses, and the effects of the foil roughness. The results of the analysis obtained from these various approaches provide a consistent and comprehensive description of the experimental findings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1392518','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1392518"><span>X-<span class="hlt">band</span> rf driven free <span class="hlt">electron</span> laser driver with optics linearization</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sun, Yipeng; Emma, Paul; Raubenheimer, Tor; Wu, Juhao</p> <p>2014-11-13</p> <p>In this paper, a compact hard X-ray free <span class="hlt">electron</span> lasers (FEL) design is proposed with all X-<span class="hlt">band</span> rf acceleration and two stage bunch compression. It eliminates the need of a harmonic rf linearization section by employing optics linearization in its first stage bunch compression. Quadrupoles and sextupoles are employed in a bunch compressor one (BC1) design, in such a way that second order longitudinal dispersion of BC1 cancels the second order <span class="hlt">energy</span> correlation in the <span class="hlt">electron</span> beam. Start-to-end 6-D simulations are performed with all the collective effects included. Emittance growth in the horizontal plane due to coherent synchrotron radiation is investigated and minimized, to be on a similar level with the successfully operating Linac coherent light source (LCLS). At a FEL radiation wavelength of 0.15 nm, a saturation length of 40 meters can be achieved by employing an undulator with a period of 1.5 cm. Without tapering, a FEL radiation power above 10 GW is achieved with a photon pulse length of 50 fs, which is LCLS-like performance. The overall length of the accelerator plus undulator is around 250 meters which is much shorter than the LCLS length of 1230 meters. That makes it possible to build hard X-ray FEL in a laboratory with limited size.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27049355','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27049355"><span>The <span class="hlt">electronic</span> <span class="hlt">band</span> structures of gadolinium chalcogenides: a first-principles prediction for neutron detecting.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Kexue; Liu, Lei; Yu, Peter Y; Chen, Xiaobo; Shen, D Z</p> <p>2016-05-11</p> <p>By converting the <span class="hlt">energy</span> of nuclear radiation to excited <span class="hlt">electrons</span> and holes, semiconductor detectors have provided a highly efficient way for detecting them, such as photons or charged particles. However, for detecting the radiated neutrons, those conventional semiconductors hardly behave well, as few of them possess enough capability for capturing these neutral particles. While the element Gd has the highest nuclear cross section, here for searching proper neutron-detecting semiconductors, we investigate theoretically the Gd chalcogenides whose <span class="hlt">electronic</span> <span class="hlt">band</span> structures have never been characterized clearly. Among them, we identify that γ-phase Gd2Se3 should be the best candidate for neutron detecting since it possesses not only the right bandgap of 1.76 eV for devices working under room temperature but also the desired indirect gap nature for charge carriers surviving longer. We propose further that semiconductor neutron detectors with single-neutron sensitivity can be realized with such a Gd-chalcogenide on the condition that their crystals can be grown with good quality.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1181633-band-rf-driven-free-electron-laser-driver-optics-linearization','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1181633-band-rf-driven-free-electron-laser-driver-optics-linearization"><span>X-<span class="hlt">band</span> rf driven free <span class="hlt">electron</span> laser driver with optics linearization</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Sun, Yipeng; Emma, Paul; Raubenheimer, Tor; ...</p> <p>2014-11-13</p> <p>In this paper, a compact hard X-ray free <span class="hlt">electron</span> lasers (FEL) design is proposed with all X-<span class="hlt">band</span> rf acceleration and two stage bunch compression. It eliminates the need of a harmonic rf linearization section by employing optics linearization in its first stage bunch compression. Quadrupoles and sextupoles are employed in a bunch compressor one (BC1) design, in such a way that second order longitudinal dispersion of BC1 cancels the second order <span class="hlt">energy</span> correlation in the <span class="hlt">electron</span> beam. Start-to-end 6-D simulations are performed with all the collective effects included. Emittance growth in the horizontal plane due to coherent synchrotron radiation ismore » investigated and minimized, to be on a similar level with the successfully operating Linac coherent light source (LCLS). At a FEL radiation wavelength of 0.15 nm, a saturation length of 40 meters can be achieved by employing an undulator with a period of 1.5 cm. Without tapering, a FEL radiation power above 10 GW is achieved with a photon pulse length of 50 fs, which is LCLS-like performance. The overall length of the accelerator plus undulator is around 250 meters which is much shorter than the LCLS length of 1230 meters. That makes it possible to build hard X-ray FEL in a laboratory with limited size.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhDT.......251B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhDT.......251B"><span>Electrospun Fibers for <span class="hlt">Energy</span>, <span class="hlt">Electronic</span>, & Environmental Applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bedford, Nicholas M.</p> <p></p> <p> applications, fibers consisting of the commonly used organic photovoltaic <span class="hlt">electron</span> donor/acceptor pair P3HT:PCBM were made by coaxial electrospinning. The inclusion of P3HT:PCBM fibers into an active layer of a organic photovoltaic device led to a ˜ 50% increase in power conversion efficiency over a thin film device of identical chemical composition and thickness. The inclusion of biological photosynthetic moieties into electrically relevant conjugated polymers was also explored for electrical applications. Polymeric fibers consisting largely of PEDOT:PSS were doped with thylakoid vesicles from spinach, and were found to act as photo-detectors. Native PEDOT:PSS does not exhibit such properties. For environmental applications, photocatalytic degradation membranes were also created by electrospinning cellulosic fibers which could be used as platforms to efficiently bind the photocatalyst TiO2. Employing different fiber-titania binding strategies, titania nanoparticles of various sizes and <span class="hlt">band</span> gap configurations were successfully incorporated into mats of non-woven cellulosic nanofibers. These mats were found to successfully degrade dyes and relevant fresh water toxins such as microcystin-LR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SurSc.644...95O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SurSc.644...95O"><span><span class="hlt">Electronic</span> structure of reconstructed InAs(001) surfaces - identification of bulk and surface <span class="hlt">bands</span> based on their symmetries</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Olszowska, Natalia; Kolodziej, Jacek J.</p> <p>2016-02-01</p> <p>Using angle-resolved photoelectron spectroscopy (ARPES) <span class="hlt">band</span> structures of indium- and arsenic-terminated InAs(001) surfaces are investigated. These surfaces are highly reconstructed, elementary cells of their lattices contain many atoms in different chemical configurations, and moreover, they are composed of domains having related but different reconstructions. These domain-type surface reconstructions result in the reciprocal spaces containing regions with well-defined k→∥-vector and regions with not-well-defined one. In the ARPES spectra most of the surface related features appear as straight lines in the indeterminate k→∥-vector space. It is shown that, thanks to differences in crystal and surface symmetries, the single photon <span class="hlt">energy</span> ARPES may be successfully used for classification of surface and bulk <span class="hlt">bands</span> of <span class="hlt">electronic</span> states on complex, highly reconstructed surfaces instead of the most often used variable photon <span class="hlt">energy</span> studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002SSCom.122..575O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002SSCom.122..575O"><span><span class="hlt">Electron</span> phonon effects on the direct <span class="hlt">band</span> gap in semiconductors: LCAO calculations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Olguín, D.; Cardona, M.; Cantarero, A.</p> <p>2002-06-01</p> <p>Using a perturbative treatment of the <span class="hlt">electron</span>-phonon interaction, we have studied the effect of phonons on the direct <span class="hlt">band</span> gap of conventional semiconductors. Our calculations are performed in the framework of the tight-binding linear combination of atomic orbitals (LCAO) approach. Within this scheme we have calculated the temperature and isotopic mass dependence of the lowest direct <span class="hlt">band</span> gap of several semiconductors with diamond and zincblende structure. Our results reproduce the overall trend of available experimental data for the <span class="hlt">band</span> gap as a function of temperature, as well as give correctly the mass dependence of the <span class="hlt">band</span> gap on isotopic. A calculation of conduction <span class="hlt">band</span> intervalley deformation potentials is also reported. Finally, calculated Debye-Waller factors are compared with X-ray and EXAFS experimental results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890029629&hterms=scanning+electron+microscopy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dscanning%2Belectron%2Bmicroscopy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890029629&hterms=scanning+electron+microscopy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dscanning%2Belectron%2Bmicroscopy"><span>Observation of interface <span class="hlt">band</span> structure by ballistic-<span class="hlt">electron</span>-emission microscopy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bell, L. D.; Kaiser, W. J.</p> <p>1988-01-01</p> <p>The paper reports an advanced ballistic <span class="hlt">electron</span> spectroscopy technique that was used to directly measure semiconductor <span class="hlt">band</span> structure properties at a subsurface interface. Two interface systems having contrasting <span class="hlt">band</span> structures were investigated by this method: Au-Si and Au-GaAs. It is concluded that the proposed method, based on scanning tunneling microscopy, enables the spatially resolved carrier-transport spectroscopy of interfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890029629&hterms=scanning+tunneling+microscopy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dscanning%2Btunneling%2Bmicroscopy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890029629&hterms=scanning+tunneling+microscopy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dscanning%2Btunneling%2Bmicroscopy"><span>Observation of interface <span class="hlt">band</span> structure by ballistic-<span class="hlt">electron</span>-emission microscopy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bell, L. D.; Kaiser, W. J.</p> <p>1988-01-01</p> <p>The paper reports an advanced ballistic <span class="hlt">electron</span> spectroscopy technique that was used to directly measure semiconductor <span class="hlt">band</span> structure properties at a subsurface interface. Two interface systems having contrasting <span class="hlt">band</span> structures were investigated by this method: Au-Si and Au-GaAs. It is concluded that the proposed method, based on scanning tunneling microscopy, enables the spatially resolved carrier-transport spectroscopy of interfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3794377','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3794377"><span>Hydrogen production by Tuning the Photonic <span class="hlt">Band</span> Gap with the <span class="hlt">Electronic</span> <span class="hlt">Band</span> Gap of TiO2</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Waterhouse, G. I. N.; Wahab, A. K.; Al-Oufi, M.; Jovic, V.; Anjum, D. H.; Sun-Waterhouse, D.; Llorca, J.; Idriss, H.</p> <p>2013-01-01</p> <p>Tuning the photonic <span class="hlt">band</span> gap (PBG) to the <span class="hlt">electronic</span> <span class="hlt">band</span> gap (EBG) of Au/TiO2 catalysts resulted in considerable enhancement of the photocatalytic water splitting to hydrogen under direct sunlight. Au/TiO2 (PBG-357 nm) photocatalyst exhibited superior photocatalytic performance under both UV and sunlight compared to the Au/TiO2 (PBG-585 nm) photocatalyst and both are higher than Au/TiO2 without the 3 dimensionally ordered macro-porous structure materials. The very high photocatalytic activity is attributed to suppression of a fraction of <span class="hlt">electron</span>-hole recombination route due to the co-incidence of the PBG with the EBG of TiO2 These materials that maintain their activity with very small amount of sacrificial agents (down to 0.5 vol.% of ethanol) are poised to find direct applications because of their high activity, low cost of the process, simplicity and stability. PMID:24108361</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JChPh.137h4703A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JChPh.137h4703A"><span>Effects of strain, d-<span class="hlt">band</span> filling, and oxidation state on the surface <span class="hlt">electronic</span> structure and reactivity of 3d perovskite surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Akhade, Sneha A.; Kitchin, John R.</p> <p>2012-08-01</p> <p>Trends in the dissociative oxygen adsorption <span class="hlt">energy</span> and oxygen vacancy formation <span class="hlt">energy</span> on cubic LaBO3 and SrBO3 perovskite (001) surfaces (where B = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu) and their dependence on strain, d-<span class="hlt">band</span> filling, and oxidation state were examined using density functional theory in the generalized gradient approximation. The effects of strain were found to be small compared to the effects of d-<span class="hlt">band</span> filling and oxidations state. <span class="hlt">Electronic</span> structure descriptors such as the d-<span class="hlt">band</span> center of the B-atom were identified for trends in the dissociative oxygen adsorption <span class="hlt">energy</span> and for the oxygen vacancy formation <span class="hlt">energy</span>. A chemical correlation between these two reaction <span class="hlt">energies</span> was also identified showing the trends in these reaction <span class="hlt">energies</span> are not independent of each other.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22596765','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22596765"><span>Combined analysis of <span class="hlt">energy</span> <span class="hlt">band</span> diagram and equivalent circuit on nanocrystal solid</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kano, Shinya E-mail: fujii@eedept.kobe-u.ac.jp; Sasaki, Masato; Fujii, Minoru E-mail: fujii@eedept.kobe-u.ac.jp</p> <p>2016-06-07</p> <p>We investigate a combined analysis of an <span class="hlt">energy</span> <span class="hlt">band</span> diagram and an equivalent circuit on nanocrystal (NC) solids. We prepared a flat silicon-NC solid in order to carry out the analysis. An <span class="hlt">energy</span> <span class="hlt">band</span> diagram of a NC solid is determined from DC transport properties. Current-voltage characteristics, photocurrent measurements, and conductive atomic force microscopy images indicate that a tunneling transport through a NC solid is dominant. Impedance spectroscopy gives an equivalent circuit: a series of parallel resistor-capacitors corresponding to NC/metal and NC/NC interfaces. The equivalent circuit also provides an evidence that the NC/NC interface mainly dominates the carrier transport through NC solids. Tunneling barriers inside a NC solid can be taken into account in a combined capacitance. Evaluated circuit parameters coincide with simple geometrical models of capacitances. As a result, impedance spectroscopy is also a useful technique to analyze semiconductor NC solids as well as usual DC transport. The analyses provide indispensable information to implement NC solids into actual <span class="hlt">electronic</span> devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JSSCh.182.1964D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JSSCh.182.1964D"><span>The <span class="hlt">electronic</span> structures of vanadate salts: Cation substitution as a tool for <span class="hlt">band</span> gap manipulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dolgos, Michelle R.; Paraskos, Alexandra M.; Stoltzfus, Matthew W.; Yarnell, Samantha C.; Woodward, Patrick M.</p> <p>2009-07-01</p> <p>The <span class="hlt">electronic</span> structures of six ternary metal oxides containing isolated vanadate ions, Ba 3(VO 4) 2, Pb 3(VO 4) 2, YVO 4, BiVO 4, CeVO 4 and Ag 3VO 4 were studied using diffuse reflectance spectroscopy and <span class="hlt">electronic</span> structure calculations. While the <span class="hlt">electronic</span> structure near the Fermi level originates largely from the molecular orbitals of the vanadate ion, both experiment and theory show that the cation can strongly influence these <span class="hlt">electronic</span> states. The observation that Ba 3(VO 4) 2 and YVO 4 have similar <span class="hlt">band</span> gaps, both 3.8 eV, shows that cations with a noble gas configuration have little impact on the <span class="hlt">electronic</span> structure. <span class="hlt">Band</span> structure calculations support this hypothesis. In Pb 3(VO 4) 2 and BiVO 4 the <span class="hlt">band</span> gap is reduced by 0.9-1.0 eV through interactions of (a) the filled cation 6 s orbitals with nonbonding O 2 p states at the top of the valence <span class="hlt">band</span>, and (b) overlap of empty 6 p orbitals with antibonding V 3 d-O 2 p states at the bottom of the conduction <span class="hlt">band</span>. In Ag 3VO 4 mixing between filled Ag 4 d and O 2 p states destabilizes states at the top of the valence <span class="hlt">band</span> leading to a large decrease in the <span class="hlt">band</span> gap ( Eg=2.2 eV). In CeVO 4 excitations from partially filled 4 f orbitals into the conduction <span class="hlt">band</span> lower the effective <span class="hlt">band</span> gap to 1.8 eV. In the Ce 1-xBi xVO 4 (0≤ x≤0.5) and Ce 1-xY xVO 4 ( x=0.1, 0.2) solid solutions the <span class="hlt">band</span> gap narrows slightly when Bi 3+ or Y 3+ are introduced. The nonlinear response of the <span class="hlt">band</span> gap to changes in composition is a result of the localized nature of the Ce 4 f orbitals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22606627','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22606627"><span>The LDA+U calculation of <span class="hlt">electronic</span> <span class="hlt">band</span> structure of GaAs</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bahuguna, B. P. Sharma, R. O.; Saini, L. K.</p> <p>2016-05-06</p> <p>We present the <span class="hlt">electronic</span> <span class="hlt">band</span> structure of bulk gallium arsenide (GaAs) using first principle approach. A series of calculations has been performed by applying norm-conserving pseudopotentials and ultrasoft non-norm-conserving pseudopotentials within the density functional theory. These calculations yield too small <span class="hlt">band</span> gap as compare to experiment. Thus, we use semiemperical approach called local density approximation plus the multi-orbital mean-field Hubbard model (LDA+U), which is quite effective in order to describe the <span class="hlt">band</span> gap of GaAs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhA.122..567C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhA.122..567C"><span>Engineering the <span class="hlt">electronic</span> structure and <span class="hlt">band</span> gap of boron nitride nanoribbon via external electric field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chegel, Raad</p> <p>2016-06-01</p> <p>By using the third nearest neighbor modified tight binding (3NN-TB) method, the <span class="hlt">electronic</span> structure and <span class="hlt">band</span> gap of BNNRs under transverse electric fields are explored. The <span class="hlt">band</span> gap of the BNNRs has a decreasing with increasing the intensity of the applied electric field, independent on the ribbon edge types. Furthermore, an analytic model for the dependence of the <span class="hlt">band</span> gap in armchair and zigzag BNNRs on the electric field is proposed. The reduction of E g is similar for some N a armchair and N z zigzag BNNRs independent of their edges.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JaJAP..44.1485S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JaJAP..44.1485S"><span>Emittance and <span class="hlt">Energy</span> Measurements of Low-<span class="hlt">Energy</span> <span class="hlt">Electron</span> Beam Using Optical Transition Radiation Techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sakamoto, Fumito; Iijima, Hokuto; Dobashi, Katsuhiro; Imai, Takayuki; Ueda, Toru; Watanabe, Takahiro; Uesaka, Mitsuru</p> <p>2005-03-01</p> <p>Emittance and <span class="hlt">energy</span> of an <span class="hlt">electron</span> beam in the range of 8 to 22 MeV were measured via optical transition radiation (OTR) techniques. The beam divergence effect on observations of the far-field OTR image at low <span class="hlt">energies</span> was studied by means of numerical analysis. The numerical analysis indicates that if the beam divergence is under 1.5 mrad, a simultaneous single-shot measurement of emittance and <span class="hlt">energy</span> is possible. The results of the single-shot experiment agree with independent measurements conducted using the quadrupole scan method and an <span class="hlt">electron</span> spectrometer. The experiments were performed with an S-<span class="hlt">band</span> linac at the Nuclear Engineering Research Laboratory, The University of Tokyo (UTNL).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27176628','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27176628"><span>Coexisting Honeycomb and Kagome Characteristics in the <span class="hlt">Electronic</span> <span class="hlt">Band</span> Structure of Molecular Graphene.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Paavilainen, Sami; Ropo, Matti; Nieminen, Jouko; Akola, Jaakko; Räsänen, Esa</p> <p>2016-06-08</p> <p>We uncover the <span class="hlt">electronic</span> structure of molecular graphene produced by adsorbed CO molecules on a copper (111) surface by means of first-principles calculations. Our results show that the <span class="hlt">band</span> structure is fundamentally different from that of conventional graphene, and the unique features of the <span class="hlt">electronic</span> states arise from coexisting honeycomb and Kagome symmetries. Furthermore, the Dirac cone does not appear at the K-point but at the Γ-point in the reciprocal space and is accompanied by a third, almost flat <span class="hlt">band</span>. Calculations of the surface structure with Kekulé distortion show a gap opening at the Dirac point in agreement with experiments. Simple tight-binding models are used to support the first-principles results and to explain the physical characteristics behind the <span class="hlt">electronic</span> <span class="hlt">band</span> structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20428528','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20428528"><span>The <span class="hlt">electronic</span> states of pyrimidine studied by VUV photoabsorption and <span class="hlt">electron</span> <span class="hlt">energy</span>-loss spectroscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>da Silva, F Ferreira; Almeida, D; Martins, G; Milosavljević, A R; Marinković, B P; Hoffmann, S V; Mason, N J; Nunes, Y; Garcia, G; Limão-Vieira, P</p> <p>2010-07-07</p> <p>The <span class="hlt">electronic</span> state spectroscopy of pyrimidine C(4)H(4)N(2) has been investigated using both high resolution VUV photoabsorption in the <span class="hlt">energy</span> range 3.7 to 10.8 eV (335 to 115 nm) and lower resolution <span class="hlt">electron</span> <span class="hlt">energy</span> loss in the range 2 to 15 eV. The low <span class="hlt">energy</span> absorption <span class="hlt">band</span>, assigned to the (pi*) <-- 7b(2)(n(N)) (1(1)B(1)<-- 1(1)A(1)) transition, at 3.85(4) eV and the vibrational progressions superimposed upon it have been observed for the first time, due to the availability of a high-resolution photon beam (0.075 nm), corresponding to 3 meV at the midpoint of the <span class="hlt">energy</span> range studied. Vibronic coupling has been shown to play an important role dictating the nature of the observed excited states, especially for the lowest (1)B(1) state. The 2(1)B(1) state is proposed to have its origin at 7.026 eV according to the vibrational excitation reported in this <span class="hlt">energy</span> region (7.8-8.4 eV). New experimental evidence of 4(1)A(1) state with a maximum cross section at 8.800 eV is supported by previous ab initio quantum chemical calculations. Rydberg series have been assigned converging to the three lowest ionisation <span class="hlt">energy</span> limits, 9.32 eV ((2)B(2)), 10.41 eV ((2)B(1)) and 11.1 eV ((2)A(1) + (2)A(2)) with new members reported for the first time and classified according to the magnitude of the quantum defects (delta). Additionally, the absolute differential cross section for inelastic <span class="hlt">electron</span> scattering has been measured for the most intense <span class="hlt">band</span> from 6.9 to 7.8 eV assigned to (1)pipi* (3(1)A(1) + 2(1)B(2)).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22907644','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22907644"><span>Spectroscopy of the simplest Criegee intermediate CH2OO: simulation of the first <span class="hlt">bands</span> in its <span class="hlt">electronic</span> and photoelectron spectra.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lee, Edmond P F; Mok, Daniel K W; Shallcross, Dudley E; Percival, Carl J; Osborn, David L; Taatjes, Craig A; Dyke, John M</p> <p>2012-09-24</p> <p>CH(2)OO, the simplest Criegee intermediate, and ozone are isoelectronic. They both play very important roles in atmospheric chemistry. Whilst extensive experimental studies have been made on ozone, there were no direct gas-phase studies on CH(2)OO until very recently when its photoionization spectrum was recorded and kinetics studies were made of some reactions of CH(2)OO with a number of molecules of atmospheric importance, using photoionization mass spectrometry to monitor CH(2)OO. In order to encourage more direct studies on CH(2)OO and other Criegee intermediates, the <span class="hlt">electronic</span> and photoelectron spectra of CH(2)OO have been simulated using high level <span class="hlt">electronic</span> structure calculations and Franck-Condon factor calculations, and the results are presented here. Adiabatic and vertical excitation <span class="hlt">energies</span> of CH(2)OO were calculated with TDDFT, EOM-CCSD, and CASSCF methods. Also, DFT, QCISD and CASSCF calculations were performed on neutral and low-lying ionic states, with single <span class="hlt">energy</span> calculations being carried out at higher levels to obtain more reliable ionization <span class="hlt">energies</span>. The results show that the most intense <span class="hlt">band</span> in the <span class="hlt">electronic</span> spectrum of CH(2) OO corresponds to the B(1)A' ← X(1)A' absorption. It is a broad <span class="hlt">band</span> in the region 250-450 nm showing extensive structure in vibrational modes involving O-O stretching and C-O-O bending. Evidence is presented to show that the <span class="hlt">electronic</span> absorption spectrum of CH(2)OO has probably been recorded in earlier work, albeit at low resolution. We suggest that CH(2)OO was prepared in this earlier work from the reaction of CH(2)I with O(2) and that the assignment of the observed spectrum solely to CH(2)IOO is incorrect. The low ionization <span class="hlt">energy</span> region of the photoelectron spectrum of CH(2)OO consists of two overlapping vibrationally structured <span class="hlt">bands</span> corresponding to one-<span class="hlt">electron</span> ionizations from the highest two occupied molecular orbitals of the neutral molecule. In each case, the adiabatic component is the most intense</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/921940','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/921940"><span>Applications for <span class="hlt">Energy</span> Recovering Free <span class="hlt">Electron</span> Lasers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>George Neil</p> <p>2007-08-01</p> <p>The availability of high-power, high-brilliance sources of tunable photons from <span class="hlt">energy</span>-recovered Free <span class="hlt">Electron</span> Lasers is opening up whole new fields of application of accelerators in industry. This talk will review some of the ideas that are already being put into production, and some of the newer ideas that are still under development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720029841&hterms=directed+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddirected%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720029841&hterms=directed+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddirected%2Benergy"><span><span class="hlt">Electron</span> <span class="hlt">energy</span> flux in the solar wind.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ogilvie, K. W.; Scudder, J. D.; Sugiura, M.</p> <p>1971-01-01</p> <p>Description of studies of <span class="hlt">electrons</span> between 10 eV and 9.9 keV in the solar wind. The transport of <span class="hlt">energy</span> in the rest frame of the plasma is evaluated and shown to be parallel to the interplanetary magnetic field. The presence of <span class="hlt">electrons</span> from solar events causes this <span class="hlt">energy</span>-flux density to exceed the heat flow due to thermal <span class="hlt">electrons</span>. In one such event, the observations are shown to be consistent with the solar-<span class="hlt">electron</span> observations made at higher <span class="hlt">energies</span>. When observations are made at a point connected to the earth's bow shock by an interplanetary-field line, a comparatively large <span class="hlt">energy</span> flux along the field toward the sun is observed, but the heat flow remains outwardly directed during this time interval. In either situation the heat flow is found to be consistent with measurements made on Vela satellites by a different method. These values, less than .01 ergs/sq cm/sec, are sufficiently low to require modifications to the Spitzer-Harm conductivity formula for use in solar-wind theories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..MARP36012E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..MARP36012E"><span>Accessing high <span class="hlt">energy</span> sub-<span class="hlt">bands</span> in bilayer graphene - a transport study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Efetov, Dmitri K.; Maher, Patrick; Glinskis, Simas; Kim, Philip</p> <p>2011-03-01</p> <p>In contrast to single layer graphene sheets with its two distinct valence and conduction <span class="hlt">bands</span> merging at the Dirac Point, multilayer graphene sheets are known to have additional sub-<span class="hlt">bands</span> at higher <span class="hlt">energies</span>. Whereas the low <span class="hlt">energy</span> sub-<span class="hlt">bands</span> in these systems are well studied, the higher <span class="hlt">energy</span> sub-<span class="hlt">bands</span> could so far not be accessed in a transport measurement of graphene samples sitting on typical Si O2 /Si back gates. Employing a poly(ethylene)oxide- CsCl O4 solid polymer electrolyte gate we demonstrate the filling up of the high <span class="hlt">energy</span> sub-<span class="hlt">bands</span> in bilayer graphene samples at carrier densities above ~ 2.7 x 1013 cm-2 . The onset of these sub-<span class="hlt">bands</span> is defined by a slight increase of the resistivity and the onset of Shubnikov de Haas (SdH) oscillations. Measurements of the magneto-resistance, the SdH oscillations and the Hall Effect enable us to deduce the carrier densities and mobilities for both, the high and low <span class="hlt">energy</span> <span class="hlt">bands</span> simultaneously. In addition, we find that the onset <span class="hlt">energy</span> of these sub-<span class="hlt">bands</span> can be tuned by varying the bilayer interlayer asymmetry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JAP...117x4303D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JAP...117x4303D"><span>Edge effects on <span class="hlt">band</span> gap <span class="hlt">energy</span> in bilayer 2H-MoS2 under uniaxial strain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dong, Liang; Wang, Jin; Namburu, Raju; O'Regan, Terrance P.; Dubey, Madan; Dongare, Avinash M.</p> <p>2015-06-01</p> <p>The potential of ultrathin MoS2 nanostructures for applications in <span class="hlt">electronic</span> and optoelectronic devices requires a fundamental understanding in their <span class="hlt">electronic</span> structure as a function of strain. Previous experimental and theoretical studies assume that an identical strain and/or stress state is always maintained in the top and bottom layers of a bilayer MoS2 film. In this study, a bilayer MoS2 supercell is constructed differently from the prototypical unit cell in order to investigate the layer-dependent <span class="hlt">electronic</span> <span class="hlt">band</span> gap <span class="hlt">energy</span> in a bilayer MoS2 film under uniaxial mechanical deformations. The supercell contains an MoS2 bottom layer and a relatively narrower top layer (nanoribbon with free edges) as a simplified model to simulate the as-grown bilayer MoS2 flakes with free edges observed experimentally. Our results show that the two layers have different <span class="hlt">band</span> gap <span class="hlt">energies</span> under a tensile uniaxial strain, although they remain mutually interacting by van der Waals interactions. The deviation in their <span class="hlt">band</span> gap <span class="hlt">energies</span> grows from 0 to 0.42 eV as the uniaxial strain increases from 0% to 6% under both uniaxial strain and stress conditions. The deviation, however, disappears if a compressive uniaxial strain is applied. These results demonstrate that tensile uniaxial strains applied to bilayer MoS2 films can result in distinct <span class="hlt">band</span> gap <span class="hlt">energies</span> in the bilayer structures. Such variations need to be accounted for when analyzing strain effects on <span class="hlt">electronic</span> properties of bilayer or multilayered 2D materials using experimental methods or in continuum models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22490729','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22490729"><span>Edge effects on <span class="hlt">band</span> gap <span class="hlt">energy</span> in bilayer 2H-MoS{sub 2} under uniaxial strain</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dong, Liang; Wang, Jin; Dongare, Avinash M.; Namburu, Raju; O'Regan, Terrance P.; Dubey, Madan</p> <p>2015-06-28</p> <p>The potential of ultrathin MoS{sub 2} nanostructures for applications in <span class="hlt">electronic</span> and optoelectronic devices requires a fundamental understanding in their <span class="hlt">electronic</span> structure as a function of strain. Previous experimental and theoretical studies assume that an identical strain and/or stress state is always maintained in the top and bottom layers of a bilayer MoS{sub 2} film. In this study, a bilayer MoS{sub 2} supercell is constructed differently from the prototypical unit cell in order to investigate the layer-dependent <span class="hlt">electronic</span> <span class="hlt">band</span> gap <span class="hlt">energy</span> in a bilayer MoS{sub 2} film under uniaxial mechanical deformations. The supercell contains an MoS{sub 2} bottom layer and a relatively narrower top layer (nanoribbon with free edges) as a simplified model to simulate the as-grown bilayer MoS{sub 2} flakes with free edges observed experimentally. Our results show that the two layers have different <span class="hlt">band</span> gap <span class="hlt">energies</span> under a tensile uniaxial strain, although they remain mutually interacting by van der Waals interactions. The deviation in their <span class="hlt">band</span> gap <span class="hlt">energies</span> grows from 0 to 0.42 eV as the uniaxial strain increases from 0% to 6% under both uniaxial strain and stress conditions. The deviation, however, disappears if a compressive uniaxial strain is applied. These results demonstrate that tensile uniaxial strains applied to bilayer MoS{sub 2} films can result in distinct <span class="hlt">band</span> gap <span class="hlt">energies</span> in the bilayer structures. Such variations need to be accounted for when analyzing strain effects on <span class="hlt">electronic</span> properties of bilayer or multilayered 2D materials using experimental methods or in continuum models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004APS..DMP.F4004B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004APS..DMP.F4004B"><span><span class="hlt">Electron</span> impact ionization at relativistic <span class="hlt">energies</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Belkacem, Ali; Cole, Kyra; Hertlein, Marcus; Feinberg, Benedict; Schriel, Ralf; Adaniya, Hidehito; Neumann, Nadine</p> <p>2004-05-01</p> <p>We used an ion time-of-flight set up based on a pulsed high-voltage extraction technique to study the charge state distribution of He, Ne, Ar, Kr and Xe atoms after impact of 0.2 to 1.5 GeV <span class="hlt">electrons</span>. The relativistic <span class="hlt">electron</span> beam is produced at the booster beamline at the Advanced Light Source at the Lawrence Berkeley National Laboratory. The yield of ions drops drastically with the charge state number. Our measurements show that the ratio of doubly-charge to singly-charged ions reaches an asymptotic limit of 0.0028 for He already at <span class="hlt">electron</span> <span class="hlt">energies</span> below 40 MeV. However we observe a very pronounced <span class="hlt">energy</span> dependence of the ratio of the doubly-charged to singly-charged ions for the heavier atoms such as Kr and Xe in the 0.2 - 1.5 GeV <span class="hlt">energy</span> range. This <span class="hlt">energy</span> dependence takes place way above the <span class="hlt">energy</span> at which theories based on the equivalent photon method or the born- approximation predict the asymptotic limit to be reached. This may be an indication of new physics coming into play in the photoionization process due to relativistic effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21011229','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21011229"><span>Low-<span class="hlt">energy</span> <span class="hlt">electron</span> scattering by pyrazine</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Winstead, Carl; McKoy, Vincent</p> <p>2007-07-15</p> <p>We report cross sections for low-<span class="hlt">energy</span> elastic <span class="hlt">electron</span> collisions with the diazabenzene molecule pyrazine, obtained from first-principles calculations. The integral elastic cross section exhibits three sharp peaks that are nominally shape resonances associated with trapping in the vacant {pi}* molecular orbitals. Although the two lowest-<span class="hlt">energy</span> resonances do in fact prove to be nearly pure single-channel shape resonances, the third contains a considerable admixture of core-excited character, and accounting for this channel coupling effect is essential to obtaining an accurate resonance <span class="hlt">energy</span>. Such resonant channel coupling has implications for <span class="hlt">electron</span> interactions with the DNA bases, especially the pyrimidine bases for which pyrazine is a close analog. In the absence of data on pyrazine itself, we compare our elastic differential cross section to measurements on benzene and find close agreement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..GECVF1001H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..GECVF1001H"><span><span class="hlt">Electronic</span> excitation of molecular hydrogen by low-<span class="hlt">energy</span> <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hargreaves, Leigh</p> <p>2016-09-01</p> <p>Molecular hydrogen is the most abundant element in the universe, particularly in interstellar plasmas such as atmospheres of gas giant planets and stars. <span class="hlt">Electron</span> collision data for hydrogen is critical to interpreting the spectroscopy of interstellar objects, as well as being of applied value for modelling technological plasmas. Hydrogen is also fundamentally interesting, as while highly accurate wave functions for this simple molecule are available, providing an accurate, ab initio, treatment the collision dynamics has proven challenging, on account of the need to have a complete description of channel coupling and polarization effects. To date, no single theoretical approach has been able to replicate experimental results across all transitions and incident <span class="hlt">energies</span>, while the experimental database that is available is far from complete and not all available measurements are in satisfactory agreement. In this talk, we present differential and integral cross section measurements for <span class="hlt">electronic</span> excitation cross sections for molecular hydrogen by low-<span class="hlt">energy</span> <span class="hlt">electron</span> impact. The data were measured at incident <span class="hlt">energies</span> below 20eV, using a well-tested crossed beam apparatus and employing a moveable gas source approach to ensure that background contributions to the scattering are accurately accounted for. These measurements are compared with new theoretical results employing the convergent close coupling approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005OExpr..13.7683O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005OExpr..13.7683O"><span><span class="hlt">Electron</span> <span class="hlt">energy</span> loss and Smith-Purcell radiation in two- and three-dimensional photonic crystals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ochiai, Tetsuyuki; Ohtaka, Kazuo</p> <p>2005-09-01</p> <p>A theoretical description of the <span class="hlt">electron</span> <span class="hlt">energy</span> loss and the Smith-Purcell radiation is presented for an <span class="hlt">electron</span> moving near a two-dimensional photonic crystal slab and a three-dimensional woodpile photonic crystal. The <span class="hlt">electron</span> <span class="hlt">energy</span> loss and the Smith-Purcell radiation spectra are well correlated with the photonic <span class="hlt">band</span> structures of these crystals and thus can be used as a probe of them. In particular, there is a selection rule concerning the symmetries of the photonic <span class="hlt">band</span> modes to be excited when the <span class="hlt">electron</span> moves in a mirror plane of the crystals. In the woodpile, a highly directional Smith-Purcell radiation is realized by using the planar defect mode inside the complete <span class="hlt">band</span> gap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19498796','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19498796"><span><span class="hlt">Electron</span> <span class="hlt">energy</span> loss and Smith-Purcell radiation in two- and three-dimensional photonic crystals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ochiai, Tetsuyuki; Ohtaka, Kazuo</p> <p>2005-09-19</p> <p>A theoretical description of the <span class="hlt">electron</span> <span class="hlt">energy</span> loss and the Smith-Purcell radiation is presented for an <span class="hlt">electron</span> moving near a two-dimensional photonic crystal slab and a three-dimensional woodpile photonic crystal. The <span class="hlt">electron</span> <span class="hlt">energy</span> loss and the Smith-Purcell radiation spectra are well correlated with the photonic <span class="hlt">band</span> structures of these crystals and thus can be used as a probe of them. In particular, there is a selection rule concerning the symmetries of the photonic <span class="hlt">band</span> modes to be excited when the <span class="hlt">electron</span> moves in a mirror plane of the crystals. In the woodpile, a highly directional Smith-Purcell radiation is realized by using the planar defect mode inside the complete <span class="hlt">band</span> gap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JMMM..439..203H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JMMM..439..203H"><span>Spin- and valley-dependent <span class="hlt">electronic</span> <span class="hlt">band</span> structure and <span class="hlt">electronic</span> heat capacity of ferromagnetic silicene in the presence of strain, exchange field and Rashba spin-orbit coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hoi, Bui Dinh; Yarmohammadi, Mohsen; Kazzaz, Houshang Araghi</p> <p>2017-10-01</p> <p>We studied how the strain, induced exchange field and extrinsic Rashba spin-orbit coupling (RSOC) enhance the <span class="hlt">electronic</span> <span class="hlt">band</span> structure (EBS) and <span class="hlt">electronic</span> heat capacity (EHC) of ferromagnetic silicene in presence of external electric field (EF) by using the Kane-Mele Hamiltonian, Dirac cone approximation and the Green's function approach. Particular attention is paid to investigate the EHC of spin-up and spin-down <span class="hlt">bands</span> at Dirac K and K‧ points. We have varied the EF, strain, exchange field and RSOC to tune the <span class="hlt">energy</span> of inter-<span class="hlt">band</span> transitions and consequently EHC, leading to very promising features for future applications. Evaluation of EF exhibits three phases: Topological insulator (TI), valley-spin polarized metal (VSPM) and <span class="hlt">band</span> insulator (BI) at given aforementioned parameters. As a new finding, we have found a quantum anomalous Hall phase in BI regime at strong RSOCs. Interestingly, the effective mass of carriers changes with strain, resulting in EHC behaviors. Here, exchange field has the same behavior with EF. Finally, we have confirmed the reported and expected symmetry results for both Dirac points and spins with the study of valley-dependent EHC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM41F2559M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM41F2559M"><span>Observations of Multi-<span class="hlt">band</span> Structures in Double Star TC-1 PEACE <span class="hlt">Electron</span> and HIA Ion Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mohan Narasimhan, K.; Fazakerley, A. N.; Grimald, S.; Dandouras, I. S.; Mihaljcic, B.; Kistler, L. M.; Owen, C. J.</p> <p>2015-12-01</p> <p>Several authors have reported inner magnetosphere observations of proton distributions confined to narrow <span class="hlt">energy</span> <span class="hlt">bands</span> in the range 1 - 25 keV (Smith and Hoffman (1974), etc). These structures have been described as "nose structures", with reference to their appearance in <span class="hlt">energy</span>-time spectrograms and are also known as "<span class="hlt">bands</span>" if they occur for extended periods of time. Multi-nose structures have been observed if 2 or more noses appear at the same time (Vallat et al., 2007). Gaps between "noses" (or "<span class="hlt">bands</span>") have been explained in terms of the competing corotation, convection and magnetic gradient drifts. Charge exchange losses in slow drift paths for steady state scenarios and the role of substorm injections have also been considered (Li et al., 2000; Ebihara et al., 2004). We analyse observations of <span class="hlt">electron</span> and ion multi-<span class="hlt">band</span> structures frequently seen in Double-Star TC1 PEACE and HIA data. We present results from statistical surveys conducted using data from the duration of the mission. Furthermore, using a combination of both statistics and simulations, we test previous theories as to possible formation mechanisms and explore other possible explanations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApSS..417...64W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApSS..417...64W"><span>Laser-excitation of <span class="hlt">electrons</span> and nonequilibrium <span class="hlt">energy</span> transfer to phonons in copper</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weber, S. T.; Rethfeld, B.</p> <p>2017-09-01</p> <p>After the irradiation of a copper sample with an ultrashort laser pulse, <span class="hlt">electrons</span> do not follow a Fermi distribution anymore but instead are in a nonequilibrium state. In contrast, the lattice cannot be excited directly by the laser pulse, due to the frequency mismatch. The <span class="hlt">energy</span> increase in the phononic system only happens due to <span class="hlt">electron</span>-phonon scattering. We investigate the initial <span class="hlt">electron</span> dynamics using full Boltzmann-type collision integrals, including material-dependent characteristics by implementing a realistic density of states. We show results on the absorbed <span class="hlt">energy</span>, details of the <span class="hlt">electronic</span> nonequilibrium and the resulting <span class="hlt">electron</span>-phonon coupling parameter in dependence on the photon <span class="hlt">energy</span>. Our results show a counteracting dependence on the photon <span class="hlt">energy</span>, which, on the one hand, enables the d-<span class="hlt">band</span> <span class="hlt">electrons</span> to absorb high-<span class="hlt">energy</span> photons and on the other hand, increases the probability of multi-photon absorption.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94o5403Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94o5403Q"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structure effects in the stopping of protons in copper</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Quashie, Edwin E.; Saha, Bidhan C.; Correa, Alfredo A.</p> <p>2016-10-01</p> <p>We present an ab initio study of the <span class="hlt">electronic</span> stopping power of protons in copper over a wide range of proton velocities v =0.02 -10 a .u . where we take into account nonlinear effects. Time-dependent density functional theory coupled with molecular dynamics is used to study <span class="hlt">electronic</span> excitations produced by energetic protons. A plane-wave pseudopotential scheme is employed to solve the time-dependent Kohn-Sham equations for a moving ion in a periodic crystal. The <span class="hlt">electronic</span> excitations and the <span class="hlt">band</span> structure determine the stopping power of the material and alter the interatomic forces for both channeling and off-channeling trajectories. Our off-channeling results are in quantitative agreement with experiments, and at low velocity they unveil a crossover region of superlinear velocity dependence (with a power of ˜1.5 ) in the velocity range v =0.07 -0.3 a .u . , which we associate to the copper crystalline <span class="hlt">electronic</span> <span class="hlt">band</span> structure. The results are rationalized by simple <span class="hlt">band</span> models connecting two separate regimes. We find that the limit of <span class="hlt">electronic</span> stopping v →0 is not as simple as phenomenological models suggest and it is plagued by <span class="hlt">band</span>-structure effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015InJPh..89.1051R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015InJPh..89.1051R"><span>Dispersion of <span class="hlt">electronic</span> <span class="hlt">bands</span> in intermetallic compound LiBe and related properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reshak, A. H.</p> <p>2015-10-01</p> <p>Based on the all-<span class="hlt">electron</span> full-potential linearized augmented plane wave within density functional theory calculations dispersion of the <span class="hlt">electronic</span> <span class="hlt">band</span> structure, total and the angular momentum resolved projected density of states, the shape of Fermi surface, the <span class="hlt">electronic</span> charge density distribution and the optical response of the intermetallic LiBe compound are performed. Seeking the influence of the different exchange correlations on the ground state properties of the intermetallic LiBe, calculations are performed within four types of exchange correlations, namely the local density approximation, general gradient approximation, Engel-Vosko generalized gradient approximation and the modified Becke-Johnson potential. It has been found that replacing the exchange correlations exhibit insignificant influence on the <span class="hlt">bands</span> dispersion, density of states and hence the optical properties. The obtained results suggest that there exists a strong hybridization between the states resulting in covalent bonds. The Fermi surface is formed by two <span class="hlt">bands</span> and the center of the Fermi surface is formed by holes. The <span class="hlt">electronic</span> charge density distribution confirms that the charge is attracted toward Be atoms and the calculated bond lengths are in good accordance with the available experimental data. To get deep insight into the <span class="hlt">electronic</span> structure, the optical properties are investigated and analyzed in accordance with the calculated <span class="hlt">band</span> structure and the density of states.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhD...50NLT02G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhD...50NLT02G"><span>A novel theoretical model for the temperature dependence of <span class="hlt">band</span> gap <span class="hlt">energy</span> in semiconductors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geng, Peiji; Li, Weiguo; Zhang, Xianhe; Zhang, Xuyao; Deng, Yong; Kou, Haibo</p> <p>2017-10-01</p> <p>We report a novel theoretical model without any fitting parameters for the temperature dependence of <span class="hlt">band</span> gap <span class="hlt">energy</span> in semiconductors. This model relates the <span class="hlt">band</span> gap <span class="hlt">energy</span> at the elevated temperature to that at the arbitrary reference temperature. As examples, the <span class="hlt">band</span> gap <span class="hlt">energies</span> of Si, Ge, AlN, GaN, InP, InAs, ZnO, ZnS, ZnSe and GaAs at temperatures below 400 K are calculated and are in good agreement with the experimental results. Meanwhile, the <span class="hlt">band</span> gap <span class="hlt">energies</span> at high temperatures (T  >  400 K) are predicted, which are greater than the experimental results, and the reasonable analysis is carried out as well. Under low temperatures, the effect of lattice expansion on the <span class="hlt">band</span> gap <span class="hlt">energy</span> is very small, but it has much influence on the <span class="hlt">band</span> gap <span class="hlt">energy</span> at high temperatures. Therefore, it is necessary to consider the effect of lattice expansion at high temperatures, and the method considering the effect of lattice expansion has also been given. The model has distinct advantages compared with the widely quoted Varshni’s semi-empirical equation from the aspect of modeling, physical meaning and application. The study provides a convenient method to determine the <span class="hlt">band</span> gap <span class="hlt">energy</span> under different temperatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22494991','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22494991"><span>Sub-<span class="hlt">band</span> gap photo-enhanced secondary <span class="hlt">electron</span> emission from high-purity single-crystal chemical-vapor-deposited diamond</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yater, J. E. Shaw, J. L.; Pate, B. B.; Feygelson, T. I.</p> <p>2016-02-07</p> <p>Secondary-<span class="hlt">electron</span>-emission (SEE) current measured from high-purity, single-crystal (100) chemical-vapor-deposited diamond is found to increase when sub-<span class="hlt">band</span> gap (3.06 eV) photons are incident on the hydrogenated surface. Although the light does not produce photoemission directly, the SEE current increases by more than a factor of 2 before saturating with increasing laser power. In <span class="hlt">energy</span> distribution curves (EDCs), the emission peak shows a corresponding increase in intensity with increasing laser power. However, the emission-onset <span class="hlt">energy</span> in the EDCs remains constant, indicating that the <span class="hlt">bands</span> are pinned at the surface. On the other hand, changes are observed on the high-<span class="hlt">energy</span> side of the distribution as the laser power increases, with a well-defined shoulder becoming more pronounced. From an analysis of this feature in the EDCs, it is deduced that upward <span class="hlt">band</span> bending is present in the near-surface region during the SEE measurements and this <span class="hlt">band</span> bending suppresses the SEE yield. However, sub-<span class="hlt">band</span> gap photon illumination reduces the <span class="hlt">band</span> bending and thereby increases the SEE current. Because the <span class="hlt">bands</span> are pinned at the surface, we conclude that the changes in the <span class="hlt">band</span> levels occur below the surface in the <span class="hlt">electron</span> transport region. Sample heating produces similar effects as observed with sub-<span class="hlt">band</span> gap photon illumination, namely, an increase in SEE current and a reduction in <span class="hlt">band</span> bending. However, the upward <span class="hlt">band</span> bending is not fully removed by either increasing laser power or temperature, and a minimum <span class="hlt">band</span> bending of ∼0.8 eV is established in both cases. The sub-<span class="hlt">band</span> gap photo-excitation mechanism is under further investigation, although it appears likely at present that defect or gap states play a role in the photo-enhanced SEE process. In the meantime, the study demonstrates the ability of visible light to modify the <span class="hlt">electronic</span> properties of diamond and enhance the emission capabilities, which may have potential impact for diamond-based vacuum <span class="hlt">electron</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JAP...119e5703Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JAP...119e5703Y"><span>Sub-<span class="hlt">band</span> gap photo-enhanced secondary <span class="hlt">electron</span> emission from high-purity single-crystal chemical-vapor-deposited diamond</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yater, J. E.; Shaw, J. L.; Pate, B. B.; Feygelson, T. I.</p> <p>2016-02-01</p> <p>Secondary-<span class="hlt">electron</span>-emission (SEE) current measured from high-purity, single-crystal (100) chemical-vapor-deposited diamond is found to increase when sub-<span class="hlt">band</span> gap (3.06 eV) photons are incident on the hydrogenated surface. Although the light does not produce photoemission directly, the SEE current increases by more than a factor of 2 before saturating with increasing laser power. In <span class="hlt">energy</span> distribution curves (EDCs), the emission peak shows a corresponding increase in intensity with increasing laser power. However, the emission-onset <span class="hlt">energy</span> in the EDCs remains constant, indicating that the <span class="hlt">bands</span> are pinned at the surface. On the other hand, changes are observed on the high-<span class="hlt">energy</span> side of the distribution as the laser power increases, with a well-defined shoulder becoming more pronounced. From an analysis of this feature in the EDCs, it is deduced that upward <span class="hlt">band</span> bending is present in the near-surface region during the SEE measurements and this <span class="hlt">band</span> bending suppresses the SEE yield. However, sub-<span class="hlt">band</span> gap photon illumination reduces the <span class="hlt">band</span> bending and thereby increases the SEE current. Because the <span class="hlt">bands</span> are pinned at the surface, we conclude that the changes in the <span class="hlt">band</span> levels occur below the surface in the <span class="hlt">electron</span> transport region. Sample heating produces similar effects as observed with sub-<span class="hlt">band</span> gap photon illumination, namely, an increase in SEE current and a reduction in <span class="hlt">band</span> bending. However, the upward <span class="hlt">band</span> bending is not fully removed by either increasing laser power or temperature, and a minimum <span class="hlt">band</span> bending of ˜0.8 eV is established in both cases. The sub-<span class="hlt">band</span> gap photo-excitation mechanism is under further investigation, although it appears likely at present that defect or gap states play a role in the photo-enhanced SEE process. In the meantime, the study demonstrates the ability of visible light to modify the <span class="hlt">electronic</span> properties of diamond and enhance the emission capabilities, which may have potential impact for diamond-based vacuum <span class="hlt">electron</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JPhCS.388a2014L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPhCS.388a2014L"><span>Low <span class="hlt">Energy</span> <span class="hlt">Electron</span> Scattering from Fuels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lopes, M. C. A.; Silva, D. G. M.; Bettega, M. H. F.; da Costa, R. F.; Lima, M. A. P.; Khakoo, M. A.; Winstead, C.; McKoy, V.</p> <p>2012-11-01</p> <p>In order to understand and optimize processes occurring during the ignition of plasma and its consequences in post-discharge for an internal combustion engine, especially considering the spark plug, we have produced in this work some basic information necessary to modeling spark ignition in alcohol- fuelled engines. Total cross sections of <span class="hlt">electron</span> scattering by methanol and ethanol molecules in the <span class="hlt">energy</span> range from 60 to 500 eV are reported, using the linear transmission method based on the Beer-Lambert law to first approximation. Aditionally to that, measurements and calculations of differential cross sections for elastic low-<span class="hlt">energy</span> (rotationally unresolved) <span class="hlt">electron</span> scattering were also discussed, for impact <span class="hlt">energies</span> of 1, 2, 5, 10, 15, 20, 30, 50, and 100 eV and for scattering angles of 5°-130°. The measurements were obtained using the relative flow method with an aperture source, and calculations using two different implementations of the Schwinger multichannel method, one that takes all <span class="hlt">electrons</span> into account and is adapted for parallel computers, and another that uses pseudopotentials and considers only the valence <span class="hlt">electrons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvM...1b4606L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvM...1b4606L"><span>Quasiparticle self-consistent G W <span class="hlt">electronic</span> <span class="hlt">band</span> structure of Cd-IV-N2 compounds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lyu, Sai; Lambrecht, Walter R. L.</p> <p>2017-07-01</p> <p>Quasiparticle self-consistent G W calculations of the <span class="hlt">electronic</span> <span class="hlt">band</span> structures of Cd-IV-N2 with group-IV elements, Si, Ge, and Sn, are reported. The lattice parameters in the P n a 21 crystal structure are obtained both in the local density approximation and generalized gradient approximation (GGA) and provide respectively an underestimate and overestimate of the lattice constants for these until now not synthesized materials. The Wyckoff positions are obtained by structural minimization. At the GGA lattice constant, which is expected to be the most reliable, CdSiN2 is found to have an indirect gap (U -Γ ) of 2.72 eV, which is 0.55 eV lower than the direct gap at Γ of 3.27 eV. In CdGeN2, the indirect gap of 2.01 eV is only 0.1 eV smaller than the direct gap of 2.11 eV, and in CdSnN2 the gap is direct and equals 0.64 eV close to that of InN, as expected. The direct/indirect nature of CdGeN2 is found to be sensitive to shear strain. The conduction <span class="hlt">band</span> effective masses decrease from CdSiN2 to CdGeN2 to CdSnSn2. The <span class="hlt">energies</span> of formation indicate these materials to be stable with the possible exception of CdSnN2.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012APS..MARX10003G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012APS..MARX10003G"><span>Pushing the limits of first-principles <span class="hlt">electron</span>-phonon calculations: from photoemission kinks to <span class="hlt">band</span> gaps</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Giustino, Feliciano</p> <p>2012-02-01</p> <p>The <span class="hlt">electron</span>-phonon interaction is key to some of the most intriguing and technologically important phenomena in condensed matter physics, ranging from superconductivity to charge density waves, electrical resistivity, and thermoelectricity. Starting from the late nineties first-principles calculations of <span class="hlt">electron</span>-phonon interactions in metals have become increasingly popular, mainly in connection with the study of conventional superconductors and with the interpretation of angle-resolved photoemission experiments. In contrast, progress on first-principles calculations of <span class="hlt">electron</span>-phonon interactions in insulators has been comparatively slower. This delay is arguably due to the conventional wisdom that the signatures of <span class="hlt">electron</span>-phonon interactions in semiconductor <span class="hlt">band</span> structures are so small that they fall within the error bar of the most accurate <span class="hlt">electronic</span> structure calculations. In order to fill this gap we developed, within the context of state-of-the-art density-functional techniques, a theory proposed by Allen and Heine for calculating the temperature dependence of <span class="hlt">band</span> gaps in semiconductors [P. B. Allen, V. Heine, J. Phys. C: Solid State Phys. 69, 2305 (1976)]. This methodology allows us to calculate both the temperature dependence of the quasiparticle <span class="hlt">energies</span> and the renormalization due to zero-point quantum fluctuations. In order to demonstrate this technique an application to the intriguing case of diamond will be discussed [F. Giustino, S. G. Louie, M. L. Cohen, Phys. Rev. Lett. 105, 265501 (2010)]. In this case the calculated temperature dependence of the direct <span class="hlt">band</span> gap agrees well with spectroscopic ellipsometry data, and the renormalization due to the <span class="hlt">electron</span>-phonon interaction is found to be spectacularly large (>0.6 eV). This unexpected finding might be only the tip of the iceberg in a research area which remains largely unexplored and which, from a first glimpse, appears rich of surprises.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyB..481..104D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyB..481..104D"><span>Threshold conditions, <span class="hlt">energy</span> spectrum and <span class="hlt">bands</span> generated by locally periodic Dirac comb potentials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dharani, M.; Shastry, C. S.</p> <p>2016-01-01</p> <p>We derive expressions for polynomials governing the threshold conditions for different types of locally periodic Dirac comb potentials comprising of attractive and combination of attractive and repulsive delta potential terms confined symmetrically inside a one dimensional box of fixed length. The roots of these polynomials specify the conditions on the potential parameters in order to generate threshold <span class="hlt">energy</span> bound states. The mathematical and numerical methods used by us were first formulated in our earlier works and it is also very briefly summarized in this paper. We report a number of mathematical results pertaining to the threshold conditions and these are useful in controlling the number of negative <span class="hlt">energy</span> states as desired. We further demonstrate the correlation between the distribution of roots of these polynomials and negative <span class="hlt">energy</span> eigenvalues. Using these results as basis, we investigate the <span class="hlt">energy</span> <span class="hlt">bands</span> in the positive <span class="hlt">energy</span> spectrum for the above specified Dirac comb potentials and also for the corresponding repulsive case. In the case of attractive Dirac comb the base <span class="hlt">energy</span> of the each <span class="hlt">band</span> excluding the first <span class="hlt">band</span> coincides with specific eigenvalue of the confining box whereas in the repulsive case it coincides with the <span class="hlt">band</span> top. We deduce systematic correlation between <span class="hlt">band</span> gaps, <span class="hlt">band</span> spreads and box eigenvalues and explain the physical reason for the vanishing of <span class="hlt">band</span> pattern at higher <span class="hlt">energies</span>. In the case of Dirac comb comprising of orderly arranged attractive and repulsive delta potentials, specific box eigenvalues occur in the middle of each <span class="hlt">band</span> excluding the first <span class="hlt">band</span>. From our study we find that by controlling the number and strength parameters of delta terms in the Dirac comb and the size of confining box it is possible to generate desired types of <span class="hlt">band</span> formations. We believe the results from our systematic analysis are useful and relevant in the study of various one dimensional systems of physical interest in areas like nanoscience.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011APS..GECJW2010R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011APS..GECJW2010R"><span>Low <span class="hlt">Energy</span> <span class="hlt">Electron</span> Impact Excitation of Water</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ralphs, Kevin; Serna, Gabriela; Hargreaves, Leigh R.; Khakoo, Murtadha A.; Winstead, Carl; McKoy, B. Vincent</p> <p>2011-10-01</p> <p>We present normalized absolute differential and integral cross-section measurements for the low <span class="hlt">energy</span> <span class="hlt">electron</span> impact excitation of the lowest dissociative 3B1, 1B1,3A1 and 1A1 states of H2O. The DCS were taken at incident <span class="hlt">energies</span> of 9 eV, 10 eV, 12 eV, 15 eV and 20 eV and scattering angles of 15° to 130° and normalized to the elastic <span class="hlt">electron</span> scattering measurements of. The DCS were obtained after a sophisticated unfolding of the <span class="hlt">electron</span> <span class="hlt">energy</span> loss spectrum of water using photoabsorption data in the literature as investigated by Thorn et al.. Our measurements extend those of to near-threshold <span class="hlt">energies</span>. We find both important agreements and differences between our DCS and those of. Comparison to our theory (multi-channel Schwinger) and that of earlier work will also be presented. Funded by an NSF grant # RUI-PHY 0968874.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EPJD...71..226L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EPJD...71..226L"><span>Low <span class="hlt">energy</span> <span class="hlt">electron</span> transport in furfural</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lozano, Ana I.; Krupa, Kateryna; Ferreira da Silva, Filipe; Limão-Vieira, Paulo; Blanco, Francisco; Muñoz, Antonio; Jones, Darryl B.; Brunger, Michael J.; García, Gustavo</p> <p>2017-09-01</p> <p>We report on an initial investigation into the transport of <span class="hlt">electrons</span> through a gas cell containing 1 mTorr of gaseous furfural. Results from our Monte Carlo simulation are implicitly checked against those from a corresponding <span class="hlt">electron</span> transmission measurement. To enable this simulation a self-consistent cross section data base was constructed. This data base is benchmarked through new total cross section measurements which are also described here. In addition, again to facilitate the simulation, our preferred <span class="hlt">energy</span> loss distribution function is presented and discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJT....37..108S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJT....37..108S"><span><span class="hlt">Energy</span> <span class="hlt">Bands</span> and Thermoelectricity of Filled Skutterudite EuRu4As_{12}</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shankar, A.; Rai, D. P.; Sandeep; Khenata, R.; Thapa, R. K.; Mandal, P. K.</p> <p>2016-11-01</p> <p>Density functional theory-based calculations of the elastic and <span class="hlt">electronic</span> properties with magnetic moments of the filled skutterudite EuRu4As_{12} have been performed in its ferromagnetic ground state. The full-potential linearized augmented plane wave (FP-LAPW) method has been used for the study presented here. The numerical values of the elastic parameters are estimated within the framework of the Voigt-Reuss-Hill approximations. The <span class="hlt">energy</span> <span class="hlt">band</span> structure calculation performed near the Fermi <span class="hlt">energy</span> level shows the metallic nature of the material with a high value of Seebeck coefficient ( S). The presence of an exchange splitting of Eu-4 f states suggests their appreciable contribution toward the magnetic behavior. The analysis of the thermal transport properties confirms the result obtained from the <span class="hlt">electronic</span> structure calculation with Seebeck coefficient of 118 μ{V/K} and the figure of merit ( ZT) value of 0.51, at room temperature. The estimated values of S and ZT indicate the possibility of the thermoelectric applications of the sample material.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007APS..MAR.N9015K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007APS..MAR.N9015K"><span>Dual character of the <span class="hlt">electronic</span> structure in YBa2Cu4O8: conduction <span class="hlt">bands</span> of CuO2 planes and CuO chains</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaminski, A.; Kondo, T.; Khasanov, R.; Karpinski, J.; Kazakov, S. M.; Zhigadlo, N. D.; Ohta, T.; Fretwell, H. M.; Palczewski, A. D.; Koll, J. D.; Mesot, J.; Rotenberg, E.; Keller, H.</p> <p>2007-03-01</p> <p>We use microprobe Angle-Resolved Photoemission Spectroscopy (μARPES) to separately investigate the <span class="hlt">electronic</span> properties of CuO2 planes and CuO chains in the high temperature superconductor, YBa2Cu4O8. In the CuO2 planes, a two dimensional (2D) <span class="hlt">electronic</span> structure with nearly momentum independent bilayer splitting is observed. The splitting <span class="hlt">energy</span> is 150 meV at (π,0), almost 50% larger than in Bi2Sr2CaCu2O8+δ and the <span class="hlt">electron</span> scattering at the Fermi level in the bonding <span class="hlt">band</span> is about 1.5 times stronger than in the antibonding <span class="hlt">band</span>. The CuO chains have a quasi one dimensional (1D) <span class="hlt">electronic</span> structure. We observe two 1D <span class="hlt">bands</span> separated by ˜ 550meV: a conducting <span class="hlt">band</span> and an insulating <span class="hlt">band</span> with an <span class="hlt">energy</span> gap of ˜240meV. We find that the conduction <span class="hlt">electrons</span> are well confined within the planes and chains with a non-trivial hybridization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..94t5126K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..94t5126K"><span>A free-<span class="hlt">electron</span> model for the Dirac <span class="hlt">bands</span> in graphene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kissinger, G. S.; Satpathy, S.</p> <p>2016-11-01</p> <p>We present a new method for describing the <span class="hlt">electronic</span> structure of graphene, by treating the honeycomb lattice as an arrangement of crisscrossing one-dimensional quantum wires. The <span class="hlt">electrons</span> travel as free particles along the wires and interfere at the three-way junctions formed by the carbon atoms. The approach produces the linearly dispersive Dirac <span class="hlt">band</span> structure as well as the chiral pseudo-spin-wave functions. When vacancies are incorporated, the model reproduces the well known zero mode states.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvP...7c4011M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvP...7c4011M"><span>Substitutional <span class="hlt">Electron</span> and Hole Doping of WSe2 : Synthesis, Electrical Characterization, and Observation of <span class="hlt">Band-to-Band</span> Tunneling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mukherjee, R.; Chuang, H. J.; Koehler, M. R.; Combs, N.; Patchen, A.; Zhou, Z. X.; Mandrus, D.</p> <p>2017-03-01</p> <p>Transition-metal dichalcogenides (TMDs) such as MoS2 , MoSe2 , and WSe2 have emerged as promising two-dimensional semiconductors. Many anticipated applications of these materials require both p -type and n -type TMDs with long-term doping stability. Here, we report on the synthesis of substitutionally doped WSe2 crystals using Nb and Re as p - and n -type dopants, respectively. Hall coefficient and gate-dependent transport measurements reveal drastically different doping properties between nominally 0.5% Nb- and 0.5% Re-doped WSe2 . While 0.5% Nb-doped WSe2 (WSe2∶Nb ) is degenerately hole doped with a nearly temperature-independent carrier density of approximately 1019 cm-3 , <span class="hlt">electrons</span> in 0.5% Re-doped WSe2 (WSe2 ∶Re ) are largely trapped in localized states below the mobility edge and exhibit thermally activated behavior. Charge transport in both WSe2∶Nb and WSe2 ∶Re is found to be limited by Coulomb scattering from ionized impurities. Furthermore, we fabricate vertical van der Waals-junction diodes consisting of multilayers of WSe2∶Nb and WSe2 ∶Re . Finally, we demonstrate reverse rectifying behavior as a direct proof of <span class="hlt">band-to-band</span> tunneling in our WSe2∶Nb /WSe2∶Re diodes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23402585','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23402585"><span>Microstructure and <span class="hlt">electronic</span> <span class="hlt">band</span> structure of pulsed laser deposited iron fluoride thin film for battery electrodes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Santos-Ortiz, Reinaldo; Volkov, Vyacheslav; Schmid, Stefan; Kuo, Fang-Ling; Kisslinger, Kim; Nag, Soumya; Banerjee, Rajarshi; Zhu, Yimei; Shepherd, Nigel D</p> <p>2013-04-10</p> <p>Battery electrodes in thin-film form are free of the binders used with traditional powder electrodes and present an ideal platform to obtain basic insight to the evolution of the electrode-electrolyte interface passivation layer, the formation of secondary phases, and the structural underpinnings of reversibility. This is particularly relevant to the not yet fully understood conversion electrode materials, which possess enormous potential for providing transformative capacity improvements in next-generation lithium-ion batteries. However, this necessitates an understanding of the <span class="hlt">electronic</span> charge transport properties and <span class="hlt">band</span> structure of the thin films. This work presents an investigation of the <span class="hlt">electron</span> transport properties of iron fluoride (FeF2) thin-film electrodes for Li-ion batteries. FeF2 thin films were prepared by pulsed-laser deposition, and their phase purity was characterized by <span class="hlt">electron</span> microscopy and diffraction. The grown materials are polycrystalline FeF2 with a P42/mnm crystallographic symmetry. Room-temperature Hall measurements reveal that as-deposited FeF2 is n-type: the Hall coefficients were negative, <span class="hlt">electron</span> mobility was 0.33 cm2/(V s) and resistivity was 0.255 Ω cm. The <span class="hlt">electronic</span> <span class="hlt">band</span> diagram of FeF2 was obtained using a combination of ultraviolet photoelectron spectroscopy, photoluminescence, photoluminescence excitation and optical absorption, which revealed that FeF2 is a direct bandgap, n-type semiconductor whose <span class="hlt">band</span> structure is characterized by a 3.4 eV bandgap, a workfunction of ∼4.51 eV, and an effective Fermi level that resides approximately 0.22 eV below the conduction <span class="hlt">band</span> edge. We propose that the shallow donor levels at 0.22 eV are responsible for the measured n-type conductivity. The <span class="hlt">band</span> diagram was used to understand <span class="hlt">electron</span> transport in FeF2 thin film and FeF2-C composite electrodes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PhRvB..73k5333Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PhRvB..73k5333Y"><span><span class="hlt">Electronic</span> states in Ge/Si quantum dots with type-II <span class="hlt">band</span> alignment initiated by space-charge spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yakimov, A. I.; Dvurechenskii, A. V.; Nikiforov, A. I.; Bloshkin, A. A.; Nenashev, A. V.; Volodin, V. A.</p> <p>2006-03-01</p> <p>Space-charge spectroscopy was employed to study <span class="hlt">electronic</span> structure of a stack of four layers of Ge quantum dots (QD’s) coherently embedded in an n -type Si(001) matrix. Evidence for an <span class="hlt">electron</span> confinement in Si in the vicinity of neutral Ge dots was found. From the temperature- and frequency-dependent measurements the <span class="hlt">electron</span> binding <span class="hlt">energy</span> was determined to be ˜50meV . Existence of localized <span class="hlt">electronic</span> states is explained by a modification of the conduction <span class="hlt">band</span> alignment induced by inhomogeneous tensile strain in Si around the buried Ge dots. To support experimental results we performed numerical analysis of three-dimensional strain distribution and <span class="hlt">electronic</span> structure of the sample under investigation. The strain distribution was found in terms of atomic positions using a valence-force-field model with a Keating interatomic potential. The <span class="hlt">electronic</span> <span class="hlt">energy</span> levels were calculated by solving a three-dimensional effective mass Schrödinger equation. The carrier confinement potential in this equation is modified by the strain distribution. The calculated confined eigenenergies agree with our experimental values deduced from the admittance spectroscopy. The data obtained in this work may serve as a guideline to interpret efficient photo- and electroluminescence as well as enhanced quantum efficiency of photodetectors and solar cells with Ge QD’s stacked in a multilayer structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/901232','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/901232"><span><span class="hlt">Band</span> gap bowing and <span class="hlt">electron</span> localization of (GaxIn1-x)N</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lee, Byounghak; Wang, Lin-Wang</p> <p>2006-05-09</p> <p>The <span class="hlt">band</span> gap bowing and the <span class="hlt">electron</span> localization ofGaxIn1-xN are calculated using both the local density approximation (LDA)and screened-exchange local density functional (sX-LDA) methods. Thecalculated sX-LDA <span class="hlt">band</span> gaps are in good agreement with the experimentallyobserved values, with errors of -0.26 and 0.09 eV for bulk GaN and InN,respectively. The LDA <span class="hlt">band</span> gap errors are 1.33 and 0.81 eV for GaN andInN, in order. In contrast to the gap itself, the <span class="hlt">band</span> gap bowingparameter is found to be very similar in sX-LDA and LDA. We identify thelocalization of hole states in GaxIn1-xN alloys along In-N-In chains. Thepredicted localizationis stronger in sX-LDA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26247853','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26247853"><span><span class="hlt">Energy</span> Impacts of Wide <span class="hlt">Band</span> Gap Semiconductors in U.S. Light-Duty Electric Vehicle Fleet.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Warren, Joshua A; Riddle, Matthew E; Graziano, Diane J; Das, Sujit; Upadhyayula, Venkata K K; Masanet, Eric; Cresko, Joe</p> <p>2015-09-01</p> <p>Silicon carbide and gallium nitride, two leading wide <span class="hlt">band</span> gap semiconductors with significant potential in electric vehicle power <span class="hlt">electronics</span>, are examined from a life cycle <span class="hlt">energy</span> perspective and compared with incumbent silicon in U.S. light-duty electric vehicle fleet. Cradle-to-gate, silicon carbide is estimated to require more than twice the <span class="hlt">energy</span> as silicon. However, the magnitude of vehicle use phase fuel savings potential is comparatively several orders of magnitude higher than the marginal increase in cradle-to-gate <span class="hlt">energy</span>. Gallium nitride cradle-to-gate <span class="hlt">energy</span> requirements are estimated to be similar to silicon, with use phase savings potential similar to or exceeding that of silicon carbide. Potential <span class="hlt">energy</span> reductions in the United States vehicle fleet are examined through several scenarios that consider the market adoption potential of electric vehicles themselves, as well as the market adoption potential of wide <span class="hlt">band</span> gap semiconductors in electric vehicles. For the 2015-2050 time frame, cumulative <span class="hlt">energy</span> savings associated with the deployment of wide <span class="hlt">band</span> gap semiconductors are estimated to range from 2-20 billion GJ depending on market adoption dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1254851','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1254851"><span>Valence-<span class="hlt">band</span> <span class="hlt">electronic</span> structure evolution of graphene oxide upon thermal annealing for optoelectronics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yamaguchi, Hisato; Ogawa, Shuichi; Watanabe, Daiki; Hozumi, Hideaki; Gao, Yongqian; Eda, Goki; Mattevi, Cecilia; Fujita, Takeshi; Yoshigoe, Akitaka; Ishizuka, Shinji; Adamska, Lyudmyla; Yamada, Takatoshi; Dattelbaum, Andrew M.; Gupta, Gautam; Doorn, Stephen K.; Velizhanin, Kirill A.; Teraoka, Yuden; Chen, Mingwei; Htoon, Han; Chhowalla, Manish; Mohite, Aditya D.; Takakuwa, Yuji</p> <p>2016-09-01</p> <p>We report valence <span class="hlt">band</span> <span class="hlt">electronic</span> structure evolution of graphene oxide (GO) upon its thermal reduction. Degree of oxygen functionalization was controlled by annealing temperatures, and an <span class="hlt">electronic</span> structure evolution was monitored using real-time ultraviolet photoelectron spectroscopy. We observed a drastic increase in density of states around the Fermi level upon thermal annealing at ~600 °C. The result indicates that while there is an apparent <span class="hlt">band</span> gap for GO prior to a thermal reduction, the gap closes after an annealing around that temperature. This trend of <span class="hlt">band</span> gap closure was correlated with electrical, chemical, and structural properties to determine a set of GO material properties that is optimal for optoelectronics. The results revealed that annealing at a temperature of ~500 °C leads to the desired properties, demonstrated by a uniform and an order of magnitude enhanced photocurrent map of an individual GO sheet compared to as-synthesized counterpart.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1254851-valence-band-electronic-structure-evolution-graphene-oxide-upon-thermal-annealing-optoelectronics','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1254851-valence-band-electronic-structure-evolution-graphene-oxide-upon-thermal-annealing-optoelectronics"><span>Valence-<span class="hlt">band</span> <span class="hlt">electronic</span> structure evolution of graphene oxide upon thermal annealing for optoelectronics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Yamaguchi, Hisato; Ogawa, Shuichi; Watanabe, Daiki; ...</p> <p>2016-09-01</p> <p>We report valence <span class="hlt">band</span> <span class="hlt">electronic</span> structure evolution of graphene oxide (GO) upon its thermal reduction. Degree of oxygen functionalization was controlled by annealing temperatures, and an <span class="hlt">electronic</span> structure evolution was monitored using real-time ultraviolet photoelectron spectroscopy. We observed a drastic increase in density of states around the Fermi level upon thermal annealing at ~600 °C. The result indicates that while there is an apparent <span class="hlt">band</span> gap for GO prior to a thermal reduction, the gap closes after an annealing around that temperature. This trend of <span class="hlt">band</span> gap closure was correlated with electrical, chemical, and structural properties to determine a setmore » of GO material properties that is optimal for optoelectronics. The results revealed that annealing at a temperature of ~500 °C leads to the desired properties, demonstrated by a uniform and an order of magnitude enhanced photocurrent map of an individual GO sheet compared to as-synthesized counterpart.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1254851','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1254851"><span>Valence-<span class="hlt">band</span> <span class="hlt">electronic</span> structure evolution of graphene oxide upon thermal annealing for optoelectronics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yamaguchi, Hisato; Ogawa, Shuichi; Watanabe, Daiki; Hozumi, Hideaki; Gao, Yongqian; Eda, Goki; Mattevi, Cecilia; Fujita, Takeshi; Yoshigoe, Akitaka; Ishizuka, Shinji; Adamska, Lyudmyla; Yamada, Takatoshi; Dattelbaum, Andrew M.; Gupta, Gautam; Doorn, Stephen K.; Velizhanin, Kirill A.; Teraoka, Yuden; Chen, Mingwei; Htoon, Han; Chhowalla, Manish; Mohite, Aditya D.; Takakuwa, Yuji</p> <p>2016-09-01</p> <p>We report valence <span class="hlt">band</span> <span class="hlt">electronic</span> structure evolution of graphene oxide (GO) upon its thermal reduction. Degree of oxygen functionalization was controlled by annealing temperatures, and an <span class="hlt">electronic</span> structure evolution was monitored using real-time ultraviolet photoelectron spectroscopy. We observed a drastic increase in density of states around the Fermi level upon thermal annealing at ~600 °C. The result indicates that while there is an apparent <span class="hlt">band</span> gap for GO prior to a thermal reduction, the gap closes after an annealing around that temperature. This trend of <span class="hlt">band</span> gap closure was correlated with electrical, chemical, and structural properties to determine a set of GO material properties that is optimal for optoelectronics. The results revealed that annealing at a temperature of ~500 °C leads to the desired properties, demonstrated by a uniform and an order of magnitude enhanced photocurrent map of an individual GO sheet compared to as-synthesized counterpart.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19730057110&hterms=ELF+Receiver&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DELF%2BReceiver','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19730057110&hterms=ELF+Receiver&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DELF%2BReceiver"><span><span class="hlt">Electron</span> concentrations calculated from the lower hybrid resonance noise <span class="hlt">band</span> observed by Ogo 3.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burtis, W. J.</p> <p>1973-01-01</p> <p>A noise <span class="hlt">band</span> at the lower hybrid resonance (LHR) is often detected by the VLF and ELF receivers on Ogo 3, using the electric antenna. In some cases the noise <span class="hlt">band</span> is at the geometric mean gyrofrequency as measured by the Goddard Space Flight Center (GSFC) magnetometer, and local LHR in a dense H(+) plasma is indicated; in such cases, <span class="hlt">electron</span> concentration can be calculated, if it is assumed that heavy ions are negligible. Observations at midlatitudes and altitudes of a few earth radii show local concentrations as low as 1.4 <span class="hlt">electrons</span>/cu cm. In one case the concentrations obtained from the LHR noise <span class="hlt">band</span> agree with those measured simultaneously by the GSFC ion mass spectrometer within a factor of 2. In another case the concentration is observed to fall by a factor of 2 in 150 km and then to decrease roughly as R to the minus fourth power, in agreement with whistler measurements outside the plasmapause.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012APS..DMP.C3004L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012APS..DMP.C3004L"><span>Low <span class="hlt">Energy</span> <span class="hlt">Electron</span> Scattering from Fuels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lopes, M. Cristina A.</p> <p>2012-06-01</p> <p>We report an investigation of processes that occur during the ignition of the plasma and its consequences in post-discharge time for an internal combustion engine, in order to find the appropriate parameters to be used in cars that operate with lean mixtures air-fuel. The relevance of this theme has attracted much attention, and has been one of the subjects of collaboration between experimental and theoretical groups in the USA and Brazil. We have produced some basic information necessary to modeling spark ignition in alcohol- fuelled engines. Total cross sections of <span class="hlt">electron</span> scattering by methanol and ethanol molecules were obtained, using the linear transmission method based on the Beer-Lambert law to first approximation. Measurements and calculations of differential cross sections for low-<span class="hlt">energy</span> (rotationally unresolved) <span class="hlt">electron</span> scattering were also obtained, for scattering angles of 5 --130 . The measurements were taken using the relative flow method with an aperture source, and calculations using two different implementations of the Schwinger multichannel method, one that takes all <span class="hlt">electrons</span> into account and is adapted for parallel computers, and another that uses pseudopotentials and considers only the valence <span class="hlt">electrons</span>. Additionally to these, computer simulation studies of <span class="hlt">electronic</span> discharge in mixtures of ethanol were performed, using a Zero-Dimensional Plasma Kinetic solver. Previous reported models for combustion of ethanol and cross sections data for momentum transfer of <span class="hlt">electron</span> collisions with ethanol were used. The time evolutions of the main species densities are reported and the ignition time delay discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPSJ...85g4707N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPSJ...85g4707N"><span>Multi-<span class="hlt">band</span> Eilenberger Theory of Superconductivity: Systematic Low-<span class="hlt">Energy</span> Projection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nagai, Yuki; Nakamura, Hiroki</p> <p>2016-07-01</p> <p>We propose the general multi-<span class="hlt">band</span> quasiclassical Eilenberger theory of superconductivity to describe quasiparticle excitations in inhomogeneous systems. With the use of low-<span class="hlt">energy</span> projection matrix, the M-<span class="hlt">band</span> quasiclassical Eilenberger equations are systematically obtained from N-<span class="hlt">band</span> Gor'kov equations. Here M is the internal degrees of freedom in the <span class="hlt">bands</span> crossing the Fermi <span class="hlt">energy</span> and N is the degree of freedom in a model. Our framework naturally includes inter-<span class="hlt">band</span> off-diagonal elements of Green's functions, which have usually been neglected in previous multi-<span class="hlt">band</span> quasiclassical frameworks. The resultant multi-<span class="hlt">band</span> Eilenberger and Andreev equations are similar to the single-<span class="hlt">band</span> ones, except for multi-<span class="hlt">band</span> effects. The multi-<span class="hlt">band</span> effects can exhibit the non-locality and the anisotropy in the mapped systems. Our framework can be applied to an arbitrary Hamiltonian (e.g., a tight-binding Hamiltonian derived by the first-principle calculation). As examples, we use our framework in various kinds of systems, such as noncentrosymmetric superconductor CePt3Si, three-orbital model for Sr2RuO4, heavy fermion CeCoIn5/YbCoIn5 superlattice, a topological superconductor with the strong spin-orbit coupling CuxBi2Se3, and a surface system on a topological insulator.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NIMPA.837..161A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NIMPA.837..161A"><span>Design, realization and test of C-<span class="hlt">band</span> accelerating structures for the SPARC_LAB linac <span class="hlt">energy</span> upgrade</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alesini, D.; Bellaveglia, M.; Biagini, M. E.; Boni, R.; Brönnimann, M.; Cardelli, F.; Chimenti, P.; Clementi, R.; Di Pirro, G.; Di Raddo, R.; Ferrario, M.; Ficcadenti, L.; Gallo, A.; Kalt, R.; Lollo, V.; Palumbo, L.; Piersanti, L.; Schilcher, T.</p> <p>2016-11-01</p> <p>The <span class="hlt">energy</span> upgrade of the SPARC_LAB photo-injector at LNF-INFN (Frascati, Italy) has been originally conceived replacing one low gradient (13 MV/m) 3 m long SLAC type S-<span class="hlt">band</span> traveling wave (TW) section with two 1.4 m long C-<span class="hlt">band</span> accelerating sections. Due to the higher gradients reached by such structures, a higher <span class="hlt">energy</span> beam can be obtained within the same accelerator footprint length. The use of C-<span class="hlt">band</span> structures for <span class="hlt">electron</span> acceleration has been adopted in a few FEL linacs in the world, among others, the Japanese Free <span class="hlt">Electron</span> Laser at SPring-8 and the SwissFEL at Paul Scherrer Institute (PSI). The C-<span class="hlt">band</span> sections are traveling wave, constant impedance structures with symmetric input and output axial couplers. Their design has been optimized for the operation with a SLED RF pulse compressor. In this paper we briefly review their design criteria and we focus on the construction, tuning, low and high-power RF tests. We also illustrate the design and realization of the dedicated low level RF system that has been done in collaboration with PSI in the framework of the EU TIARA project. Preliminary experimental results appear to confirm the operation of such structures with accelerating gradients larger than 35 MV/m.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/934451','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/934451"><span>Variable <span class="hlt">Energy</span> 2-MeV S-<span class="hlt">Band</span> Linac for X-ray and Other Applications</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>H. Bender; D. Schwellenbach; R. Sturges; R. Trainham</p> <p>2008-07-01</p> <p>This paper describes the design and operation of a compact, 2-MeV, S-<span class="hlt">band</span> linear accelerator (linac) with variable <span class="hlt">energy</span> tuning and short-pulse operation down to 15 ps with 100-A peak current. The design consists of a buncher cavity for short-pulse operation and two coupled resonator sections for acceleration. Single-pulse operation is accomplished through a fast injector system with a 219-MHz subharmonic buncher. The machine is intended to support a variety of applications, such as x-ray and <span class="hlt">electron</span> beam diagnostic development, and recently, <span class="hlt">electron</span> diffraction studies of phase transitions in shocked materials.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvB..93s5211H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvB..93s5211H"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structure trends of perovskite halides: Beyond Pb and Sn to Ge and Si</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Ling-yi; Lambrecht, Walter R. L.</p> <p>2016-05-01</p> <p>The trends in <span class="hlt">electronic</span> <span class="hlt">band</span> structure are studied in the cubic A B X3 halide perovskites for A =Cs ; B =Pb , Sn, Ge, Si; and X =I , Br, Cl. The gaps are found to decrease from Pb to Sn and from Ge to Si, but increase from Sn to Ge. The trend is explained in terms of the atom s levels of the group-IV element and the atomic sizes which changes the amount of hybridization with X -p and hence the valence bandwidth. Along the same series spin-orbit coupling also decreases and this tends to increase the gap because of the smaller splitting of the conduction <span class="hlt">band</span> minimum. Both effects compensate each other to a certain degree. The trend with halogens is to reduce the gap from Cl to I, i.e., with decreasing electronegativity. The role of the tolerance factor in avoiding octahedron rotations and octahedron edge sharing is discussed. The Ge containing compounds have tolerance factor t >1 and hence do not show the series of octahedral rotation distortions and the existence of edge-sharing octahedral phases known for Pb and Sn-based compounds, but rather a rhombohedral distortion. CsGeI3 is found to have a suitable gap for photovoltaics both in its cubic (high-temperature) and rhombohedral (low-temperature) phases. The structural stability of the materials in the different phases is also discussed. We find the rhombohedral phase to have lower total <span class="hlt">energy</span> and slightly larger gaps but to present a less significant distortion of the <span class="hlt">band</span> structure than the edge-sharing octahedral phases, such as the yellow phase in CsSnI3. The corresponding silicon based compounds have not yet been synthesized and therefore our estimates are less certain but indicate a small gap for cubic CsSiI3 and CsSiBr3 of about 0.2 ±0.2 eV and 0.8 ±0.6 eV for CsSiCl3. The intrinsic stability of the Si compounds is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1045193','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1045193"><span>Advanced X-<span class="hlt">Band</span> Test Accelerator for High Brightness <span class="hlt">Electron</span> and Gamma Ray Beams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Marsh, Roark; Anderson, Scott; Barty, Christopher; Chu, Tak Sum; Ebbers, Chris; Gibson, David; Hartemann, Fred; Adolphsen, Chris; Jongewaard, Erik; Raubenheimer, Tor; Tantawi, Sami; Vlieks, Arnold; Wang, Juwen; /SLAC</p> <p>2012-07-03</p> <p>In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-<span class="hlt">band</span> rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the <span class="hlt">electron</span> <span class="hlt">energy</span> so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1009656','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1009656"><span>ADVANCED X-<span class="hlt">BAND</span> TEST ACCELERATOR FOR HIGH BRIGHTNESS <span class="hlt">ELECTRON</span> AND GAMMA RAY BEAMS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Marsh, R A; Anderson, S G; Barty, C P; Chu, T S; Ebbers, C A; Gibson, D J; Hartemann, F V; Adolphsen, C; Jongewaard, E N; Raubenheimer, T; Tantawi, S G; Vlieks, A E; Wang, J W</p> <p>2010-05-12</p> <p>In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-<span class="hlt">band</span> rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the <span class="hlt">electron</span> <span class="hlt">energy</span> so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PPNL...13..991K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PPNL...13..991K"><span>Acceleration of polarized <span class="hlt">electrons</span> UPTO ultrahigh <span class="hlt">energies</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koop, I.; Otboev, A.; Shatunov, P.; Shatunov, Yu.; Mane, S.</p> <p>2016-12-01</p> <p>A wide world discussion have been opened few years ago about future e + e - collider after the Higgsboson discovery. Besides utterly high luminosity this machine has to operate with polarized beams. We shall overview in this paper problems and practical possibilities to satisfy second requirements of the future collider. The radiative beam polarization at this 100 km machine will be very long procedure. On other side, at the present time there are developed intensive polarized <span class="hlt">electron</span> sources based on ArGa photo cathodes with polarization about 90 percents. We show, that fast <span class="hlt">electron</span> synchrotron equipped pair Siberian Snake is able to provide to accelerate polarized <span class="hlt">electrons</span> up to the top <span class="hlt">energy</span> of the collider.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/8186','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/8186"><span><span class="hlt">Energy</span> Transformation in Molecular <span class="hlt">Electronic</span> Systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kasha, Michael</p> <p>1999-05-17</p> <p>This laboratory has developed many new ideas and methods in the <span class="hlt">electronic</span> spectroscopy of molecules. This report covers the contract period 1993-1995. A number of the projects were completed in 1996, and those papers are included in the report. The DOE contract was terminated at the end of 1995 owing to a reorganizational change eliminating nationally the projects under the Office of Health and Environmental Research, U. S. Department of <span class="hlt">Energy</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999AcSpA..55.1143A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999AcSpA..55.1143A"><span>Thermodynamic consequence of the new attribution of <span class="hlt">bands</span> in the <span class="hlt">electronic</span> absorption spectrum of <span class="hlt">electron</span> donor-iodine-solvent systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abramov, Sergey P.</p> <p>1999-06-01</p> <p>The subject review pays attention to the peculiarities in behaviour of <span class="hlt">bands</span> in the <span class="hlt">electronic</span> absorption spectra of <span class="hlt">electron</span> donor-iodine-solvent systems, the appearance of which is associated with the intermolecular interaction of molecular iodine with <span class="hlt">electron</span> donor organic molecules. The new concept of the bands’ attribution to the isomeric equilibrium molecular charge-transfer complexes (CTCs) of CTC-I and CTC-II types is considered. The features of possible phase transitions in the solid state are discussed on the basis of the thermodynamic properties and <span class="hlt">electronic</span> structures of the CTC-I and CTC-II in <span class="hlt">electron</span> donor-iodine-solvent systems. The stabilisation of the CTC-II structure with the temperature lowering coincided in many cases with the electrons’ localisation in the solid state structures having charge-transfer bonds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvA..94c2703W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvA..94c2703W"><span>Low-<span class="hlt">energy</span> <span class="hlt">electron</span> scattering from cyanamide</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Kedong; Guo, Shuangcheng; Meng, Ju; Huang, Xiaotian; Wang, Yongfeng</p> <p>2016-09-01</p> <p>The low-<span class="hlt">energy</span> <span class="hlt">electron</span> collisions with cyanamide molecule are investigated by using the UK molecular R -matrix codes for <span class="hlt">electron</span> <span class="hlt">energies</span> ranging from 0.01 eV to 10 eV. Three models including static-exchange, static-exchange plus polarization, and close-coupling (CC) approximations are employed to reveal the dynamic interaction. Elastic (integrated and differential), momentum-transfer, and excitation cross sections from the ground state to the three low-lying <span class="hlt">electron</span> excited states have been presented. Two shape resonances, two core-excited resonances, and two Feshbach resonances are detected in the CC approximation. The role of active space in the target and scattering problem including the resonances is discussed. The precise resonance parameters are found to be sensitive to the treatment of polarization effects employed. These resonances may be responsible for the fragments observed in a recent experiment of the dissociative <span class="hlt">electron</span> attachments to cyanamide. Since the cyanamide molecule has a large permanent dipole moment, a Born closure procedure is used to account for the contribution of partial waves higher than l =4 to obtain converged cross sections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22415776','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22415776"><span>An <span class="hlt">electron</span> <span class="hlt">energy</span>-loss study of picene and chrysene based charge transfer salts</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Müller, Eric; Mahns, Benjamin; Büchner, Bernd; Knupfer, Martin</p> <p>2015-05-14</p> <p>The <span class="hlt">electronic</span> excitation spectra of charge transfer compounds built from the hydrocarbons picene and chrysene, and the strong <span class="hlt">electron</span> acceptors F{sub 4}TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) and TCNQ (7,7,8,8-tetracyanoquinodimethan) have been investigated using <span class="hlt">electron</span> <span class="hlt">energy</span>-loss spectroscopy. The corresponding charge transfer compounds have been prepared by co-evaporation of the pristine constituents. We demonstrate that all investigated combinations support charge transfer, which results in new <span class="hlt">electronic</span> excitation features at low <span class="hlt">energy</span>. This might represent a way to synthesize low <span class="hlt">band</span> gap organic semiconductors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25247447','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25247447"><span><span class="hlt">Energy</span> <span class="hlt">band</span> gap and optical transition of metal ion modified double crossover DNA lattices.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dugasani, Sreekantha Reddy; Ha, Taewoo; Gnapareddy, Bramaramba; Choi, Kyujin; Lee, Junwye; Kim, Byeonghoon; Kim, Jae Hoon; Park, Sung Ha</p> <p>2014-10-22</p> <p>We report on the <span class="hlt">energy</span> <span class="hlt">band</span> gap and optical transition of a series of divalent metal ion (Cu(2+), Ni(2+), Zn(2+), and Co(2+)) modified DNA (M-DNA) double crossover (DX) lattices fabricated on fused silica by the substrate-assisted growth (SAG) method. We demonstrate how the degree of coverage of the DX lattices is influenced by the DX monomer concentration and also analyze the <span class="hlt">band</span> gaps of the M-DNA lattices. The <span class="hlt">energy</span> <span class="hlt">band</span> gap of the M-DNA, between the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO), ranges from 4.67 to 4.98 eV as judged by optical transitions. Relative to the <span class="hlt">band</span> gap of a pristine DNA molecule (4.69 eV), the <span class="hlt">band</span> gap of the M-DNA lattices increases with metal ion doping up to a critical concentration and then decreases with further doping. Interestingly, except for the case of Ni(2+), the onset of the second absorption <span class="hlt">band</span> shifts to a lower <span class="hlt">energy</span> until a critical concentration and then shifts to a higher <span class="hlt">energy</span> with further increasing the metal ion concentration, which is consistent with the evolution of electrical transport characteristics. Our results show that controllable metal ion doping is an effective method to tune the <span class="hlt">band</span> gap <span class="hlt">energy</span> of DNA-based nanostructures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARC50011G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARC50011G"><span><span class="hlt">Energy</span> Dependence and Scaling Property of Localization Length near a Gapped Flat <span class="hlt">Band</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ge, Li; Tureci, Hakan</p> <p></p> <p>Using a tight-binding model for a one-dimensional Lieb lattice, we show that the localization length near a gapped flat <span class="hlt">band</span> behaves differently from the typical Urbach tail in a <span class="hlt">band</span> gap: instead of reducing monotonically as the <span class="hlt">energy</span> E moves away from the flat <span class="hlt">band</span> <span class="hlt">energy</span> Ef, the presence of the flat <span class="hlt">band</span> causes a nonmonotonic <span class="hlt">energy</span> dependence of the localization length. This <span class="hlt">energy</span> dependence follows a scaling property when the <span class="hlt">energy</span> is within the spread (W) of uniformly distributed diagonal disorder, i.e. the localization length is only a function of (E-Ef)/W. Several other lattices are compared to distinguish the effect of the flat <span class="hlt">band</span> on the localization length, where we eliminate, shift, or duplicate the flat <span class="hlt">band</span>, without changing the dispersion relations of other <span class="hlt">bands</span>. Using the top right element of the Green's matrix, we derive an analytical relation between the density of states and the localization length, which shines light on these properties of the latter, including a summation rule for its inverse. This work is partially supported by NSF under Grant No. DMR-1506987.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JAP...122k3102M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JAP...122k3102M"><span>Effect of Sr doping on the <span class="hlt">electronic</span> <span class="hlt">band</span> structure and optical properties of ZnO: A first principle calculation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mahmood, Asad; Tezcan, Fatih; Kardaş, Gülfeza; Karadaǧ, Faruk</p> <p>2017-09-01</p> <p>Incorporating impurities in ZnO provide opportunities to manipulate its <span class="hlt">electronic</span> and optical properties, which can be exploited for optoelectronic device applications. Among various elements doped in ZnO crystal structure, limited attempts have been accounted for the Sr-doped ZnO system. Further, no theoretical evidence has been reported so far to explore the Sr-doped ZnO frameworks. Here, we report first principle study for the pure and Sr-doped ZnO (Zn1-xSrxO) structure. We employed the Perdew-Burke-Ernzerhof exchange-correlation function parameters in generalized gradient approximations. In light of these estimations, we calculated the <span class="hlt">electronic</span> <span class="hlt">band</span> gap, density of states, and optical parameters, for example, absorption, dielectric functions, reflectivity, refractive index, and <span class="hlt">energy</span>-loss. The studies suggested that Sr incorporation expanded the optical <span class="hlt">band</span> gap of ZnO. In addition, the <span class="hlt">energy</span>-loss significantly increased with Sr content which might be associated with an increase in the degree of disorder in the crystal lattice with Sr incorporation. Also, significant changes were seen in the optical properties of ZnO with Sr content in the low <span class="hlt">energy</span> region. The theoretical results were likewise compared with the previously reported experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22399363','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22399363"><span><span class="hlt">Electron</span> transport and <span class="hlt">electron</span> <span class="hlt">energy</span> distributions within the wurtzite and zinc-blende phases of indium nitride: Response to the application of a constant and uniform electric field</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Siddiqua, Poppy; Hadi, Walid A.; Salhotra, Amith K.; O'Leary, Stephen K.; Shur, Michael S.</p> <p>2015-03-28</p> <p>Within the framework of an ensemble semi-classical three-valley Monte Carlo <span class="hlt">electron</span> transport simulation approach, we critically contrast the nature of the <span class="hlt">electron</span> transport that occurs within the wurtzite and zinc-blende phases of indium nitride in response to the application of a constant and uniform electric field. We use the <span class="hlt">electron</span> <span class="hlt">energy</span> distribution and its relationship with the <span class="hlt">electron</span> transport characteristics in order to pursue this analysis. For the case of zinc-blende indium nitride, only a peak corresponding to the <span class="hlt">electrons</span> within the lowest <span class="hlt">energy</span> conduction <span class="hlt">band</span> valley is observed, this peak being seen to broaden and shift to higher <span class="hlt">energies</span> in response to increases in the applied electric field strength, negligible amounts of upper <span class="hlt">energy</span> conduction <span class="hlt">band</span> valley occupancy being observed. In contrast, for the case of wurtzite indium nitride, in addition to the aforementioned lowest <span class="hlt">energy</span> conduction <span class="hlt">band</span> valley peak in the <span class="hlt">electron</span> <span class="hlt">energy</span> distribution, and its broadening and shifting to higher <span class="hlt">energies</span> in response to increases in the applied electric field strength, beyond a certain critical electric field strength, 30 kV/cm for the case of this particular material, upper <span class="hlt">energy</span> conduction <span class="hlt">band</span> valley occupancy is observed, this occupancy being further enhanced in response to further increases in the applied electric field strength. Reasons for these results are provided. The potential for device consequences is then commented upon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApPhL.107w1605B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApPhL.107w1605B"><span><span class="hlt">Band</span> <span class="hlt">energy</span> control of molybdenum oxide by surface hydration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Butler, Keith T.; Crespo-Otero, Rachel; Buckeridge, John; Scanlon, David O.; Bovill, Edward; Lidzey, David; Walsh, Aron</p> <p>2015-12-01</p> <p>The application of oxide buffer layers for improved carrier extraction is ubiquitous in organic <span class="hlt">electronics</span>. However, the performance is highly susceptible to processing conditions. Notably, the interface stability and <span class="hlt">electronic</span> structure is extremely sensitive to the uptake of ambient water. In this study we use density functional theory calculations to asses the effects of adsorbed water on the <span class="hlt">electronic</span> structure of MoOx, in the context of polymer-fullerene solar cells based on PCDTBT. We obtain excellent agreement with experimental values of the ionization potential for pristine MoO3 (010). We find that IP and EA values can vary by as much as 2.5 eV depending on the oxidation state of the surface and that adsorbed water can either increase or decrease the IP and EA depending on the concentration of surface water.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22486181','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22486181"><span><span class="hlt">Band</span> <span class="hlt">energy</span> control of molybdenum oxide by surface hydration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Butler, Keith T. Walsh, Aron; Crespo-Otero, Rachel; Buckeridge, John; Scanlon, David O.; Bovill, Edward; Lidzey, David</p> <p>2015-12-07</p> <p>The application of oxide buffer layers for improved carrier extraction is ubiquitous in organic <span class="hlt">electronics</span>. However, the performance is highly susceptible to processing conditions. Notably, the interface stability and <span class="hlt">electronic</span> structure is extremely sensitive to the uptake of ambient water. In this study we use density functional theory calculations to asses the effects of adsorbed water on the <span class="hlt">electronic</span> structure of MoO{sub x}, in the context of polymer-fullerene solar cells based on PCDTBT. We obtain excellent agreement with experimental values of the ionization potential for pristine MoO{sub 3} (010). We find that IP and EA values can vary by as much as 2.5 eV depending on the oxidation state of the surface and that adsorbed water can either increase or decrease the IP and EA depending on the concentration of surface water.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvB..89d1407M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvB..89d1407M"><span>Effects of extrinsic and intrinsic perturbations on the <span class="hlt">electronic</span> structure of graphene: Retaining an effective primitive cell <span class="hlt">band</span> structure by <span class="hlt">band</span> unfolding</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Medeiros, Paulo V. C.; Stafström, Sven; Björk, Jonas</p> <p>2014-01-01</p> <p>We use a <span class="hlt">band</span> unfolding technique to recover an effective primitive cell picture of the <span class="hlt">band</span> structure of graphene under the influence of different types of perturbations. This involves intrinsic perturbations, such as structural defects, and external ones, comprising nitrogen substitutions and the inclusion of graphene in adsorbed systems. In such cases, the <span class="hlt">band</span> unfolding provides a reliable and efficient tool for quantitatively analyzing the effect of doping and defects on the <span class="hlt">electronic</span> structure of graphene. We envision that this approach will become a standard method in the computational analysis of graphene's <span class="hlt">electronic</span> structure in related systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23646612','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23646612"><span>Spin-dependent <span class="hlt">energy</span> <span class="hlt">bands</span> and spin polarization in two-dimensional spin-orbit lateral superlattices.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, R L; Qi, D X; Wang, D L; Li, J; Peng, R W; Huang, R S; Wang, Mu</p> <p>2013-02-01</p> <p>In this work, we theoretically investigate the spin-split <span class="hlt">energy</span> <span class="hlt">bands</span> of <span class="hlt">electrons</span> and spin-polarized transport in two-dimensional (2D) spin-orbit lateral superlattices (SOLSLs), where the square rods with Rashba spin-orbit coupling (SOC) are distributed periodically by applying gate voltages on the semiconductor. Within the Landauer framework of ballistic transport, the <span class="hlt">energy</span> <span class="hlt">bands</span>, the electrical conductance, the spin polarization and the spin-dependent <span class="hlt">electronic</span> charge distributions have been calculated. It is found that the <span class="hlt">energy</span> minibands are formed and the <span class="hlt">energy</span> levels are split up by the Rashba SOC. As a result, the spin-polarized conductance is obtained even in the absence of external magnetic fields and magnetic materials. Meanwhile, the spin polarization can approach high values in the SOLSLs by manipulating the strength of SOC. Furthermore, the spin-dependent <span class="hlt">electronic</span> charge distributions have been obtained, which present a clear picture of spin-polarized conductance. Our investigations have the potential applications in spin-based quantum devices and semiconductor spintronics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22483186','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22483186"><span><span class="hlt">Energy</span> <span class="hlt">band</span> bowing parameter in MgZnO alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, Xu; Saito, Katsuhiko; Tanaka, Tooru; Nishio, Mitsuhiro; Guo, Qixin; Nagaoka, Takashi; Arita, Makoto</p> <p>2015-07-13</p> <p>We report on bandgap bowing parameters for wurtzite and cubic MgZnO alloys from a study of high quality and single phase films in all Mg content range. The Mg contents in the MgZnO films were accurately determined using the <span class="hlt">energy</span> dispersive spectrometer and X-ray photoelectron spectroscopy (XPS). The measurement of bandgap <span class="hlt">energies</span> by examining the onset of inelastic <span class="hlt">energy</span> loss in core-level atomic spectra from XPS is proved to be valid for determining the bandgap of MgZnO films. The dependence of the <span class="hlt">energy</span> bandgap on Mg content is found to deviate downwards from linearity. Fitting of the bandgap data resulted in two bowing parameters of 2.01 ± 0.04 eV and 1.48 ± 0.11 eV corresponding to wurtzite and cubic MgZnO films, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/554063','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/554063"><span>Investigation of macro deformation <span class="hlt">bands</span> in fatigued [001] Cu single crystals by <span class="hlt">electron</span> channeling contrast technique</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gong, B.; Wang, Z.; Chen, D.; Wang, Z.</p> <p>1997-11-15</p> <p>In recent years, <span class="hlt">electron</span> channeling contrast (ECC) technique accomplished in conventional scanning <span class="hlt">electron</span> microscopes (SEM) has received much interest in studying dislocation configuration in deformed materials, especially in cyclically deformed materials. This technique can not only provide a real and wide view of dislocation substructures conveniently, but also make it possible to establish relationship between the surface structures, such as slip <span class="hlt">bands</span>, and the bulk dislocation structures due to the unique feature of this technique. The present study is to use ECC technique to reveal the dislocation substructures of macro deformation <span class="hlt">bands</span> formed in fatigued [001] Cu single crystals. The ECC results will also be correlated with those of light microscopy and transmission <span class="hlt">electron</span> microscopy (TEM) studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MARS47015J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MARS47015J"><span>Understanding the <span class="hlt">electronic</span> <span class="hlt">band</span> structure of Pt-alloys for surface reactivity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jung, Jongkeun; Kim, Beomyoung; Hong, Ji Sook; Jin, Tae Won; Shim, Ji Hoon; Nemsak, Slavomir; Denlinger, Jonathan D.; Masashi, Arita; Kenya, Shimada; Kim, Changyoung; Mun, Bongjin Simon</p> <p></p> <p>In polymer exchange membrane fuel cell (PEMFC), the oxygen reduction reaction (ORR) at cathode side has been continuously investigated due to its critical importance in performance of fuel cell. So far, even with best industrial catalyst made with Pt, the performance of ORR is too far below from the commercial purpose. In 2007, Stamenkovic et al. showed that Pt alloys with 3- dtransition metal exhibited significantly improved ORR performance and pointed out the altered <span class="hlt">electronic</span> structure of surface as the major contributing factor for enhanced ORR. Since 1990, with the advance of DFT calculation, the trend of surface chemical reactivity is explained with the analysis of d-<span class="hlt">band</span> structures, known as d-<span class="hlt">band</span> model. While d-<span class="hlt">band</span> provides valid insight on surface chemical reactivity based on the valence <span class="hlt">band</span> DOS, the relation between surface work function and DOS has not been well understood. The element-specific local <span class="hlt">electronic</span> <span class="hlt">band</span> structure of Pt alloys are identified by ARPES measurement, and the correlation between surface work function and local charge density is investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21370508','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21370508"><span>The <span class="hlt">electronic</span> structures of vanadate salts: Cation substitution as a tool for <span class="hlt">band</span> gap manipulation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dolgos, Michelle R.; Paraskos, Alexandra M.; Stoltzfus, Matthew W.; Yarnell, Samantha C.; Woodward, Patrick M.</p> <p>2009-07-15</p> <p>The <span class="hlt">electronic</span> structures of six ternary metal oxides containing isolated vanadate ions, Ba{sub 3}(VO{sub 4}){sub 2}, Pb{sub 3}(VO{sub 4}){sub 2}, YVO{sub 4}, BiVO{sub 4}, CeVO{sub 4} and Ag{sub 3}VO{sub 4} were studied using diffuse reflectance spectroscopy and <span class="hlt">electronic</span> structure calculations. While the <span class="hlt">electronic</span> structure near the Fermi level originates largely from the molecular orbitals of the vanadate ion, both experiment and theory show that the cation can strongly influence these <span class="hlt">electronic</span> states. The observation that Ba{sub 3}(VO{sub 4}){sub 2} and YVO{sub 4} have similar <span class="hlt">band</span> gaps, both 3.8 eV, shows that cations with a noble gas configuration have little impact on the <span class="hlt">electronic</span> structure. <span class="hlt">Band</span> structure calculations support this hypothesis. In Pb{sub 3}(VO{sub 4}){sub 2} and BiVO{sub 4} the <span class="hlt">band</span> gap is reduced by 0.9-1.0 eV through interactions of (a) the filled cation 6s orbitals with nonbonding O 2p states at the top of the valence <span class="hlt">band</span>, and (b) overlap of empty 6p orbitals with antibonding V 3d-O 2p states at the bottom of the conduction <span class="hlt">band</span>. In Ag{sub 3}VO{sub 4} mixing between filled Ag 4d and O 2p states destabilizes states at the top of the valence <span class="hlt">band</span> leading to a large decrease in the <span class="hlt">band</span> gap (E{sub g}=2.2 eV). In CeVO{sub 4} excitations from partially filled 4f orbitals into the conduction <span class="hlt">band</span> lower the effective <span class="hlt">band</span> gap to 1.8 eV. In the Ce{sub 1-x}Bi{sub x}VO{sub 4} (0<=x<=0.5) and Ce{sub 1-x}Y{sub x}VO{sub 4} (x=0.1, 0.2) solid solutions the <span class="hlt">band</span> gap narrows slightly when Bi{sup 3+} or Y{sup 3+} are introduced. The nonlinear response of the <span class="hlt">band</span> gap to changes in composition is a result of the localized nature of the Ce 4f orbitals. - Graphical abstract: The <span class="hlt">electronic</span> structures of six vanadate salts, Ba{sub 3}(VO{sub 4}){sub 2}, Pb{sub 3}(VO{sub 4}){sub 2}, YVO{sub 4}, BiVO{sub 4}, Ag{sub 3}VO{sub 4} and CeVO{sub 4}, are studied. The results show that the oxygen to vanadium charge transfer, which is largely responsible for the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22486804','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22486804"><span>Importance of the tuning of <span class="hlt">band</span> position in optimizing the <span class="hlt">electronic</span> coupling and photocatalytic activity of nanocomposite</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jin, Xiaoyan; Mok, Eun Kyung; Baek, Ji-Won; Park, Sang-Hyun; Hwang, Seong-Ju</p> <p>2015-10-15</p> <p>The <span class="hlt">electronic</span> coupling and photocatalytic activity of Ag{sub 2}CO{sub 3}–TiO{sub 2} nanocomposite can be optimized by the fine-tuning of the <span class="hlt">band</span> position of titanium oxide with nitrogen doping. The increase of the valence <span class="hlt">band</span> <span class="hlt">energy</span> of TiO{sub 2} by N-doping leads not only to the enhanced absorption of visible light but also to the promoted hole transfer from Ag{sub 2}CO{sub 3} to TiO{sub 2}, resulting in the efficient spatial separation of photogenerated <span class="hlt">electrons</span> and holes. While the undoped Ag{sub 2}CO{sub 3}–TiO{sub 2} nanocomposite shows an inferior photocatalytic activity to the pure Ag{sub 2}CO{sub 3}, the photocatalyst performance of N-doped nanocomposite is better than those of Ag{sub 2}CO{sub 3} and undoped Ag{sub 2}CO{sub 3}–TiO{sub 2} nanocomposite. This observation underscores a significant enhancement of the photocatalytic activity of nanocomposite upon N-doping, a result of enhanced <span class="hlt">electronic</span> coupling between the hybridized species. The present results clearly demonstrate the importance of the fine-tuning of <span class="hlt">band</span> position in optimizing the photocatalytic activity of hybrid-type photocatalysts. - Highlights: • The <span class="hlt">band</span> position of Ag{sub 2}CO{sub 3}–TiO{sub 2} can be effectively tailored by nitrogen doping. • The N-doping leads to the improvement of charge separation. • The N-doped Ag{sub 2}CO{sub 3}–TiO{sub 2} shows high photocatalytic activity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title41-vol2/pdf/CFR-2010-title41-vol2-sec101-26-508.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title41-vol2/pdf/CFR-2010-title41-vol2-sec101-26-508.pdf"><span>41 CFR 101-26.508 - <span class="hlt">Electronic</span> data processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>).</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-07-01</p> <p>... processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>). 101-26.508 Section 101-26.508... Programs § 101-26.508 <span class="hlt">Electronic</span> data processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>). Procurement by Federal agencies of EDP tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title41-vol2/pdf/CFR-2011-title41-vol2-sec101-26-508.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title41-vol2/pdf/CFR-2011-title41-vol2-sec101-26-508.pdf"><span>41 CFR 101-26.508 - <span class="hlt">Electronic</span> data processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>).</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-07-01</p> <p>... processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>). 101-26.508 Section 101-26.508... Programs § 101-26.508 <span class="hlt">Electronic</span> data processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>). Procurement by Federal agencies of EDP tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title41-vol2/pdf/CFR-2012-title41-vol2-sec101-26-508.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title41-vol2/pdf/CFR-2012-title41-vol2-sec101-26-508.pdf"><span>41 CFR 101-26.508 - <span class="hlt">Electronic</span> data processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>).</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-07-01</p> <p>... processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>). 101-26.508 Section 101-26.508... Programs § 101-26.508 <span class="hlt">Electronic</span> data processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>). Procurement by Federal agencies of EDP tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title41-vol2/pdf/CFR-2013-title41-vol2-sec101-26-508.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title41-vol2/pdf/CFR-2013-title41-vol2-sec101-26-508.pdf"><span>41 CFR 101-26.508 - <span class="hlt">Electronic</span> data processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>).</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-07-01</p> <p>... processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>). 101-26.508 Section 101-26.508... Programs § 101-26.508 <span class="hlt">Electronic</span> data processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>). Procurement by Federal agencies of EDP tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title41-vol2/pdf/CFR-2014-title41-vol2-sec101-26-508.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title41-vol2/pdf/CFR-2014-title41-vol2-sec101-26-508.pdf"><span>41 CFR 101-26.508 - <span class="hlt">Electronic</span> data processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>).</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-07-01</p> <p>... processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>). 101-26.508 Section 101-26.508... Programs § 101-26.508 <span class="hlt">Electronic</span> data processing (EDP) tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>). Procurement by Federal agencies of EDP tape and instrumentation tape (wide and intermediate <span class="hlt">band</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/892578','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/892578"><span>Experimental Work With Photonic <span class="hlt">Band</span> Gap Fiber: Building A Laser <span class="hlt">Electron</span> Accelerator</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lincoln, Melissa; Ischebeck, Rasmus; Nobel, Robert; Siemann, Robert; /SLAC</p> <p>2006-09-29</p> <p>In the laser acceleration project E-163 at the Stanford Linear Accelerator Center, work is being done toward building a traveling wave accelerator that uses as its accelerating structure a length of photonic <span class="hlt">band</span> gap fiber. The small scale of the optical fiber allows radiation at optical wavelengths to be used to provide the necessary accelerating <span class="hlt">energy</span>. Optical wavelength driving <span class="hlt">energy</span> in a small structure yields higher accelerating fields. The existence of a speed-of-light accelerating mode in a photonic <span class="hlt">band</span> gap fiber has been calculated previously [1]. This paper presents an overview of several of the experimental challenges posed in the development of the proposed photonic <span class="hlt">band</span> gap fiber accelerator system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995ZPhyD..34..283O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995ZPhyD..34..283O"><span>High-resolution <span class="hlt">electron</span> microscopy and <span class="hlt">electron</span> <span class="hlt">energy</span>-loss spectroscopy of giant palladium clusters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oleshko, V.; Volkov, V.; Gijbels, R.; Jacob, W.; Vargaftik, M.; Moiseev, I.; van Tendeloo, G.</p> <p>1995-12-01</p> <p>Combined structural and chemical characterization of cationic polynuclear palladium coordination compounds Pd561L60(OAc)180, where L=1,10-phenantroline or 2,2'-bipyridine has been carried out by high-resolution <span class="hlt">electron</span> microscopy (HREM) and analytical <span class="hlt">electron</span> microscopy methods including <span class="hlt">electron</span> <span class="hlt">energy</span>-loss spectroscopy (EELS), zero-loss <span class="hlt">electron</span> spectroscopic imaging, and <span class="hlt">energy</span>-dispersive X-ray spectroscopy (EDX). The cell structure of the cluster matter with almost completely uniform metal core size distributions centered around 2.3 ±0.5 nm was observed. Zero-loss <span class="hlt">energy</span> filtering allowed to improve the image contrast and resolution. HREM images showed that most of the palladium clusters had a cubo-octahedral shape. Some of them had a distorted icosahedron structure exhibiting multiple twinning. The selected-area <span class="hlt">electron</span> diffraction patterns confirmed the face centered cubic structure with lattice parameter close to that of metallic palladium. The <span class="hlt">energy</span>-loss spectra of the populations of clusters contained several <span class="hlt">bands</span>, which could be assigned to the delayed Pd M4, 5-edge at 362 eV, the Pd M3-edge at 533 eV and the Pd M2-edge at 561 eV, the NK-edge at about 400 eV, the O K-edge at 532 eV overlapping with the Pd M3-edge and the carbon C K-edge at 284 eV. Background subtraction was applied to reveal the exact positions and fine structure of low intensity elemental peaks. EELS evaluations have been confirmed by EDX. The recorded series of the Pd M-edges and the N K-edge in the spectra of the giant palladium clusters obviously were related to Pd-Pd- and Pd-ligand bonding.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998APS..MAR.G2705M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998APS..MAR.G2705M"><span>Model GW determination of <span class="hlt">band</span> gaps and <span class="hlt">electronic</span> properties of strained layer InAsSb/InAs superlattices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mannstadt, W.; Asahi, R.; Freeman, A. J.; Picozzi, S.; Continenza, A.</p> <p>1998-03-01</p> <p>A strong interest is still devoted to the InAs_1-xSb_x/InAs(111) system due to the opportunity to tune the <span class="hlt">band</span> gap as a function of the growth conditions. Lattice mismatch, strain, alloy composition and layers thickness determine the <span class="hlt">electronic</span> and transport properies of these systems. We investigated this system using our full-potential linearized augmented plane wave (FLAPW) method for thin films (Wimmer,Krakauer,Weinert and A.J.Freeman, Phys.Rev.B24, 864 (1981)) and bulk solids, to study overlayers, sandwiches and superlattices. Our method includes atomic force and total <span class="hlt">energy</span> determinations of the equilibrium structures, as well as the model GW approximation(F.Gygi and A.Baldereschi, Phys.Rev.Lett. 62, 2160 (1989)) to obtain accurate <span class="hlt">band</span> gaps. This allows us to investigate the influence of strain, structural relaxation and alloying on the <span class="hlt">electronic</span> structure and the <span class="hlt">band</span> gap. Results for bulk InAs, InSb and InAs_1-xSb_x, at different x compositions and for ordered superlattices will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.H23I..04H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.H23I..04H"><span>Analytical solutions for bacterial <span class="hlt">energy</span> taxis (chemotaxis): traveling bacterial <span class="hlt">bands</span> and their role in groundwater remediation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hilpert, M.; Long, W.</p> <p>2007-12-01</p> <p>Motile bacteria may form <span class="hlt">bands</span> that travel with a constant speed of propagation through a medium containing a dissolved substrate, to which they respond <span class="hlt">energy</span> tactically. We generalize the analytical solution by Keller and Segel for such <span class="hlt">bands</span> by accounting for (1) the presence of a porous medium, (2) substrate consumption described by a Monod kinetics model, and (3) an <span class="hlt">energy</span> tactic response model derived by Rivero et al. We also comment on the potential role of traveling bacterial <span class="hlt">bands</span> in the remediation of groundwater contamination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1259764-electronic-structure-descriptor-discovery-narrow-band-red-emitting-phosphors','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1259764-electronic-structure-descriptor-discovery-narrow-band-red-emitting-phosphors"><span><span class="hlt">Electronic</span> structure descriptor for the discovery of narrow-<span class="hlt">band</span> red-emitting phosphors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Wang, Zhenbin; Chu, Iek -Heng; Zhou, Fei; ...</p> <p>2016-05-09</p> <p>Narrow-<span class="hlt">band</span> red-emitting phosphors are a critical component of phosphor-converted light-emitting diodes for highly efficient illumination-grade lighting. In this work, we report the discovery of a quantitative descriptor for narrow-<span class="hlt">band</span> Eu2+-activated emission identified through a comparison of the <span class="hlt">electronic</span> structures of known narrow-<span class="hlt">band</span> and broad-<span class="hlt">band</span> phosphors. We find that a narrow emission bandwidth is characterized by a large splitting of more than 0.1 eV between the two highest Eu2+ 4f7 <span class="hlt">bands</span>. By incorporating this descriptor in a high-throughput first-principles screening of 2259 nitride compounds, we identify five promising new nitride hosts for Eu2+-activated red-emitting phosphors that are predicted to exhibit goodmore » chemical stability, thermal quenching resistance, and quantum efficiency, as well as narrow-<span class="hlt">band</span> emission. Lastly, our findings provide important insights into the emission characteristics of rare-earth activators in phosphor hosts and a general strategy to the discovery of phosphors with a desired emission peak and bandwidth.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1259764','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1259764"><span><span class="hlt">Electronic</span> structure descriptor for the discovery of narrow-<span class="hlt">band</span> red-emitting phosphors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, Zhenbin; Chu, Iek -Heng; Zhou, Fei; Ong, Shyue Ping</p> <p>2016-05-09</p> <p>Narrow-<span class="hlt">band</span> red-emitting phosphors are a critical component of phosphor-converted light-emitting diodes for highly efficient illumination-grade lighting. In this work, we report the discovery of a quantitative descriptor for narrow-<span class="hlt">band</span> Eu<sup>2+</sup>-activated emission identified through a comparison of the <span class="hlt">electronic</span> structures of known narrow-<span class="hlt">band</span> and broad-<span class="hlt">band</span> phosphors. We find that a narrow emission bandwidth is characterized by a large splitting of more than 0.1 eV between the two highest Eu<sup>2+</sup> 4<i>f</i><sup>7</sup> <span class="hlt">bands</span>. By incorporating this descriptor in a high-throughput first-principles screening of 2259 nitride compounds, we identify five promising new nitride hosts for Eu<sup>2+</sup>-activated red-emitting phosphors that are predicted to exhibit good chemical stability, thermal quenching resistance, and quantum efficiency, as well as narrow-<span class="hlt">band</span> emission. Lastly, our findings provide important insights into the emission characteristics of rare-earth activators in phosphor hosts and a general strategy to the discovery of phosphors with a desired emission peak and bandwidth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JaJAP..55e1202K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JaJAP..55e1202K"><span>Interacting quasi-<span class="hlt">band</span> theory for <span class="hlt">electronic</span> states in compound semiconductor alloys: Wurtzite structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kishi, Ayaka; Oda, Masato; Shinozuka, Yuzo</p> <p>2016-05-01</p> <p>This paper reports on the <span class="hlt">electronic</span> states of compound semiconductor alloys of wurtzite structure calculated by the recently proposed interacting quasi-<span class="hlt">band</span> (IQB) theory combined with empirical sp3 tight-binding models. Solving derived quasi-Hamiltonian 24 × 24 matrix that is characterized by the crystal parameters of the constituents facilitates the calculation of the conduction and valence <span class="hlt">bands</span> of wurtzite alloys for arbitrary concentrations under a unified scheme. The theory is applied to III-V and II-VI wurtzite alloys: cation-substituted Al1- x Ga x N and Ga1- x In x N and anion-substituted CdS1- x Se x and ZnO1- x S x . The obtained results agree well with the experimental data, and are discussed in terms of mutual mixing between the quasi-localized states (QLS) and quasi-average <span class="hlt">bands</span> (QAB): the latter <span class="hlt">bands</span> are approximately given by the virtual crystal approximation (VCA). The changes in the valence and conduction <span class="hlt">bands</span>, and the origin of the <span class="hlt">band</span> gap bowing are discussed on the basis of mixing character.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24484152','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24484152"><span>Origins of <span class="hlt">electronic</span> <span class="hlt">band</span> gap reduction in Cr/N codoped TiO2.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Parks Cheney, C; Vilmercati, P; Martin, E W; Chiodi, M; Gavioli, L; Regmi, M; Eres, G; Callcott, T A; Weitering, H H; Mannella, N</p> <p>2014-01-24</p> <p>Recent studies indicated that noncompensated cation-anion codoping of wide-<span class="hlt">band</span>-gap oxide semiconductors such as anatase TiO2 significantly reduces the optical <span class="hlt">band</span> gap and thus strongly enhances the absorption of visible light [W. Zhu et al., Phys. Rev. Lett. 103, 226401 (2009)]. We used soft x-ray spectroscopy to fully determine the location and nature of the impurity levels responsible for the extraordinarily large (∼1 eV) <span class="hlt">band</span> gap reduction of noncompensated codoped rutile TiO2. It is shown that Cr/N codoping strongly enhances the substitutional N content, compared to single element doping. The <span class="hlt">band</span> gap reduction is due to the formation of Cr 3d3 levels in the lower half of the gap while the conduction <span class="hlt">band</span> minimum is comprised of localized Cr 3d and delocalized N 2p states. <span class="hlt">Band</span> gap reduction and carrier delocalization are critical elements for efficient light-to-current conversion in oxide semiconductors. These findings thus raise the prospect of using codoped oxide semiconductors with specifically engineered <span class="hlt">electronic</span> properties in a variety of photovoltaic and photocatalytic applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1259764','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1259764"><span><span class="hlt">Electronic</span> structure descriptor for the discovery of narrow-<span class="hlt">band</span> red-emitting phosphors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, Zhenbin; Chu, Iek -Heng; Zhou, Fei; Ong, Shyue Ping</p> <p>2016-05-09</p> <p>Narrow-<span class="hlt">band</span> red-emitting phosphors are a critical component of phosphor-converted light-emitting diodes for highly efficient illumination-grade lighting. In this work, we report the discovery of a quantitative descriptor for narrow-<span class="hlt">band</span> Eu<sup>2+</sup>-activated emission identified through a comparison of the <span class="hlt">electronic</span> structures of known narrow-<span class="hlt">band</span> and broad-<span class="hlt">band</span> phosphors. We find that a narrow emission bandwidth is characterized by a large splitting of more than 0.1 eV between the two highest Eu<sup>2+</sup> 4<i>f</i><sup>7</sup> <span class="hlt">bands</span>. By incorporating this descriptor in a high-throughput first-principles screening of 2259 nitride compounds, we identify five promising new nitride hosts for Eu<sup>2+</sup>-activated red-emitting phosphors that are predicted to exhibit good chemical stability, thermal quenching resistance, and quantum efficiency, as well as narrow-<span class="hlt">band</span> emission. Lastly, our findings provide important insights into the emission characteristics of rare-earth activators in phosphor hosts and a general strategy to the discovery of phosphors with a desired emission peak and bandwidth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22591665','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22591665"><span>Modification of <span class="hlt">electronic</span> properties of graphene by using low-<span class="hlt">energy</span> K{sup +} ions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kim, Jingul; Lee, Paengro; Ryu, Mintae; Park, Heemin; Chung, Jinwook</p> <p>2016-05-02</p> <p>Despite its superb <span class="hlt">electronic</span> properties, the semi-metallic nature of graphene with no <span class="hlt">band</span> gap (E{sub g}) at the Dirac point has been a stumbling block for its industrial application. We report an improved means of producing a tunable <span class="hlt">band</span> gap over other schemes by doping low <span class="hlt">energy</span> (10 eV) potassium ions (K{sup +}) on single layer graphene formed on 6H-SiC(0001) surface, where the noble Dirac nature of the π-<span class="hlt">band</span> remains almost unaltered. The changes in the π-<span class="hlt">band</span> induced by K{sup +} ions reveal that the <span class="hlt">band</span> gap increases gradually with increasing dose (θ) of the ions up to E{sub g} = 0.65 eV at θ = 1.10 monolayers, demonstrating the tunable character of the <span class="hlt">band</span> gap. Our core level data for C 1s, Si 2p, and K 2p suggest that the K{sup +}-induced asymmetry in charge distribution among carbon atoms drives the opening of <span class="hlt">band</span> gap, which is in sharp contrast with no <span class="hlt">band</span> gap when neutral K atoms are adsorbed on graphene. This tunable K{sup +}-induced <span class="hlt">band</span> gap in graphene illustrates its potential application in graphene-based nano-<span class="hlt">electronics</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23005659','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23005659"><span>Effect of <span class="hlt">electron</span>-phonon interaction range for a half-filled <span class="hlt">band</span> in one dimension.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hohenadler, Martin; Assaad, Fakher F; Fehske, Holger</p> <p>2012-09-14</p> <p>We demonstrate that fermion-boson models with nonlocal interactions can be simulated at finite <span class="hlt">band</span> filling with the continuous-time quantum Monte Carlo method. We apply this method to explore the influence of the <span class="hlt">electron</span>-phonon interaction range for a half-filled <span class="hlt">band</span> in one dimension, covering the full range from the Holstein to the Fröhlich regime. The phase diagram contains metallic, Peierls, and phase-separated regions. Nonlocal interactions suppress the Peierls instability, and thereby lead to almost degenerate power-law exponents for charge and pairing correlations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22254138','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22254138"><span>Enlarged <span class="hlt">band</span> gap and <span class="hlt">electron</span> switch in graphene-based step-barrier structure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lu, Wei-Tao Ye, Cheng-Zhi; Li, Wen</p> <p>2013-11-04</p> <p>We study the transmission through a step-barrier in gapped graphene and propose a method to enlarge the <span class="hlt">band</span> gap. The step-barrier structure consists of two or more barriers with different strengths. It is found that the <span class="hlt">band</span> gap could be effectively enlarged and controlled by adjusting the barrier strengths in the light of the mass term. Klein tunneling at oblique incidence is suppressed due to the asymmetry of step-barrier, contrary to the cases in single-barrier and superlattices. Furthermore, a tunable conductance channel could be opened up in the conductance gap, suggesting an application of the structure as an <span class="hlt">electron</span> switch.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AIPC.1214...42K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1214...42K"><span>Development of an L-<span class="hlt">Band</span> RF <span class="hlt">Electron</span> Gun for SASE in the Infrared Region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kashiwagi, Shigeru; Kato, Ryukou; Isoyama, Goro; Hayano, Hitoshi; Urakawa, Junji</p> <p>2010-02-01</p> <p>We conduct research on Self-Amplified Spontaneous Emission (SASE) in the infrared region using the 40 MeV, 1.3 GHz L-<span class="hlt">band</span> linac of Osaka University. The linac equipped with a thermionic <span class="hlt">electron</span> gun can accelerate a high-intensity single-bunch beam though its normalized emittance is high. In order to advance the research on SASE, we have begun development of an RF gun for the L-<span class="hlt">band</span> linac in collaboration with KEK. We will report conceptual design of the RF gun and present the status of development of another RF gun for STF at KEK.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23920165','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23920165"><span>Phase analysis on dual-phase steel using <span class="hlt">band</span> slope of <span class="hlt">electron</span> backscatter diffraction pattern.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kang, Jun-Yun; Park, Seong-Jun; Moon, Man-Been</p> <p>2013-08-01</p> <p>A quantitative and automated phase analysis of dual-phase (DP) steel using <span class="hlt">electron</span> backscatter diffraction (EBSD) was attempted. A ferrite-martensite DP microstructure was produced by intercritical annealing and quenching. An EBSD map of the microstructure was obtained and post-processed for phase discrimination. <span class="hlt">Band</span> slope (BS), which was a measure of pattern quality, exhibited much stronger phase contrast than another conventional one, <span class="hlt">band</span> contrast. Owing to high sensitivity to lattice defect and little orientation dependence, BS provided handiness in finding a threshold for phase discrimination. Its grain average gave a superior result on the discrimination and volume fraction measurement of the constituent phases in the DP steel.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28604864','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28604864"><span>From the Kohn-Sham <span class="hlt">band</span> gap to the fundamental gap in solids. An integer <span class="hlt">electron</span> approach.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Baerends, E J</p> <p>2017-06-21</p> <p>It is often stated that the Kohn-Sham occupied-unoccupied gap in both molecules and solids is "wrong". We argue that this is not a correct statement. The KS theory does not allow to interpret the exact KS HOMO-LUMO gap as the fundamental gap (difference (I - A) of <span class="hlt">electron</span> affinity (A) and ionization <span class="hlt">energy</span> (I), twice the chemical hardness), from which it indeed differs, strongly in molecules and moderately in solids. The exact Kohn-Sham HOMO-LUMO gap in molecules is much below the fundamental gap and very close to the much smaller optical gap (first excitation <span class="hlt">energy</span>), and LDA/GGA yield very similar gaps. In solids the situation is different: the excitation <span class="hlt">energy</span> to delocalized excited states and the fundamental gap (I - A) are very similar, not so disparate as in molecules. Again the Kohn-Sham and LDA/GGA <span class="hlt">band</span> gaps do not represent (I - A) but are significantly smaller. However, the special properties of an extended system like a solid make it very easy to calculate the fundamental gap from the ground state (neutral system) <span class="hlt">band</span> structure calculations entirely within a density functional framework. The correction Δ from the KS gap to the fundamental gap originates from the response part v(resp) of the exchange-correlation potential and can be calculated very simply using an approximation to v(resp). This affords a calculation of the fundamental gap at the same level of accuracy as other properties of crystals at little extra cost beyond the ground state bandstructure calculation. The method is based on integer <span class="hlt">electron</span> systems, fractional <span class="hlt">electron</span> systems (an ensemble of N- and (N + 1)-<span class="hlt">electron</span> systems) and the derivative discontinuity are not invoked.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JChPh.137s4112K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JChPh.137s4112K"><span><span class="hlt">Electronic</span> <span class="hlt">energy</span> transfer: Localized operator partitioning of <span class="hlt">electronic</span> <span class="hlt">energy</span> in composite quantum systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khan, Yaser; Brumer, Paul</p> <p>2012-11-01</p> <p>A Hamiltonian based approach using spatially localized projection operators is introduced to give precise meaning to the chemically intuitive idea of the <span class="hlt">electronic</span> <span class="hlt">energy</span> on a quantum subsystem. This definition facilitates the study of <span class="hlt">electronic</span> <span class="hlt">energy</span> transfer in arbitrarily coupled quantum systems. In particular, the decomposition scheme can be applied to molecular components that are strongly interacting (with significant orbital overlap) as well as to isolated fragments. The result defines a consistent <span class="hlt">electronic</span> <span class="hlt">energy</span> at all internuclear distances, including the case of separated fragments, and reduces to the well-known Förster and Dexter results in their respective limits. Numerical calculations of coherent <span class="hlt">energy</span> and charge transfer dynamics in simple model systems are presented and the effect of collisionally induced decoherence is examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810057018&hterms=energy+Solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Denergy%2BSolar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810057018&hterms=energy+Solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Denergy%2BSolar"><span>Propagation of low <span class="hlt">energy</span> solar <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Anderson, K. A.; Mcfadden, J. P.; Lin, R. P.</p> <p>1981-01-01</p> <p>Two events are reported in which 2-10 keV <span class="hlt">electrons</span> of solar <span class="hlt">energy</span> have undergone significant adiabatic mirroring and pitch angle scattering in large scale magnetic structures in the interplanetary medium within a distance of about 0.5 AU from the earth. <span class="hlt">Electrons</span> of 3 keV, typical of the <span class="hlt">energies</span> measured, have a speed of about one-tenth of the speed of light, so that their travel time from the sun at 0 deg pitch angle would be about 100 minutes. Their cyclotron radius is about 20 km for a pitch angle of 30 deg, and a field of magnitude of 5 nT, and the cyclotron period is about 7.1 milliseconds. The <span class="hlt">electrons</span> are scattered by spatial variations in the interplanetary magnetic field. When the spatial variations are convected past a stationary spacecraft by a 500 km/sec solar wind, they are seen as temporal fluctuations at a frequency of about 3 Hz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25083648','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25083648"><span>Direct observation of radiation-belt <span class="hlt">electron</span> acceleration from <span class="hlt">electron</span>-volt <span class="hlt">energies</span> to megavolts by nonlinear whistlers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mozer, F S; Agapitov, O; Krasnoselskikh, V; Lejosne, S; Reeves, G D; Roth, I</p> <p>2014-07-18</p> <p>The mechanisms for accelerating <span class="hlt">electrons</span> from thermal to relativistic <span class="hlt">energies</span> in the terrestrial magnetosphere, on the sun, and in many astrophysical environments have never been verified. We present the first direct observation of two processes that, in a chain, cause this acceleration in Earth's outer radiation belt. The two processes are parallel acceleration from <span class="hlt">electron</span>-volt to kilovolt <span class="hlt">energies</span> by parallel electric fields in time-domain structures (TDS), after which the parallel <span class="hlt">electron</span> velocity becomes sufficiently large for Doppler-shifted upper <span class="hlt">band</span> whistler frequencies to be in resonance with the <span class="hlt">electron</span> gyration frequency, even though the <span class="hlt">electron</span> <span class="hlt">energies</span> are kilovolts and not hundreds of kilovolts. The <span class="hlt">electrons</span> are then accelerated by the whistler perpendicular electric field to relativistic <span class="hlt">energies</span> in several resonant interactions. TDS are packets of electric field spikes, each spike having duration of a few hundred microseconds and containing a local parallel electric field. The TDS of interest resulted from nonlinearity of the parallel electric field component in oblique whistlers and consisted of ∼ 0.1 msec pulses superposed on the whistler waveform with each such spike containing a net parallel potential the order of 50 V. Local magnetic field compression from remote activity provided the free <span class="hlt">energy</span> to drive the two processes. The expected temporal correlations between the compressed magnetic field, the nonlinear whistlers with their parallel electric field spikes, the <span class="hlt">electron</span> flux and the <span class="hlt">electron</span> pitch angle distributions were all observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvL.113c5001M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvL.113c5001M"><span>Direct Observation of Radiation-Belt <span class="hlt">Electron</span> Acceleration from <span class="hlt">Electron</span>-Volt <span class="hlt">Energies</span> to Megavolts by Nonlinear Whistlers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mozer, F. S.; Agapitov, O.; Krasnoselskikh, V.; Lejosne, S.; Reeves, G. D.; Roth, I.</p> <p>2014-07-01</p> <p>The mechanisms for accelerating <span class="hlt">electrons</span> from thermal to relativistic <span class="hlt">energies</span> in the terrestrial magnetosphere, on the sun, and in many astrophysical environments have never been verified. We present the first direct observation of two processes that, in a chain, cause this acceleration in Earth's outer radiation belt. The two processes are parallel acceleration from <span class="hlt">electron</span>-volt to kilovolt <span class="hlt">energies</span> by parallel electric fields in time-domain structures (TDS), after which the parallel <span class="hlt">electron</span> velocity becomes sufficiently large for Doppler-shifted upper <span class="hlt">band</span> whistler frequencies to be in resonance with the <span class="hlt">electron</span> gyration frequency, even though the <span class="hlt">electron</span> <span class="hlt">energies</span> are kilovolts and not hundreds of kilovolts. The <span class="hlt">electrons</span> are then accelerated by the whistler perpendicular electric field to relativistic <span class="hlt">energies</span> in several resonant interactions. TDS are packets of electric field spikes, each spike having duration of a few hundred microseconds and containing a local parallel electric field. The TDS of interest resulted from nonlinearity of the parallel electric field component in oblique whistlers and consisted of ˜0.1 msec pulses superposed on the whistler waveform with each such spike containing a net parallel potential the order of 50 V. Local magnetic field compression from remote activity provided the free <span class="hlt">energy</span> to drive the two processes. The expected temporal correlations between the compressed magnetic field, the nonlinear whistlers with their parallel electric field spikes, the <span class="hlt">electron</span> flux and the <span class="hlt">electron</span> pitch angle distributions were all observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995PhDT.......125H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995PhDT.......125H"><span>Study of Low <span class="hlt">Energy</span> <span class="hlt">Electron</span> Inelastic Scattering Mechanisms Using Spin Sensitive Techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsu, Hongbing</p> <p>1995-01-01</p> <p>Spin sensitive <span class="hlt">electron</span> spectroscopies were used to study low <span class="hlt">energy</span> <span class="hlt">electron</span> inelastic scattering from metal surfaces and thin films. In these experiments, a beam of spin polarized <span class="hlt">electrons</span> from a GaAs source is directed on the sample surface, and the spin polarization and intensity are measured as a function of <span class="hlt">energy</span> loss and scattering angle by a Mott <span class="hlt">electron</span> polarimeter coupled with a concentric hemispherical <span class="hlt">energy</span> analyzer. Systematic studies of the angular dependence of inelastically scattered <span class="hlt">electrons</span> were conducted on a Cu(100) surface, and Mo/Cu(100), non-magnetized Fe/Cu(100), and Co/Cu(100) films. The polarization and intensity of scattered <span class="hlt">electrons</span> were measured as function of <span class="hlt">energy</span> loss and scattering angle. Further studies were also conducted on Ag(100) surface and amorphous Cu/Ag(100) films. From the experimental results, the angular distributions of dipole and impact scattered <span class="hlt">electrons</span> can be determined individually and both are found to peak in the specular scattering direction. Preliminary studies were conducted on magnetized Co/Cu(100) films. The spin dependent scattering intensity asymmetry was measured, with a clearly observable peak at <span class="hlt">energy</span> loss of ~1 eV, which coincides with the <span class="hlt">band</span> splitting. The polarizations of secondary <span class="hlt">electrons</span> produced by an unpolarized primary beam were also measured. The polarizations can be related to the <span class="hlt">band</span> polarization of magnetized cobalt films.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3556892','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3556892"><span>Effect of <span class="hlt">Electronic</span> Acceptor Segments on Photophysical Properties of Low-<span class="hlt">Band</span>-Gap Ambipolar Polymers</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Yuanzuo; Cui, Jingang; Zhao, Jianing; Liu, Jinglin; Song, Peng; Ma, Fengcai</p> <p>2013-01-01</p> <p>Stimulated by a recent experimental report, charge transfer and photophysical properties of donor-acceptor ambipolar polymer were studied with the quantum chemistry calculation and the developed 3D charge difference density method. The effects of <span class="hlt">electronic</span> acceptor strength on the structure, <span class="hlt">energy</span> levels, <span class="hlt">electron</span> density distribution, ionization potentials, and <span class="hlt">electron</span> affinities were also obtained to estimate the transporting ability of hole and <span class="hlt">electron</span>. With the developed 3D charge difference density, one visualizes the charge transfer process, distinguishes the role of molecular units, and finds the relationship between the role of DPP and excitation <span class="hlt">energy</span> for the three polymers during photo-excitation. PMID:23365549</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23365549','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23365549"><span>Effect of <span class="hlt">electronic</span> acceptor segments on photophysical properties of low-<span class="hlt">band</span>-gap ambipolar polymers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Yuanzuo; Cui, Jingang; Zhao, Jianing; Liu, Jinglin; Song, Peng; Ma, Fengcai</p> <p>2013-01-01</p> <p>Stimulated by a recent experimental report, charge transfer and photophysical properties of donor-acceptor ambipolar polymer were studied with the quantum chemistry calculation and the developed 3D charge difference density method. The effects of <span class="hlt">electronic</span> acceptor strength on the structure, <span class="hlt">energy</span> levels, <span class="hlt">electron</span> density distribution, ionization potentials, and <span class="hlt">electron</span> affinities were also obtained to estimate the transporting ability of hole and <span class="hlt">electron</span>. With the developed 3D charge difference density, one visualizes the charge transfer process, distinguishes the role of molecular units, and finds the relationship between the role of DPP and excitation <span class="hlt">energy</span> for the three polymers during photo-excitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvB..95w5105Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvB..95w5105Z"><span>Dynamical <span class="hlt">electron</span>-phonon coupling, G W self-consistency, and vertex effect on the <span class="hlt">electronic</span> <span class="hlt">band</span> gap of ice and liquid water</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ziaei, Vafa; Bredow, Thomas</p> <p>2017-06-01</p> <p>We study the impact of dynamical <span class="hlt">electron</span>-phonon (el-ph) effects on the <span class="hlt">electronic</span> <span class="hlt">band</span> gap of ice and liquid water by accounting for frequency-dependent Fan contributions in the el-ph mediated self-<span class="hlt">energy</span> within the many-body perturbation theory (MBPT). We find that the dynamical el-ph coupling effects greatly reduce the static el-ph <span class="hlt">band</span>-gap correction of the hydrogen-rich molecular ice crystal from-2.46 to -0.23 eV in great contrast to the result of Monserrat et al. [Phys. Rev. B 92, 140302 (2015), 10.1103/PhysRevB.92.140302]. This is of particular importance as otherwise the static el-ph gap correction would considerably reduce the <span class="hlt">electronic</span> <span class="hlt">band</span> gap, leading to considerable underestimation of the intense peaks of optical absorption spectra of ice which would be in great disagreement to experimental references. By contrast, the static el-ph gap correction of liquid water is very moderate (-0.32 eV), and inclusion of dynamical effects slightly reduces the gap correction to -0.19 eV. Further, we determine the diverse sensitivity of ice and liquid water to the G W self-consistency and show that the <span class="hlt">energy</span>-only self-consistent approach (GnWn ) exhibits large implicit vertex character in comparison to the quasiparticle self-consistent approach, for which an explicit calculation of vertex corrections is necessary for good agreement with experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27845925','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27845925"><span>2D Tl-Pb compounds on Ge(1 1 1) surface: atomic arrangement and <span class="hlt">electronic</span> <span class="hlt">band</span> structure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gruznev, D V; Bondarenko, L V; Tupchaya, A Y; Eremeev, S V; Mihalyuk, A N; Chou, J P; Wei, C M; Zotov, A V; Saranin, A A</p> <p>2017-01-25</p> <p>Structural transformations and evolution of the <span class="hlt">electron</span> <span class="hlt">band</span> structure in the (Tl, Pb)/Ge(1 1 1) system have been studied using low-<span class="hlt">energy</span> <span class="hlt">electron</span> diffraction, scanning tunneling microscopy, angle-resolved photoelectron spectroscopy and density functional theory calculations. The two 2D Tl-Pb compounds on Ge(1 1 1), [Formula: see text]-(Tl, Pb) and [Formula: see text]-(Tl, Pb), have been found and their composition, atomic arrangement and <span class="hlt">electron</span> properties has been characterized. The (Tl, Pb)/Ge(1 1 1)[Formula: see text] compound is almost identical to the alike (Tl, Pb)/Si(1 1 1)[Formula: see text] system from the viewpoint of its atomic structure and <span class="hlt">electronic</span> properties. They contain 1.0 ML of Tl atoms arranged into a honeycomb network of chained trimers and 1/3 ML of Pb atoms occupying the centers of the honeycomb units. The (Tl, Pb)/Ge(1 1 1)[Formula: see text] compound contains six Tl atoms and seven Pb atoms per [Formula: see text] unit cell (i.e.  ∼0.67 ML Tl and  ∼0.78 ML Pb). Its atomic structure can be visualized as consisting of Pb hexagons surrounded by Tl trimers. The (Tl, Pb)/Ge(1 1 1)[Formula: see text] and (Tl, Pb)/Ge(1 1 1)[Formula: see text] compounds are metallic and their <span class="hlt">band</span> structures contain spin-split surface-state <span class="hlt">bands</span>. By analogy with the (Tl, Pb)/Si(1 1 1)[Formula: see text], these (Tl, Pb)/Ge(1 1 1) compounds are believed to be promising objects for prospective studies of superconductivity in one-atom-layer systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPCM...29c5001G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPCM...29c5001G"><span>2D Tl-Pb compounds on Ge(1 1 1) surface: atomic arrangement and <span class="hlt">electronic</span> <span class="hlt">band</span> structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gruznev, D. V.; Bondarenko, L. V.; Tupchaya, A. Y.; Eremeev, S. V.; Mihalyuk, A. N.; Chou, J. P.; Wei, C. M.; Zotov, A. V.; Saranin, A. A.</p> <p>2017-01-01</p> <p>Structural transformations and evolution of the <span class="hlt">electron</span> <span class="hlt">band</span> structure in the (Tl, Pb)/Ge(1 1 1) system have been studied using low-<span class="hlt">energy</span> <span class="hlt">electron</span> diffraction, scanning tunneling microscopy, angle-resolved photoelectron spectroscopy and density functional theory calculations. The two 2D Tl-Pb compounds on Ge(1 1 1), \\sqrt{3}× \\sqrt{3} -(Tl, Pb) and 3× 3 -(Tl, Pb), have been found and their composition, atomic arrangement and <span class="hlt">electron</span> properties has been characterized. The (Tl, Pb)/Ge(1 1 1)\\sqrt{3}× \\sqrt{3} compound is almost identical to the alike (Tl, Pb)/Si(1 1 1)\\sqrt{3}× \\sqrt{3} system from the viewpoint of its atomic structure and <span class="hlt">electronic</span> properties. They contain 1.0 ML of Tl atoms arranged into a honeycomb network of chained trimers and 1/3 ML of Pb atoms occupying the centers of the honeycomb units. The (Tl, Pb)/Ge(1 1 1)3× 3 compound contains six Tl atoms and seven Pb atoms per 3× 3 unit cell (i.e.  ˜0.67 ML Tl and  ˜0.78 ML Pb). Its atomic structure can be visualized as consisting of Pb hexagons surrounded by Tl trimers. The (Tl, Pb)/Ge(1 1 1)\\sqrt{3}× \\sqrt{3} and (Tl, Pb)/Ge(1 1 1)3× 3 compounds are metallic and their <span class="hlt">band</span> structures contain spin-split surface-state <span class="hlt">bands</span>. By analogy with the (Tl, Pb)/Si(1 1 1)\\sqrt{3}× \\sqrt{3} , these (Tl, Pb)/Ge(1 1 1) compounds are believed to be promising objects for prospective studies of superconductivity in one-atom-layer systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21776667','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21776667"><span><span class="hlt">Electron-electron</span> correlations in square-well quantum dots: direct <span class="hlt">energy</span> minimization approach.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Goto, Hidekazu; Hirose, Kikuji</p> <p>2011-04-01</p> <p><span class="hlt">Electron-electron</span> correlations in two-dimensional square-well quantum dots are investigated using the direct <span class="hlt">energy</span> minimization scheme. Searches for groundstate charges and spin configurations are performed with varying the sizes of dots and the number of <span class="hlt">electrons</span>. For a two-<span class="hlt">electron</span> system, a standout difference between the configurations with and without counting correlation <span class="hlt">energy</span> is demonstrated. The emergence and melting of Wigner-molecule-like structures arising from the interplay between the kinetic <span class="hlt">energy</span> and Coulombic interaction <span class="hlt">energy</span> are described. <span class="hlt">Electron-electron</span> correlation <span class="hlt">energies</span> and addition <span class="hlt">energy</span> spectra are calculated, and special <span class="hlt">electron</span> numbers related to peculiar effects of the square well are extracted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22519353','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22519353"><span>The nature of the low <span class="hlt">energy</span> <span class="hlt">band</span> of the Fenna-Matthews-Olson complex: vibronic signatures.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Caycedo-Soler, Felipe; Chin, Alex W; Almeida, Javier; Huelga, Susana F; Plenio, Martin B</p> <p>2012-04-21</p> <p>Based entirely upon actual experimental observations on <span class="hlt">electron</span>-phonon coupling, we develop a theoretical framework to show that the lowest <span class="hlt">energy</span> <span class="hlt">band</span> of the Fenna-Matthews-Olson complex exhibits observable features due to the quantum nature of the vibrational manifolds present in its chromophores. The study of linear spectra provides us with the basis to understand the dynamical features arising from the vibronic structure in nonlinear spectra in a progressive fashion, starting from a microscopic model to finally performing an inhomogeneous average. We show that the discreteness of the vibronic structure can be witnessed by probing the diagonal peaks of the nonlinear spectra by means of a relative phase shift in the waiting time resolved signal. Moreover, we demonstrate that the photon-echo and non-rephasing paths are sensitive to different harmonics in the vibrational manifold when static disorder is taken into account. Supported by analytical and numerical calculations, we show that non-diagonal resonances in the 2D spectra in the waiting time, further capture the discreteness of vibrations through a modulation of the amplitude without any effect in the signal intrinsic frequency. This fact generates a signal that is highly sensitive to correlations in the static disorder of the excitonic <span class="hlt">energy</span> albeit protected against dephasing due to inhomogeneities of the vibrational ensemble.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JChPh.137k4508R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JChPh.137k4508R"><span>Comprehensive studies of the <span class="hlt">electronic</span> structure of pristine and potassium doped chrysene investigated by <span class="hlt">electron</span> <span class="hlt">energy</span>-loss spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roth, Friedrich; Mahns, Benjamin; Schönfelder, Ronny; Hampel, Silke; Nohr, Markus; Büchner, Bernd; Knupfer, Martin</p> <p>2012-09-01</p> <p>We have performed <span class="hlt">electron</span> <span class="hlt">energy</span>-loss spectroscopy studies in order to investigate the <span class="hlt">electronic</span> properties of chrysene molecular solids. The valence <span class="hlt">band</span> <span class="hlt">electronic</span> excitation spectra and the C 1s core level excitations have been measured for pristine and potassium doped chrysene. The core level studies show a fine structure which signals the presence of four close lying conduction <span class="hlt">bands</span> close to the Fermi level. Upon potassium doping, these <span class="hlt">bands</span> are filled with <span class="hlt">electrons</span>, and we have reached a doping level of about K2.7chrysene. Furthermore, undoped chrysene is characterized by an optical gap of about 3.3 eV and five, relatively weak, excitonic features following the excitation onset. Doping induces major changes in the <span class="hlt">electronic</span> excitation spectra, with a new, prominent low <span class="hlt">energy</span> excitation at about 1.3 eV. The results of a Kramers-Kronig analysis indicate that this new feature can be assigned to a charge carrier plasmon in the doped material, and momentum dependent studies reveal a negative plasmon dispersion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApPRv...4b1301H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPRv...4b1301H"><span><span class="hlt">Energy</span> <span class="hlt">band</span> offsets of dielectrics on InGaZnO4</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hays, David C.; Gila, B. P.; Pearton, S. J.; Ren, F.</p> <p>2017-06-01</p> <p>Thin-film transistors (TFTs) with channels made of hydrogenated amorphous silicon (a-Si:H) and polycrystalline silicon (poly-Si) are used extensively in the display industry. Amorphous silicon continues to dominate large-format display technology, but a-Si:H has a low <span class="hlt">electron</span> mobility, μ ˜ 1 cm2/V s. Transparent, conducting metal-oxide materials such as Indium-Gallium-Zinc Oxide (IGZO) have demonstrated <span class="hlt">electron</span> mobilities of 10-50 cm2/V s and are candidates to replace a-Si:H for TFT backplane technologies. The device performance depends strongly on the type of <span class="hlt">band</span> alignment of the gate dielectric with the semiconductor channel material and on the <span class="hlt">band</span> offsets. The factors that determine the conduction and valence <span class="hlt">band</span> offsets for a given material system are not well understood. Predictions based on various models have historically been unreliable and <span class="hlt">band</span> offset values must be determined experimentally. This paper provides experimental <span class="hlt">band</span> offset values for a number of gate dielectrics on IGZO for next generation TFTs. The relationship between <span class="hlt">band</span> offset and interface quality, as demonstrated experimentally and by previously reported results, is also explained. The literature shows significant variations in reported <span class="hlt">band</span> offsets and the reasons for these differences are evaluated. The biggest contributor to conduction <span class="hlt">band</span> offsets is the variation in the bandgap of the dielectrics due to differences in measurement protocols and stoichiometry resulting from different deposition methods, chemistry, and contamination. We have investigated the influence of valence <span class="hlt">band</span> offset values of strain, defects/vacancies, stoichiometry, chemical bonding, and contamination on IGZO/dielectric heterojunctions. These measurements provide data needed to further develop a predictive theory of <span class="hlt">band</span> offsets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/564930','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/564930"><span>Spins, Parity, Excitation <span class="hlt">Energies</span>, and Octupole Structure of an Excited Superdeformed <span class="hlt">Band</span> in {sup 194}Hg and Implications for Identical <span class="hlt">Bands</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hackman, G.; Khoo, T.L.; Carpenter, M.P.; Lauritsen, T.; Calderin, I.J.; Janssens, R.V.; Ackermann, D.; Ahmad, I.; Agarwala, S.; Blumenthal, D.J.; Fischer, S.M.; Nisius, D.; Reiter, P.; Young, J.; Amro, H.; Lopez-Martens, A.; Hannachi, F.; Korichi, A.; Amro, H.; Moore, E.F.; Lee, I.Y.; Macchiavelli, A.O.; Do Nakatsukasa, T.</p> <p>1997-11-01</p> <p>An excited superdeformed <span class="hlt">band</span> in {sup 194}Hg , observed to decay directly to both normal-deformed and superdeformed yrast states, is proposed to be a K{sup {pi}}=2{sup {minus}} octupole vibrational <span class="hlt">band</span>, based on its excitation <span class="hlt">energies</span>, spins, and likely parity. The transition <span class="hlt">energies</span> are identical to those of the yrast superdeformed <span class="hlt">band</span> in {sup 192}Hg , but originate from levels with different spins and parities. The evolution of transition <span class="hlt">energies</span> with spin suggests that cancellations between pairing and particle alignment are partly responsible for the identical transition <span class="hlt">energies</span>. {copyright} {ital 1997} {ital The American Physical Society}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1299786','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1299786"><span>Oligomeric state of human erythrocyte <span class="hlt">band</span> 3 measured by fluorescence resonance <span class="hlt">energy</span> homotransfer.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Blackman, S M; Piston, D W; Beth, A H</p> <p>1998-01-01</p> <p>The oligomeric state of the erythrocyte anion exchange protein, <span class="hlt">band</span> 3, has been assayed by resonance <span class="hlt">energy</span> homotransfer. Homotransfer between oligomeric subunits, labeled with eosin-5-maleimide at Lys430 in the transmembrane domain, has been demonstrated by steady-state and time-resolved fluorescence spectroscopy, and is readily observed by its depolarization of the eosin fluorescence. Polarized fluorescence measurements of HPLC-purified <span class="hlt">band</span> 3 oligomers indicate that eosin homotransfer increases progressively with increasing species size. This shows that homotransfer also occurs between labeled <span class="hlt">band</span> 3 dimers as well as within the dimers, making fluorescence anisotropy measurements sensitive to <span class="hlt">band</span> 3 self-association. Treatment of ghost membranes with either Zn2+ or melittin, agents that cluster <span class="hlt">band</span> 3, significantly decreases the anisotropy as a result of the increased homotransfer within the <span class="hlt">band</span> 3 clusters. By comparison with the anisotropy of species of known oligomeric state, the anisotropy of erythrocyte ghost membranes at 37 degrees C is consistent with dimeric and/or tetrameric <span class="hlt">band</span> 3, and does not require postulation of a fraction of large clusters. Proteolytic removal of the cytoplasmic domain of <span class="hlt">band</span> 3, which significantly increases the rotational mobility of the transmembrane domain, does not affect its oligomeric state, as reported by eosin homotransfer. These results support a model in which interaction with the membrane skeleton restricts the mobility of <span class="hlt">band</span> 3 without significantly altering its self-association state. PMID:9675213</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995JChPh.102.2522B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995JChPh.102.2522B"><span>Ab initio <span class="hlt">electronic</span> structure of a small <span class="hlt">band</span> gap polymer: Poly-aminosquaraine</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brocks, G.</p> <p>1995-02-01</p> <p>Poly-aminosquaraine is the prototype of a class of organic polymers which recently has been shown to provide a route towards small <span class="hlt">band</span> gap materials. We predict that poly-aminosquaraine has a small <span class="hlt">band</span> gap of ˜0.5 eV. Our prediction is based upon a detailed analysis of first-principles calculations of the geometrical and the <span class="hlt">electronic</span> structure, using the Car-Parrinello technique of simultaneous optimization. We analyze the <span class="hlt">bands</span> around the Fermi level in terms of a simple tight-binding model based upon the highest occupied and lowest occupied (HOMO/LUMO) states of the individual squaraine molecules. The small <span class="hlt">band</span> gap of the polymer is shown to be the result of the small splitting between the occupied and the unoccupied states of the squaraine molecule combined with a favorable hybridization in the polymer. It should be possible to analyze the <span class="hlt">electronic</span> structure of a wide class of squaraine based polymers in the same way.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015CoTPh..64..395Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015CoTPh..64..395Z"><span><span class="hlt">Energy</span> <span class="hlt">Band</span> and Josephson Dynamics of Spin-Orbit Coupled Bose-Einstein Condensates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Xin; Yu, Zi-Fa; Xue, Ju-Kui</p> <p>2015-10-01</p> <p>We theoretically investigate the <span class="hlt">energy</span> <span class="hlt">band</span> structure and Josephson dynamics of a spin-orbit coupled Bose-Einstein condensate in a double-well potential. We study the <span class="hlt">energy</span> <span class="hlt">band</span> structure and the corresponding tunneling dynamics of the system by properly adjusting the SO coupling, Raman coupling, Zeeman field and atomic interactions. The coupled effects of SO coupling, Raman coupling, Zeeman field and atomic interactions lead to the appearance of complex <span class="hlt">energy</span> <span class="hlt">band</span> structure including the loop structure. Particularly, the emergence of the loop structure in <span class="hlt">energy</span> <span class="hlt">band</span> also depends on SO coupling, Raman coupling, Zeeman field and atomic interactions. Correspondingly, the Josephson dynamics of the system are strongly related to the <span class="hlt">energy</span> <span class="hlt">band</span> structure. Especially, the emergence of the loop structure results in complex tunneling dynamics, including suppression-revival transitions and self-trapping of atoms transfer between two spin states and two wells. This engineering provides a possible means for studying <span class="hlt">energy</span> level and corresponding dynamics of two-species SO coupled BECs. Supported by the National Natural Science Foundation of China under Grant Nos. 11274255 and 11305132, by Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No. 20136203110001, by the Natural Science Foundation of Gansu province under Grant No. 2011GS04358, and by Creation of Science and Technology of Northwest Normal University under Grant Nos. NWNU-KJCXGC-03-48, NWNU-LKQN-12-12</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT.......274S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT.......274S"><span>Extreme <span class="hlt">Band</span> Engineering of III-Nitride Nanowire Heterostructures for <span class="hlt">Electronic</span> and Photonic Application</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sarwar, ATM Golam</p> <p></p> <p>Bottom-up nanowires are attractive for realizing semiconductor devices with extreme heterostructures because strain relaxation through the nanowire sidewalls allows the combination of highly lattice mismatched materials without creating dislocations. The resulting nanowires are used to fabricate light-emitting diodes (LEDs), lasers, solar cells, and sensors. The aim of this work is to investigate extreme heterostructures, which are impossible or very hard to realize in conventional planar films, exploiting the strain accommodation property of nanowires and engineer their <span class="hlt">band</span> structure for novel <span class="hlt">electronic</span> and photonic applications. To this end, in this thesis, III-Nitride semiconductor nanowires are investigated. In the first part of this work, a complete growth phase diagram of InN nanowires on silicon using plasma assisted molecular beam epitaxy is developed, and structural and optical characteristics are mapped as a function of growth parameters. Next, a novel up-side down pendeoepitaxial growth of InN forming mushroom-like microstructures is demonstrated and detail structural and optical characterizations are performed. Based on this, a method to grow strain-free large area single crystalline InN or thin film is proposed and the growth of InN on patterned GaN is investigated. The optimized growth conditions developed for InN are further used to grow InGaN nanowires graded over the whole composition range. Numerical <span class="hlt">energy</span> <span class="hlt">band</span> simulation is performed to better understand the effect of polarization charge on photo-carrier transport in these extremely graded nanowires. A novel photodetector device with negative differential photocurrent is demonstrated using the graded InGaN nanowires. In the second part of this thesis, polarization-induced nanowire light emitting diodes (PINLEDs) are investigated. The electrical and optical properties of the nanowire heterostructure are engineered and optimized for ultraviolet and deep ultraviolet applications. The electrical</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhRvB..76c5123D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhRvB..76c5123D"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structure and Fermi surface of ferromagnetic Tb: Experiment and theory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Döbrich, K. M.; Bihlmayer, G.; Starke, K.; Prieto, J. E.; Rossnagel, K.; Koh, H.; Rotenberg, E.; Blügel, S.; Kaindl, G.</p> <p>2007-07-01</p> <p>We have investigated the bulk valence-<span class="hlt">band</span> structure of Tb metal in the ferromagnetic phase by angle-resolved photoelectron spectroscopy and full-potential-linearized-augmented-plane-wave calculations. The experiments were performed at undulator beamline 7.0.1 of the Advanced Light Source using a three-axis rotatable low-temperature goniometer and a display-type photoelectron spectrometer that give access to a large region of momentum space. The results of our calculations, which make use of recent progress in the theoretical description of the magnetic properties of 4f metals, are in remarkably good agreement with experiment. This can be best seen from a comparison of the <span class="hlt">electronic</span> structure in high-symmetry directions, at critical points, on Fermi contours, and at <span class="hlt">band</span> crossings with the Fermi level. To our knowledge, the present work represents the most detailed combined experimental and theoretical study of the <span class="hlt">electronic</span> structure of a magnetic lanthanide metal to date.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4830422','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4830422"><span>Room-Temperature <span class="hlt">Electron</span> Spin Relaxation of Triarylmethyl Radicals at X- and Q-<span class="hlt">bands</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Krumkacheva, Olesya A.; Strizhakov, Rodion K.; Rogozhnikova, Olga Yu.; Troitskaya, Tatiana I.</p> <p>2016-01-01</p> <p>Triarylmethyl radicals (trityls, TAMs) represent a relatively new class of spin labels. The long relaxation of trityls at room temperature in liquid solutions makes them a promising alternative for traditional nitroxides. In this work we have synthesized a series of TAMs including perdeuterated Finland trityl (D36 form) , mono-, di-, and tri-ester derivatives of Finland-D36 trityl, deuterated form of OX63, dodeca-n-butyl homologue of Finland trityl, and triamide derivatives of Finland trityl with primary and secondary amines attached. We have studied room-temperature relaxation properties of these TAMs in liquids using pulsed <span class="hlt">Electron</span> Paramagnetic Resonance (EPR) at two microwave frequency <span class="hlt">bands</span>. We have found the clear dependence of phase memory time (Tm~T2) on magnetic field: room-temperature Tm values are ~1.5-2.5 times smaller at Q-<span class="hlt">band</span> (34 GHz, 1.2 T) compared to X-<span class="hlt">band</span> (9 GHz, 0.3 T). This trend is ascribed to the contribution from g-anisotropy that is negligible at lower magnetic fields but comes into play at Q-<span class="hlt">band</span>. In agreement with this, while T1~Tm at X-<span class="hlt">band</span>, we observe T1>Tm at Q-<span class="hlt">band</span> due to increased contributions from incomplete motional averaging of g-anisotropy. In addition, the viscosity dependence shows that (1/Tm-1/T1) is proportional to the tumbling correlation time of trityls. Based on the analysis of previous data and results of the present work, we conclude that in general situation where spin label is at least partly mobile, X-<span class="hlt">band</span> is most suitable for application of trityls for room-temperature pulsed EPR distance measurements. PMID:26001103</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JAP...119n3103S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JAP...119n3103S"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structure and optical gain of GaNxBiyAs1-x-y/GaAs pyramidal quantum dots</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Song, Zhi-Gang; Bose, Sumanta; Fan, Wei-Jun; Li, Shu-Shen</p> <p>2016-04-01</p> <p>The <span class="hlt">electronic</span> <span class="hlt">band</span> structure and optical gain of GaNxBiyAs1-x-y/GaAs pyramidal quantum dots (QDs) are investigated using the 16-<span class="hlt">band</span> k ṡ p model with constant strain. The optical gain is calculated taking both homogeneous and inhomogeneous broadenings into consideration. The effective <span class="hlt">band</span> gap falls as we increase the composition of nitrogen (N) and bismuth (Bi) and with an appropriate choice of composition we can tune the emission wavelength to span within 1.3 μm-1.55 μm, for device application in fiber technology. The extent of this red shift is more profound in QDs compared with bulk material due to quantum confinement. Other factors affecting the emission characteristics include virtual crystal, strain profile, <span class="hlt">band</span> anticrossing (BAC), and valence <span class="hlt">band</span> anticrossing (VBAC). The strain profile has a profound impact on the <span class="hlt">electronic</span> structure, specially the valence <span class="hlt">band</span> of QDs, which can be determined using the composition distribution of wave functions. All these factors eventually affect the optical gain spectrum. With an increase in QD size, we observe a red shift in the emission <span class="hlt">energy</span> and emergence of secondary peaks owing to transitions or greater <span class="hlt">energy</span> compared with the fundamental transition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22608745','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22608745"><span><span class="hlt">Electronic</span> <span class="hlt">band</span> structure and optical properties of antimony selenide under pressure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Abhijit, B.K.; Jayaraman, Aditya; Molli, Muralikrishna</p> <p>2016-05-23</p> <p>In this work we present the optical properties of Antimony Selenide (Sb{sub 2}Se{sub 3}) under ambient conditions and under pressure of 9.2 GPa obtained using first principles calculations. We investigated the <span class="hlt">electronic</span> <span class="hlt">band</span> structure using the FP-LAPW method within the sphere of the density functional theory. Optical properties like refractive index, absorption coefficient and optical conductivity are calculated using the WIEN2k code.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27233269','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27233269"><span>Virus Isolation and Preparation of Sucrose-<span class="hlt">Banded</span> Chikungunya Virus Samples for Transmission <span class="hlt">Electron</span> Microscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lim, Chang-Kweng</p> <p>2016-01-01</p> <p>Virus isolation and purification is an invaluable technique in virology to detect and characterize viruses. This chapter describes a large-scale Chikungunya virus (CHIKV) propagation and purification methods by using discontinuous sucrose gradient, and sample preparation for transmission <span class="hlt">electron</span> microscopy. Sucrose-<span class="hlt">banding</span> yields large quantities of high-titer (10(10) pfu/ml) CHIKV stocks. Such stocks are stable for years when stored at -70 °C.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApPhL.111g1902Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApPhL.111g1902Z"><span>Tri-<span class="hlt">band</span> miniaturized wide-angle and polarization-insensitive metasurface for ambient <span class="hlt">energy</span> harvesting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Xuanming; Liu, Haixia; Li, Long</p> <p>2017-08-01</p> <p>In this paper, a tri-<span class="hlt">band</span> miniaturized wide-angle and polarization-insensitive metasurface is proposed as an ambient <span class="hlt">energy</span> collector. The metasurface is composed of a subwavelength butterfly-type closed-ring (BCR) array attached to a low-loss substrate with a metallic ground. Each unit cell of the <span class="hlt">energy</span> harvesting metasurface has only one harvesting port. Its <span class="hlt">energy</span> harvesting efficiency for different polarization and incident angles was analyzed, and the results show that the maximum harvesting efficiency is 90%, 83%, and 81% at the three frequency <span class="hlt">bands</span> of 0.9 GHz, 2.6 GHz, and 5.7 GHz, respectively. Moreover, a prototype of the 7 × 7 BCR metasurface harvesting array was fabricated and measured. The experimental results validate that the proposed metasurface performs well under transverse electric and transverse magnetic polarization and is suitable for wide-angle incident <span class="hlt">energy</span> harvesting in the three frequency <span class="hlt">bands</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22555818','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22555818"><span>Decomposition of methionine by low <span class="hlt">energy</span> <span class="hlt">electrons</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kopyra, Janina; Szamrej, Iwona; Abdoul-Carime, Hassan; Farizon, Bernadette; Farizon, Michel</p> <p>2012-06-14</p> <p>In this work, we present the results from low <span class="hlt">energy</span> (<12 eV) <span class="hlt">electron</span> impact on isolated methionine, Met. We show that dissociative <span class="hlt">electron</span> attachment is the operative mechanism for the sulfur content amino-acid fragmentation. The two most dominant fragments are attributed to the (Met-H)(-) and (C(4)NOH(5))(-) ions that are formed at <span class="hlt">energy</span> below 2 eV. The formation of the latter anion is accompanied by the loss of neutral counterparts, which are most likely a water molecule and highly toxic methanethiol, CH(3)SH. Further fragments are associated with the damage at the sulfur end of the amino acid, producing the methyl sulfide anion CH(3)S(-) or sulfur containing neutrals. In the context of radiation induced damage to biological material at the nano-scale level, the present interest of methionine arises from the implication of the molecule in biological processes (e.g., S-adenosyl methionine for the stimulation of DNA methyltransferase reactions or protein synthesis).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997APS..PAC..3V35L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997APS..PAC..3V35L"><span>W-<span class="hlt">Band</span> Free <span class="hlt">Electron</span> Laser for High Gradient Structure Research</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lidia, S. M.; Whittum, D. H.; Donohue, J. T.</p> <p>1997-05-01</p> <p>We discuss the use of a free <span class="hlt">electron</span> laser in support of material stress studies of W-<span class="hlt">band</span> high-gradient accelerating structures. We propose the use of the linear induction accelerator LELIA (CEA/CESTA, France) to generate a 1-kiloamp, 80-ns FWHM <span class="hlt">electron</span> pulse. We present a design for a helical FEL TE_11 amplifier that will generate high peak power (100's MW) at 93 GHz. We support our design with analytical estimates of gain, and with numerical simulations of power and phase development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26655671','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26655671"><span>Time-resolved observation of <span class="hlt">band</span>-gap shrinking and <span class="hlt">electron</span>-lattice thermalization within X-ray excited gallium arsenide.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ziaja, Beata; Medvedev, Nikita; Tkachenko, Victor; Maltezopoulos, Theophilos; Wurth, Wilfried</p> <p>2015-12-11</p> <p>Femtosecond X-ray irradiation of solids excites energetic photoelectrons that thermalize on a timescale of a few hundred femtoseconds. The thermalized <span class="hlt">electrons</span> exchange <span class="hlt">energy</span> with the lattice and heat it up. Experiments with X-ray free-<span class="hlt">electron</span> lasers have unveiled so far the details of the <span class="hlt">electronic</span> thermalization. In this work we show that the data on transient optical reflectivity measured in GaAs irradiated with femtosecond X-ray pulses can be used to follow <span class="hlt">electron</span>-lattice relaxation up to a few tens of picoseconds. With a dedicated theoretical framework, we explain the so far unexplained reflectivity overshooting as a result of <span class="hlt">band</span>-gap shrinking. We also obtain predictions for a timescale of <span class="hlt">electron</span>-lattice thermalization, initiated by conduction <span class="hlt">band</span> <span class="hlt">electrons</span> in the temperature regime of a few eVs. The conduction and valence <span class="hlt">band</span> carriers were then strongly non-isothermal. The presented scheme is of general applicability and can stimulate further studies of relaxation within X-ray excited narrow <span class="hlt">band</span>-gap semiconductors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JChPh.138s4306D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JChPh.138s4306D"><span>Low-<span class="hlt">energy</span> <span class="hlt">electron</span> collisions with thiophene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>da Costa, R. F.; Varella, M. T. do N.; Lima, M. A. P.; Bettega, M. H. F.</p> <p>2013-05-01</p> <p>We report on elastic integral, momentum transfer, and differential cross sections for collisions of low-<span class="hlt">energy</span> <span class="hlt">electrons</span> with thiophene molecules. The scattering calculations presented here used the Schwinger multichannel method and were carried out in the static-exchange and static-exchange plus polarization approximations for <span class="hlt">energies</span> ranging from 0.5 eV to 6 eV. We found shape resonances related to the formation of two long-lived π* anion states. These resonant structures are centered at the <span class="hlt">energies</span> of 1.00 eV (2.85 eV) and 2.82 eV (5.00 eV) in the static-exchange plus polarization (static-exchange) approximation and belong to the B1 and A2 symmetries of the C2v point group, respectively. Our results also suggest the existence of a σ* shape resonance in the B2 symmetry with a strong d-wave character, located at around 2.78 eV (5.50 eV) as obtained in the static-exchange plus polarization (static-exchange) calculation. It is worth to mention that the results obtained at the static-exchange plus polarization level of approximation for the two π* resonances are in good agreement with the <span class="hlt">electron</span> transmission spectroscopy results of 1.15 eV and 2.63 eV measured by Modelli and Burrow [J. Phys. Chem. A 108, 5721 (2004), 10.1021/jp048759a]. The existence of the σ* shape resonance is in agreement with the observations of Dezarnaud-Dandiney et al. [J. Phys. B 31, L497 (1998), 10.1088/0953-4075/31/11/004] based on the <span class="hlt">electron</span> transmission spectra of dimethyl(poly)sulphides. A comparison among the resonances of thiophene with those of pyrrole and furan is also performed and, altogether, the resonance spectra obtained for these molecules point out that <span class="hlt">electron</span> attachment to π* molecular orbitals is a general feature displayed by these five-membered heterocyclic compounds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23697417','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23697417"><span>Low-<span class="hlt">energy</span> <span class="hlt">electron</span> collisions with thiophene.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>da Costa, R F; Varella, M T do N; Lima, M A P; Bettega, M H F</p> <p>2013-05-21</p> <p>We report on elastic integral, momentum transfer, and differential cross sections for collisions of low-<span class="hlt">energy</span> <span class="hlt">electrons</span> with thiophene molecules. The scattering calculations presented here used the Schwinger multichannel method and were carried out in the static-exchange and static-exchange plus polarization approximations for <span class="hlt">energies</span> ranging from 0.5 eV to 6 eV. We found shape resonances related to the formation of two long-lived π∗ anion states. These resonant structures are centered at the <span class="hlt">energies</span> of 1.00 eV (2.85 eV) and 2.82 eV (5.00 eV) in the static-exchange plus polarization (static-exchange) approximation and belong to the B1 and A2 symmetries of the C2v point group, respectively. Our results also suggest the existence of a σ∗ shape resonance in the B2 symmetry with a strong d-wave character, located at around 2.78 eV (5.50 eV) as obtained in the static-exchange plus polarization (static-exchange) calculation. It is worth to mention that the results obtained at the static-exchange plus polarization level of approximation for the two π∗ resonances are in good agreement with the <span class="hlt">electron</span> transmission spectroscopy results of 1.15 eV and 2.63 eV measured by Modelli and Burrow [J. Phys. Chem. A 108, 5721 (2004)]. The existence of the σ∗ shape resonance is in agreement with the observations of Dezarnaud-Dandiney et al. [J. Phys. B 31, L497 (1998)] based on the <span class="hlt">electron</span> transmission spectra of dimethyl(poly)sulphides. A comparison among the resonances of thiophene with those of pyrrole and furan is also performed and, altogether, the resonance spectra obtained for these molecules point out that <span class="hlt">electron</span> attachment to π∗ molecular orbitals is a general feature displayed by these five-membered heterocyclic compounds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21860072','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21860072"><span>Tracking the <span class="hlt">energies</span> of one-dimensional sub-<span class="hlt">band</span> edges in quantum point contacts using dc conductance measurements.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Micolich, A P; Zülicke, U</p> <p>2011-09-14</p> <p>The semiconductor quantum point contact has long been a focal point for studies of one-dimensional (1D) <span class="hlt">electron</span> transport. Their electrical properties are typically studied using ac conductance methods, but recent work has shown that the dc conductance can be used to obtain additional information, with a density-dependent Landé effective g-factor recently reported (Chen et al 2009 Phys. Rev. B 79 081301). We discuss previous dc conductance measurements of quantum point contacts, demonstrating how valuable additional information can be extracted from the data. We provide a comprehensive and general framework for dc conductance measurements that provides a path to improving the accuracy of existing data and obtaining useful additional data. A key aspect is that dc conductance measurements can be used to map the <span class="hlt">energy</span> of the 1D sub-<span class="hlt">band</span> edges directly, giving new insight into the physics that takes place as the spin-split 1D sub-<span class="hlt">bands</span> populate. Through a re-analysis of the data obtained by Chen et al, we obtain two findings. The first is that the 2↓ sub-<span class="hlt">band</span> edge closely tracks the source chemical potential when it first begins populating before dropping more rapidly in <span class="hlt">energy</span>. The second is that the 2↑ sub-<span class="hlt">band</span> populates more rapidly as the sub-<span class="hlt">band</span> edge approaches the drain potential. This second finding suggests that the spin-gap may stop opening, or even begin to close again, as the 2↑ sub-<span class="hlt">band</span> continues populating, consistent with recent theoretical calculations and experimental studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JPhCS.388a2017W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JPhCS.388a2017W"><span>Low-<span class="hlt">energy</span> <span class="hlt">electron</span> collisions with biomolecules</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Winstead, Carl; McKoy, Vincent</p> <p>2012-11-01</p> <p>We report recent progress in applying the Schwinger multichannel computational method to the interactions of slow <span class="hlt">electrons</span> with biomolecules. Calculations on constituents of DNA, including nucleobases, phosphate esters, and models of the backbone sugar, have provided insight into the nature of the low-<span class="hlt">energy</span> shape resonances, and thereby into possible sites and mechanisms for <span class="hlt">electron</span> attachment that may lead to strand-breaking. At the same time, more approximate calculations on larger assemblies such as nucleosides and deoxyadenosine monophosphate indicate how the resonance properties of the subunits will or will not persist in DNA itself. We are pursuing a similar strategy for another major class of biomolecules, the proteins, by beginning with fixed-nuclei studies of the constituent amino acids; here we present preliminary results for the simplest amino acid, glycine. We also describe efforts directed at an improved understanding <span class="hlt">electron</span> collisions with alcohols, which, in addition to basic scientific interest, may prove useful in the modeling of ignition and combustion within biofuel-powered engines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AcSpA..71.2005T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AcSpA..71.2005T"><span>Towards a comprehensive <span class="hlt">electronic</span> database of polycyclic aromatic hydrocarbons and its application in constraining the identities of possible carriers of the diffuse interstellar <span class="hlt">bands</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tan, Xiaofeng</p> <p>2009-01-01</p> <p>A theoretical approach is developed to pre-select individual polycyclic aromatic hydrocarbons (PAHs) as possible carriers of the diffuse interstellar <span class="hlt">bands</span> (DIBs). In this approach, a computer program is used to enumerate all PAH molecules with up to a specific number of fused benzene rings. Fast quantum chemical calculations are then employed to calculate the <span class="hlt">electronic</span> transition <span class="hlt">energies</span>, oscillator strengths, and rotational constants of these molecules. An <span class="hlt">electronic</span> database of all PAHs with up to any specific number of benzene rings can be constructed this way. Comparison of the <span class="hlt">electronic</span> transition <span class="hlt">energies</span>, oscillator strengths, and rotational <span class="hlt">band</span> contours of all PAHs in the database with astronomical spectra allows one to constrain the identities of individual PAHs as possible carriers of some of the intense narrow DIBs. Using the current database containing up to 10 benzene rings we have pre-selected 8 closed-shell PAHs as possible carriers of the famous λ6614 DIB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22304002','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22304002"><span>Fermi level stabilization and <span class="hlt">band</span> edge <span class="hlt">energies</span> in Cd{sub x}Zn{sub 1−x}O alloys</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Detert, Douglas M.; Tom, Kyle B.; Dubon, Oscar D.; Battaglia, Corsin; Javey, Ali; Denlinger, Jonathan D.; Lim, Sunnie H. N.; Anders, André; Yu, Kin M.; Walukiewicz, Wladek</p> <p>2014-06-21</p> <p>We have measured the <span class="hlt">band</span> edge <span class="hlt">energies</span> of Cd{sub x}Zn{sub 1−x}O thin films as a function of composition by three independent techniques: we determine the Fermi level stabilization <span class="hlt">energy</span> by pinning the Fermi level with ion irradiation, measure the binding <span class="hlt">energy</span> of valence <span class="hlt">band</span> states and core levels by X-ray photoelectron spectroscopy, and probe shifts in the conduction <span class="hlt">band</span> and valence <span class="hlt">band</span> density of states using soft X-ray absorption and emission spectroscopy, respectively. The three techniques find consensus in explaining the origin of compositional trends in the optical-bandgap narrowing upon Cd incorporation in wurtzite ZnO and widening upon Zn incorporation in rocksalt CdO. The conduction <span class="hlt">band</span> minimum is found to be stationary for both wurtzite and rocksalt alloys, and a significant upward rise of the valence <span class="hlt">band</span> maximum accounts for the majority of these observed bandgap changes. Given these <span class="hlt">band</span> alignments, alloy disorder scattering is found to play a negligible role in decreasing the <span class="hlt">electron</span> mobility for all alloys. These <span class="hlt">band</span> alignment details, combined with the unique optical and electrical properties of the two phase regimes, make CdZnO alloys attractive candidates for photoelectrochemical water splitting applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT........81W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT........81W"><span>Probing the <span class="hlt">band</span> structure and local <span class="hlt">electronic</span> properties of low-dimensional semiconductor structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walrath, Jenna Cherie</p> <p></p> <p>Low-dimensional semiconductor structures are important for a wide variety of applications, and recent advances in nanoscale fabrication are paving the way for increasingly precise nano-engineering of a wide range of materials. It is therefore essential that the physics of materials at the nanoscale are thoroughly understood to unleash the full potential of nanotechnology, requiring the development of increasingly sophisticated instrumentation and modeling. Of particular interest is the relationship between the local density of states (LDOS) of low-dimensional structures and the <span class="hlt">band</span> structure and local <span class="hlt">electronic</span> properties. This dissertation presents the investigation of the <span class="hlt">band</span> structure, LDOS, and local <span class="hlt">electronic</span> properties of nanostructures ranging from zero-dimensional (0D) quantum dots (QDs) to two-dimensional (2D) thin films, synthesizing computational and experimental approaches including Poisson-Schrodinger <span class="hlt">band</span> structure calculations, scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and scanning thermoelectric microscopy (SThEM). A method is presented for quantifying the local Seebeck coefficient (S) with SThEM, using a quasi-3D conversion matrix approach to directly convert temperature gradient-induced voltages S. For a GaAs p-n junction, the resulting S-profile is consistent with that computed using the free carrier concentration profile. This combined computational-experimental approach is expected to enable nanoscale measurements of S across a wide variety of heterostructure interfaces. The local carrier concentration, n, is profiled across epitaxial InAs/GaAs QDs, where SThEM is used to profile the temperature gradient-induced voltage, which is converted to a profile of the local S and finally to an n profile. The S profile is converted to a conduction <span class="hlt">band</span>-edge profile and compared with Poisson-Schrodinger <span class="hlt">band</span>-edge simulations. The combined computational-experimental approach suggests a reduced n in the QD center in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015npjCM...115001Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015npjCM...115001Y"><span>The origin of <span class="hlt">electronic</span> <span class="hlt">band</span> structure anomaly in topological crystalline insulator group-IV tellurides</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ye, Zhen-Yu; Deng, Hui-Xiong; Wu, Hui-Zhen; Li, Shu-Shen; Wei, Su-Huai; Luo, Jun-Wei</p> <p>2015-11-01</p> <p>Group-IV tellurides have exhibited exotic <span class="hlt">band</span> structures. Specifically, despite the fact that Sn sits between Ge and Pb in the same column of the periodic table, cubic SnTe is a topological crystalline insulator with <span class="hlt">band</span> inversion, but both isovalent GeTe and PbTe are trivial semiconductors with normal <span class="hlt">band</span> order. By performing first-principles <span class="hlt">band</span> structure calculations, we unravel the origin of this abnormal behaviour by using symmetry analysis and the atomic orbital <span class="hlt">energy</span> levels and atomic sizes of these elements. In group-IV tellurides, the s lone pair <span class="hlt">band</span> of the group-IV element is allowed by symmetry to couple with the anion valence p <span class="hlt">band</span> at the L-point, and such s-p coupling leads to the occurrence of bandgap at the L-point. We find that such s-p coupling is so strong in SnTe that it inverts the <span class="hlt">band</span> order near the bandgap; however, it is not strong enough in both GeTe and PbTe, so they remain normal semiconductors. The reason for this is the incomplete screening of the core of the relatively tight-binding Ge 4s orbital by its 3d orbitals and the large atomic size and strong relativistic effect in Pb, respectively. Interestingly, we also find that the rhombohedral distortion removes the inversion symmetry and the reduced s-p coupling transforms the α-SnTe back to a normal semiconductor. Our study demonstrates that, in addition to spin-orbital coupling, strain and interface dipole fields, inter-orbital coupling is another effective way to engineer the topological insulators.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OptMa..53..134K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OptMa..53..134K"><span>Effects of optical <span class="hlt">band</span> gap <span class="hlt">energy</span>, <span class="hlt">band</span> tail <span class="hlt">energy</span> and particle shape on photocatalytic activities of different ZnO nanostructures prepared by a hydrothermal method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klubnuan, Sarunya; Suwanboon, Sumetha; Amornpitoksuk, Pongsaton</p> <p>2016-03-01</p> <p>The dependence of the crystallite size and the <span class="hlt">band</span> tail <span class="hlt">energy</span> on the optical properties, particle shape and oxygen vacancy of different ZnO nanostructures to catalyse photocatalytic degradation was investigated. The ZnO nanoplatelets and mesh-like ZnO lamellae were synthesized from the PEO19-b-PPO3 modified zinc acetate dihydrate using aqueous KOH and CO(NH2)2 solutions, respectively via a hydrothermal method. The <span class="hlt">band</span> tail <span class="hlt">energy</span> of the ZnO nanostructures had more influence on the <span class="hlt">band</span> gap <span class="hlt">energy</span> than the crystallite size. The photocatalytic degradation of methylene blue increased as a function of the irradiation time, the amount of oxygen vacancy and the intensity of the (0 0 0 2) plane. The ZnO nanoplatelets exhibited a better photocatalytic degradation of methylene blue than the mesh-like ZnO lamellae due to the migration of the photoelectrons and holes to the (0 0 0 1) and (0 0 0 -1) planes, respectively under the internal electric field, that resulted in the enhancement of the photocatalytic activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MAR.J7011G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MAR.J7011G"><span>Micro-metric <span class="hlt">electronic</span> patterning of a topological <span class="hlt">band</span> structure using a photon beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Golden, Mark; Frantzeskakis, Emmanouil; de Jong, Nick; Huang, Yingkai; Wu, Dong; Pan, Yu; de Visser, Anne; van Heumen, Erik; van Bay, Tran; Zwartsenberg, Berend; Pronk, Pieter; Varier Ramankutty, Shyama; Tytarenko, Alona; Xu, Nan; Plumb, Nick; Shi, Ming; Radovic, Milan; Varkhalov, Andrei</p> <p>2015-03-01</p> <p>The only states crossing EF in ideal, 3D TIs are topological surface states. Single crystals of Bi2Se3andBi2Te3 are too defective to exhibit bulk-insulating behaviour, and ARPES shows topologically trivial 2DEGs at EF in the surface region due to downward <span class="hlt">band</span> bending. Ternary & quaternary alloys of Bi /Te /Se /Sb hold promise for obtaining bulk-insulating crystals. Here we report ARPES data from quaternary, bulk-insulating, Bi-based TIs. Shortly after cleavage in UHV, downward <span class="hlt">band</span> bending pulls the bulk conduction <span class="hlt">band</span> below EF, once again frustrating the ``topological only'' ambition for the Fermi surface. However, there is light at the end of the tunnel: we show that a super-<span class="hlt">band</span>-gap photon beam generates a surface photovoltage sufficient to flatten the <span class="hlt">bands</span>, thereby recovering the ideal, ``topological only'' situation. In our bulk-insulating quaternary TIs, this effect is local in nature, and permits the writing of arbitrary, micron-sized patterns in the topological <span class="hlt">energy</span> landscape at the surface. Support from FOM, NWO and the EU is gratefully acknowledged.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SSSci..14.1673C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SSSci..14.1673C"><span>Metal impurities in crystallographic voids of beta-rhombohedral boron lattice: Binding <span class="hlt">energies</span> and <span class="hlt">electron</span> levels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chkhartishvili, Levan; Murusidze, Ivane; Darchiashvili, Maguli; Tsagareishvili, Otar; Gabunia, Domenti</p> <p>2012-11-01</p> <p>Applying quasi-classical approach, the binding <span class="hlt">energies</span> and <span class="hlt">electron</span> levels of metal impurities (Li, Mg, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Hf, Ta, and Re) introduced into crystallographic voids of types A, D and E in the beta-rhombohedral boron lattice are calculated. Binding <span class="hlt">energies</span> are estimated as ˜1 eV-60 eV per bond. The most of the obtained metal-boron bond lengths are very close to the mean radii of voids in the undoped crystal. Relatively light impurities (from Li to Cu) are found to form donor <span class="hlt">electron</span> states directly inside the conduction <span class="hlt">band</span>, i.e., they cause metallization of the material being introduced at sufficiently high concentrations. Heavy impurities (from Zr to Re) form shallow or deep donor levels inside the <span class="hlt">band</span> gap or even valence <span class="hlt">band</span> depending on dopants and voids of accommodation.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhRvL.109f6404I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhRvL.109f6404I"><span>High-<span class="hlt">Energy</span> Anomaly in the <span class="hlt">Band</span> Dispersion of the Ruthenate Superconductor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iwasawa, H.; Yoshida, Y.; Hase, I.; Shimada, K.; Namatame, H.; Taniguchi, M.; Aiura, Y.</p> <p>2012-08-01</p> <p>We reveal a “high-<span class="hlt">energy</span> anomaly” (HEA) in the <span class="hlt">band</span> dispersion of the unconventional ruthenate superconductor Sr2RuO4, by means of high-resolution angle-resolved photoemission spectroscopy (ARPES) with tunable <span class="hlt">energy</span> and polarization of incident photons. This observation provides another class of correlated materials exhibiting this anomaly beyond high-Tc cuprates. We demonstrate that two distinct types of <span class="hlt">band</span> renormalization associated with and without the HEA occur as a natural consequence of the energetics in the bandwidth and the <span class="hlt">energy</span> scale of the HEA. Our results are well reproduced by a simple analytical form of the self-<span class="hlt">energy</span> based on the Fermi-liquid theory, indicating that the HEA exists at a characteristic <span class="hlt">energy</span> scale of the multielectron excitations. We propose that the HEA universally emerges if the systems have such a characteristic <span class="hlt">energy</span> scale inside of the bandwidth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhSS...58.1257K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhSS...58.1257K"><span><span class="hlt">Electronic</span> structure of the conduction <span class="hlt">band</span> upon the formation of ultrathin fullerene films on the germanium oxide surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Komolov, A. S.; Lazneva, E. F.; Gerasimova, N. B.; Panina, Yu. A.; Baramygin, A. V.; Zashikhin, G. D.</p> <p>2016-06-01</p> <p>The results of the investigation of the <span class="hlt">electronic</span> structure of the conduction <span class="hlt">band</span> in the <span class="hlt">energy</span> range 5-25 eV above the Fermi level E F and the interfacial potential barrier upon deposition of aziridinylphenylpyrrolofullerene (APP-C60) and fullerene (C60) films on the surface of the real germanium oxide ((GeO2)Ge) have been presented. The content of the oxide on the (GeO2)Ge surface has been determined using X-ray photoelectron spectroscopy. The <span class="hlt">electronic</span> properties have been measured using the very low <span class="hlt">energy</span> <span class="hlt">electron</span> diffraction (VLEED) technique in the total current spectroscopy (TCS) mode. The regularities of the change in the fine structure of total current spectra (FSTCS) with an increase in the thickness of the APP-C60 and C60 coatings to 7 nm have been investigated. A comparison of the structures of the FSTCS maxima for the C60 and APP-C60 films has made it possible to reveal the <span class="hlt">energy</span> range (6-10 eV above the Fermi level E F) in which the <span class="hlt">energy</span> states are determined by both the π* and σ* states and the FSTCS spectra have different structures of the maxima for the APP-C60 and unsubstituted C60 films. The formation of the interfacial potential barrier upon deposition of APP-C60 and C60 on the (GeO2)Ge surface is accompanied by an increase in the work function of the surface E vac- E F by the value of 0.2-0.3 eV, which corresponds to the transfer of the <span class="hlt">electron</span> density from the substrate to the organic films under investigation. The largest changes occur with an increase in the coating thickness to 3 nm, and with further deposition of APP-C60 and C60, the work function of the surface changes only slightly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995PhRvB..5111433G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995PhRvB..5111433G"><span>Femtosecond spectroscopy of <span class="hlt">electron-electron</span> and <span class="hlt">electron</span>-phonon <span class="hlt">energy</span> relaxation in Ag and Au</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Groeneveld, Rogier H. M.; Sprik, Rudolf; Lagendijk, Ad</p> <p>1995-05-01</p> <p>We show experimentally that the <span class="hlt">electron</span> distribution of a laser-heated metal is a nonthermal distribution on the time scale of the <span class="hlt">electron</span>-phonon (e-ph) <span class="hlt">energy</span> relaxation time τE. We measured τE in 45-nm Ag and 30-nm Au thin films as a function of lattice temperature (Ti=10-300 K) and laser-<span class="hlt">energy</span> density (Ul=0.3-1.3 J cm-3), combining femtosecond optical transient-reflection techniques with the surface-plasmon polariton resonance. The experimental effective e-ph <span class="hlt">energy</span> relaxation time decreased from 710-530 fs and 830-530 fs for Ag and Au, respectively, when temperature is lowered from 300 to 10 K. At various temperatures we varied Ul between 0.3-1.3 J cm-3 and observed that τE is independent from Ul within the given range. The results were first compared to theoretical predictions of the two-temperature model (TTM). The TTM is the generally accepted model for e-ph <span class="hlt">energy</span> relaxation and is based on the assumption that <span class="hlt">electrons</span> and lattice can be described by two different time-dependent temperatures Te and Ti, implying that the two subsystems each have a thermal distribution. The TTM predicts a quasiproportional relation between τE and Ti in the perturbative regime where τE is not affected by Ul. Hence, it is shown that the measured dependencies of τE on lattice temperature and <span class="hlt">energy</span> density are incompatible with the TTM. It is proven that the TTM assumption of a thermal <span class="hlt">electron</span> distribution does not hold especially under our experimental conditions of low laser power and lattice temperature. The <span class="hlt">electron</span> distribution is a nonthermal distribution on the picosecond time scale of e-ph <span class="hlt">energy</span> relaxation. We developed a new model, the nonthermal <span class="hlt">electron</span> model (NEM), in which we account for the (finite) <span class="hlt">electron-electron</span> (e-e) and <span class="hlt">electron</span>-phonon dynamics simultaneously. It is demonstrated that incomplete <span class="hlt">electron</span> thermalization yields a slower e-ph <span class="hlt">energy</span> relaxation in comparison to the thermalized limit. With the NEM we are able to give a consistent</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.4217M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.4217M"><span>Simulation of <span class="hlt">energy</span>-dependent <span class="hlt">electron</span> diffusion processes in the Earth's outer radiation belt</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Q.; Li, W.; Thorne, R. M.; Nishimura, Y.; Zhang, X.-J.; Reeves, G. D.; Kletzing, C. A.; Kurth, W. S.; Hospodarsky, G. B.; Henderson, M. G.; Spence, H. E.; Baker, D. N.; Blake, J. B.; Fennell, J. F.; Angelopoulos, V.</p> <p>2016-05-01</p> <p>The radial and local diffusion processes induced by various plasma waves govern the highly energetic <span class="hlt">electron</span> dynamics in the Earth's radiation belts, causing distinct characteristics in <span class="hlt">electron</span> distributions at various <span class="hlt">energies</span>. In this study, we present our simulation results of the energetic <span class="hlt">electron</span> evolution during a geomagnetic storm using the University of California, Los Angeles 3-D diffusion code. Following the plasma sheet <span class="hlt">electron</span> injections, the <span class="hlt">electrons</span> at different <span class="hlt">energy</span> <span class="hlt">bands</span> detected by the Magnetic <span class="hlt">Electron</span> Ion Spectrometer (MagEIS) and Relativistic <span class="hlt">Electron</span> Proton Telescope (REPT) instruments on board the Van Allen Probes exhibit a rapid enhancement followed by a slow diffusive movement in differential <span class="hlt">energy</span> fluxes, and the radial extent to which <span class="hlt">electrons</span> can penetrate into depends on <span class="hlt">energy</span> with closer penetration toward the Earth at lower <span class="hlt">energies</span> than higher <span class="hlt">energies</span>. We incorporate radial diffusion, local acceleration, and loss processes due to whistler mode wave observations to perform a 3-D diffusion simulation. Our simulation results demonstrate that chorus waves cause <span class="hlt">electron</span> flux increase by more than 1 order of magnitude during the first 18 h, and the subsequent radial extents of the energetic <span class="hlt">electrons</span> during the storm recovery phase are determined by the coupled radial diffusion and the pitch angle scattering by EMIC waves and plasmaspheric hiss. The radial diffusion caused by ULF waves and local plasma wave scattering are <span class="hlt">energy</span> dependent, which lead to the observed <span class="hlt">electron</span> flux variations with <span class="hlt">energy</span> dependences. This study suggests that plasma wave distributions in the inner magnetosphere are crucial for the <span class="hlt">energy</span>-dependent intrusions of several hundred keV to several MeV <span class="hlt">electrons</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NJPh...18k3054B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NJPh...18k3054B"><span>Pairing mechanism of heavily <span class="hlt">electron</span> doped FeSe systems: dynamical tuning of the pairing cutoff <span class="hlt">energy</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bang, Yunkyu</p> <p>2016-11-01</p> <p>We studied the pairing mechanism of the heavily <span class="hlt">electron</span> doped FeSe (HEDIS) systems, which commonly have one incipient hole band—a <span class="hlt">band</span> top below the Fermi level by a finite <span class="hlt">energy</span> distance ε b —at Γ point and ordinary <span class="hlt">electron</span> <span class="hlt">bands</span> at M points in Brillouin zone (BZ). We found that the system allows two degenerate superconducting solutions with the exactly same T c in clean limit: the incipient {s}{he}+/- -gap ({{{Δ }}}h-\</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JKPS...69..573H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JKPS...69..573H"><span>The hybridizations of cobalt 3 d <span class="hlt">bands</span> with the <span class="hlt">electron</span> <span class="hlt">band</span> structure of the graphene/cobalt interface on a tungsten substrate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hwang, Jinwoong; Hwang, Choongyu; Chung, Nak-Kwan; N'Diaye, A. D.; Schmid, A. K.; Denlinger, Jonathan</p> <p>2016-08-01</p> <p>The interface between graphene and a ferromagnetic substrate has attracted recent research interests due to its potential for spintronic applications. We report an angle-resolved photoemission spectroscopy study on the interface between graphene and cobalt epitaxially grown on a tungsten substrate. We find that the <span class="hlt">electron</span> <span class="hlt">band</span> structure of the interface exhibits clear discontinuities at the crossing points with cobalt 3 d <span class="hlt">bands</span>. These observations indicate strong hybridizations between the <span class="hlt">electronic</span> states in the interface and provide an important clue to understand the intriguing electromagnetic properties of the graphene/ferromagnet interface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1176927','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1176927"><span>Strategic <span class="hlt">Energy</span> Management Plan for the Santa Ynez <span class="hlt">Band</span> of Chumash Indians</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Davenport, Lars; Smythe, Louisa; Sarquilla, Lindsey; Ferguson, Kelly</p> <p>2015-03-27</p> <p>This plan outlines the Santa Ynez <span class="hlt">Band</span> of Chumash Indians’ comprehensive <span class="hlt">energy</span> management strategy including an assessment of current practices, a commitment to improving <span class="hlt">energy</span> performance and reducing overall <span class="hlt">energy</span> use, and recommended actions to achieve these goals. Vision Statement The primary objective of the Strategic <span class="hlt">Energy</span> Management Plan is to implement <span class="hlt">energy</span> efficiency, <span class="hlt">energy</span> security, conservation, education, and renewable <span class="hlt">energy</span> projects that align with the economic goals and cultural values of the community to improve the health and welfare of the tribe. The intended outcomes of implementing the <span class="hlt">energy</span> plan include job creation, capacity building, and reduced <span class="hlt">energy</span> costs for tribal community members, and tribal operations. By encouraging <span class="hlt">energy</span> independence and local power production the plan will promote self-sufficiency. Mission & Objectives The Strategic <span class="hlt">Energy</span> Plan will provide information and suggestions to guide tribal decision-making and provide a foundation for effective management of <span class="hlt">energy</span> resources within the Santa Ynez <span class="hlt">Band</span> of Chumash Indians (SYBCI) community. The objectives of developing this plan include; Assess current <span class="hlt">energy</span> demand and costs of all tribal enterprises, offices, and facilities; Provide a baseline assessment of the SYBCI’s <span class="hlt">energy</span> resources so that future progress can be clearly and consistently measured, and current usage better understood; Project future <span class="hlt">energy</span> demand; Establish a system for centralized, ongoing tracking and analysis of tribal <span class="hlt">energy</span> data that is applicable across sectors, facilities, and activities; Develop a unifying vision that is consistent with the tribe’s long-term cultural, social, environmental, and economic goals; Identify and evaluate the potential of opportunities for development of long-term, cost effective <span class="hlt">energy</span> sources, such as renewable <span class="hlt">energy</span>, <span class="hlt">energy</span> efficiency and conservation, and other feasible supply- and demand-side options; and Build the SYBCI’s capacity for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25850680','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25850680"><span><span class="hlt">Electronic</span> Spectroscopy of [FePAH](+) Complexes in the Region of the Diffuse Interstellar <span class="hlt">Bands</span>: Multireference Wave Function Studies on [FeC6H6](+).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lanza, Mathieu; Simon, Aude; Ben Amor, Nadia</p> <p>2015-06-11</p> <p>The low-<span class="hlt">energy</span> states and <span class="hlt">electronic</span> spectrum in the near-infrared-visible region of [FeC6H6](+) are studied by theoretical approaches. An exhaustive exploration of the potential <span class="hlt">energy</span> surface of [FeC6H6](+) is performed using the density functional theory method. The ground state is found to be a (4)A1 state. The structures of the lowest <span class="hlt">energy</span> states ((4)A2 and (4)A1) are used to perform multireference wave function calculations by means of the multistate complete active space with perturbation at the second order method. Contrary to the density functional theory results ((4)A1 ground state), multireference perturbative calculations show that the (4)A2 state is the ground state. The vertical <span class="hlt">electronic</span> spectrum is computed and compared with the astronomical diffuse interstellar <span class="hlt">bands</span>, a set of near-infrared-visible <span class="hlt">bands</span> detected on the extinction curve in our and other galaxies. Many transitions are found in this domain, corresponding to d → d, d → 4s, or d → π* excitations, but few are allowed and, if they are, their oscillation strengths are small. Even though some <span class="hlt">band</span> positions could match some of the observed <span class="hlt">bands</span>, the relative intensities do not fit, making the contribution of the [Fe-C6H6](+) complexes to the diffuse interstellar <span class="hlt">bands</span> questionable. This work, however, lays the foundation for the studies of polycyclic aromatic hydrocarbons (PAHs) complexed to Fe cations that are more likely to possess d → π* and π → π* transitions in the diffuse interstellar <span class="hlt">bands</span> domain. PAH ligands indeed possess a larger number of π and π* orbitals, respectively, higher and lower in <span class="hlt">energy</span> than those of C6H6, which are expected to lead to lower <span class="hlt">energy</span> d → π* and π → π* transitions in [FePAH](+) than in [FeC6H6](+) complexes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5274018','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5274018"><span><span class="hlt">Energy</span> transformation in molecular <span class="hlt">electronic</span> systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kasha, M.</p> <p>1985-07-25</p> <p>Our new optical pumping spectroscopy (steady state, and double-laser pulse) allows the production and study of the unstable rare tautomer in its ground and excited states, including picosecond dynamic studies. Molecules under study here included 7-azaindole (model for biological purines), 3-hydroxyflavone (model for plant flavones), lumichrome, and other heterocyclics. New detailed molecular mechanisms for proton transfer are derived, especially with catalytic assisting molecules. A new proton-transfer laser of extraordinary efficiency has become a side dividend, possibly worth of industrial development. The excited and highly reactive singlet molecular oxygen species /sup 1/..delta../sub g/) has proven to be ubiquitous in chemical peroxide systems and in physically excited sensitizer-oxygen systems. Hyperbaric oxygen mechanisms in biology probably involve singlet oxygen. We have undertaken a spectroscopic study of tris - dibenzoylmethane chelates of Al, Gd, Eu, and Yb trivalent ions. These chelates offer a variety of <span class="hlt">electronic</span> behaviors, from Z-effects on ..pi..-<span class="hlt">electron</span> spin-orbital coupling (Al, Gd) to Weissman intramolecular <span class="hlt">energy</span> transfer to 4f mestable levels (Eu, Gd). Elegant new spectroscopic resolution at 77K permits separation of tautomeric, parasitic self-absorption, dissociation, and cage effects to be resolved. 18 refs., 4 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985etme.book.....K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985etme.book.....K"><span><span class="hlt">Energy</span> transformation in molecular <span class="hlt">electronic</span> systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kasha, M.</p> <p>1985-07-01</p> <p>Our new optical pumping spectroscopy allows the production and study of the unstable rate tautomer in its ground and excited states, including picosecond dynamic studies. Molecules under study here included 7-azaindole 3-hydroxyflavone, lumichrome, and other heterocyclics. New detailed molecular mechanisms for proton transfer are derived, especially with catalytic assisting molecules. A new proton-transfer laser of extraordinary efficiency has become a side dividend, possibly worthy of industrial development. The excited and highly reactive singlet molecular oxygen species (1) DELTA sub g has proven to be ubiquitous in chemical peroxide systems and in physically excited sensitizer-oxygen systems. Hyperbaric oxygen mechanisms in biology probably involve singlet oxygen. We have undertaken a spectroscopic study of trisdibenzoylmethane chelates of Al, Gd, Eu, and Yb trivalent ions. These chelates offer a variety of <span class="hlt">electronic</span> behaviors, from Z-effects on (PI)--<span class="hlt">electron</span> spin-orbital coupling (Al, Gd) to Weissman intramolecular <span class="hlt">energy</span> transfer to 4f mestable levels (Eu, Gd). Elegant new spectroscopic resolution at 77K permits separation of tautomeric, parasitic self-absorption, dissociation, and cage effects to be resolved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvB..92t5129S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvB..92t5129S"><span>Effect of <span class="hlt">electron</span> correlations on the Fe3Si and α -FeSi2 <span class="hlt">band</span> structure and optical properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sandalov, Igor; Zamkova, Natalia; Zhandun, Vyacheslav; Tarasov, Ivan; Varnakov, Sergey; Yakovlev, Ivan; Solovyov, Leonid; Ovchinnikov, Sergey</p> <p>2015-11-01</p> <p>We use the Vienna ab initio simulation package (vasp) for evaluation of the quasiparticle spectra and their spectral weights within Hedin's GW approximation (GWA) for Fe3Si and α -FeSi2 within the non-self-consistent one-shot approximation G0W0 and self-consistent scGWA with the vertex corrections in the particle-hole channel, taken in the form of two-point kernel. As input for G0W0 , the <span class="hlt">band</span> structure and wave functions evaluated within the generalized gradient corrected local-density approximation to density functional theory (GGA) have been used. The spectral weights of quasiparticles in these compounds deviate from unity everywhere and show nonmonotonic behavior in those parts of <span class="hlt">bands</span> where the delocalized states contribute to their formation. The G0W0 and scGWA spectral weights are the same within 2%-5%. The scGWA shows a general tendency to return G0W0 <span class="hlt">bands</span> to their GGA positions for the delocalized states, while in the flat <span class="hlt">bands</span> it flattens even more. Variable angle spectroscopic ellipsometry measurements at T =296 K on grown single-crystalline ˜50 -nm-thick films of Fe3Si on n -Si(111) wafer have been performed in the interval of <span class="hlt">energies</span> ω ˜(1.3 -5 ) eV. The comparison of G0W0 and scGW theory with experimental real and imaginary parts of permittivity, refractive index, extinction and absorption coefficients, reflectivity, and <span class="hlt">electron</span> <span class="hlt">energy</span> loss function shows that both G0W0 and scGW qualitatively describe experiment correctly, the position of the low-<span class="hlt">energy</span> peaks is described better by the scGW theory, however, its detailed structure is not observed in the experimental curves. We suggest that the angle-resolved photoemission spectroscopy experiments, which can reveal the fine details of the quasiparticle <span class="hlt">band</span> structure and spectral weights, could help to understand (i) if the scGWA with this type of vertex correction is sufficiently good for description of these iron silicides and, possibly, (ii) why some features of calculated permittivity are</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001APS..MARN25008Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001APS..MARN25008Z"><span><span class="hlt">Electronic</span> and Magnetic Properties of Mn_xGa_1-xAs: Role of Mn= Defect <span class="hlt">Bands</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Yu-Jun; Geng, W. T.; Freeman, A. J.</p> <p>2001-03-01</p> <p>A detailed description of the <span class="hlt">electronic</span> structure is crucial for underst anding Mn_xGa_1-xAs, a potential semiconductor spin-device materia l. In this work, a wide range of Mn concentration for Mn_xGa_1-xAs (x=3D3.125%, 6.25%, 12.5%, 25.0%, 50.0%) is studied by first-princip les full-potential linearized augmented plane wave (FLAPW)(Wimme r, Krakauer, Weinert, and Freeman, PRB 24), 864 (1981). calculation s with GGA. At all concentrations studied, the ferromagnetic (FM) state i s lower in <span class="hlt">energy</span> than the paramagnetic (PM) and antiferromagnetic (AFM) states, confirming that Mn atoms stay magnetic with well localized magnet ic moments of 4.00 μ_B. The calculated <span class="hlt">band</span> structure shows that Mn d oping also forms defect <span class="hlt">bands</span>, and makes (Ga,Mn)As p-type conducting by p roviding holes. Furthermore, an s-d population inversion is found in the Mn <span class="hlt">electronic</span> configuration, which results from the strong Mn p-d mixing. The induced As moments are substantial (about -0.15μB per Mn atom, and almost independent of x) -- in accord with a recent observed negati ve As magnetic circular dichroism (MCD) signal.(B. Beschoten, et al), Phys. Rev. Lett. 83, 3073 (1999).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25665635','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25665635"><span>Half-filled <span class="hlt">energy</span> <span class="hlt">bands</span> induced negative differential resistance in nitrogen-doped graphene.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Xiao-Fei; Lian, Ke-Yan; Qiu, Qi; Luo, Yi</p> <p>2015-03-07</p> <p>Nitrogen-doping brings novel properties and promising applications into graphene, but the underlying mechanism is still in debate. To determine the key factor in motivating the negative differential resistance (NDR) behaviour of nitrogen-doped graphene, the <span class="hlt">electronic</span> structure and transport properties of an 11-dimer wide nitrogen-doped armchair graphene nanoribbon (N-AGNR) were systematically studied by first principles calculations. Both the effect of interaction between N-dopants and the effect of doping-sublattice on the NDR were examined for the first time. Taking into account the two effects, N-AGNR becomes metallic or semiconducting depending on the doping configuration, and its Fermi level varies in a large range. NDR was firmly verified not to be intrinsic for N-AGNRs. However, it is totally determined by whether nitrogen-doping induces half-filled <span class="hlt">energy</span> <span class="hlt">bands</span> (HFEBs) because it is HFEBs that cross the Fermi level and determine the transport properties of N-AGNR under low biases. With the bias increasing, the transmission spectrum near the Fermi level showed a flag shape, and therefore, the corresponding transport channel is totally suppressed at a certain bias, resulting in the NDR behaviour with a configuration-dependent peak-to-valley current ratio (PVCR) up to 10(4). Our findings give new insights into the microscopic mechanism of chemical doping induced NDR behaviour and will be useful in building NDR-based nanodevices in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JPhD...47m5109K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JPhD...47m5109K"><span>Synthesis, characterization and <span class="hlt">band</span> gap <span class="hlt">energy</span> of poly(ɛ-caprolactone)/Sr-MSA nano-composite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kannammal, L.; Palanikumar, S.; Meenarathi, B.; Yelilarasi, A.; Anbarasan, R.</p> <p>2014-04-01</p> <p>A mercaptosuccinic acid (MSA) decorated Sr nano-particle (NP) was prepared and characterized by using various analytical techniques and was used as a chemical initiator for the ring opening polymerization (ROP) of ɛ-caprolactone (CL). The ROP of CL was carried out at various experimental conditions under N2 atmosphere with mild stirring. The initiating efficiency of MSA-decorated Sr NP was tested in terms of Fourier transform infrared-relative intensity, melting temperature (Tm), degradation temperature (Td) and molecular weight (Mw) of poly(ɛ-caprolactone) (PCL), differential scanning calorimetry, UV-visible spectroscopy, field emission scanning <span class="hlt">electron</span> microscopy, thermogravimetric analysis and gel permeation chromatography analytical techniques. The nuclear magnetic resonance spectrum confirms the chemical structure of PCL. While increasing the [M/I] ratio, the Mw of PCL was linearly increased. The <span class="hlt">band</span> gap <span class="hlt">energy</span> of Sr was determined from the UV-visible spectrum. The reflectance study proves the hydrophobic nature of the Sr-hybrid and its nano-composite formation with PCL.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25563693','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25563693"><span>Toxicity of metal oxide nanoparticles in Escherichia coli correlates with conduction <span class="hlt">band</span> and hydration <span class="hlt">energies</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kaweeteerawat, Chitrada; Ivask, Angela; Liu, Rong; Zhang, Haiyuan; Chang, Chong Hyun; Low-Kam, Cecile; Fischer, Heidi; Ji, Zhaoxia; Pokhrel, Suman; Cohen, Yoram; Telesca, Donatello; Zink, Jeffrey; Mädler, Lutz; Holden, Patricia A; Nel, Andre; Godwin, Hilary</p> <p>2015-01-20</p> <p>Metal oxide nanoparticles (MOx NPs) are used for a host of applications, such as <span class="hlt">electronics</span>, cosmetics, construction, and medicine, and as a result, the safety of these materials to humans and the environment is of considerable interest. A prior study of 24 MOx NPs in mammalian cells revealed that some of these materials show hazard potential. Here, we report the growth inhibitory effects of the same series of MOx NPs in the bacterium Escherichia coli and show that toxicity trends observed in E. coli parallel those seen previously in mammalian cells. Of the 24 materials studied, only ZnO, CuO, CoO, Mn2O3, Co3O4, Ni2O3, and Cr2O3 were found to exert significant growth inhibitory effects; these effects were found to relate to membrane damage and oxidative stress responses in minimal trophic media. A correlation of the toxicological data with physicochemical parameters of MOx NPs revealed that the probability of a MOx NP being toxic increases as the hydration enthalpy becomes less negative and as the conduction <span class="hlt">band</span> <span class="hlt">energy</span> approaches those of biological molecules. These observations are consistent with prior results observed in mammalian cells, revealing that mechanisms of toxicity of MOx NPs are consistent across two very different taxa. These results suggest that studying nanotoxicity in E. coli may help to predict toxicity patterns in higher organisms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MPLB...3050224J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MPLB...3050224J"><span>Effective parameters in beam acoustic metamaterials based on <span class="hlt">energy</span> <span class="hlt">band</span> structures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jing, Li; Wu, Jiu Hui; Guan, Dong; Hou, Mingming; Kuan, Lu; Shen, Li</p> <p>2016-07-01</p> <p>We present a method to calculate the effective material parameters of beam acoustic metamaterials. The effective material parameters of a periodic beam are calculated as an example. The dispersion relations and <span class="hlt">energy</span> <span class="hlt">band</span> structures of this beam are calculated. Subsequently, the effective material parameters of the beam are investigated by using the <span class="hlt">energy</span> <span class="hlt">band</span> structures. Then, the modal analysis and transmission properties of the beams with finite cells are simulated in order to confirm the correctness of effective approximation. The results show that the periodic beam can be equivalent to the homogeneous beam with dynamic effective material parameters in passband.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001PhRvL..87l2501L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001PhRvL..87l2501L"><span>Coulomb <span class="hlt">Energy</span> Differences in T = 1 Mirror Rotational <span class="hlt">Bands</span> in 50Fe and 50Cr</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lenzi, S. M.; Mărginean, N.; Napoli, D. R.; Ur, C. A.; Zuker, A. P.; de Angelis, G.; Algora, A.; Axiotis, M.; Bazzacco, D.; Belcari, N.; Bentley, M. A.; Bizzeti, P. G.; Bizzeti-Sona, A.; Brandolini, F.; von Brentano, P.; Bucurescu, D.; Cameron, J. A.; Chandler, C.; de Poli, M.; Dewald, A.; Eberth, H.; Farnea, E.; Gadea, A.; Garces-Narro, J.; Gelletly, W.; Grawe, H.; Isocrate, R.; Joss, D. T.; Kalfas, C. A.; Klug, T.; Lampman, T.; Lunardi, S.; Martínez, T.; Martínez-Pinedo, G.; Menegazzo, R.; Nyberg, J.; Podolyak, Zs.; Poves, A.; Ribas, R. V.; Rossi Alvarez, C.; Rubio, B.; Sánchez-Solano, J.; Spolaore, P.; Steinhardt, T.; Thelen, O.; Tonev, D.; Vitturi, A.; von Oertzen, W.; Weiszflog, M.</p> <p>2001-09-01</p> <p>Gamma rays from the N = Z-2 nucleus 50Fe have been observed, establishing the rotational ground state <span class="hlt">band</span> up to the state Jπ = 11+ at 6.994 MeV excitation <span class="hlt">energy</span>. The experimental Coulomb <span class="hlt">energy</span> differences, obtained by comparison with the isobaric analog states in its mirror 50Cr, confirm the qualitative interpretation of the backbending patterns in terms of successive alignments of proton and neutron pairs. A quantitative agreement with experiment has been achieved by exact shell model calculations, incorporating the differences in radii along the yrast <span class="hlt">bands</span>, and properly renormalizing the Coulomb matrix elements in the pf model space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhCS.773a2027U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhCS.773a2027U"><span>Triple Hybrid <span class="hlt">Energy</span> Harvesting Interface <span class="hlt">Electronics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Uluşan, H.; Chamanian, S.; Pathirana, W. M. P. R.; Zorlu, Ö.; Muhtaroğlu, A.; Külah, H.</p> <p>2016-11-01</p> <p>This study presents a novel triple hybrid system that combines simultaneously generated power from thermoelectric (TE), vibration-based electromagnetic (EM) and piezoelectric (PZT) harvesters for a relatively high power supply capability. In the proposed solution each harvesting source utilizes a distinct power management circuit that generates a DC voltage suitable for combining the three parallel supplies. The circuits are designed and implemented in 180 nm standard CMOS technology, and are terminated with a schottky diode to avoid reverse current flow. The harvested AC signal from the EM harvester is rectified with a self-powered AC-DC doubler, which utilizes active diode structures to minimize the forward- bias voltage drop. The PZT interface <span class="hlt">electronics</span> utilizes a negative voltage converter as the first stage, followed by synchronous power extraction and DC-to-DC conversion through internal switches, and an external inductor. The ultra-low voltage DC power harvested by the TE generator is stepped up through a charge-pump driven by an LC oscillator with fully- integrated center-tapped differential inductors. Test results indicate that hybrid <span class="hlt">energy</span> harvesting circuit provides more than 1 V output for load resistances higher than 100 kΩ (10 μW) where the stand-alone harvesting circuits are not able to reach 1 V output. This is the first hybrid harvester circuit that simultaneously extracts <span class="hlt">energy</span> from three independent sources, and delivers a single DC output.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850026436','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850026436"><span>The <span class="hlt">energy</span> spectra of solar flare <span class="hlt">electrons</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Evenson, P. A.; Hovestadt, D.; Meyer, P.; Moses, D.</p> <p>1985-01-01</p> <p>A survey of 50 <span class="hlt">electron</span> <span class="hlt">energy</span> spectra from .1 to 100 MeV originating from solar flares was made by the combination of data from two spectrometers onboard the International Sun Earth Explorer-3 spacecraft. The observed spectral shapes of flare events can be divided into two classes through the criteria of fit to an acceleration model. This standard two step acceleration model, which fits the spectral shape of the first class of flares, involves an impulsive step that accelerates particles up to 100 keV and a second step that further accelerates these particles up to 100 MeV by a single shock. This fit fails for the second class of flares that can be characterized as having excessively hard spectra above 1 MeV relative to the predictions of the model. Correlations with soft X-ray and meter radio observations imply that the acceleration of the high <span class="hlt">energy</span> particles in the second class of flares is dominated by the impulsive phase of the flares.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1887833','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1887833"><span>Microwave <span class="hlt">energy</span> fixation for <span class="hlt">electron</span> microscopy.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Login, G. R.; Dvorak, A. M.</p> <p>1985-01-01</p> <p>We have demonstrated that microwave <span class="hlt">energy</span> (MW) can be used in conjunction with chemical cross-linking agents in order to rapidly fix cell suspensions and tissue blocks for <span class="hlt">electron</span> microscopy in 7-9 seconds. The optimal MW fixation method involved immersing tissues up to 1 cu cm in dilute aldehyde fixation and immediately irradiating the specimens in a conventional microwave oven for 9 seconds to 50 C. Ultrastructural preservation of samples irradiated by MW <span class="hlt">energy</span> was comparable to that of the control samples immersed in aldehyde fixative for 2 hours at 25 C. Stereologic analysis showed that tissue blocks fixed by the MW fixation method did not cause organelles such as liver mitochondria and salivary gland granules to shrink or to swell. Potential applications for this new fixation technology include the investigation of rapid intracellular processes (eg, vesicular transport) and preservation of proteins that are difficult to demonstrate with routine fixation methods (eg, antigens and enzymes). Images Figure 4 Figure 5 Figure 2 Figure 3 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 PMID:3927740</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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