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Sample records for ito substrate modification

  1. ITO DBR electrodes fabricated on PET substrate for organic electronics.

    PubMed

    Tien, W C; Chu, A K

    2014-02-24

    A conductive distributed Bragg reflector (DBR) fabricated on PET substrate using the single indium tin oxide (ITO) material is proposed. The large index contrast of the DBRs was obtained by depositing alternating layers of dense and porous ITO films. The high refractive index of the dense ITO films was achieved by long-throw radio-frequency magnetron sputtering technique at room temperature. On the other hand, the porous ITO films with low refractive index were fabricated by supercritical CO2 (SCCO2) treatment at 60 °C. The index contrast of the dense and porous ITO films as larger as 0.59 at blue spectral range was obtained. For the 4.5-period ITO DBR fabricated on PET substrate, the reflectance and sheet resistance of 85.1% and 47 Ω/◻ were achieved at 475 nm.

  2. LAPS and SPIM Imaging Using ITO-Coated Glass as the Substrate Material.

    PubMed

    Zhang, De-Wen; Wu, Fan; Krause, Steffi

    2017-08-01

    Light-addressable potentiometric sensors (LAPS) and scanning photo-induced impedance microscopy (SPIM) use photocurrent measurements for spatiotemporal imaging of ion concentrations, electrical potentials, and impedance. In this work, ITO-coated glass was confirmed to produce photocurrents at anodic potentials with 405 nm diode laser illumination. Therefore, it was developed as a low cost and robust substrate material for LAPS and SPIM imaging compared to traditional expensive ultrathin Si substrates. ITO showed good ac photocurrent and pH response without surface modification and insulator. Local photocurrents were produced by scanning a focused laser beam across the sample, which proved the light addressability of ITO-coated glass. With a high-impedance PMMA dot deposited onto the ITO as a model system, a lateral resolution of about 2.3 μm was achieved.

  3. ITO Modification for Efficient Inverted Organic Solar Cells.

    PubMed

    Susarova, Diana K; Akkuratov, Alexander V; Kukharenko, Andrey I; Cholakh, Seif O; Kurmaev, Ernst Z; Troshin, Pavel A

    2017-10-03

    We demonstrate a facile approach to designing transparent electron-collecting electrodes by depositing thin layers of medium and low work function metals on top of transparent conductive metal oxides (TCOs) such as ITO and FTO. The modified electrodes were fairly stable for months under ambient conditions and maintained their electrical characteristics. XPS spectroscopy data strongly suggested integration of the deposited metal in the TCO structure resulting in additional doping of the conducting oxide at the interface. Kelvin probe microscopy measurements revealed a significant decrease in the ITO work function after modification. Organic solar cells based on three different conjugated polymers have demonstrated state of the art performances in inverted device geometry using Mg- or Yb-modified ITO as electron collecting electrode. The simplicity of the proposed approach and the excellent ambient stability of the modified ITO electrodes allows one to expect their wide utilization in research laboratories and electronic industry.

  4. Phosphonic Acid Functionalized Asymmetric Phthalocyanines: Synthesis, Modification of Indium Tin Oxide (ITO), and Charge Transfer

    SciTech Connect

    Polaske, Nathan W.; Lin, Hsiao-Chu; Tang, Anna; Mayukh, Mayank; Oquendo, Luis E.; Green, John; Ratcliff, Erin L.; Armstrong, Neal R.; Saavedra, S. Scott; McGrath, Dominic V.

    2011-12-20

    Metalated and free-base A₃B-type asymmetric phthalocyanines (Pcs) bearing, in the asymmetric quadrant, a flexible alkyl linker of varying chain lengths terminating in a phosphonic acid (PA) group have been synthesized. Two parallel series of asymmetric Pc derivatives bearing aryloxy and arylthio substituents are reported, and their synthesis and characterization through NMR, combustion analysis, and MALDI-MS are described. We also demonstrate the modification of indium tin oxide (ITO) substrates using the PA functionalized asymmetric Pc derivatives and monitoring their electrochemistry. The PA functionalized asymmetric Pcs were anchored to the ITO surface through chemisorption and their electrochemical properties characterized using cyclic voltammetry to investigate the effects of PA structure on the thermodynamics and kinetics of charge transfer. Ionization energies of the modified ITO surfaces were measured using ultraviolet photoemission spectroscopy.

  5. Modification and Wettability Study ITO Glass Coated with ZnO Film by Electrochemical Deposition and Hydrothermal Deposition.

    PubMed

    Fang, Mei; Zou, Changwei; Gong, Manfeng

    2016-03-01

    ITO glass is a substrate often utilized to construct various IT devices and sensors, favored for its excellent characteristics such as rapid electron transfer kinetics, non-toxicity, chemical stability, and high electron transmission. In this paper, film with ZnO-modified nanostructures on ITO glass was fabricated by both electrochemical deposition and hydrothermal deposition, respectively. The ZnO film as-deposited was then modified by surface modification reagent (FOTMS) to obtain a hydrophobic surface. SEM, XRD, and ZYGO were used to characterize their properties. The contact angles were then measured to characterize and compare the wettability of non-modified ITO glass and ITO glass modified by zinc oxide films.

  6. Flexible diode of polyaniline/ITO heterojunction on PET substrate

    NASA Astrophysics Data System (ADS)

    Bera, A.; Deb, K.; Kathirvel, V.; Bera, T.; Thapa, R.; Saha, B.

    2017-10-01

    Hybrid organic-inorganic heterojunction between polyaniline and ITO film coated on flexible polyethylene terephthalate (PET) substrate has been prepared through vapor phase polymerization process. Polaron and bipolaron like defect states induced hole transport and exceptional mobility makes polyaniline a noble hole transport layer. Thus a p-n junction has been obtained between the hole transport layer of polyaniline and highly conductive n-type layer of ITO film. The synthesis process was carried out using FeCl3 as polymerizing agent in the oxidative chemical polymerization process. The prepared polyaniline has been found to be crystalline on characterization through X-ray diffraction measurement. X-ray photoelectron spectroscopic measurements were done for compositional analysis of the prepared film. The UV-vis-NIR absorbance spectra obtained for polyaniline shows the characteristics absorbance as observed for highly conductive polyaniline and confirms the occurrence of partially oxidized emeraldine form of polyaniline. The energy band gap of the polyaniline has been obtained as 2.52 eV, by analyzing the optical transmittance spectra. A rectifying behavior has been observed in the electrical J-V plot, which is of great significance in designing polymer based flexible electronic devices.

  7. Properties of ITO thin films deposited on amorphous and crystalline substrates with e-beam evaporation

    NASA Astrophysics Data System (ADS)

    Wang, R. X.; Beling, C. D.; Djurisic, A. B.; Li, S.; Fung, S.

    2004-06-01

    Indium tin oxide (ITO) thin films were deposited using the e-beam evaporation method on amorphous and crystalline substrates under identical conditions. The properties of the films were investigated using optical transmittance, XRD and XPS techniques. It was found that the properties of the films depend strongly on the nature of the substrate surface. Analysis suggests that changes in chemical composition and microstructure of the ITO films deposited on crystalline and amorphous substrates are responsible for the differences in optical properties.

  8. Effect of ITO surface modification on the OLED device lifetime.

    PubMed

    Yu, Szu-Yen; Chang, Jung-Hung; Wang, Po-Sheng; Wu, Chi-I; Tao, Yu-Tai

    2014-07-01

    Pretreatment of the indium tin oxide (ITO) surface is generally adopted to improve the charge injection and device performance in the fabrication of organic light-emitting diodes (OLEDs). For the common approaches of surface treatment, such as oxygen plasma treatment, self-assembled monolayer (SAM) adsorption, and the PEDOT:PSS coating, different effects on the device lifetime were observed. A distinctly different driving voltage change with device operation time was obtained and was correlated with the device lifetime. The fast increase in driving voltage for devices based on oxygen-plasma-treated ITO is attributed to the work function change as a result of the change in the composition of the interface with device operation, whereas a rather stable work function for SAM-modified ITO is suggested due to the permanent dipoles associated with the monolayer and the protecting effect of the covalently bound monolayer on the surface composition.

  9. Surface Engineering of ITO Substrates to Improve the Memory Performance of an Asymmetric Conjugated Molecule with a Side Chain.

    PubMed

    Hou, Xiang; Cheng, Xue-Feng; Xiao, Xin; He, Jing-Hui; Xu, Qing-Feng; Li, Hua; Li, Na-Jun; Chen, Dong-Yun; Lu, Jian-Mei

    2017-09-05

    Organic multilevel random resistive access memory (RRAM) devices with an electrode/organic layer/electrode sandwich-like structure suffer from poor reproducibility, such as low effective ternary device yields and a wide threshold voltage distribution, and improvements through organic material renovation are rather limited. In contrast, engineering of the electrode surfaces rather than molecule design has been demonstrated to boost the performance of organic electronics effectively. Herein, we introduce surface engineering into organic multilevel RRAMs to enhance their ternary memory performance. A new asymmetric conjugated molecule composed of phenothiazine and malononitrile with a side chain (PTZ-PTZO-CN) was fabricated in an indium tin oxide (ITO)/PTZ-PTZO-CN/Al sandwich-like memory device. Modification of the ITO substrate with a phosphonic acid (PA) prior to device fabrication increased the ternary device yield (the ratio of effective ternary device) and narrowed the threshold voltage distribution. The crystallinity analysis revealed that PTZ-PTZO-CN grown on untreated ITO crystallized into two phases. After the surface engineering of ITO, this crystalline ambiguity was eliminated and a sole crystal phase was obtained that was the same as in the powder state. The unified crystal structure and improved grain mosaicity resulted in a lower threshold voltage and, therefore, a higher ternary device yield. Our result demonstrated that PA modification also improved the memory performance of an asymmetric conjugated molecule with a side chain. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Thickness Dependence of Properties of ITO Films Deposited on PET Substrates.

    PubMed

    Kim, Seon Tae; Kim, Tae Gyu; Cho, Hyun; Yoon, Su Jong; Kim, Hye Sung; Kim, Jin Kon

    2016-02-01

    Indium tin oxide (ITO) films with various thicknesses from 104 nm to 513 nm were prepared onto polyethylene terephthalate (PET) substrates by using r.f. magnetron sputtering without intentionally heating the substrates. The structural, optical, and electrical properties of ITO films were investigated as a function of film thickness. It was found that the amorphous nature of the ITO film was dominant below the thickness of about 200 nm but the degree of the crystallinity increased with an increasing thickness above the thickness of about 250 nm, resulting in the increase of carrier concentration and therefore reducing the electrical resistivity from 5.1 x 10(-3) to 9.4 x 10(-4) omega x cm. The average transmittance (400-800 nm) of the ITO deposited PET substrates decreased as the film thickness was increasing and was above 80% for the thickness below 315 nm. The results show that the improvement of the film crystallinity with the film thickness contributes to the increase of the carrier concentration and the enhancement of the electrical conductivity.

  11. F2-laser patterning of indium tin oxide (ITO) thin film on glass substrate

    NASA Astrophysics Data System (ADS)

    Xu, M. Y.; Li, J.; Lilge, L. D.; Herman, P. R.

    2006-10-01

    This paper reports the controlled micromachining of 100 nm thick indium tin oxide (ITO) thin films on glass substrates with a vacuum-ultraviolet 157 nm F2 laser. Partial to complete film removal was observed over a wide fluence window from 0.49 J/cm2 to an optimized single pulse fluence of 4.5 J/cm2 for complete film removal. Optical microscopy, atomic force microscopy, and energy dispersive X-ray analysis show little substrate or collateral damage by the laser pulse which conserved the stoichiometry, optical transparency and electrical conductivity of ITO coating adjacent to the trenches. At higher fluence, a parallel micron sized channel can be etched in the glass substrate. The high photon energy and top-hat beam homogenized optical system of the F2 laser opens new means for direct structuring of electrodes and microchannels in biological microfluidic systems or in optoelectronics.

  12. A sensitive plasmonic copper(II) sensor based on gold nanoparticles deposited on ITO glass substrate.

    PubMed

    Ding, Lijun; Gao, Yan; Di, Junwei

    2016-09-15

    Gold nanoparticles (Au NPs) based plasmonic probe was developed for sensitive and selective detection of Cu(2+) ion. The Au NPs were self-assembled on transparent indium tin oxide (ITO) film coated glass substrate using poly dimethyl diallyl ammonium chloride (PDDA) as a linker and then calcined at 400°C to obtain pure Au NPs on ITO surface (ITO/Au NPs). The probe was fabricated by functionalizing l-cysteine (Cys) on to gold surface (ITO/Au NPs/Cys). The strong chelation of Cu(2+) with Cys formed a stable Cys-Cu complex, and resulted in the red-shift of localized surface plasmon resonance (LSPR) peak of the Au NPs. The introduction of bovine serum albumin (BSA) as the second complexant could form complex of Cys-Cu-BAS and further markedly enhanced the red-shift of the LSPR peak. This plasmonic probe provided a highly sensitive and selective detection towards Cu(2+) ions, with a wide linear detection range (10(-11)-10(-5)M) over 6 orders of magnitude. The simple and cost-effective probe was successfully applied to the determination of Cu(2+) in real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Electrochemical detection of nitrite on poly(pyronin Y)/graphene nanocomposites modified ITO substrate

    NASA Astrophysics Data System (ADS)

    Şinoforoğlu, Mehmet; Dağcı, Kader; Alanyalıoğlu, Murat; Meral, Kadem

    2016-06-01

    The present study reports on an easy preparation of poly(pyronin Y)/graphene (poly(PyY)/graphene) nanocomposites thin films on indium tin oxide coated glass substrates (ITO). The thin films of poly(PyY)/graphene nanocomposites are prepared by a novel method consisting of three steps; (i) preparation of graphene oxide (GO) thin films on ITO by spin-coating method, (ii) self-assembly of PyY molecules from aqueous solution onto the GO thin film, (iii) surface-confined electropolymerization (SCEP) of the adsorbed PyY molecules on the GO thin film. The as-prepared poly(PyY)/graphene nanocomposites thin films are characterized by using electroanalytical and spectroscopic techniques. Afterwards, the graphene-based polymeric dye thin film on ITO is used as an electrode in an electrochemical cell. Its performance is tested for electrochemical detection of nitrite. Under optimized conditions, the electrocatalytical effect of the nanocomposites thin film through electrochemical oxidation of nitrite is better than that of GO coated ITO.

  14. Preferential orientation growth of ITO thin film on quartz substrate with ZnO buffer layer by magnetron sputtering technique

    NASA Astrophysics Data System (ADS)

    Du, Wenhan; Yang, Jingjing; Xiong, Chao; Zhao, Yu; Zhu, Xifang

    2017-07-01

    In order to improve the photoelectric transformation efficiency of thin-film solar cells, one plausible method was to improve the transparent conductive oxides (TCO) material property. In-doped tin oxide (ITO) was an important TCO material which was used as a front contact layer in thin-film solar cell. Using magnetron sputtering deposition technique, we prepared preferential orientation ITO thin films on quartz substrate. XRD and SEM measurements were used to characterize the crystalline structure and morphology of ITO thin films. The key step was adding a ZnO thin film buffer layer before ITO deposition. ZnO thin film buffer layer increases the nucleation center numbers and results in the (222) preferential orientation growth of ITO thin films.

  15. Characterization of sprayed TiO2 on ITO substrates for solar cell applications.

    PubMed

    Arunachalam, A; Dhanapandian, S; Manoharan, C; Sridhar, R

    2015-10-05

    Titanium dioxide (TiO2) thin films had been deposited with various substrate temperatures by spray pyrolysis technique onto ITO substrates. All films exhibited polycrystalline nature with the preferred orientation along (101) plane. At the substrate temperature 450 °C, the film favored the formation of anatase phase. The higher substrate temperature (475 °C) favored the appearance of rutile structure. The SEM image of the film at substrate temperature (Ts=450 °C) showed high structural quality with the porous nature. The typical AFM image of TiO2 film deposited at the substrate temperature, 450 °C depicted the regular arrangement of fine closely packed tetragonal structured grains. The transmittance of the spectra exhibited above 85% with energy band gap of 3.6 eV. From the study of photoluminescence, the emission at 417 nm, 437 nm and with weak emission at 551 nm was observed, which confirmed the lesser defects in the samples. The electrical resistivity was found to be 6.856×10(1) Ω cm for the substrate temperature 450 °C. The efficiency of anatase TiO2 photoelectrode deposited at the substrate temperature 450 °C based cell was much higher than the efficiency of TiO2 photoelectrode deposited at the substrate temperature 475 °C based cell.

  16. Synthesis of amorphous platinum nanofibers directly on an ITO substrate and its heterogeneous catalytic hydrogenation characterization.

    PubMed

    Balouch, Aamna; Ali Umar, Akrajas; Mawarnis, Elvy Rahmi; Md Saad, Siti Khatijah; Mat Salleh, Muhamad; Abd Rahman, Mohd Yusri; Kityk, I V; Oyama, Munetaka

    2015-04-15

    This paper reports a facile, solution-phase approach to synthesizing a one-dimensional amorphous face-centered-cubic (fcc) platinum (a-Pt) nanostructure (nanofibers) directly on an indium-tin oxide (ITO) substrate. The electron microscopy analysis result shows that the a-Pt nanofiber has a diameter and length of approximately 50 nm and 1 μm, respectively, and is grown in high density on the entire surface of the ITO substrate. The X-ray photoelectron spectroscopy analysis result further reveals that the a-Pt nanofibers feature metallic properties with highly reactive surface chemistry, promising novel performance in electrochemistry, catalysis, and sensors. A synergetic interplay between the formic acid reducing agent and the hexamethylenetetramine surfactant in the reduction of Pt ions is assumed as the driving force for the formation of the amorphous phase in the Pt nanostructure. The catalytic properties of a-Pt were examined in the acetone hydrogenation reaction under microwave irradiation. a-Pt shows excellent heterogeneous catalytic properties for converting acetone to isopropyl alcohol with turnover number and frequency as high as 400 and 140 min(-1), respectively. The preparation and formation mechanism of the a-Pt nanofibers will be discussed in detail in this paper.

  17. Laser scribing of indium tin oxide (ITO) thin films deposited on various substrates for touch panels

    NASA Astrophysics Data System (ADS)

    Tseng, Shih-Feng; Hsiao, Wen-Tse; Huang, Kuo-Cheng; Chiang, Donyau; Chen, Ming-Fei; Chou, Chang-Pin

    2010-12-01

    In this study, a Nd:YAG laser with wavelength of 1064 nm is used to scribe the indium tin oxide (ITO) thin films coated on three types of substrate materials, i.e. soda-lime glass, polycarbonate (PC), and cyclic-olefin-copolymer (COC) materials with thickness of 20 nm, 30 nm, and 20 nm, respectively. The effect of exposure time adjusted from 10 μs to 100 μs on the ablated mark width, depth, and electrical properties of the scribed film was investigated. The maximum laser power of 2.2 W was used to scribe these thin films. In addition, the surface morphology, surface reaction, surface roughness, optical properties, and electrical conductivity properties were measured by a scanning electron microscope, a three-dimensional confocal laser scanning microscope, an atomic force microscope, and a four-point probe. The measured results of surface morphology show that the residual ITO layer was produced on the scribed path with the laser exposure time at 10 μs and 20 μs. The better edge qualities of the scribed lines can be obtained when the exposure time extends from 30 μs to 60 μs. When the laser exposure time is longer than 60 μs, the partially burned areas of the scribed thin films on PC and COC substrates are observed. Moreover, the isolated line width and resistivity values increase when the laser exposure time increases.

  18. Gradual modification of ITO particle's crystal structure and optical properties by pulsed UV laser irradiation in a free liquid jet.

    PubMed

    Lau, Marcus; Straube, Thomas; Aggarwal, A Vikas; Hagemann, Ulrich; de Oliveira Viestel, Bernardo; Hartmann, Nils; Textor, Torsten; Lutz, Harald; Gutmann, Jochen S; Barcikowski, Stephan

    2017-05-09

    Indium tin oxide (ITO) particle coatings are known for high transparency in the visible, good conductive properties and near-infrared absorption. These properties depend on ITO particle's stoichiometric composition, defects and size. Here we present a method to gradually change ITO particle's optical properties by a simple and controlled laser irradiation process. The defined irradiation process and controlled energy dose input allows one to engineer the absorption and transmission of coatings made from these particles. We investigate the role of the surrounding solvent, influence of laser fluence and the specific energy dose targeting modification of the ITO particle's morphology and chemistry by stepwise laser irradiation in a free liquid jet. TEM, SEM, EDX, XPS, XRD and Raman are used to elucidate the structural, morphological and chemical changes of the laser-induced ITO particles. On the basis of these results the observed modification of the optical properties is tentatively attributed to chemical changes, e.g. laser-induced defects or partial reduction.

  19. Chemical Modification of n-Type-Material Naphthalene Diimide on ITO for Efficient and Stable Inverted Polymer Solar Cells.

    PubMed

    Li, Zhendong; Liu, Yanfeng; Zhang, Kaicheng; Wang, Zhaowei; Huang, Peng; Li, Dahua; Zhou, Yi; Song, Bo

    2017-09-05

    To provide orthogonal solvent processable surface modification and improve the device stability of bulk-heterojunction polymer solar cells (PSCs), n-type semiconducting material naphthalene diimide (NDI) was chemically introduced onto the ITO surface as a cathode interlayer (CIL) using 3-bromopropyltrimethoxysilane (BrTMS) as a coupling agent. After modification, the work function of ITO can be decreased from 4.70 to 4.23 eV. The modified ITO cathode was applied in inverted PSCs based on PTB7-Th:PC71BM. With the CIL modification, a champion power conversion efficiency (PCE) of 5.87% was achieved, showing a dramatic improvement compared to that of devices (PCE = 3.58%) without CIL. More importantly, with these chemical bonded interlayers, the stability of inverted PSCs was greatly enhanced. The improved PCE and stability can be attributed to the increased open-circuit voltage and the formation of robust chemical bonds in NDI-TMS films, respectively. This study demonstrated that chemical modification of ITO with n-type semiconducting materials provides an avenue for not only solving the solvent orthogonal problem but also improving the device performance in terms of the PCE and the stability.

  20. Design and development of plasmonic nanostructured electrodes for ITO-free organic photovoltaic cells on rigid and highly flexible substrates.

    PubMed

    Richardson, Beau J; Zhu, Leize; Yu, Qiuming

    2017-04-21

    Indium tin oxide (ITO) is the most common transparent electrode used in organic photovoltaics (OPVs), yet limited indium reserves and poor mechanical properties make it non-ideal for large-scale OPV production. To replace ITO, we designed, fabricated, and deployed plasmonic nanostructured electrodes in inverted OPV devices. We found that active layer absorption is significantly impacted by ZnO thickness which affects the optical field distribution inside the resonant cavity formed between the plasmonic nanostructured electrode and top electrode. High quality Cr/Au nanostructured electrodes were fabricated by nanoimprint lithography and deployed in ITO-free inverted devices on glass. Devices with thinner ZnO showed a PCE as high as 5.70% and higher J SC's than devices on thicker ZnO, in agreement with finite-difference time-domain simulations. In addition, as the active layer was made optically thin, ITO-based devices showed diminished J SC while the resonant cavity effect from plasmonic nanostructured electrodes retained J SC. Preliminary ITO-free, flexible devices on PET showed a PCE of 1.82% and those fabricated on ultrathin and conformable Parylene substrates yielded an initial PCE over 1%. The plasmonic electrodes and device designs in this work show promise for developing highly functioning conformable devices that can be applied to numerous needs for lightweight, ubiquitous power generation.

  1. Design and development of plasmonic nanostructured electrodes for ITO-free organic photovoltaic cells on rigid and highly flexible substrates

    NASA Astrophysics Data System (ADS)

    Richardson, Beau J.; Zhu, Leize; Yu, Qiuming

    2017-04-01

    Indium tin oxide (ITO) is the most common transparent electrode used in organic photovoltaics (OPVs), yet limited indium reserves and poor mechanical properties make it non-ideal for large-scale OPV production. To replace ITO, we designed, fabricated, and deployed plasmonic nanostructured electrodes in inverted OPV devices. We found that active layer absorption is significantly impacted by ZnO thickness which affects the optical field distribution inside the resonant cavity formed between the plasmonic nanostructured electrode and top electrode. High quality Cr/Au nanostructured electrodes were fabricated by nanoimprint lithography and deployed in ITO-free inverted devices on glass. Devices with thinner ZnO showed a PCE as high as 5.70% and higher J SC’s than devices on thicker ZnO, in agreement with finite-difference time-domain simulations. In addition, as the active layer was made optically thin, ITO-based devices showed diminished J SC while the resonant cavity effect from plasmonic nanostructured electrodes retained J SC. Preliminary ITO-free, flexible devices on PET showed a PCE of 1.82% and those fabricated on ultrathin and conformable Parylene substrates yielded an initial PCE over 1%. The plasmonic electrodes and device designs in this work show promise for developing highly functioning conformable devices that can be applied to numerous needs for lightweight, ubiquitous power generation.

  2. Bendable ITO-free Organic Solar Cells with Highly Conductive and Flexible PEDOT:PSS Electrodes on Plastic Substrates.

    PubMed

    Fan, Xi; Wang, Jinzhao; Wang, Hanbin; Liu, Xiang; Wang, Hao

    2015-08-05

    Flexible and transparent electrodes have great potential for photon transmission and charge-carrier collection for next generation electronics compared to rigid electronics with indium tin oxide (ITO)-coated glass substrates. This study describes a comprehensive study of the electrical, morphological, optical, structural, and mechanical properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PSS) films treated by methanol and methanesulfonic acid (MSA), which are coated on hydrophobic flexible plastic substrates. Such a film coated on hydrophobic plastic substrates exhibits a high conductivity up to 3560 S cm(-1) and a good mechanical flexibility. Moreover, the use of the films to fabricate bendable ITO-free organic solar cells (OSCs) integrated on plastic substrates was presented. The bendable devices based on P3HT:PCBM not only exhibit a high power conversion efficiency (PCE) up to 3.92%, which is comparable to 4.30% of the rigid devices with ITO-coated glass substrates, but also keep about 80% in PCE of the initial value after 100 time bending with a bending radius of 14 mm in the ambient atmosphere. This work provides a novel route to dramatically improve the conductivity of PSS electrodes, as well as the mechanical flexibility of highly efficient organic electronics with the flexible electrodes.

  3. Surface Modification of Nanocellulose Substrates

    NASA Astrophysics Data System (ADS)

    Zoppe, Justin Orazio

    Cellulose fibers constitute an important renewable raw material that is utilized in many commercial applications in non-food, paper, textiles and composite materials. Chemical functionalization is an important approach for improving the properties of cellulose based materials. Different approaches are used to graft polymeric chains onto cellulose substrates, which can be classified by two principal routes, namely 'grafting onto' or 'grafting from' methods. Never-dried cellulose nanocrystals (CNCs) or nanowhiskers produced from sulfuric acid hydrolysis of ramie fibers were used as substrates for surface chemical functionalization with various macromolecules. In addition, the use of cellulose nanocrystals to reinforce poly(epsilon-caprolactone) (PCL) nanofibers was studied. Chemical grafting with low molecular weight polycaprolactone diol onto cellulose nanocrystals was carried out in an attempt to improve the interfacial adhesion with the fiber matrix. Significant improvements in the mechanical properties of the nanofibers after reinforcement with unmodified cellulose nanocrystals were confirmed. Fiber webs from PCL reinforced with 2.5% unmodified CNCs showed ca. 1.5-fold increase in Young's modulus and ultimate strength compared to PCL webs. The CNCs were also grafted with poly(N-isopropylacrylamide) (poly(NiPAAm)) brushes via surface-initiated single-electron transfer living radical polymerization (SI-SETLRP) under various conditions at room temperature. The grafting process depended on the initiator and/or monomer concentrations used. No observable damage occurred to the CNCs after grafting, as determined by X-ray diffraction. Size exclusion chromatography analyses of polymer chains cleaved from the cellulose nanocrystals indicated that a higher degree of polymerization was achieved by increasing initiator or monomer loading, most likely caused by local heterogeneities yielding higher rates of polymerization. In addition, the colloidal stability and thermo

  4. Highly conductive PEDOT:PSS on flexible substrate as ITO-free anode for polymer solar cells

    SciTech Connect

    Del Mauro, A. De Girolamo; Ricciardi, R.; Montanino, M.; Morvillo, P.; Minarini, C.

    2014-05-15

    In this work, highly conductive anode based on PEDOT:PSS is proposed as substitute of Indio-Tin Oxide (ITO) in flexible solar cells. The anodic conductive polymer was spin coated on a 125 μm thick polyethylene naphthalate (PEN) substrate. The obtained film was characterized in terms of structure and physical- chemical proprieties. The obtained results are very promising and the conductive film will be investigated in future as electrode in a complete polymeric solar cell.

  5. High performance hydrogen sensor based on Mn implanted ZnO nanowires array fabricated on ITO substrate.

    PubMed

    Renitta, A; Vijayalakshmi, K

    2017-08-01

    In the present research, we propose a novel approach for the detection of hydrogen gas using Mn implanted ZnO nanowires fabricated onto ITO coated glass substrate by chemical spray pyrolysis deposition. The effect of Mn concentration on the structural, optical and morphological properties of ZnO films were investigated. X-ray diffraction studies showed that the Mn implanted ZnO films were grown as a polycrystalline hexagonal wurtzite phase without any impurities. The (101) peak position of ZnO-Mn films was shifted towards a lower angle with increasing Mn concentration. The optical band gap decreased from 3.45eV to 3.23eV with increasing Mn content. PL spectra, revealed sharp and strong near band edge emission which suggests that ZnO nanowires exhibit high crystalline quality. FE-SEM images of Mn implanted ZnO show perfectly aligned nanowires for all the films fabricated on ITO. The material (Zn, O, Mn) was confirmed by EDX spectra. The hydrogen sensing mechanism of the Mn implanted ZnO nanowire sensor was also discussed. It was found that H2 response was significantly enhanced by more than one order of magnitude with increasing Mn doping concentrations. The studied ZnO-Mn films coated on ITO substrate can be used as a low cost and easy-fabrication hydrogen sensing material. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Optical properties of Au-Ag core-shell nanorods on glass and ITO substrates

    NASA Astrophysics Data System (ADS)

    Tsuru, Yukiko; Nakashima, Naotoshi; Niidome, Yasuro

    2012-07-01

    Gold-silver core-shell nanorods were deposited on glass and ITO plates. SEM observations indicated that some of these nanorods were standing on the ITO plate. The extinction spectra of the plates were measured by varying the angles of incidence of p-polarized monitor light. Deconvolution of these spectra gave six bands in the visible region. The dependence of the peak intensities on the incident angles indicated that the bands at 390 and 420 nm originated from surface plasmon bands in the transverse direction of the nanorods.

  7. Synthesis and Analysis of MnTiO3 Thin Films on ITO Coated Glass Substrates

    NASA Astrophysics Data System (ADS)

    Martin, Emerick; Sahiner, Mehmet-Alper

    Perovskites like Manganese Titanium Oxide have interesting chemical properties that may be advantageous to the development of p-n junction photovoltaic cells. Due to the limited understanding behind the compound, it is essential to know the characteristics of it when it is deposited in thin film form. The cells were created using pulsed laser deposition method for two separate mediums (first layers after ITO). ZnO was deposited onto ITO glass for the first sample. For the second sample, a layer of pure Molybdenum was deposited onto the ITO glass. The MnTiO3 was then deposited onto both samples. There was a target thickness of 1000 Angstroms, but ellipsometry shows that, for the Mo based sample, that film thickness was around 1500 Angstroms. There were inconclusive results for the ZnO based sample. The concentration of active carriers was measured using a Hall Effect apparatus for the Mo based sample. The XRD analyses were used to confirm the perovskite structure of the films. Measurements for photoelectric conversion efficiency were taken using a Keathley 2602 ScourceMeter indicated low values for efficiency. The structural information that is correlated with the low electrical performance of this sample will be discussed. SHU-NJSGC Summer 2015 Fellowship.

  8. Effects of substrate bias power on the surface of ITO electrodes during O2/CF4 plasma treatment and the resulting performance of organic light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Han, D. M.; Lee, J. H.; Jeong, K. H.; Lee, J. G.

    2010-08-01

    During surface treatment using O2/CF4 plasma chemistry, the bias power applied to the indium-tin-oxide(ITO) substrate significantly degrades the electrical and optical performance of the organic light emitting diode (OLED) formed on the ITO electrode as a result of the formation of CFx polymer, In-Sn-F compounds, and structural defects. Application of bias power to the substrate effectively increases the sheath potential over the substrate and thus the flux of CFx + ion created in the O2/CF4 plasma, which leads to the production of CFx polymers as well as structural defects.

  9. Electrochemical growth of CoNi and Pt-CoNi soft magnetic composites on an alkanethiol monolayer-modified ITO substrate.

    PubMed

    Escalera-López, D; Gómez, E; Vallés, E

    2015-07-07

    CoNi and Pt-CoNi magnetic layers on indium-tin oxide (ITO) substrates modified by an alkanethiol self-assembled monolayer (SAM) have been electrochemically obtained as an initial stage to prepare semiconducting layer-SAM-magnetic layer hybrid structures. The best conditions to obtain the maximum compactness of adsorbed layers of dodecanethiol (C12-SH) on ITO substrate have been studied using contact angle, AFM, XPS and electrochemical tests. The electrochemical characterization (electrochemical probe or voltammetric response in blank solutions) is fundamental to ensure the maximum blocking of the substrate. Although the electrodeposition process on the SAM-modified ITO substrate is very slow if the blocking of the surface is significant, non-cracked metallic layers of CoNi, with or without a previously electrodeposited seed-layer of platinum, have been obtained by optimizing the deposition potentials. Initial nucleation is expected to take place at the pinhole defects of the C12-SH SAM, followed by a mushroom-like growth regime through the SAM interface that allows the formation of a continuous metallic layer electrically connected to the ITO surface. Due to the potential of the methodology, the preparation of patterned metallic deposits on ITO substrate using SAMs with different coverage as templates is feasible.

  10. Optoelectronic properties and interfacial durability of CNT and ITO on boro-silicate glass and PET substrates with nano- and heterostructural aspects

    NASA Astrophysics Data System (ADS)

    Park, Joung-Man; Wang, Zuo-Jia; Kwon, Dong-Jun; DeVries, Lawrence

    2011-02-01

    Nano- and hetero-structures of carbon nanotube (CNT) and indium tin oxide (ITO) can control significantly piezoelectric and optoelectronic properties in Microelectromechanical Systems (MEMS) as sensing and actuator under cyclic loading. Optimized preparing conditions were obtained for multi-functional purpose of the specimen by obtaining the best dispersion and turbidity in the solution. Optical transmittance and electrical properties were investigated for CNT and ITO dipping and spraying coating on boro-silicate glass and polyethylene terephthalate (PET) substrates by electrical resistance measurement under cyclic loading and wettability test. Uniform dip-coating was performed using Wilhelmy plate method due to its simple and convenience. Spraying coating was applied to the specimen additionally. The change in the electrical resistance and optical properties of coated layer were mainly dependent upon the number of dip-coating, the concentration of CNT and ITO solutions, and the surface treatment condition. Electric properties of coating layers were measured using four-point probe method, and surface resistance was calculated using a dual configuration method. Optical transmittance of CNT and ITO coated PET film was also evaluated using UV spectrum. Surface energy and their hydrophilic and hydrophobic properties of CNT and ITO coated substrates were investigated by wettability test via static and dynamic contact angle measurements. As the elapsing time of cyclic loading passed, the stability of surface resistance and thus comparative interfacial adhesion between coated layer and substrates was evaluated to compare the thermodynamic work of adhesion, Wa. As dip-coating number increased, surface resistance of coated CNT decreased, whereas the transmittance decreased step-by-step due to the thicker CNT and ITO networked layer. Nano- and heterostructural effects of CNT and ITO solution on the optical and electrical effects have been studied continuously.

  11. Fabrication of hetero-junction diode using NiO thin film on ITO/glass substrate

    NASA Astrophysics Data System (ADS)

    Soni, Sonali; Sharma, Vinay; Kuanr, Bijoy K.

    2016-05-01

    Fabrication, characterization and testing of hetero-junctions of NiO thin films were done. Nickel films were evaporated on polished ITO coated glass substrates using thermal deposition. The films were annealed at high temperatures in the presence of oxygen to obtain NiO films. The rectifying current-voltage (I-V) properties confirmed that a hetero-junction diode was successfully formed. The AC and DC behavior of hetero-junction using DC silver-probes were determined. The threshold voltage, ideality factor and reverse saturation current of hetero junction were determined. We have compared these I-V characteristics with semiconducting PN junction diode. To test the device characteristics, we used the structure as a diode clipper at various frequencies. It is showed that our device is a better high-frequency junction-device than a normal PN junction diode.

  12. Facile fabrication of crack-free large-area 2D WO3 inverse opal films by a 'dynamic hard-template' strategy on ITO substrates.

    PubMed

    Li, Hua; Thériault, Jolaine; Rousselle, Bruno; Subramanian, Balaji; Robichaud, Jacques; Djaoued, Yahia

    2014-02-28

    A 'dynamic hard-template' infiltration strategy for crack-free large-area synthesis of 2D WO3 inverse opal (IO) films on ITO substrates using a wide range of sizes of sacrificial PS spheres is reported. Thus prepared WO3 IO films were successfully used as an active electrode in the fabrication of an electrochromic device.

  13. Back interface effect on the topography and magnetism relationship studied from Ni nano-coatings: role of ITO and Cu substrates

    NASA Astrophysics Data System (ADS)

    Ebothé, Jean; Nzoghe-Mendome, Lény; Khamis Aloufy, Affaf

    2015-12-01

    A comparative study is here reported on the role of ITO and Cu substrates in the surface growth, topography and the magnetism of mesoscopic scale thick nanocrystallized Ni electrocoatings in the thickness interval 60 < d < 1200 nm. The cathodic voltammetry (C-V) technique used for the coating formation engenders conglomerated grain patterns with ITO and spaced needle-like features with Cu. These surface configurations are particularly marked with the thinnest samples. They undergo a noticeable smoothing with the coating thickness increase. The magnetic reversal (MR) of the Ni samples on Cu is ruled by the spin rotation mechanism. A transition from the domain wall (DW) motion mechanism to the spin rotation one occurs with ITO while the d value increases. The study of the topography-magnetism relationship reveals that the spin rotation mechanism of the Ni samples is incoherent with both substrates. The co-existence of the Bloch magnetic domains (MD)B and the Néel domain wall (DW)N types is identified for ITO in the thinner (rougher) Ni samples associated with the DW motion MR. The same sequence occurs for Cu for the thicker (smoother) samples linked to the spin rotation MR, as long as their normalized roughness values are confined below σ o‧ ≈ 0.15.

  14. Efficient photocatalytic decolorization of some textile dyes using Fe ions doped polyaniline film on ITO coated glass substrate.

    PubMed

    Haspulat, Bircan; Gülce, Ahmet; Gülce, Handan

    2013-09-15

    In this study, the photocatalytic decolorization of four commercial textile dyes with different structures has been investigated using electrochemically synthesized polyaniline and Fe ions doped polyaniline on ITO coated glass substrate as photocatalyst in aqueous solution under UV irradiation for the first time. Scanning electron microscopy, atomic force microscopy, FT-IR spectra, UV-vis spectroscopy measurements were used to characterize the electrochemically synthesized polymer film photocatalyst. Film hydrophilicity was assessed from contact angle measurements. The results show that both of the polymer films exhibit good photocatalytic performance. Surprisingly, it was determined that by using Fe(II) ions during polymerization, it is possible to modify the surface roughness and wettability of the produced polyaniline films which favors their photocatalytic activity in water-based solutions. All four of the used dyes (methylene blue, malachite green, methyl orange and methyl red) were completely decolorizated in 90 min of irradiation under UV light by using Fe ions doped polyaniline at the dye concentration of 1.5 × 10(-5)M, while the decolorization of those dyes were between 43% and 83% by using polyaniline as photocatalyst. Hence, it may be a viable technique for the safe disposal of textile wastewater into waste streams.

  15. Evaluation of the single yeast cell's adhesion to ITO substrates with various surface energies via ESEM nanorobotic manipulation system.

    PubMed

    Shen, Yajing; Ahmad, Mohd Ridzuan; Nakajima, Masahiro; Kojima, Seiji; Homma, Michio; Fukuda, Toshio

    2011-12-01

    Cell-surface adhesion force is important for cell activities and the development of bio materials. In this paper, a method for in situ single cell (W303) adhesion force measurement was proposed based on nanorobotic manipulation system inside an environment scanning electron microscope (ESEM). An end effector was fabricated from a commercial atomic force microscope (AFM) cantilever by focused ion beam (FIB) etching. The spring constant of it was calibrated by nanomanipulation approach. Three kinds of hydrophilic and hydrophobic ITO plates were prepared by using VUV-irradiation and OTS coating techniques. The shear adhesion strength of the single yeast cell to each substrate was measured based on the deflection of the end effector. The results demonstrated that the cell adhesion force was larger under the wet condition in the ESEM environment than in the aqueous condition. It also showed that the cell adhesion force to hydrophilic surface was larger than that to the hydrophobic surface. Studies of single cell's adhesion on various plate surfaces and environments could give new insights into the tissue engineering and biological field.

  16. Ferroelectric Properties of CaBi4Ti4O15 Thin Films on Ito/glass Substrates Prepared by Sol-Gel Technology

    NASA Astrophysics Data System (ADS)

    Cheng, Chien-Min; Kuan, Ming-Chang; Chen, Kai-Hunag; Tsai, Jen-Hwan

    In this study, ferroelectric CaBi4Ti4O15 (CBT) thin films prepared by sol-gel method and deposited on ITO/glass substrates for applications in system-on-panel (SOP) devices were fabricated and investigated. The electrical and physical characteristics of as-deposited and annealed CBT thin films for metal-ferroelectric-metal (MFM) structures was discussed and investigated. In addition, the ferroelectric properties in annealed CBT thin films on ITO/glass substrate showed and exhibited clear polarization versus electrical field curves. From p-E curves, the 2Pr value and coercive field of annealed CBT thin films were calculated to be 10μC/cm2 and 180 kV/cm, respectively. Finally, the maximum capacitance, leakage current density, and transmittance within the ultraviolet-visible (UV-vis) spectrum were also investigated and discussed.

  17. Ultraviolet-assisted direct patterning and low-temperature formation of flexible ZrO2 resistive switching arrays on PET/ITO substrates.

    PubMed

    Li, Lingwei; Chen, Yuanqing; Yin, Xiaoru; Song, Yang; Li, Na; Niu, Jinfen; Wu, Huimin; Qu, Wenwen

    2017-10-06

    We demonstrate a low-cost and facile photochemical solution method to prepare the ZrO2 resistive switching arrays as memristive units on flexible PET/ITO substrates. ZrO2 solution sensitive to UV light of 337nm was synthesized using zirconium n-butyl alcohol as precursor, and benzoylacetone as complexing agent. After the dip-coated ZrO2 gel films were irradiated through a mask under the UV lamp (with wavelength of 325~365nm) at room temperature and rinsed in ethanol, the ZrO2 gel arrays were obtained on PET/ITO substrates. Subsequently, the ZrO2 gel arrays were irradiated by deep UV (DUV) light of 254nm and 185nm at 150oC, resulting in the amorphous ZrO2 memristive micro-arrays. The ZrO2 units on flexible PET/ITO substrates exhibited excellent memristive properties. A high ratio of 104 of on-state and off-state resistance was obtained. The resistive switching behavior of the flexible device remained stable after being bent for 103 times. The device showed stable flexibility up to a minimum bending diameter of 1.25cm. © 2017 IOP Publishing Ltd.

  18. Electrical Properties Analysis of Copper doped CdTe/CdS Deposited Thin Films on ITO Coated Glass Substrates

    NASA Astrophysics Data System (ADS)

    Lesinski, Darren; Flaherty, James; Sahiner, M. Alper

    CdTe proves to be a viable source for renewable energy in the form of photovoltaic conversion. While CdTe/CdS naturally provide interesting results adding dopants to the cell can yield higher conversion efficiencies. Copper, famous for its electrical properties, can be used as a dopant in the CdTe layer. In conjunction with its dopant characteristics Copper also improves cell performance by acting as a low resistant and high current back contact. All thin films were synthesized using pulsed laser deposition onto ITO coated glass substrates. The CdS layer across all cells has an approximate thickness of 1500 Angstroms. The following CdTe layer has an approximate thickness of 5500 Angstroms. This created the base cell that was then doped. Cu, typically deposited using sublimation or vapor deposition, was done by PLD as well. Two of the three base cells were treated with Cu using the same deposition parameters. The third cell also received a CdCl treatment on top of the Cu layer to understand the effect when the oxygen layer is deferred. Ellipsometer measurements were used to confirm layer thickness. XRD analysis was used to confirm the presence of Cu and the crystal structure of the thin films. A Hall Effect Measurement system was used to measure active charge carrier concentration introduced by dopant. Also, a Keithley sourcemeter was utilized to determine photovoltaic properties. Notable results discussed will be the effects of Copper dopant on the electrical properties of CdS/CdTe based solar cells.

  19. Inorganic Surface Modification of Nonwoven Polymeric Substrates

    NASA Astrophysics Data System (ADS)

    Halbur, Jonathan Chandler

    In this study, atomic layer deposition (ALD), a vapor phase inorganic thin film deposition technique, is used to modify the surface of a range of industrially relevant polymers to enhance surface properties or impart additional functionalities. Several unique demonstrations of polymer surface modification are presented including uniform nanomaterial photodeposition to the surface of nonowoven fabrics and the first application of photocatalytic thin film coated nonwovens for advanced filtration of heavy metals from solution. Recent advances in polymer synthesis and processing technologies have resulted in the production of novel polymer systems with unique chemistries and sub-micron scale dimensions. As a result, advanced fiber systems have received much attention for potential use in a wide range of industrially and medically important applications such as advanced and selective filtration, catalysis, flexible electronics, and tissue engineering. However, tailoring the surface properties of the polymer is still needed in order to realize the full range of advanced applications, which can be difficult given the high complexity and non-uniformity of nonwoven polymeric structures. Uniform and controllable inorganic surface modification of nonwovens allows the introduction or modification of many crucial polymer properties with a wide range of application methods.

  20. ITO/poly(aniline)/sol-gel glass: An optically transparent, pH-responsive substrate for supported lipid bilayers.

    PubMed

    Al-Obeidi, Ahmed; Ge, Chenhao; Orosz, Kristina S; Saavedra, S Scott

    2013-01-01

    Described here is fabrication of a pH-sensitive, optically transparent transducer composed of a planar indium-tin oxide (ITO) electrode overcoated with a a poly(aniline) (PANI) thin film and a porous sol-gel layer. Adsorption of the PANI film renders the ITO electrode sensitive to pH, whereas the sol-gel spin-coated layer makes the upper surface compatible with fusion of phospholipid vesicles to form a planar supported lipid bilayer (PSLB). The response to changes in the pH of the buffer contacting the sol-gel/PANI/ITO electrode is pseudo-Nernstian with a slope of 52 mV/pH over a pH range of 4-9. Vesicle fusion forms a laterally continuous PSLB on the upper sol-gel surface that is fluid with a lateral lipid diffusion coefficient of 2.2 μm(2)/s measured by fluorescence recovery after photobleaching. Due to its lateral continuity and lack of defects, the PSLB blocks the pH response of the underlying electrode to changes in the pH of the overlying buffer. This architecture is simpler to fabricate than previously reported ITO electrodes derivatized for PSLB formation, and should be useful for optical monitoring of proton transport across supported membranes derivatized with ionophores and ion channels.

  1. Electrical and photocatalytic properties of boron-doped ZnO nanostructure grown on PET-ITO flexible substrates by hydrothermal method.

    PubMed

    Wang, Wei; Ai, Taotao; Yu, Qi

    2017-02-13

    Boron-doped zinc oxide sheet-spheres were synthesized on PET-ITO flexible substrates using a hydrothermal method at 90 °C for 5 h. The results of X-ray diffraction and X-ray photoelectron spectroscopy indicated that the B atoms were successfully doped into the ZnO lattice, the incorporation of B led to an increase in the lattice constant of ZnO and a change in its internal stress. The growth mechanism of pure ZnO nanorods and B-doped ZnO sheet-spheres was specifically investigated. The as-prepared BZO/PET-ITO heterojunction possessed obvious rectification properties and its positive turn-on voltage was 0.4 V. The carrier transport mechanisms involved three models such as hot carrier tunneling theory, tunneling recombination, and series-resistance effect were explored. The BZO/PET-ITO nanostructures were more effective than pure ZnO to degrade the RY 15, and the degradation rate reached 41.45%. The decomposition process with BZO nanostructure followed first-order reaction kinetics. The photocurrent and electrochemical impedance spectroscopy revealed that the B-doping could promote the separation of photo-generated electron-hole pairs, which was beneficial to enhance the photocatalytic activity. The photocurrent density of B-doped and pure ZnO/PET-ITO were 0.055 mA/cm(2) and 0.016 mA/cm(2), respectively. The photocatalytic mechanism of the sample was analyzed by the energy band theory.

  2. Electrical and photocatalytic properties of boron-doped ZnO nanostructure grown on PET-ITO flexible substrates by hydrothermal method

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Ai, Taotao; Yu, Qi

    2017-02-01

    Boron-doped zinc oxide sheet-spheres were synthesized on PET-ITO flexible substrates using a hydrothermal method at 90 °C for 5 h. The results of X-ray diffraction and X-ray photoelectron spectroscopy indicated that the B atoms were successfully doped into the ZnO lattice, the incorporation of B led to an increase in the lattice constant of ZnO and a change in its internal stress. The growth mechanism of pure ZnO nanorods and B-doped ZnO sheet-spheres was specifically investigated. The as-prepared BZO/PET-ITO heterojunction possessed obvious rectification properties and its positive turn-on voltage was 0.4 V. The carrier transport mechanisms involved three models such as hot carrier tunneling theory, tunneling recombination, and series-resistance effect were explored. The BZO/PET-ITO nanostructures were more effective than pure ZnO to degrade the RY 15, and the degradation rate reached 41.45%. The decomposition process with BZO nanostructure followed first-order reaction kinetics. The photocurrent and electrochemical impedance spectroscopy revealed that the B-doping could promote the separation of photo-generated electron-hole pairs, which was beneficial to enhance the photocatalytic activity. The photocurrent density of B-doped and pure ZnO/PET-ITO were 0.055 mA/cm2 and 0.016 mA/cm2, respectively. The photocatalytic mechanism of the sample was analyzed by the energy band theory.

  3. Electrical and photocatalytic properties of boron-doped ZnO nanostructure grown on PET–ITO flexible substrates by hydrothermal method

    PubMed Central

    Wang, Wei; Ai, Taotao; Yu, Qi

    2017-01-01

    Boron-doped zinc oxide sheet-spheres were synthesized on PET–ITO flexible substrates using a hydrothermal method at 90 °C for 5 h. The results of X-ray diffraction and X-ray photoelectron spectroscopy indicated that the B atoms were successfully doped into the ZnO lattice, the incorporation of B led to an increase in the lattice constant of ZnO and a change in its internal stress. The growth mechanism of pure ZnO nanorods and B-doped ZnO sheet-spheres was specifically investigated. The as-prepared BZO/PET–ITO heterojunction possessed obvious rectification properties and its positive turn-on voltage was 0.4 V. The carrier transport mechanisms involved three models such as hot carrier tunneling theory, tunneling recombination, and series-resistance effect were explored. The BZO/PET–ITO nanostructures were more effective than pure ZnO to degrade the RY 15, and the degradation rate reached 41.45%. The decomposition process with BZO nanostructure followed first-order reaction kinetics. The photocurrent and electrochemical impedance spectroscopy revealed that the B-doping could promote the separation of photo-generated electron-hole pairs, which was beneficial to enhance the photocatalytic activity. The photocurrent density of B-doped and pure ZnO/PET–ITO were 0.055 mA/cm2 and 0.016 mA/cm2, respectively. The photocatalytic mechanism of the sample was analyzed by the energy band theory. PMID:28211923

  4. Electrooptical properties and structural features of amorphous ITO

    SciTech Connect

    Amosova, L. P.

    2015-03-15

    Thin indium-tin oxide (ITO) films are deposited onto cold substrates by magnetron-assisted sputtering. The dependences of the structural, electrical, and optical properties of the films on the oxygen content in the atmosphere of sputtering and the growth rate are studied. It is shown that, if the substrate temperature is no higher than the ITO crystallization temperature and the conditions of growth deviate from the optimal relationship between the oxygen pressure and the growth rate, the resistance of the layers can be six or seven orders of magnitude higher than the resistance of conducting amorphous layers and reach hundreds of megaohms. At the same time, the optical properties of insulating layers in the visible spectral region are completely identical to the properties of the conducing amorphous modification. A conceptual model of defects responsible for the insulating properties of amorphous ITO is proposed.

  5. Transparent, superhydrophobic, and wear-resistant coatings on glass and polymer substrates using SiO2, ZnO, and ITO nanoparticles.

    PubMed

    Ebert, Daniel; Bhushan, Bharat

    2012-08-07

    It is of significant interest to create surfaces that simultaneously exhibit high water contact angle, low contact angle hysteresis, and high transmission of visible light, as well as mechanical wear resistance for industrial applications. The fabrication of such surfaces has often involved complex or expensive processes, required techniques that were not suitable for a variety of substrates and particles, required surface post-treatment, or lacked wear resistance. A systematic study has been performed in which transparent superhydrophobic surfaces were created on glass, polycarbonate, and poly(methyl methacrylate) (PMMA) substrates using surface-functionalized SiO(2), ZnO, and indium tin oxide (ITO) nanoparticles. The contact angle, contact angle hysteresis, and optical transmittance were measured for samples using all particle-substrate combinations. To examine wear resistance, multiscale wear experiments were performed using an atomic force microscope (AFM) and a water jet apparatus.

  6. High-performance of PEDOT/PSS free organic solar cells on an air-plasma-treated ITO substrate.

    PubMed

    Choi, Jong Kil; Jin, Ming Liang; An, Cheng Jin; Kim, Dae Woo; Jung, Hee-Tae

    2014-07-23

    In this work, we demonstrate the high-performance of a PEDOT:PSS free organic photovoltaic cell (OPVC) using an air-plasma modified ITO surface, followed by controlled solvent evaporation and annealing of the P3HT:PCBM photoactive layer. Ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), and conductive atomic force microscopy (c-AFM) results show that the work function of ITO was increased to as high as that of PEDOT:PSS (5.2 eV) after air-plasma treatment, along with significantly enhanced electrical homogeneity. From the dynamic secondary ion mass spectroscopy (DSIMS) results, we confirm that the thermodynamic stability of the slow-dried active layer is attributed to the uniform vertical compositional distribution on the air plasma treated ITO surface, even after thermal annealing at 150 °C for 10 min. The resulting device has an open-circuit voltage of 0.65 V, a fill factor of 63%, and a power conversion efficiency of 3.38%, providing a high performance PEDOT:PSS free OPVC device.

  7. Structure, optical and electrical properties of Bi2VO5.5 films deposited on ITO/glass substrates by chemical solution method

    NASA Astrophysics Data System (ADS)

    Guo, Ming; Shen, Yude; Liu, Changxin; Yang, Pingxiong

    2011-02-01

    Bismuth vanadate (Bi2VO5.5) thin films were fabricated on indium-doped tin oxide (ITO)-coated glass substrates by chemical solution method combined with a rapid thermal annealing process. The structure of the films was characterized with X-ray diffraction and atomic force microscopy. The Bi2VO5.5 films annealed at 600 °C showed a good match with the ITO coated glass substrates and had a desired perovskite structure with high (00l) preferred orientation. The spherical grains with a homogeneous distribution of high crystallinity and packing density were observed. Optical properties of the Bi2VO5.5 thin films were studied by Raman spectra and the lattice vibration modes of the films were obtained. A low frequency dielectric dispersion was observed in the films. Dielectric constant and loss was about 75 and 0.076 at 10kHz, respectively. The ac conductivity obeyed Jonscher's universal power law, which may be originated a possible hopping mechanism for Bi2VO5.5 thin films. The complex impedance traces revealed material dielectric dispersion nature and the presence of grain effects in the films.

  8. CuS p-type thin film characterization deposited on Ti, ITO and glass substrates using spray pyrolysis deposition (SPD) for light emitting diode (LED) application

    SciTech Connect

    Sabah, Fayroz A.; Ahmed, Naser M. Hassan, Z. Azzez, Shrook A.; Rasheed, Hiba S.; Al-Hazim, Nabeel Z.

    2016-07-06

    The copper sulphide (CuS) thin films were grown with good adhesion by spray pyrolysis deposition (SPD) on Ti, ITO and glass substrates at 200 °C. The distance between nozzle and substrate is 30 cm. The composition was prepared by mixing copper chloride CuCl{sub 2}.2H{sub 2}O as a source of Cu{sup 2+} and sodium thiosulfate Na{sub 2}S{sub 2}O{sub 3}.5H{sub 2}O as a source of and S{sup 2−}. Two concentrations (0.2 and 0.4 M) were used for each CuCl{sub 2} and Na{sub 2}S{sub 2}O{sub 3} to be prepared and then sprayed (20 ml). The process was started by spraying the solution for 3 seconds and after 10 seconds the cycle was repeated until the solution was sprayed completely on the hot substrates. The structural characteristics were studied using X-ray diffraction; they showed covellite CuS hexagonal crystal structure for 0.2 M concentration, and covellite CuS hexagonal crystal structure with two small peaks of chalcocite Cu{sub 2}S hexagonal crystal structure for 0.4 M concentration. Also the surface and electrical characteristics were investigated using Field Emission Scanning Electron Microscopy (FESEM) and current source device, respectively. The surface study for the CuS thin films showed nanorods to be established for 0.2 M concentration and mix of nanorods and nanoplates for 0.4 M concentration. The electrical study showed ohmic behavior and low resistivity for these films. Hall Effect was measured for these thin films, it showed that all samples of CuS are p- type thin films and ensured that the resistivity for thin films of 0.2 M concentration was lower than that of 0.4 M concentration; and for the two concentrations CuS thin film deposited on ITO had the lowest resistivity. This leads to the result that the conductivity was high for CuS thin film deposited on ITO substrate, and the conductivity of the three thin films of 0.2 M concentration was higher than that of 0.4 M concentration.

  9. CuS p- type thin film characterization deposited on Ti, ITO and glass substrates using spray pyrolysis deposition (SPD) for light emitting diode (LED) application

    NASA Astrophysics Data System (ADS)

    Sabah, Fayroz A.; Ahmed, Naser M.; Hassan, Z.; Rasheed, Hiba S.; Azzez, Shrook A.; Al-Hazim, Nabeel Z.

    2016-07-01

    The copper sulphide (CuS) thin films were grown with good adhesion by spray pyrolysis deposition (SPD) on Ti, ITO and glass substrates at 200 °C. The distance between nozzle and substrate is 30 cm. The composition was prepared by mixing copper chloride CuCl2.2H2O as a source of Cu2+ and sodium thiosulfate Na2S2O3.5H2O as a source of and S2-. Two concentrations (0.2 and 0.4 M) were used for each CuCl2 and Na2S2O3 to be prepared and then sprayed (20 ml). The process was started by spraying the solution for 3 seconds and after 10 seconds the cycle was repeated until the solution was sprayed completely on the hot substrates. The structural characteristics were studied using X-ray diffraction; they showed covellite CuS hexagonal crystal structure for 0.2 M concentration, and covellite CuS hexagonal crystal structure with two small peaks of chalcocite Cu2S hexagonal crystal structure for 0.4 M concentration. Also the surface and electrical characteristics were investigated using Field Emission Scanning Electron Microscopy (FESEM) and current source device, respectively. The surface study for the CuS thin films showed nanorods to be established for 0.2 M concentration and mix of nanorods and nanoplates for 0.4 M concentration. The electrical study showed ohmic behavior and low resistivity for these films. Hall Effect was measured for these thin films, it showed that all samples of CuS are p- type thin films and ensured that the resistivity for thin films of 0.2 M concentration was lower than that of 0.4 M concentration; and for the two concentrations CuS thin film deposited on ITO had the lowest resistivity. This leads to the result that the conductivity was high for CuS thin film deposited on ITO substrate, and the conductivity of the three thin films of 0.2 M concentration was higher than that of 0.4 M concentration.

  10. SURFACE MODIFICATION OF ZIRCALOY-4 SUBSTRATES WITH NICKEL ZIRCONIUM INTERMETALLICS

    SciTech Connect

    Luscher, Walter G.; Gilbert, Edgar R.; Pitman, Stan G.; Love, Edward F.

    2013-02-01

    Surfaces of Zircaloy-4 (Zr-4) substrates were modified with nickel-zirconium (NiZr) intermetallics to tailor oxidation performance for specialized applications. Surface modification was achieved by electroplating Zr-4 substrates with nickel (Ni) and then performing thermal treatments to fully react the Ni plating with the substrates, which resulted in a coating of NiZr intermetallics on the substrate surfaces. Both plating thickness and thermal treatment were evaluated to determine the effects of these fabrication parameters on oxidation performance and to identify an optimal surface modification process. Isothermal oxidation tests were performed on surface-modified materials at 290°, 330°, and 370°C under a constant partial pressure of oxidant (i.e., 1 kPa D2O in dry Ar at 101 kPa) for 64 days. Test results revealed an enhanced, transient oxidation rate that decreased asymptotically toward the rate of the Zr-4 substrate. Oxidation kinetics were analyzed from isothermal weight gain data, which were correlated with microstructure, hydrogen pickup, strength, and hardness.

  11. Surface Modification of Polymer Substrates for Biomedical Applications.

    PubMed

    Neděla, Oldřich; Slepička, Petr; Švorčík, Václav

    2017-09-21

    While polymers are widely utilized materials in the biomedical industry, they are rarely used in an unmodified state. Some kind of a surface treatment is often necessary to achieve properties suitable for specific applications. There are multiple methods of surface treatment, each with their own pros and cons, such as plasma and laser treatment, UV lamp modification, etching, grafting, metallization, ion sputtering and others. An appropriate treatment can change the physico-chemical properties of the surface of a polymer in a way that makes it attractive for a variety of biological compounds, or, on the contrary, makes the polymer exhibit antibacterial or cytotoxic properties, thus making the polymer usable in a variety of biomedical applications. This review examines four popular methods of polymer surface modification: laser treatment, ion implantation, plasma treatment and nanoparticle grafting. Surface treatment-induced changes of the physico-chemical properties, morphology, chemical composition and biocompatibility of a variety of polymer substrates are studied. Relevant biological methods are used to determine the influence of various surface treatments and grafting processes on the biocompatibility of the new surfaces-mammalian cell adhesion and proliferation is studied as well as other potential applications of the surface-treated polymer substrates in the biomedical industry.

  12. Covalent Assembled Monolayers of Homo- and Heteroleptic Fe(II)-Terpyridyl Complexes on SiOx and ITO-Coated Glass Substrates: An Experimental and Theoretical Study.

    PubMed

    Mondal, Dr Prakash Chandra; Singh, Vikram; Manna, Arun K; Zharnikov, Michael

    2017-09-14

    Well-defined Fe(II)-terpyridyl monolayers were fabricated on SiOx and conductive ITO-coated glass substrates via covalent bond formation between the metallo-organic complexes and a pre-assembled coupling layer. Three different homo- and heteroleptic complexes with the terminal pyridyl, amine, and phenyl groups were tested. All the films were found to be densely packed, homogeneous, and consisting of upright standing molecules. They exhibited high thermal (up to ~220°C) and temporal (up to 5h at 100°C) stability. The UV-vis spectra of the monolayers showed a pronounced metal-to-ligand charge-transfer bands with a significant red-shift as compared to the solution spectra of the respective metallo-ligands in the case of pendant pyridyl group quaternized with the coupling layer, while the shift was significantly smaller when the coupling layer was bonded to the primary amine (NH2) group of the complex. The cyclic voltammograms of the monolayers showed reversible, one-electron redox behavior and suggested strong electronic coupling between the confined molecules and the underlying substrate. The analysis of the electrochemistry data allowed also to estimate the charge-transfer rate constant between the metal centre and the substrate. Additionally, detailed quantum chemical calculations were performed to support and rationalize the experimentally observed photophysical properties of the Fe(II)-terpyridyl complexes both in solution state and bound to a SiOx-based substrate. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Growth and physical properties of p-Zn x Cd1- x S thin films thermally evaporated on ITO-coated glass substrates

    NASA Astrophysics Data System (ADS)

    Yoon, Eun Jeong; Han, Dong Hun; Lee, Jeoung Ju; Lee, Jong Duk; Kang, Kwang Yong; Lee, Seung Hwan; Shewale, Prashant Shivaji

    2015-01-01

    Zn x Cd1- x S ( x = 0.15, 0.44, 0.62, 0.80, and 0.95) thin films of about 340 nm in thickness were deposited on indium-tin-oxide (ITO)-coated glass substrates by using thermal evaporation of high-purity ZnS and CdS mixed tablets in high vacuum. X-ray diffraction spectra showed that the Zn x Cd1- x S thin films were preferentially grown along the (111) orientation. The Zn x Cd1- x S crystal structure was a mixture structure of the ZnS and the CdS cubic zincblende structures with lattice constants a = 5.670 Å to a = 5.734 Å for CdS and a = 5.437 Å for ZnS. The ( αh ν)2 vs. h ν plots for the Zn x Cd1- x S thin films showed that all samples had direct transition band gaps. The energy band gaps of the Zn x Cd1- x S thin films increased monotonically from 2.45 eV for x = 0.15 to 3.37 eV for x = 0.95. The dynamical behavior of the charge carriers in the Zn x Cd1- x S thin films was investigated by using the photoinduced discharge characteristics (PIDC) technique.

  14. Effects of annealing temperature on optical, morphological, and electrical characteristics of polyfluorene-derivative thin films on ITO glass substrate.

    PubMed

    Lim, Way Foong; Quah, Hock Jin; Hassan, Zainuriah

    2016-02-20

    The effects of postdeposition annealing temperature (125°C-200°C) toward optical, morphological, and electrical characteristics of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(1,4-phenylene)] end capped with dimethylphenyl group deposited on indium tin oxide glass substrates were investigated. Green and red-infrared photoluminescence emissions, originating from П-conjugation aggregates and keto-type defects did not attenuate the intensity of the blue emission peak. This suggested that the aggregates and defects might serve as local traps for radiative recombination. In samples annealed at 125°C-175°C, a decreasing optical energy gap (E(g)) that decreased barrier height as well as an increasing amount of traps have increased current conduction via thermionic emission and trap-assisted tunneling. Nonetheless, an acquisition of the largest E(g) and amount of traps testified that thermionic emission was dominating current conduction, surpassing trap-assisted tunneling in samples annealed at 200°C.

  15. Deposition and characterization of CdSe nanoparticles layer on ITO/PET flexible substrate by electrophoretic deposition

    NASA Astrophysics Data System (ADS)

    Yaacob, Khatijah A.; Yi, Liang Shu; Ishak, Muhamad Nizam

    2017-07-01

    CdSe nanoparticles with various sizes were successfully synthesized using hot injection method. UV-vis Spectroscopy (UV-vis) was done to identify the absorption wavelength and then use to calculate the particle size of CdSe nanoparticles. The small nanoparticles were categorized as 2.77 nm, 3.06 nm and 3.52 nm whereas 4.06 nm and 5.43 nm were categorized as big nanoparticles. All these samples were undergone up to 4 times purification. Zeta Potential and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) were done on these purified CdSe nanoparticles for quantitative analysis. Then these nanoparticle were deposited on the flexible substrate using electrophoretic deposition technique. The deposition efficiency of CdSe nanoparticles was influenced by the applied voltage. The applied voltage for big nanoparticles was larger than the small nanoparticles. When number of purification increases, the applied voltage for small size CdSe nanoparticles showed a decreasing trend whereas big size CdSe nanoparticles showed the reverse pattern.

  16. Ultrahydrophobic surface modification of polymeric fibers and inorganic substrates

    NASA Astrophysics Data System (ADS)

    Ramaratnam, Karthik

    The wettability of a solid surface is a very important property, and is governed by both the chemical composition and the geometrical microstructure of the surface. Wettability and repellency are important properties of solid surfaces from both fundamental and practical aspects. The wettability of the solid surface is a characteristic property of materials and strongly depends on both the surface energy and the surface roughness. These properties may be approached by mimicking hydrophobic structures created by nature on lotus leaf surface. The lotus effect is based on surface roughness caused by different microstructures together with the hydrophobic properties of the epicuticular wax. The present study investigates the basic principles involved in the fabrication of lotus-like materials on both fibrous and inorganic substrates utilizing the two essential requirements, surface roughness and hydrophobicity. The surface roughness was created either by a porous or a bumpy profile while the hydrophobicity was achieved by grafting a non-fluorinated hydrophobic polymer. For the porous profiles, polymer blend systems showing phase separation were utilized whereas the bumpy profiles were achieved using nanoparticles such as calcium carbonate, silver, or silica particles. In the last part of the research, functionalization of silica nanoparticles was investigated and the development of a universal modification step to obtain the ultrahydrophobic property is reported. In this approach, the adsorption of the polymer and the nanoparticles to fibers has been optimized and the self-cleaning effect of these fabrics modified with silica nanoparticles has also been demonstrated.

  17. Studies on polyurethane adhesives and surface modification of hydrophobic substrates

    NASA Astrophysics Data System (ADS)

    Krishnamoorthy, Jayaraman

    studies involved making functionalized, thickness-controlled, wettability-controlled multilayers on hydrophobic substrates and the adsorption of carboxylic acid-terminated poly(styrene-b-isoprene) on alumina/silica substrates. Poly(vinyl alcohol) has been shown to adsorb onto hydrophobic surfaces irreversibly due to hydrophobic interactions. This thin semicrystalline coating is chemically modified using acid chlorides, butyl isocyanate and butanal to form thicker and hydrophobic coatings. The products of the modification reactions allow adsorption of a subsequent layer of poly(vinyl alcohol) that could subsequently be hydrophobized. This 2-step (adsorption/chemical modification) allows layer-by-layer deposition to prepare coatings with thickness, chemical structure and wettability control on any hydrophobic surface. Research on adsorption characteristics of carboxylic acid-terminated poly(styrene-b-isoprene) involved syntheses of block copolymers with the functional group present at specific ends. Comparative adsorption studies for carboxylic acid-terminated and hydrogen-terminated block copolymers was carried out on alumina and silica substrates.

  18. Preparation of regularly structured nanotubular TiO2 thin films on ITO and their modification with thin ALD-grown layers

    NASA Astrophysics Data System (ADS)

    Tupala, Jere; Kemell, Marianna; Härkönen, Emma; Ritala, Mikko; Leskelä, Markku

    2012-03-01

    Nanotubular titanium dioxide thin films were prepared by anodization of titanium metal films evaporated on indium tin oxide (ITO) coated glass. A facile method to enhance the adhesion of the titanium film to the ITO glass was developed. An optimum thickness of 550 nm for the evaporated titanium was found to keep the film adhered to ITO during the anodization. The films were further modified by growing amorphous titania, alumina and tantala thin films conformally in the nanotubes by atomic layer deposition (ALD). The optical, electrical and physical properties of the different structures were compared. It was shown that even 5 nm thin layers can modify the properties of the nanotubular titanium dioxide films.

  19. Preparation of regularly structured nanotubular TiO2 thin films on ITO and their modification with thin ALD-grown layers.

    PubMed

    Tupala, Jere; Kemell, Marianna; Härkönen, Emma; Ritala, Mikko; Leskelä, Markku

    2012-03-30

    Nanotubular titanium dioxide thin films were prepared by anodization of titanium metal films evaporated on indium tin oxide (ITO) coated glass. A facile method to enhance the adhesion of the titanium film to the ITO glass was developed. An optimum thickness of 550 nm for the evaporated titanium was found to keep the film adhered to ITO during the anodization. The films were further modified by growing amorphous titania, alumina and tantala thin films conformally in the nanotubes by atomic layer deposition (ALD). The optical, electrical and physical properties of the different structures were compared. It was shown that even 5 nm thin layers can modify the properties of the nanotubular titanium dioxide films.

  20. Highly Sensitive and Flexible Strain Sensors Based on Patterned ITO Nanoparticle Channels.

    PubMed

    Lee, Do Hoon; Park, Jonghyurk; Lee, Jong-Kwon; Heo, Kwang; Lee, Dong-Jin; Lee, Ye Rim; Lee, Byung Yang

    2017-10-10

    We demonstrate a highly sensitive and flexible bending strain sensors using tin-doped indium oxide (ITO) nanoparticles (NPs) assembled in line patterns on flexible substrates. By utilizing transparent ITO NPs without any surface modifications, we could produce strain sensors with adjustable gauge factors and optical transparency. We were able to control the dimensional and electrical properties of the sensors, such as channel height and resistance, by controlling the NP assembly speed. Furthermore, we were able to generate controlled gauge factor with values ranging from 18 to 157, which are higher than previous cases using metallic Cr NPs and comparable to those using Au NPs. The alignment of the ITO NPs in parallel lines resulted in low crosstalk between the transverse and longitudinal bending directions. Finally, our sensor showed high optical transmittance, up to ~93% at 500 nm wavelength, which is desirable for flexible electronic applications. © 2017 IOP Publishing Ltd.

  1. Fully transparent high performance thin film transistors with bilayer ITO/Al-Sn-Zn-O channel structures fabricated on glass substrate.

    PubMed

    Cong, Yingying; Han, Dedong; Dong, Junchen; Zhang, Shengdong; Zhang, Xing; Wang, Yi

    2017-05-04

    In this work, fully transparent high performance double-channel indium-tin-oxide/Al-Sn-Zn-O thin-film transistors (ITO/ATZO TFTs) are successfully fabricated on glass by radio frequency (RF) magnetron sputtering. The ITO layer acts as the bottom channel layer to increase the channel carrier concentration. The top ATZO channel layer, which is deposited via high oxygen partial pressure in the sputtering process, is useful to control the minimum off-state current. After annealing, the ITO/ATZO TFT demonstrates outstanding electrical performances, including a high ON/OFF current ratio (Ion/Ioff) of 3.5 × 10(8), a steep threshold swing (SS) of 142.2 mV/decade, a superior saturation mobility (μsat) of 246.0 cm(2)/Vs, and a threshold voltage VT of 0.5 V. The operation mechanisms for double-channel structures are also clarified.

  2. Nanoparticles Modified ITO Based Biosensor

    NASA Astrophysics Data System (ADS)

    Khan, M. Z. H.

    2017-04-01

    Incorporation of nanomaterials with controlled molecular architecture shows great promise in improving electronic communication between biomolecules and the electrode substrate. In electrochemical applications metal nanoparticles (NPs) modified electrodes have been widely used and are emerging as candidates to develop highly sensitive electrochemical sensors. There has been a growing technological interest in modified indium tin oxide (ITO) electrodes due to their prominent optoelectronic properties and their wide use as a transducing platform. The introduction of NPs into the transducing platform is commonly achieved by their adsorption onto conventional electrode surfaces in various forms, including that of a composite. The aim of this review is to discuss the role of metallic NPs for surface fabrication of ITO thin films leading to detection of specific biomolecules and applications as a biosensor platform.

  3. Nanoparticles Modified ITO Based Biosensor

    NASA Astrophysics Data System (ADS)

    Khan, M. Z. H.

    2016-12-01

    Incorporation of nanomaterials with controlled molecular architecture shows great promise in improving electronic communication between biomolecules and the electrode substrate. In electrochemical applications metal nanoparticles (NPs) modified electrodes have been widely used and are emerging as candidates to develop highly sensitive electrochemical sensors. There has been a growing technological interest in modified indium tin oxide (ITO) electrodes due to their prominent optoelectronic properties and their wide use as a transducing platform. The introduction of NPs into the transducing platform is commonly achieved by their adsorption onto conventional electrode surfaces in various forms, including that of a composite. The aim of this review is to discuss the role of metallic NPs for surface fabrication of ITO thin films leading to detection of specific biomolecules and applications as a biosensor platform.

  4. Effect of modification substrate on the microstructure of hydroxyapatite coating

    NASA Astrophysics Data System (ADS)

    Realpe-Jaramillo, J.; Morales-Morales, J. A.; González-Sánchez, J. A.; Cabanzo, R.; Mejía-Ospino, E.; Rodríguez-Pereira, J.

    2017-01-01

    Bioactive hydroxyapatite (HA) coatings were fabricated by a precipitation, sol-gel and dip-coating method. The effects of the aging time and the base used to adjust pH and substrate materials on the phases and microstructures of HA coatings were studied by field emission scanning electron microscopy FESEM, energy dispersive spectroscopy EDS, X-ray photoelectron spectroscopy XPS, and the vibrations of the phosphate groups were determined by Raman spectroscopy. The results showed that all the films were composed of the phases of TiO2 and HA. With coated titanium substrate with TiO2, the crystallinity of the HA coating increases, the structure became more compact and the Ca/P ratio increased because of the loss of P in the films. The addition of sodium hydroxide (adjusting the pH level to about 10) can increase the HA content in the coating. XPS and EDS results for steel substrate and titanium showed poor calcium content as obtained with a Ca/P ratio of 1.38 and 1.58, respectively, composition is similar to that of natural apatite. However, spectroscopic results suggest the presence of a mixture of hydroxyapatite and octacalcium phosphate. The different substrate materials have a high influence on the microstructure of the separated double films. However, hydroxyapatite nanopowders coatings were obtained using a simple method, with potential biomedical applications.

  5. Modification of polymeric substrates using surface-grafted nanoscaffolds

    NASA Astrophysics Data System (ADS)

    Thompson, Kimberlee Fay

    Surface grafting and modification of poly(acrylic acid) (PAA) were performed on nylon 6,6 carpet fibers to achieve permanent stain and soil resistance. PAA was grafted to nylon and modified with 1H, 1H-pentadecafluorooctyl amine (PDFOA) using an amidation agent, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM). The first goal was to optimize acrylamide modification of PAA in solution. Aqueous reactions with taurine, hydroxyethyl amine, and butyl amine progressed ˜100%, while PDFOA reactions in MeOH progressed ˜80%. Reaction products precipitated at 77% butyl or 52% PDFOA acrylamide contents. The second goal was to optimize the PAA grafting process. First, PAA was adsorbed onto nylon 6,6 films. Next, DMTMM initiated grafting of adsorbed PAA. PAA surface coverage was ˜78%, determined by contact angle analysis of the top 0.1--1 nm and x-ray photoelectron spectroscopy (XPS) analysis of the top 3--10 nm. The third goal was to modify PAA grafted nylon films with butyl amine and PDFOA. Randomly methylated beta-cyclodextrin (RAMEB) solubilized PDFOA in water. Contact angle detected ˜100% surface reaction for each amine, while XPS detected ˜77% butyl amine (H2O) and ˜50% for PDFOA (MeOH or H2O pH = 7) reactions. In H2O pH = 12, the PDFOA reaction progressed ˜89%, perhaps due to greater efficiency, access and solubility. The fourth goal was to perform surface depth profiling via angle-resolved XPS analysis (ARXPS). The PAA surface coverage from contact angle and XPS was confirmed. Further, adsorbed PAA was thicker than grafted PAA, supporting the theory that PAA adsorption occurs in thick layers onto nylon followed by DMTMM-activated spreading and grafting of thinner PAA layers across the surface. The PDFOA reaction in McOH produced a highly fluorinated but thin exterior and an unreacted PAA interior. The PDFOA reaction in H 2O pH = 12 produced a completely fluorinated exterior and highly fluorinated interior. Thus surface modification levels

  6. Effect of Se flux on CuGaSe2 absorbers deposited on ITO-coated SLG substrates by using a three-stage co-evaporation process

    NASA Astrophysics Data System (ADS)

    Yoo, Jinsu; Eo, Young-Joo; Cho, Jun-Sik; Yun, Jae-Ho; Choi, Jang Hun; Kim, Kihwan; Park, Ju Hyung; Kong, Seong Ho

    2016-11-01

    As the key factor for top-cell application in a tandem structure, wide-bandgap chalcopyrite CuGaSe2 (CGS) absorbers were deposited at a thickness of 2 μm on soda-lime glass (SLG) which was coated with radio-frequency sputtered indium-tin-oxide (ITO) films. The semi-transparent CGS absorbers with a bandgap energy of 1.65 eV were grown by using a three-stage co-evaporation process with Cu, Ga, and Se elemental sources. During CGS absorber growth, the composition ratio [Cu]/[Ga] was fixed at about 0.85 and the Se-to-Ga flux ratio P [ Se]/[ Ga] was varied from 22 to 61 by increasing the temperature of the Se source. In this study, the compositional, structural, optical and electrical properties of top-cell CGS absorbers, which absorbed the short wavelength range of the solar spectrums for tandem solar cell application, were investigated as a function of the Se flux. On the basis of our experimental results, the highest CGS solar cell efficiency of 4.7 % in the cell structure described as Al/ZnO:Al/i-ZnO/CdS/CGS/ITO/SLG was demonstrated using a P [ Se]/[ Ga] value of 22.

  7. Surface Modification of Polymer Substrates by Oxygen Ion Irradiation

    SciTech Connect

    Takaoka, G. H.; Ryuto, H.; Araki, R.; Yakushiji, T.

    2008-11-03

    Oxygen cluster ions and/or monomer ions were used for the sputtering and the surface modification of polymers such as polycarbonate (PC) and polyethylene terephthalate (PET). For the case of oxygen cluster ion irradiation, the sputtered depth increased with increase of the acceleration voltage, and the sputtering yield was much larger than that by the monomer ion irradiation. The sputtered particles represented the polymer structure, which indicated that the bond scission by the cluster ion irradiation resulted in an ejection of monomer molecule through the intermolecular collision. On the other hand, for the oxygen monomer ion irradiation, the implanted depth increased with increase of the acceleration voltage, and the bond scission occurred at the deep region through the binary collision with the high energetic ions. Therefore, the sputtering yield for the polymer surfaces decreased, and the sputtering effect became very small. Furthermore, the simultaneous use of oxygen cluster and monomer ions was more effective for oxidation of the PET surfaces rather than the monomer ion irradiation or the cluster ion irradiation. As a result, the contact angle measurement showed that the wettability of the PET surfaces irradiated by the simultaneous use of oxygen cluster and monomer ions was much enhanced.

  8. Surface Modification of Polymer Substrates by Oxygen Ion Irradiation

    NASA Astrophysics Data System (ADS)

    Takaoka, G. H.; Ryuto, H.; Araki, R.; Yakushiji, T.

    2008-11-01

    Oxygen cluster ions and/or monomer ions were used for the sputtering and the surface modification of polymers such as polycarbonate (PC) and polyethylene terephthalate (PET). For the case of oxygen cluster ion irradiation, the sputtered depth increased with increase of the acceleration voltage, and the sputtering yield was much larger than that by the monomer ion irradiation. The sputtered particles represented the polymer structure, which indicated that the bond scission by the cluster ion irradiation resulted in an ejection of monomer molecule through the intermolecular collision. On the other hand, for the oxygen monomer ion irradiation, the implanted depth increased with increase of the acceleration voltage, and the bond scission occurred at the deep region through the binary collision with the high energetic ions. Therefore, the sputtering yield for the polymer surfaces decreased, and the sputtering effect became very small. Furthermore, the simultaneous use of oxygen cluster and monomer ions was more effective for oxidation of the PET surfaces rather than the monomer ion irradiation or the cluster ion irradiation. As a result, the contact angle measurement showed that the wettability of the PET surfaces irradiated by the simultaneous use of oxygen cluster and monomer ions was much enhanced.

  9. Surface modification of substrates for bacteria and cell culture.

    NASA Astrophysics Data System (ADS)

    Baede, Tom; Sladek, Raymond; Stoffels, Eva

    2006-10-01

    The plasma needle is a medical device that consists of a tungsten wire placed in a tube through which helium flows. A RF voltage frequency of 13.05 MHz is applied to the wire to produce the plasma. The device has a non-thermal effect and is therefore suited for both organic and inorganic surfaces. It was designed to manipulate tissues, but can also be used to modify the bacterial adhesion properties of material surfaces. The surface modification has a number of applications, most notably cell culture and the preventive treatment of caries. The research consists of two sets of experiments. In the first experiments the effect of the plasma treatment on the wettability was studied by means of contact angle measurements. The wettability quantifies the hydrophilic behavior of a surface. Plasma treatment with the plasma needle significantly increased the wettability of the studied materials. The persistence of the wettability change was also examined. For some materials the effect was only temporary. Bacteria are very particular about the surfaces they adhere to and the wettability of the surface plays an important role in their preference. The next set of experiments dealt with the effect of plasma treatment on bacterial adhesion. This effect was measured by comparing the growth rates of E. coli and S. mutans bacteria that were cultured on both plasma and non-treated surfaces. The effect appears to be species specific.

  10. The Evolution of Substrate Specificity by tRNA Modification Enzymes.

    PubMed

    McKenney, Katherine M; Rubio, Mary Anne T; Alfonzo, Juan D

    2017-01-01

    All types of nucleic acids in cells undergo naturally occurring chemical modifications, including DNA, rRNA, mRNA, snRNA, and most prominently tRNA. Over 100 different modifications have been described and every position in the purine and pyrimidine bases can be modified; often the sugar is also modified [1]. In tRNA, the function of modifications varies; some modulate global and/or local RNA structure, and others directly impact decoding and may be essential for viability. Whichever the case, the overall importance of modifications is highlighted by both their evolutionary conservation and the fact that organisms use a substantial portion of their genomes to encode modification enzymes, far exceeding what is needed for the de novo synthesis of the canonical nucleotides themselves [2]. Although some modifications occur at exactly the same nucleotide position in tRNAs from the three domains of life, many can be found at various positions in a particular tRNA and their location may vary between and within different tRNAs. With this wild array of chemical diversity and substrate specificities, one of the big challenges in the tRNA modification field has been to better understand at a molecular level the modes of substrate recognition by the different modification enzymes; in this realm RNA binding rests at the heart of the problem. This chapter will focus on several examples of modification enzymes where their mode of RNA binding is well understood; from these, we will try to draw general conclusions and highlight growing themes that may be applicable to the RNA modification field at large. © 2017 Elsevier Inc. All rights reserved.

  11. Patterning of ITO with picosecond lasers

    NASA Astrophysics Data System (ADS)

    Račiukaitis, Gediminas; Brikas, Marijus; Gedvilas, Mindaugas; Darčianovas, Gediminas

    2007-02-01

    Indium-tin oxide (ITO) is the main material for making transparent electrodes in electronic devices and flat panel displays. Laser-direct-write technology has been widely used for patterning ITO. The well defined edges and good electrical isolation at a short separation are required for the modern OLED and RFID devices of high packing density. High repetition rate lasers with a short, picosecond pulse width offer new possibilities for high efficiency structuring of transparent conductors on glass and other substrates. The results of patterning the ITO film on glass with picosecond lasers at various wavelengths are presented. Laser radiation initiated ablation of the material, forming trenches in ITO. Profile of the trenches was analyzed with a phase contrast optical microscope, a stylus type profiler, SEM and AFM. Clean removal of the ITO layer was achieved with the 266 nm radiation when laser fluence was above the threshold at 0.20 J/cm2, while for the 355 nm radiation the threshold was higher, above 0.46 J/cm2. The glass substrate was damaged in the area where the fluence was higher than 1.55 J/cm2. The 532 nm radiation allowed getting well defined trenches, but a lot of residues in the form of dust were generated on the surface. UV radiation at the 266 nm provided the widest working window for ITO ablation without damage of the substrate. Use of UV laser radiation with fluences close to the ablation threshold made it possible to minimize surface contamination and the recast ridge formation during the process.

  12. Substrate and head group modifications for enhanced stability in molecular electronic devices

    NASA Astrophysics Data System (ADS)

    Ferrato, Michael-Anthony

    Poor Self-Assembled Monolayer (SAM) stability is a barrier which impedes the incorporation of molecular layers as functional components in electronic device architectures. Here we investigate the molecular electronic characteristics of two well established approaches to enhancing SAM stability. In Chapter 2 we investigate the electrochemical modification of Au substrates by the underpotential deposition of silver monolayers (AgUPD). In Chapter 3 we study chelating dithiophosphinic acid (DTPA) head groups to anchor SAM molecules to substrates. Based on molecular electronic characterization using EGaIn Tip testbeds, we observed that AgUPD substrates maintained the inherent electronic character of n-alkanethiolate SAMs, but reduced charge transport by almost 1 order of magnitude as compared with the same SAMs on bulk Au substrates. Similar molecular electronic characterization of (diphenyl)dithiophosphinic acid SAMs on Au substrates revealed that the DTPA head group induced a ~3 order of magnitude drop in charge transport as compared with analogous thiophenol SAMs.

  13. Modulus of Elasticity and Thermal Expansion Coefficient of ITO Film

    SciTech Connect

    Carter, Austin D.; Elhadj, S.

    2016-06-24

    The purpose of this experiment was to determine the modulus of elasticity (E) and thermal expansion coefficient (α) of RF sputtered Indium Tin Oxide (ITO) as a function of temperature (T), and to collect ITO film stress data. In order to accomplish that goal, the Toho FLX-2320-S thin film stress measurement machine was used to collect both single stress and stress-temperature data for ITO coated fused silica and sapphire substrates. The stress measurement function of the FLX-2320-S cannot be used to calculate the elastic modulus of the film because the Stoney formula incorporates the elastic modulus of the substrate, rather than of the film itself.

  14. Protein adsorption to graphene surfaces controlled by chemical modification of the substrate surfaces.

    PubMed

    Kamiya, Yasutaka; Yamazaki, Kenji; Ogino, Toshio

    2014-10-01

    We have investigated effects of the support substrate surfaces on properties of the attached graphene flakes by observing protein adsorption to the graphene surfaces on SiO2/Si substrates that are modified with self-assembled monolayers to control their hydrophilicity. Using atomic force microscopy operated in aqueous environment, we found that high-density clusters of agglomerated avidin molecules form on the graphene flakes in the areas supported by a hydrophobic substrate surface, whereas very low density of large avidin clusters form at the edge of graphene flakes in the area supported by a hydrophilic surface. These results demonstrate that hydrophilicity of the support surface affects hydrophilicity of the graphene surface also in aqueous environment and that surface modification of the support substrate is a useful technique to control protein adsorption phenomena on graphene surfaces for realization of high sensitive graphene biosensors.

  15. SERS-based ultrasensitive detection of organophosphorus nerve agents via substrate's surface modification.

    PubMed

    Zhao, Qian; Liu, Guangqiang; Zhang, Hongwen; Zhou, Fei; Li, Yue; Cai, Weiping

    2017-02-15

    Highly efficient detection of the organicphosphor nerve agents such as sarin and soman, based on surface enhanced Raman scattering (SERS) effect, has been in challenge due to their weak adsorption property on coin metals. In this paper, a new strategy is presented to achieve the SERS-based ultrasensitive detection of sarin-simulated agent methanephosphonic acid (MPA) via the surface modification of SERS-substrates. The Au-coated Si nanocone array is surface-modified with 2-aminoethanethiol and used as SERS-substrate for detection of MPA. It has been shown that the modified substrate could preferentially capture MPA molecules in the solution with coupling agent and induce amidation reaction. The reaction products are still bound or anchor on the substrate's surface. The MPA molecules can thus be detected by Raman spectral measurement of the solution-soaked SERS-substrate. The minimum detection level is down to ∼1ppb. The Raman peak intensity versus the MPA concentration is subject to a linear double logarithmic relation from ∼1ppb to ∼1000ppm, which is attributed to Freundlich adsorption of MPA on the surface-modified SERS substrate. This study provides a new way for the highly efficient SERS-based detection of the organophosphorus nerve agents and some other target molecules weakly interacted with metal substrates.

  16. The Effect of Substrate Temperature on Surface Modification of Polystyrene by using Nitrogen Plasma

    NASA Astrophysics Data System (ADS)

    Novi, A. F.; Santjojo, D. J. D. H.; Masruroh

    2017-05-01

    Studies on the effect of substrate temperature on the modification process of a thin layer of polystyrene samples deposited on glass by using spin coating technique have been conducted. The polystyrene thin film surface was modified by using nitrogen plasma generated in a vacuum reactor by a capacitive plasma generator with a frequency of 40 kHz. The substrate temperature was set by variation of 60, 70 and 80 °C during the modification process to determine the effect of substrate temperature on the level of roughness and hydrophobicity of the film. Observations were conducted by using optical microscopy, optical micro-profiler, and measuring the contact angle of liquid. The results showed a decrease in roughness due to modification at a temperature of 60 °C and 70 °C. On the other hand, the treatment at a temperature of 80 °C resulted in an increase of roughness. By measuring the contact angle, it was proven that hydrophobicity is not only influenced by the surface roughness of thin layers.

  17. Effects of different substrate surface modifications on the epitaxial ZnO/Si

    NASA Astrophysics Data System (ADS)

    Wang, Peng; Jin, Changlian; Zhan, Huahan; Chen, Xiaohang; Xu, Fuchun; Zhou, Yinghui; Wang, Huiqiong; Kang, Junyong

    2013-09-01

    To produce high quality ZnO/Si for the applications in short wavelength optoelectronic devices, the effects of different silicon surface modifications on the overgrown ZnO thin film were investigated. Samples were grown by a plasma assistant molecular beam epitaxy at room temperature, avoiding the oxidation of the Si surface and the thermal stress caused by difference of the thermal expansion coefficients between ZnO and silicon. Different modifications on the Si(100) substrate surface including nitridation, oxidation, and depositions of Mg and Zn, were employed. The effects on the overgrown ZnO layers and the interlayer SiOx were investigated by atomic force microscopy, photoluminescence, X-ray diffraction and auger depth electron spectroscopy. All the modifications were effective in different degrees at reducing the SiOx amorphous layer. However, different mechanisms resulted in distinct performance in crystal structure and optical property.

  18. Electrochemical characterization of organosilane-functionalized nanostructured ITO surfaces

    NASA Astrophysics Data System (ADS)

    Pruna, R.; Palacio, F.; López, M.; Pérez, J.; Mir, M.; Blázquez, O.; Hernández, S.; Garrido, B.

    2016-08-01

    The electroactivity of nanostructured indium tin oxide (ITO) has been investigated for its further use in applications such as sensing biological compounds by the analysis of redox active molecules. ITO films were fabricated by using electron beam evaporation at different substrate temperatures and subsequently annealed for promoting their crystallization. The morphology of the deposited material was monitored by scanning electron microscopy, confirming the deposition of either thin films or nanowires, depending on the substrate temperature. Electrochemical surface characterization revealed a 45 % increase in the electroactive surface area of nanostructured ITO with respect to thin films, one third lower than the geometrical surface area variation determined by atomic force microscopy. ITO surfaces were functionalized with a model organic molecule known as 6-(ferrocenyl)hexanethiol. The chemical attachment was done by means of a glycidoxy compound containing a reactive epoxy group, the so-called 3-glycidoxypropyltrimethoxy-silane. ITO functionalization was useful for determining the benefits of nanostructuration on the surface coverage of active molecules. Compared to ITO thin films, an increase in the total peak height of 140 % was observed for as-deposited nanostructured electrodes, whereas the same measurement for annealed electrodes resulted in an increase of more than 400 %. These preliminary results demonstrate the ability of nanostructured ITO to increase the surface-to-volume ratio, conductivity and surface area functionalization, features that highly benefit the performance of biosensors.

  19. Electrochemical characterization of organosilane-functionalized nanostructured ITO surfaces

    SciTech Connect

    Pruna, R. Palacio, F.; López, M.; Mir, M.; Blázquez, O.; Hernández, S.; Garrido, B.

    2016-08-08

    The electroactivity of nanostructured indium tin oxide (ITO) has been investigated for its further use in applications such as sensing biological compounds by the analysis of redox active molecules. ITO films were fabricated by using electron beam evaporation at different substrate temperatures and subsequently annealed for promoting their crystallization. The morphology of the deposited material was monitored by scanning electron microscopy, confirming the deposition of either thin films or nanowires, depending on the substrate temperature. Electrochemical surface characterization revealed a 45 % increase in the electroactive surface area of nanostructured ITO with respect to thin films, one third lower than the geometrical surface area variation determined by atomic force microscopy. ITO surfaces were functionalized with a model organic molecule known as 6-(ferrocenyl)hexanethiol. The chemical attachment was done by means of a glycidoxy compound containing a reactive epoxy group, the so-called 3-glycidoxypropyltrimethoxy-silane. ITO functionalization was useful for determining the benefits of nanostructuration on the surface coverage of active molecules. Compared to ITO thin films, an increase in the total peak height of 140 % was observed for as-deposited nanostructured electrodes, whereas the same measurement for annealed electrodes resulted in an increase of more than 400 %. These preliminary results demonstrate the ability of nanostructured ITO to increase the surface-to-volume ratio, conductivity and surface area functionalization, features that highly benefit the performance of biosensors.

  20. Thickness dependent optical properties of PEMA and (PEMA){sub 0.85}/(ZnO){sub 0.15} nanocomposite films deposited by spray pyrolysis technique on ITO substrate

    SciTech Connect

    Thakur, Anjna Thakur, Priya; Yadav, Kamlesh

    2016-05-06

    In this paper, poly (ethyl methacrylate) (PEMA) and (PEMA){sub 0.85}/(ZnO){sub 0.15} nanocomposite films for 2, 3, 4 and 5 minutes have been deposited by spray pyrolysis technique on indium tin oxide (ITO) coated substrate. The effect of thickness of the film on the morphological and optical properties of PEMA and (PEMA){sub 0.85}/(ZnO){sub 0.15} nanocomposite films are studied. The morphological and optical properties of pure PEMA and (PEMA){sub 0.85}/(ZnO){sub 0.15} nanocomposite films are compared. The field emission scanning electron microscopy (FESEM) shows that as the thickness of film increases, uniformity of films increases. It is found from UV-Visible spectra that the energy band gap decreases with increasing the deposition time and refractive index increases with increasing the thickness of the film. The band gap of the nanocomposites is found less than the pure polymer film and opposite trend is observed for refractive index. The optical absorption of PEMA/ZnO nanocomposite films is higher than pure PEMA film. The thickness of the nanocomposite film plays a significant role in the tunability of the optical properties.

  1. MOCVD growth of GaN on Si through novel substrate modification techniques

    NASA Astrophysics Data System (ADS)

    Gagnon, Jarod C.

    GaN is a semiconductor material with great potential for use in high power electronics and optoelectronics due to the high electron mobility, high breakdown voltage, high thermal stability, and large direct bandgap of GaN. Si is a desirable substrate material for GaN heteroepitaxy due to the low cost of production, large wafer sizes available, and current widespread use in the electronics industry. The growth of GaN/Si devices suffers from the lattice and CTE mismatches between GaN and Si and therefore multiple methods of strain reduction have been employed to counter these effects. In this work we presented two novel methods of substrate modification to promote the growth of device quality GaN on Si. Initial work focused on the implantation of AlN/Si(111) substrates with N+ ions below the AlN/Si(111) interface. A reduction in the initial compressive stress in GaN films as well as the degree of tensile stress generation during growth was observed on implanted samples. Optical microscopy of the GaN surfaces showed reduced channeling crack density on implanted substrates. Transmission electron microscopy (TEM) studies showed a disordered layer in the Si substrate at the implantation depth which consisted of a mixture of polycrystalline and amorphous Si. Evidence was provided to suggest that the disordered layer at the implantation depth was acting as a compliant layer which decoupled the GaN film from the bulk Si substrate and partially accommodated the tensile stress formed during growth and cooling. A reduction in threading dislocation (TD) density on ion implanted substrates was also observed. Additional studies showed that by increasing the lateral size of AlN islands, the tensile growth stress and TD density in GaN films on ion implanted substrates could be further reduced. XRD studies showed an expansion of the AlN lattice on implanted substrates with larger lateral island sizes. The final tensile growth stress of films on implanted substrates was further

  2. Highly transparent conductive ITO/Ag/ITO trilayer films deposited by RF sputtering at room temperature

    NASA Astrophysics Data System (ADS)

    Ren, Ningyu; Zhu, Jun; Ban, Shiliang

    2017-05-01

    ITO/Ag/ITO (IAI) trilayer films were deposited on glass substrate by radio frequency magnetron sputtering at room temperature. A high optical transmittance over 94.25% at the wavelength of 550 nm and an average transmittance over the visual region of 88.04% were achieved. The calculated value of figure of merit (FOM) reaches 80.9 10-3 Ω-1 for IAI films with 15-nm-thick Ag interlayer. From the morphology and structural characterization, IAI films could show an excellent correlated electric and optical performance if Ag grains interconnect with each other on the bottom ITO layer. These results indicate that IAI trilayer films, which also exhibit low surface roughness, will be well used in optoelectronic devices.

  3. Surface modification of several dental substrates by non-thermal, atmospheric plasma brush

    PubMed Central

    Chen, Mingsheng; Zhang, Ying; Driver, M. Sky; Caruso, Anthony N.; Yu, Qingsong; Wang, Yong

    2013-01-01

    Objective The purpose of this study was to reveal the effectiveness of non-thermal atmospheric plasma brush in surface wettability and modification of four dental substrates. Methods Specimens of dental substrates including dentin, enamel, and two composites Filtek Z250, Filtek LS Silorane were prepared (~2 mm thick, ~10 mm diameter). The prepared surfaces were treated for 5–45 s with a non-thermal atmospheric plasma brush working at temperatures from 36 to 38 °C. The plasma-treatment effects on these surfaces were studied with contact-angle measurement, X-ray photoemission spectroscopy (XPS) and scanning electron microscopy (SEM). Results The non-thermal atmospheric argon plasma brush was very efficient in improving the surface hydrophilicity of four substrates studied. The results indicated that water contact angle values decreased considerably after only 5 s plasma treatment of all these substrates. After 30 s treatment, the values were further reduced to <5°, which was close to a value for super hydrophilic surfaces. XPS analysis indicated that the percent of elements associated with mineral in dentin/enamel or fillers in the composites increased. In addition, the percent of carbon (%C) decreased while %O increased for all four substrates. As a result, the O/C ratio increased dramatically, suggesting that new oxygen-containing polar moieties were formed on the surfaces after plasma treatment. SEM surface images indicated that no significant morphology change was induced on these dental substrates after exposure to plasmas. Significance Without affecting the bulk properties, a super-hydrophilic surface could be easily achieved by the plasma brush treatment regardless of original hydrophilicity/hydrophobicity of dental substrates tested. PMID:23755823

  4. Surface modification of cellulosic substrates via atmospheric pressure plasma polymerization of acrylic acid: Structure and properties

    NASA Astrophysics Data System (ADS)

    Garcia-Torres, Jose; Sylla, Dioulde; Molina, Laura; Crespo, Eulalia; Mota, Jordi; Bautista, Llorenç

    2014-06-01

    Surface chemical modification of cellulose-based substrates has been carried out by atmospheric pressure plasma enhanced chemical vapor deposition (AP-PECVD) of acrylic acid. The structure/properties relationship of the samples was studied as a function of the plasma experimental conditions. Acrylic acid monomer/helium ratio and treatment speed clearly influences the wettability properties of the paper substrate: advancing contact angle values were reduced to the half if compare to non-treated paper. Surface morphology of the films did not greatly vary at short polymerization times but fibers were covered by a poly(acrylic acid) film at longer times. FTIR and XPS techniques allowed detecting the retention of carboxylic acid groups/moieties. The possibility to quickly design architectures with tunable carboxylic functions by modifying the plasma processing parameters is shown.

  5. Highly ordered, accessible and nanocrystalline mesoporous TiO₂ thin films on transparent conductive substrates.

    PubMed

    Violi, Ianina L; Perez, M Dolores; Fuertes, M Cecilia; Soler-Illia, Galo J A A

    2012-08-01

    Highly porous (V(mesopore) = 25-50%) and ordered mesoporous titania thin films (MTTF) were prepared on ITO (indium tin oxide)-covered glass by a fast two-step method. The effects of substrate surface modification and thermal treatment on pore order, accessibility and crystallinity of the MTTF were systematically studied for MTTF deposited onto bare and titania-modified ITO. MTTF exposed briefly to 550 °C resulted in highly ordered films with grid-like structures, enlarged pore size, and increased accessible pore volume when prepared onto the modified ITO substrate. Mesostructure collapse and no significant change in pore volume were observed for MTTF deposited on bare ITO substrates. Highly crystalline anatase was obtained for MTTF prepared on the modified-ITO treated at high temperatures, establishing the relationship between grid-like structures and titania crystallization. Photocatalytic activity was maximized for samples with increased crystallization and high accessible pore volume. In this manner, a simple way of designing materials with optimized characteristics for optoelectronic applications was achieved through the modification of the ITO surface and a controlled thermal treatment.

  6. ZnO nanostructures directly grown on paper and bacterial cellulose substrates without any surface modification layer.

    PubMed

    Costa, Saionara V; Gonçalves, Agnaldo S; Zaguete, Maria A; Mazon, Talita; Nogueira, Ana F

    2013-09-21

    In this report, hierarchical ZnO nano- and microstructures were directly grown for the first time on a bacterial cellulose substrate and on two additional different papers by hydrothermal synthesis without any surface modification layer. Compactness and smoothness of the substrates are two important parameters that allow the growth of oriented structures.

  7. Enhancing the Properties of Carbon and Gold Substrates by Surface Modification

    SciTech Connect

    Harnisch, Jennifer Anne

    2001-01-01

    The properties of both carbon and gold substrates are easily affected by the judicious choice of a surface modification protocol. Several such processes for altering surface composition have been published in literature. The research presented in this thesis primarily focuses on the development of on-column methods to modify carbon stationary phases used in electrochemically modulated liquid chromatography (EMLC). To this end, both porous graphitic carbon (PGC) and glassy carbon (GC) particles have been modified on-column by the electroreduction of arenediazonium salts and the oxidation of arylacetate anions (the Kolbe reaction). Once modified, the carbon stationary phases show enhanced chromatographic performance both in conventional liquid chromatographic columns and EMLC columns. Additionally, one may also exploit the creation of aryl films to by electroreduction of arenediazonium salts in the creation of nanostructured materials. The formation of mercaptobenzene film on the surface of a GC electrode provides a linking platform for the chemisorption of gold nanoparticles. After deposition of nanoparticles, the surface chemistry of the gold can be further altered by self-assembled monolayer (SAM) formation via the chemisorption of a second thiol species. Finally, the properties of gold films can be altered such that they display carbon-like behavior through the formation of benzenehexathiol (BHT) SAMs. BHT chemisorbs to the gold surface in a previously unprecedented planar fashion. Carbon and gold substrates can be chemically altered by several methodologies resulting in new surface properties. The development of modification protocols and their application in the analytical arena is considered herein.

  8. Fabrication of robust hydrogel coatings on polydimethylsiloxane substrates using micropillar anchor structures with chemical surface modification.

    PubMed

    Zhang, Hongbin; Bian, Chao; Jackson, John K; Khademolhosseini, Farzad; Burt, Helen M; Chiao, Mu

    2014-06-25

    A durable hydrophilic and protein-resistant surface of polydimethylsiloxane (PDMS) based devices is desirable in many biomedical applications such as implantable and microfluidic devices. This paper describes a stable antifouling hydrogel coating on PDMS surfaces. The coating method combines chemical modification and surface microstructure fabrication of PDMS substrates. Three-(trimethoxysilyl)propyl methacrylates containing C═C groups were used to modify PDMS surfaces with micropillar array structures fabricated by a replica molding method. The micropillar structures increase the surface area of PDMS surfaces, which facilitates secure bonding with a hydrogel coating compared to flat PMDS surfaces. The adhesion properties of the hydrogel coating on PDMS substrates were characterized using bending, stretching and water immersion tests. Long-term hydrophilic stability (maintaining a contact angle of 55° for a month) and a low protein adsorption property (35 ng/cm(2) of adsorbed BSA-FITC) of the hydrogel coated PDMS were demonstrated. This coating method is suitable for PDMS modification with most crosslinkable polymers containing C═C groups, which can be useful for improving the anti-biofouling performance of PDMS-based biomedical microdevices.

  9. N-terminal modifications of cellular proteins: The enzymes involved, their substrate specificities and biological effects

    PubMed Central

    Varland, Sylvia; Osberg, Camilla; Arnesen, Thomas

    2015-01-01

    The vast majority of eukaryotic proteins are N-terminally modified by one or more processing enzymes. Enzymes acting on the very first amino acid of a polypeptide include different peptidases, transferases, and ligases. Methionine aminopeptidases excise the initiator methionine leaving the nascent polypeptide with a newly exposed amino acid that may be further modified. N-terminal acetyl-, methyl-, myristoyl-, and palmitoyltransferases may attach an acetyl, methyl, myristoyl, or palmitoyl group, respectively, to the α-amino group of the target protein N-terminus. With the action of ubiquitin ligases, one or several ubiquitin molecules are transferred, and hence, constitute the N-terminal modification. Modifications at protein N-termini represent an important contribution to proteomic diversity and complexity, and are essential for protein regulation and cellular signaling. Consequently, dysregulation of the N-terminal modifying enzymes is implicated in human diseases. We here review the different protein N-terminal modifications occurring co- or post-translationally with emphasis on the responsible enzymes and their substrate specificities. PMID:25914051

  10. Nanoscale patterning of a self-assembled monolayer by modification of the molecule–substrate bond

    PubMed Central

    Shen, Cai

    2014-01-01

    Summary The intercalation of Cu at the interface of a self-assembled monolayer (SAM) and a Au(111)/mica substrate by underpotential deposition (UPD) is studied as a means of high resolution patterning. A SAM of 2-(4'-methylbiphenyl-4-yl)ethanethiol (BP2) prepared in a structural phase that renders the Au substrate completely passive against Cu-UPD, is patterned by modification with the tip of a scanning tunneling microscope. The tip-induced defects act as nucleation sites for Cu-UPD. The lateral diffusion of the metal at the SAM–substrate interface and, thus, the pattern dimensions are controlled by the deposition time. Patterning down to the sub-20 nm range is demonstrated. The difference in strength between the S–Au and S–Cu bond is harnessed to develop the latent Cu-UPD image into a patterned binary SAM. Demonstrated by the exchange of BP2 by adamantanethiol (AdSH) this is accomplished by a sequence of reductive desorption of BP2 in Cu free areas followed by adsorption of AdSH. The appearance of Au adatom islands upon the thiol exchange suggests that the interfacial structures of BP2 and AdSH SAMs are different. PMID:24778947

  11. Nanoscale patterning of a self-assembled monolayer by modification of the molecule-substrate bond.

    PubMed

    Shen, Cai; Buck, Manfred

    2014-01-01

    The intercalation of Cu at the interface of a self-assembled monolayer (SAM) and a Au(111)/mica substrate by underpotential deposition (UPD) is studied as a means of high resolution patterning. A SAM of 2-(4'-methylbiphenyl-4-yl)ethanethiol (BP2) prepared in a structural phase that renders the Au substrate completely passive against Cu-UPD, is patterned by modification with the tip of a scanning tunneling microscope. The tip-induced defects act as nucleation sites for Cu-UPD. The lateral diffusion of the metal at the SAM-substrate interface and, thus, the pattern dimensions are controlled by the deposition time. Patterning down to the sub-20 nm range is demonstrated. The difference in strength between the S-Au and S-Cu bond is harnessed to develop the latent Cu-UPD image into a patterned binary SAM. Demonstrated by the exchange of BP2 by adamantanethiol (AdSH) this is accomplished by a sequence of reductive desorption of BP2 in Cu free areas followed by adsorption of AdSH. The appearance of Au adatom islands upon the thiol exchange suggests that the interfacial structures of BP2 and AdSH SAMs are different.

  12. Ultrathin and ultrasmooth Au films as transparent electrodes in ITO-free organic light-emitting devices.

    PubMed

    Bi, Yan-Gang; Feng, Jing; Ji, Jin-Hai; Chen, Yang; Liu, Yu-Shan; Li, Yun-Fei; Liu, Yue-Feng; Zhang, Xu-Lin; Sun, Hong-Bo

    2016-05-21

    An ultrathin, ultrasmooth and flexible Au film as an alternative of the indium-tin oxide (ITO) electrode in organic light-emitting devices (OLEDs) has been reported. The 7 nm Au film shows excellent surface morphology, optical and electronic characteristics including a root-mean-square roughness of 0.35 nm, a high transparency of 72% at 550 nm, and a sheet resistance of 23.75 Ω sq(-1). These features arise from the surface modification of the glass substrate by using a SU-8 film, which fixes metal atoms via chemical bond interactions between Au and SU-8 film to suppress the island growth mode. A 17% enhancement in current efficiency has been obtained from the OLEDs based on the ultrathin Au electrodes compared to that of the devices with the ITO electrodes. The OLEDs with the ultrathin Au/SU-8 anodes exhibit high flexibility and mechanical robustness.

  13. Modification of luciferase to be a substrate for plant aspartic proteinase.

    PubMed Central

    Amidon, W J; Pfeil, J E; Gal, S

    1999-01-01

    The possibility of using firefly luciferase as a substrate for an aspartic proteinase was explored. Several amino acid modifications to the C-terminus of the luciferase were created on the basis of the known substrate of the Arabidopsis thaliana aspartic proteinase, pro-(barley lectin). One luciferase with the sequence Arg-Asp-Gly-Val-Phe-Ala-Ala instead of the native Arg-Glu-Ile-Leu-Ile-Lys-Ala at position -15 to -9 relative to the C-terminus of native luciferase was found to possess 17% of the original luciferase activity. When this modified luciferase was incubated with the aspartic proteinase, a specific loss in activity occurred that was not observed with the original luciferase. However, both enzymes seemed very sensitive to the acidic conditions required for aspartic proteinase activity. The other versions of luciferase with different numbers of pro-(barley lectin) amino acids were not active luciferases. This provided information on the structural requirements of the C-terminal portion of the protein for luciferase activity. The luciferase proteins were also monitored during the digestion by using Western blots and some were shown to be substrates for the aspartic proteinase. Contrary to what had been expected, the modified luciferase that incorporated the pro-(barley lectin) sequences was not simply cleaved at the engineered site but at additional positions in the protein. The Arabidopsis aspartic proteinase cleaved two other standard protein substrates at many sites, suggesting that this proteinase could have a role in the degradation of proteins in addition to processing propeptides in plants. PMID:10510310

  14. Ultrathin and ultrasmooth Au films as transparent electrodes in ITO-free organic light-emitting devices

    NASA Astrophysics Data System (ADS)

    Bi, Yan-Gang; Feng, Jing; Ji, Jin-Hai; Chen, Yang; Liu, Yu-Shan; Li, Yun-Fei; Liu, Yue-Feng; Zhang, Xu-Lin; Sun, Hong-Bo

    2016-05-01

    An ultrathin, ultrasmooth and flexible Au film as an alternative of the indium-tin oxide (ITO) electrode in organic light-emitting devices (OLEDs) has been reported. The 7 nm Au film shows excellent surface morphology, optical and electronic characteristics including a root-mean-square roughness of 0.35 nm, a high transparency of 72% at 550 nm, and a sheet resistance of 23.75 Ω sq-1. These features arise from the surface modification of the glass substrate by using a SU-8 film, which fixes metal atoms via chemical bond interactions between Au and SU-8 film to suppress the island growth mode. A 17% enhancement in current efficiency has been obtained from the OLEDs based on the ultrathin Au electrodes compared to that of the devices with the ITO electrodes. The OLEDs with the ultrathin Au/SU-8 anodes exhibit high flexibility and mechanical robustness.An ultrathin, ultrasmooth and flexible Au film as an alternative of the indium-tin oxide (ITO) electrode in organic light-emitting devices (OLEDs) has been reported. The 7 nm Au film shows excellent surface morphology, optical and electronic characteristics including a root-mean-square roughness of 0.35 nm, a high transparency of 72% at 550 nm, and a sheet resistance of 23.75 Ω sq-1. These features arise from the surface modification of the glass substrate by using a SU-8 film, which fixes metal atoms via chemical bond interactions between Au and SU-8 film to suppress the island growth mode. A 17% enhancement in current efficiency has been obtained from the OLEDs based on the ultrathin Au electrodes compared to that of the devices with the ITO electrodes. The OLEDs with the ultrathin Au/SU-8 anodes exhibit high flexibility and mechanical robustness. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00599c

  15. Surface modification of a WTi thin film on Si substrate by nanosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Petrović, S.; Gaković, B.; Peruško, D.; Trtica, M.; Radak, B.; Panjan, P.; Miljanić, Š.

    2008-04-01

    Interaction of a nanosecond transversely excited atmospheric (TEA) CO 2 laser, operating at 10.6 μm, with tungsten-titanium thin film (190 nm) deposited on silicon of n-type (1 0 0) orientation, was studied. Multi-pulse irradiation was performed in air atmosphere with laser energy densities in the range 24-49 J/cm 2. The energy absorbed from the laser beam was mainly converted to thermal energy, which generated a series of effects. The following morphological changes were observed: (i) partial ablation/exfoliation of the WTi thin film, (ii) partial modification of the silicon substrate with formation of polygonal grains, (iii) appearance of hydrodynamic features including nano-globules. Torch-like plumes started appearing in front of the target after several laser pulses.

  16. Surface modification of polymeric substrates by plasma-based ion implantation

    NASA Astrophysics Data System (ADS)

    Okuji, S.; Sekiya, M.; Nakabayashi, M.; Endo, H.; Sakudo, N.; Nagai, K.

    2006-01-01

    Plasma-based ion implantation (PBII) as a tool for polymer modification is studied. Polymeric films have good performances for flexible use, such as food packaging or electronic devices. Compared with inorganic rigid materials, polymers generally have large permeability for gases and moisture, which causes packaged contents and devices to degrade. In order to add a barrier function, surface of polymeric films are modified by PBII. One of the advantageous features of this method over deposition is that the modified surface does not have peeling problem. Besides, micro-cracks due to mechanical stress in the modified layer can be decreased. From the standpoint of mass production, conventional ion implantation that needs low-pressure environment of less than 10-3 Pa is not suitable for continuous large-area processing, while PBII works at rather higher pressure of several Pa. In terms of issues mentioned above, PBII is one of the most expected techniques for modification on flexible substrates. However, the mechanism how the barrier function appears by ion implantation is not well explained so far. In this study, various kinds of polymeric films, including polyethyleneterephthalate (PET), are modified by PBII and their barrier characteristics that depend on the ion dose are evaluated. In order to investigate correlations of the barrier function with implanted ions, modified surface is analyzed with X-ray photoelectron spectroscopy (XPS). It is assumed that the diffusion and sorption coefficients are changed by ion implantation, resulting in higher barrier function.

  17. Structural modification of herboxidiene by substrate-flexible cytochrome P450 and glycosyltransferase.

    PubMed

    Jha, Amit Kumar; Dhakal, Dipesh; Van, Pham Thi Thuy; Pokhrel, Anaya Raj; Yamaguchi, Tokutaro; Jung, Hye Jin; Yoon, Yeo Joon; Sohng, Jae Kyung

    2015-04-01

    Herboxidiene is a natural product produced by Streptomyces chromofuscus exhibiting herbicidal activity as well as antitumor properties. Using different substrate-flexible cytochrome P450s and glycosyltransferase, different novel derivatives of herboxidiene were generated with structural modifications by hydroxylation or epoxidation or conjugation with a glucose moiety. Moreover, two isomers of herboxidiene containing extra tetrahydrofuran or tetrahydropyran moiety in addition to the existing tetrahydropyran moiety were characterized. The hydroxylated products for both of these compounds were also isolated and characterized from S. chromofuscus PikC harboring pikC from the pikromycin gene cluster of Streptomyces venezuelae and S. chromofuscus EryF harboring eryF from the erythromycin gene cluster of Saccharopolyspora erythraea. The compounds generated were characterized by high-resolution quadrupole-time-of-flight electrospray ionization mass spectrometry (HR-QTOF-ESI/MS) and (1)H- and (13)C-nuclear magnetic resonance (NMR) analyses. The evaluation of antibacterial activity against three Gram-positive bacteria, Micrococcus luteus, Bacillus subtilis, and Staphylococcus aureus, indicated that modification resulted in a transition from anticancer to antibacterial potency.

  18. ITOS/space shuttle study

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The results are reported of a study to explore the potential cost reductions in the operational ITOS weather satellite program as a consequence of shuttle/bug availability for satellite placement and retrieval, and satellite servicing and maintenance. The study program was divided into shuttle impact on equipment and testing costs, and shuttle impact on overall future ITOS operational program costs, and shuttle impact on configuration. It is concluded that savings in recurring spacecraft costs can be realized in the 1978 ITOS program, if a space shuttle is utilized.

  19. Better Organic Ternary Memory Performance through Self-Assembled Alkyltrichlorosilane Monolayers on Indium Tin Oxide (ITO) Surfaces.

    PubMed

    Hou, Xiang; Cheng, Xue-Feng; Zhou, Jin; He, Jing-Hui; Xu, Qing-Feng; Li, Hua; Li, Na-Jun; Chen, Dong-Yun; Lu, Jian-Mei

    2017-09-18

    Recently surface engineering of the indium-tin oxide (ITO) electrode of sandwich-like organic electric memory is found to effectively improve their memory performances. However, there are few methods to modify ITO substrates. In this paper, we have successfully prepared alkyltrichlorosicane self-assembled monolayers (SAMs) on ITO substrates, and resistive random access memory devices are fabricated on these surfaces. Compared to the unmodified ITO substrates, organic molecules SA-Bu grown on these SAM-modified ITO substrates have rougher surface morphologies but smaller mosaicity. The organic layer on SAM-modified ITO further aged to eliminate the crystalline phase diversity. In consequence, the ternary memory yield are effetively improved to 40~47%. Our results suggest that insertion of alkyltrichlorosicanes self-assembled monolayer could be an efficient method to improve the performance of organic memory. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Roll-to-Roll sputtered ITO/Cu/ITO multilayer electrode for flexible, transparent thin film heaters and electrochromic applications.

    PubMed

    Park, Sung-Hyun; Lee, Sang-Mok; Ko, Eun-Hye; Kim, Tae-Ho; Nah, Yoon-Chae; Lee, Sang-Jin; Lee, Jae Heung; Kim, Han-Ki

    2016-09-22

    We fabricate high-performance, flexible, transparent electrochromic (EC) films and thin film heaters (TFHs) on an ITO/Cu/ITO (ICI) multilayer electrode prepared by continuous roll-to-roll (RTR) sputtering of ITO and Cu targets. The RTR-sputtered ICI multilayer on a 700 mm wide PET substrate at room temperature exhibits a sheet resistance of 11.8 Ω/square and optical transmittance of 73.9%, which are acceptable for the fabrication of flexible and transparent EC films and TFHs. The effect of the Cu interlayer thickness on the electrical and optical properties of the ICI multilayer was investigated in detail. The bending and cycling fatigue tests demonstrate that the RTR-sputtered ICI multilayer was more flexible than a single ITO film because of high strain failure of the Cu interlayer. The flexible and transparent EC films and TFHs fabricated on the ICI electrode show better performances than reference EC films and TFHs with a single ITO electrode. Therefore, the RTR-sputtered ICI multilayer is the best substitute for the conventional ITO film electrode in order to realize flexible, transparent, cost-effective and large-area EC devices and TFHs that can be used as flexible and smart windows.

  1. Roll-to-Roll sputtered ITO/Cu/ITO multilayer electrode for flexible, transparent thin film heaters and electrochromic applications

    PubMed Central

    Park, Sung-Hyun; Lee, Sang-Mok; Ko, Eun-Hye; Kim, Tae-Ho; Nah, Yoon-Chae; Lee, Sang-Jin; Lee, Jae Heung; Kim, Han-Ki

    2016-01-01

    We fabricate high-performance, flexible, transparent electrochromic (EC) films and thin film heaters (TFHs) on an ITO/Cu/ITO (ICI) multilayer electrode prepared by continuous roll-to-roll (RTR) sputtering of ITO and Cu targets. The RTR-sputtered ICI multilayer on a 700 mm wide PET substrate at room temperature exhibits a sheet resistance of 11.8 Ω/square and optical transmittance of 73.9%, which are acceptable for the fabrication of flexible and transparent EC films and TFHs. The effect of the Cu interlayer thickness on the electrical and optical properties of the ICI multilayer was investigated in detail. The bending and cycling fatigue tests demonstrate that the RTR-sputtered ICI multilayer was more flexible than a single ITO film because of high strain failure of the Cu interlayer. The flexible and transparent EC films and TFHs fabricated on the ICI electrode show better performances than reference EC films and TFHs with a single ITO electrode. Therefore, the RTR-sputtered ICI multilayer is the best substitute for the conventional ITO film electrode in order to realize flexible, transparent, cost-effective and large-area EC devices and TFHs that can be used as flexible and smart windows. PMID:27653830

  2. Roll-to-Roll sputtered ITO/Cu/ITO multilayer electrode for flexible, transparent thin film heaters and electrochromic applications

    NASA Astrophysics Data System (ADS)

    Park, Sung-Hyun; Lee, Sang-Mok; Ko, Eun-Hye; Kim, Tae-Ho; Nah, Yoon-Chae; Lee, Sang-Jin; Lee, Jae Heung; Kim, Han-Ki

    2016-09-01

    We fabricate high-performance, flexible, transparent electrochromic (EC) films and thin film heaters (TFHs) on an ITO/Cu/ITO (ICI) multilayer electrode prepared by continuous roll-to-roll (RTR) sputtering of ITO and Cu targets. The RTR-sputtered ICI multilayer on a 700 mm wide PET substrate at room temperature exhibits a sheet resistance of 11.8 Ω/square and optical transmittance of 73.9%, which are acceptable for the fabrication of flexible and transparent EC films and TFHs. The effect of the Cu interlayer thickness on the electrical and optical properties of the ICI multilayer was investigated in detail. The bending and cycling fatigue tests demonstrate that the RTR-sputtered ICI multilayer was more flexible than a single ITO film because of high strain failure of the Cu interlayer. The flexible and transparent EC films and TFHs fabricated on the ICI electrode show better performances than reference EC films and TFHs with a single ITO electrode. Therefore, the RTR-sputtered ICI multilayer is the best substitute for the conventional ITO film electrode in order to realize flexible, transparent, cost-effective and large-area EC devices and TFHs that can be used as flexible and smart windows.

  3. Hypomelanosis of Ito with hemimegalencephaly.

    PubMed

    Sharma, Suvasini; Sankhyan, Naveen; Kabra, Madhulika; Kumar, Atin

    2009-11-15

    Hypomelanosis of Ito is a neurocutaneous syndrome characterized by hypopigmented lesions occurring in streaks and whorls located on the trunk, head or extremities. The associated neurological manifestations include mental retardation, seizures, language disabilities and motor system dysfunction. Hemihypertrophy has also been described in this syndrome. We present a 3-month-old male infant with Hypomelanosis of Ito, hemi-hypertrophy and hemi-megalencephaly.

  4. ITO/InP solar cells: A comparison of devices fabricated by ion beam and RF sputtering of the ITO

    NASA Technical Reports Server (NTRS)

    Coutts, T. J.

    1987-01-01

    This work was performed with the view of elucidating the behavior of indium tin oxide/indium phosphide (ITO/InP) solar cells prepared by RF and ion beam sputtering. It was found that using RF sputter deposition of the ITO always leads to more efficient devices than ion beam sputter deposition. An important aspect of the former technique is the exposure of the single crystal p-InP substrates to a very low plasma power prior to deposition. Substrates treated in this manner have also been used for ion beam deposition of ITO. In this case the cells behave very similarly to the RF deposited cells, thus suggesting that the lower power plasma exposure (LPPE) is the crucial process step.

  5. Research on the optical and electrical properties of ITO thin film using magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Cai, Changlong; Zhai, Yujia; Huang, Jing; Yang, Xu; Liu, Weiguo; Gao, Aihua

    2009-12-01

    Due to excellent photoelectrical properties, ITO thin films become the indispensable flat transparent electrode for their practical applications in the flat-panel displays, touch screens, solar cells and electrochromic devices. Therefore, it's very necessary to study photoelectrical properties of ITO films. In this paper, ITO thin films were prepared on the glass substrates by DC magnetron sputtering technology, and measured the transmittance of ITO thin films in the visible region using the spectrophotometer; the resistivities were measured with the four-probe instrument. The effects of sputtering pressure, oxygen-argon flow ratio and sputtering power was researched on photoelectrical performance of ITO thin films. The results show that, the optimum parameters of ITO films prepared are: sputtering pressure 0.6Pa, oxygen-argon flow ratio 1:40, sputtering power 108W. The average transmittance in the visible area is 81.18%, resistivity is 8.9197 × 10-3Ω.cm.

  6. Research on the optical and electrical properties of ITO thin film using magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Cai, Changlong; Zhai, Yujia; Huang, Jing; Yang, Xu; Liu, Weiguo; Gao, Aihua

    2010-03-01

    Due to excellent photoelectrical properties, ITO thin films become the indispensable flat transparent electrode for their practical applications in the flat-panel displays, touch screens, solar cells and electrochromic devices. Therefore, it's very necessary to study photoelectrical properties of ITO films. In this paper, ITO thin films were prepared on the glass substrates by DC magnetron sputtering technology, and measured the transmittance of ITO thin films in the visible region using the spectrophotometer; the resistivities were measured with the four-probe instrument. The effects of sputtering pressure, oxygen-argon flow ratio and sputtering power was researched on photoelectrical performance of ITO thin films. The results show that, the optimum parameters of ITO films prepared are: sputtering pressure 0.6Pa, oxygen-argon flow ratio 1:40, sputtering power 108W. The average transmittance in the visible area is 81.18%, resistivity is 8.9197 × 10-3Ω.cm.

  7. Surface modification of ceramic and metallic alloy substrates by laser raster-scanning

    NASA Astrophysics Data System (ADS)

    Ramos Grez, Jorge Andres

    This work describes the feasibility of continuous wave laser-raster scan-processing under controlled atmospheric conditions as employed in three distinct surface modification processes: (a) surface roughness reduction of indirect-Selective Laser Sintered 420 martensitic stainless steel-40 wt. % bronze infiltrated surfaces; (b) Si-Cr-Hf-C coating consolidation over 3D carbon-carbon composites cylinders; (c) dendritic solidification structures of Mar-M 247 confined powder precursor grown from polycrystalline Alloy 718 substrates. A heat transfer model was developed to illustrate that the aspect ratio of the laser scanned pattern and the density of scanning lines play a significant role in determining peak surface temperature, heating and cooling rates and melt resident times. Comprehensive characterization of the surface of the processed specimens was performed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), optical metallography, X-ray diffraction (XRD), and, in certain cases, tactile profilometry. In Process (a), it was observed that a 24% to 37% roughness Ra reduction could be accomplished from the as-received value of 2.50+/-0.10 microns for laser energy densities ranging from 350 to 500 J/cm2. In Process (b), complete reactive wetting of carbon-carbon composite cylinders surface was achieved by laser melting a Si-Cr-Hf-C slurry. Coatings showed good thermal stability at 1000°C in argon, and, when tested in air, a percent weight reduction rate of -6.5 wt.%/hr was achieved. A soda-glass overcoat applied over the coated specimens by conventional means revealed a percent weight reduction rate between -1.4 to -2.2 wt.%/hr. Finally, in Process (c), microstructure of the Mar-M 247 single layer deposits, 1 mm in height, grown on Alloy 718 polycrystalline sheets, resulted in a sound metallurgical bond, low porosity, and uniform thickness. Polycrystalline dendrites grew preferentially along the [001] direction from the substrate up to 400

  8. Investigation of restriction-modification enzymes from M. varians RFL19 with a new type of specificity toward modification of substrate.

    PubMed Central

    Butkus, V; Klimasauskas, S; Kersulyte, D; Vaitkevicius, D; Lebionka, A; Janulaitis, A

    1985-01-01

    The characterization of MvaI restriction-modification enzymes, isolated from Micrococcus varians RFL19, is reported. Both enzymes recognize the 5'CC decreases (A/T)GG nucleotide sequence. The endonuclease cleaves the sequence at the position indicated by the arrow, whereas the methylase modifies the internal cytosine, yielding N4-methylcytosine. This type of modification protects the substrate from R.MvaI cleavage. 5-Methylcytosine in the same position of the recognition sequence does not protect the substrate from R.MvaI cleavage. R.MvaI proved to be the first example of a restriction endonuclease differentiating the position of the methyl group in the heterocyclic ring of cytosine, located in the same site of the recognition sequence. M.MvaI modifies DNA dcm+ in vitro yielding N4,5-dimethylcytosine. N4-methylcytosine cannot be differentiated from cytosine using the Maxam-Gilbert DNA sequencing procedure. Images PMID:2994011

  9. Rapid fabrication of a silicon modification layer on silicon carbide substrate.

    PubMed

    Bai, Yang; Li, Longxiang; Xue, Donglin; Zhang, Xuejun

    2016-08-01

    We develop a kind of magnetorheological (MR) polishing fluid for the fabrication of a silicon modification layer on a silicon carbide substrate based on chemical theory and actual polishing requirements. The effect of abrasive concentration in MR polishing fluid on material removal rate and removal function shape is investigated. We conclude that material removal rate will increase and tends to peak value as the abrasive concentration increases to 0.3 vol. %, and the removal function profile will become steep, which is a disadvantage to surface frequency error removal at the same time. The removal function stability is also studied and the results show that the prepared MR polishing fluid can satisfy actual fabrication requirements. An aspheric reflective mirror of silicon carbide modified by silicon is well polished by combining magnetorheological finishing (MRF) using two types of MR polishing fluid and computer controlled optical surfacing (CCOS) processes. The surface accuracy root mean square (RMS) is improved from 0.087λ(λ=632.8  nm) initially to 0.020λ(λ=632.8  nm) in 5.5 h total and the tool marks resulting from MRF are negligible. The PSD analysis results also shows that the final surface is uniformly polished.

  10. The Influence of Laser Induced Consolidation on the Ablation Threshold of Nanoparticulate ITO-layers

    NASA Astrophysics Data System (ADS)

    Mikschl, Florian; Baum, Marcus; Heberle, Johannes; Alexeev, Ilya; Schmidt, Michael

    Indium tin oxide (ITO) is one of the few materials, which combines optical transparency in the wavelength range of visible light and electrical conductivity. It offers a wide range of applications in the field of optoelectronic devices such as solar cells or displays. To the present day, ITO is commonly deposited in a vacuum environment. Deposition under vacuum atmosphere is a cost-intensive process and not compatible with modern manufacturing techniques, like roll-to-roll processing. To overcome this limitation we propose the generation of ITO layers by deposition of ITO nanoparticles under atmospheric conditions.For the generation of functional devices structured layers are required. The exact damage threshold of nanoparticulate ITO layers is essential to minimize influence of the structuring process on the substrate.In our measurements we used three different substrates, spin coated layers, annealed layers and consolidated layers.

  11. Substrate-specific modifications on magnetic iron oxide nanoparticles as an artificial peroxidase for improving sensitivity in glucose detection.

    PubMed

    Liu, Yanping; Yu, Faquan

    2011-04-08

    Magnetic iron oxide nanoparticles (MION) were recently found to act as a peroxidase with intrinsic advantages over natural counterparts. Their limited affinity toward catalysis substrates, however, dramatically reduces their utility. In this paper, some effective groups were screened out and conjugated on MION as substrate-specific modifications for improving MION's affinity to substrates and hence utility. Nanoparticles of four different superficial structures were synthesized and characterized by TEM, size, zeta potential and SQUID, and assayed for peroxidase activity. Glucose detection was selected as an application model system to evaluate the bonus thereof. Catalysis was found to follow Michaelis-Menten kinetics. Sulfhydryl groups incorporated on MION (SH-MION) notably improve the affinity toward a substrate (hydrogen peroxide) and so do amino groups (NH₂-MION) toward another substrate, proved by variation in the determined kinetic parameters. A synergistically positive effect was observed and an apparently elevated detection sensitivity and a significantly lowered detection limit of glucose were achieved when integrated with both sulfhydryl and amino groups (SH-NH₂-MION). Our findings suggest that substrate-specific surface modifications are a straightforward and robust strategy to improve MION peroxidase-like activity. The high activity extends magnetic nanoparticles to wide applications other than glucose detection.

  12. Transparent Conductive ITO/Ag/ITO Electrode Deposited at Room Temperature for Organic Solar Cells

    NASA Astrophysics Data System (ADS)

    Kim, Jun Ho; Kang, Tae-Woon; Kwon, Sung-Nam; Na, Seok-In; Yoo, Young-Zo; Im, Hyeong-Seop; Seong, Tae-Yeon

    2017-01-01

    We investigated the optical and electrical properties of room-temperature-deposited indium-tin-oxide (ITO)/Ag (19 nm)/ITO multilayer films as a function of ITO layer thickness. The optical and electrical properties of the ITO/Ag/ITO films were compared with those of high-temperature-deposited ITO-only films for use as an anode in organic solar cells (OSCs). The ITO/Ag/ITO multilayer films had sheet resistances in the range 5.40-5.78 Ω/sq, while the ITO-only film showed 14.18 Ω/sq. The carrier concentration of the ITO/Ag/ITO films gradually decreased from 2.01 × 1022 to 7.20 × 1021 cm-3 as the ITO thickness increased from 17 nm to 83 nm. At 530 nm, the transmittance of the ITO/Ag/ITO (50 nm/19 nm/50 nm) films was 90%, while that of the ITO-only film gave 96.5%. The multilayer film had a smooth surface with a root mean square (RMS) roughness of 0.49 nm. Poly (3-hexylthiophene) (P3HT):[6,6]-phenyl-C61 butyric acid methylester (PCBM) bulk heterojunction (BHJ)-based OSCs fabricated with the ITO/Ag/ITO (50 nm/19 nm/50 nm) film showed a power conversion efficiency (PCE) (2.84%) comparable to that of OSCs with a conventional ITO-only anode (3.48%).

  13. Re-crystallization of ITO films after carbon irradiation

    NASA Astrophysics Data System (ADS)

    Usman, Muhammad; Khan, Shahid; Khan, Majid; Abbas, Turab Ali

    2017-01-01

    2.0 MeV carbon ion irradiation effects on Indium Tin Oxide (ITO) thin films on glass substrate are investigated. The films are irradiated with carbon ions in the fluence range of 1 × 1013 to 1 × 1015 ions/cm2. The irradiation induced effects in ITO are compared before and after ion bombardment by systematic study of structural, optical and electrical properties of the films. The XRD results show polycrystalline nature of un-irradiated ITO films which turns to amorphous state after 1 × 1013 ions/cm2 fluence of carbon ions. Further increase in ion fluence to 1 × 1014 ions/cm2 re-crystallizes the structure and retains for even higher fluences. A gradual decrease in the electrical conductivity and transmittance of irradiated samples is observed with increasing ion fluence. The band gap of the films is observed to be decreased after carbon irradiation.

  14. Optical properties of ITO nanocoatings for photovoltaic and energy building applications

    NASA Astrophysics Data System (ADS)

    Kaplani, E.; Kaplanis, S.; Panagiotaras, D.; Stathatos, E.

    2014-10-01

    Targeting energy savings in buildings, photovoltaics and other sectors, significant research activity is nowadays focused on the production of spectral selective nanocoatings. In the present study an ITO coating on glass substrate is prepared from ITO powder, characterized and analysed. The spectral transmittance and reflectance of the ITO coated glass and of two other commercially developed ITO coatings on glass substrate were measured and compared. Furthermore, a simulation algorithm was developed to determine the optical properties of the ITO coatings in the visible, solar and near infrared regions in order to assess the impact of the ITO coatings in the energy performance of buildings, and particularly the application in smart windows. In addition, the current density produced by a PV assuming each of the ITO coated glass served as a cover was computed, in order to assess their effect in PV performance. The preliminary ITO coating prepared and the two other coatings exhibit different optical properties and, thus, have different impact on energy performance. The analysis assists in a better understanding of the desired optical properties of nanocoatings for improved energy performance in PV and buildings.

  15. Enhanced superhydrophilicity and thermal stability of ITO surface with patterned ceria coatings

    NASA Astrophysics Data System (ADS)

    Xue, Mingshan; Peng, Na; Li, Changquan; Ou, Junfei; Wang, Fajun; Li, Wen

    2015-02-01

    Surface wettability of solid materials is significant for both fundamental research and engineering applications. Compared with most existing fabrication methods of superhydrophilic surfaces by UV exposure or chemical modification, in this work, a superhydrophilic ceria coating on ITO substrate is developed by a fast, simple one-step method. It is found that the superhydrophilicity of ceria coatings is strongly dependent on both the patterned microstructures benefiting the capillary effect and the peculiar chemical composition of ceria inducing numerous oxygen vacancies and large surface free energy. Owing to the inherent physical stability of ceria, such a superhydrophilic ceria coating exhibits an excellently thermal stability at both room temperature and higher temperature. These results open up new avenues for the underlying applications of superhydrophilic coatings, such as heat transfer/dissipation.

  16. Significant Enhancement of the Adhesion between Metal Films and Polymer Substrates by UV-Ozone Surface Modification in Nanoscale.

    PubMed

    Liu, Junshan; He, Licheng; Wang, Liang; Man, Yuncheng; Huang, Luyi; Xu, Zheng; Ge, Dan; Li, Jingmin; Liu, Chong; Wang, Liding

    2016-11-09

    Polymer metallization is extensively used in a variety of micro- and nanosystem technologies. However, the deposited metal film exhibits poor adhesion to polymer substrates, which may cause difficulties in many applications. In this work, ultraviolet (UV)-ozone surface modification is for the first time put forward to enhance the adhesion between metal films and polymer substrates. The adhesion of sputtered Cu films on UV-ozone modified poly(methyl methacrylate) (PMMA) substrates is enhanced by a factor of 6, and that of Au films is improved by a factor of 10. Moreover, metal films on the modified PMMA substrates can withstand a long-time liquid immersion. To understand the mechanism for the adhesion enhancement, the surface modification is studied with contact angle measurements, attenuated total reflection Fourier-transform infrared spectrometry (ATR-FTIR) and atomic force microscopy (AFM). Detailed characterization results indicate that the significant adhesion enhancement is attributed to the increases of both the surface wettability by generating some polar functional groups and the roughness of the surface in nanoscale. To demonstrate this novel polymer metallization method, a 6-in. PMMA chip with arrays of three-electrode electrochemical microsensors is designed and fabricated, and the microsensor exhibits excellent reproducibility, uniformity, and long-term stability.

  17. Towards promising modification of GeSi nanostructures via self-assembly on miscut Si(001) substrates

    NASA Astrophysics Data System (ADS)

    Zhou, Tong; Zhong, Zhenyang

    2016-03-01

    Self-assembled GeSi nanostructures on miscut Si(001) substrates are studied systematically with regard to the miscut angle and azimuth, the amount of Ge and the growth temperature. The comprehensive dependence of the spatial arrangement, which can exhibit one- and two-dimensional (1D and 2D) ordering, as well as the shape and density, of GeSi nanostructures on the miscut angle is observed. The orientation and side-walls of the 1D ordered in-plane GeSi nanowires on miscut Si(001) substrates are intimately associated with the miscut azimuth towards the <110> or <010> directions. Furthermore, the unique evolution of the GeSi nanostructures with the amount of Ge and the growth temperature on miscut Si (001) substrates towards the <010> direction is discovered. Such promising features of self-assembled GeSi nanostructures on miscut Si (001) substrates are explained in terms of the thermodynamics and growth kinetics, which are both affected significantly by the substrate vicinality. These results demonstrate that the miscut substrates offer a promising degree of freedom for the feasible modification of self-assembled nanostructures.

  18. Facile modification of silica substrates provides a platform for direct-writing surface click chemistry.

    PubMed

    Oberhansl, Sabine; Hirtz, Michael; Lagunas, Anna; Eritja, Ramon; Martinez, Elena; Fuchs, Harald; Samitier, Josep

    2012-02-20

    Please click here: a facile two-step functionalization strategy for silicon oxide-based substrates generates a stable platform for surface click chemistry via direct writing. The suitability of the obtained substrates is proven by patterning with two different direct-writing techniques and three different molecules.

  19. ITO/ATO bilayer transparent electrodes with enhanced light scattering, thermal stability and electrical conductance

    NASA Astrophysics Data System (ADS)

    Guillén, C.; Montero, J.; Herrero, J.

    2016-10-01

    Transparent electrodes based on In2O3:Sn (ITO) and SnO2:Sb (ATO) thin films have been deposited by sputtering at room temperature on soda lime glass (SLG) substrates. The preparation conditions were adjusted to obtain 250 nm-thick ITO layers with high conductivity and textured ATO coatings with various thicknesses from 80 to 200 nm. These ITO and ATO films have been combined to enhance the optical scattering and the electrical conductivity of the bilayer electrodes. Besides, a suitable ATO coating can prevent the oxidation of the ITO underlayer, thus increasing the stability of the overall electrical performance. With this purpose the structure, morphology, optical and electrical properties have been analysed comparatively for SLG/ITO, SLG/ATO and SLG/ITO/ATO samples after heating in air at 500 °C, studying the influence of the ATO layer thickness on the light scattering and thermal stability of the electrodes. In this way, a minimum sheet resistance of 8 Ω/sq has been achieved with a 120 nm-thick ATO film deposited on the 250 nm-thick ITO layer; such stacked electrode has visible transmittance near 80% and average haze HT = 10%, showing superior stability, light scattering and electrical performance than the isolated ITO and ATO films.

  20. Photocatalytic degradation of methyl orange over ITO/Cds/ZnO interface composite films.

    PubMed

    Wei, Shouqiang; Shao, Zhongcai; Lu, Xudong; Liu, Ying; Cao, Linlin; He, Yan

    2009-01-01

    ITO/CdS/ZnO interface composite films were successfully prepared by subsequent electrodeposition of CdS and ZnO onto indium tin oxide (ITO) glass substrates. The obtained ITO/CdS/ZnO composite films were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis spectroscopy. The photocatalytic activity of ITO/CdS/ZnO composite films were investigated using methyl orange (MO) as a model organic compound under UV light irradiation. The influence of operating parameters on MO degradation including initial concentration of MO, pH value of solution, and inorganic anion species over the composite films were examined. A blue shift of absorption threshold was observed for the ITO/CdS/ZnO film in comparison with ITO/ZnO film. ITO/CdS/ZnO composite films prepared under specific conditions showed a higher photocatalytic activity than that of ITO/ZnO films. It was also found that the photocatalytic degradation of MO on the composite films followed pseudo-first order kinetics.

  1. Modification of the surface state of rough substrates by two different varnishes and influence on the reflected light

    NASA Astrophysics Data System (ADS)

    Elias, Mady; René de la Rie, E.; Delaney, John K.; Charron, Eric; Morales, Kathryn M.

    2006-10-01

    Modification of the visual appearance when a rough surface is covered by a varnish is mostly attributed to the levelling of the substrate surface, which depends on the molecular weight of the varnish. The topography of varnished surfaces, however, has never been measured directly. Surfaces of varnishes applied over glass substrates of varying roughness were studied, therefore, using mechanical profilometry. Two different varnishes made with a low and a high molecular weight resin were studied. Both varnishes lower the r.m.s. roughness of the substrates and filter the high spatial frequencies. These results are amplified for the varnish containing the low molecular weight resin. The light reflected by the varnished samples is modelled from these topographical data. Its angular distribution, calculated from the probability density of slopes is presented, taking into account separately the air/varnish and the varnish/substrate interfaces. These analyses are presented in a back-scattering configuration. They show that varnishing significantly reduces the angular width of the reflected light and that this effect is magnified for the low molecular weight resin. Modelling furthermore shows that the influence of the roughness of the varnish/substrate interface is negligible in the total reflected light.

  2. Comparative study on gamma irradiation and cold plasma pretreatment for a cellulosic substrate modification with phenolic compounds

    NASA Astrophysics Data System (ADS)

    Irimia, Anamaria; Ioanid, Ghiocel Emil; Zaharescu, Traian; Coroabă, Adina; Doroftei, Florica; Safrany, Agnes; Vasile, Cornelia

    2017-01-01

    The efficiency of the activation of the cellulose/chitin mix substrate by cold plasma or γ-radiation exposure in order to modify it with bioactive compounds was studied. The eugenol or vegetable oils such as grape seed oil and rosehip seed oil have been grafted onto activated substrate. The examination of modified cellulose/chitin mix substrate by ATR-FTIR spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy confirms that the structural and morphological changes took place in both cases. The grafting degrees of the surface layer estimated from XPS data varied from 31.1% to 58.7% for air cold plasma activation and from 9.7% to 22.8% for γ-irradiation treatment. They depend both on bioactive compound used and procedure of substrate activation. Higher grafting degree are obtain by using vegetable oils than in the case of modification with eugenol and the air cold plasma activation seems to be much efficient than γ-irradiation. By grafting the polymeric substrate with bioactive compounds, antimicrobial and antioxidant properties have been conferred. Such materials can be considered promising for food packaging applications and medical textiles and also the applied procedures are environmental friendly ones.

  3. Laser surface modification of titanium substrate for pulsed laser deposition of highly adherent hydroxyapatite.

    PubMed

    Rajesh, P; Muraleedharan, C V; Komath, Manoj; Varma, Harikrishna

    2011-07-01

    Biomedical implant devices made out of titanium and its alloys are benefited by a modified surface or a bioactive coating to enhance bone bonding ability and to function effectively in vivo for the intended period of time. In this respect hydroxyapatite coating developed through pulsed laser deposition is a promising approach. Since the success of the bioactive ceramic coated implant depends mainly on the substrate-coating strength; an attempt has been made to produce micro patterned surface structure on titanium substrate for adherent hydroxyapatite coating. A pulsed Nd-YAG laser beam (355 nm) with 10 Hz repetition rate was used for surface treatment of titanium as well as hydroxyapatite deposition. The unfocussed laser beam was used to modify the substrate surface with 500-18,000 laser pulses while keeping the polished substrate in water. Hydroxyapatite deposition was done in a vacuum deposition chamber at 400 °C with the focused laser beam under 1 × 10⁻³ mbar oxygen pressure. Deposits were analyzed to understand the physico-chemical, morphological and mechanical characteristics. The obtained substrate and coating surface morphology indicates that laser treatment method can provide controlled micro-topography. Scratch test analysis and microindentation hardness values of coating on laser treated substrate indicate higher mechanical adhesion with respect to coatings on untreated substrates.

  4. Surface modification of SERS substrates with plasma-polymerized trimethylsilane nanocoating

    NASA Astrophysics Data System (ADS)

    Kim, Young Jo; Sun, Xin; Jones, John E.; Lin, Mengshi; Yu, Qingsong; Li, Hao

    2015-03-01

    Surface-enhanced Raman scattering (SERS) substrates were modified by depositing a nanometer-thick polymer coating on top of SERS-active surface. This thin hydrophobic nanocoating, achieved by low temperature plasma polymerization of trimethylsilane, was found to reduce surface energy of SERS substrate and in turn help relieve the analyte spreading on the surface of SERS substrates. Detection of melamine molecules with these surface-modified SERS substrates showed that this plasma nanocoating improved, not significantly though, SERS sensitivity in comparison with unmodified SERS substrates. It is believed that the increased hydrophobicity induced by this plasma nanocoating had two folds of beneficial effects on SERS sensitivity. First, the as-produced hydrophobic surface gave rise to preconcentration effect due to the reduced contact area between analyte molecules and the substrate surface. Second, the decreased surface energy of SERS substrates was helpful in placing analyte molecules in SERS hot spots. These two combined gains were deemed to outweigh the loss of SERS sensitivity caused by enlarged distance between metal surface and analyte molecules.

  5. Atom-scale covalent electrochemical modification of single-layer graphene on SiC substrates by diaryliodonium salts

    SciTech Connect

    Gearba, Raluca I.; Mueller, Kory M.; Veneman, Peter A.; Holliday, Bradley J.; Chan, Calvin K.; Stevenson, Keith J.

    2015-05-09

    Owing to its high conductivity, graphene holds promise as an electrode for energy devices such as batteries and photovoltaics. However, to this end, the work function and doping levels in graphene need to be precisely tuned. One promising route for modifying graphene’s electronic properties is via controlled covalent electrochemical grafting of molecules. We show that by employing diaryliodonium salts instead of the commonly used diazonium salts, spontaneous functionalization is avoided. This then allows for precise tuning of the grafting density. Moreover, by employing bis(4-nitrophenyl)iodonium(III) tetrafluoroborate (DNP) salt calibration curves, the surface functionalization density (coverage) of glassy carbon was controlled using cyclic voltammetry in varying salt concentrations. These electro-grafting conditions and calibration curves translated directly over to modifying single layer epitaxial graphene substrates (grown on insulating 6H-SiC (0 0 0 1)). In addition to quantifying the functionalization densities using electrochemical methods, samples with low grafting densities were characterized by low-temperature scanning tunneling microscopy (LT-STM). We show that the use of buffer-layer free graphene substrates is required for clear observation of the nitrophenyl modifications. Furthermore, atomically-resolved STM images of single site modifications were obtained, showing no preferential grafting at defect sites or SiC step edges as supposed previously in the literature. Most of the grafts exhibit threefold symmetry, but occasional extended modifications (larger than 4 nm) were observed as well.

  6. Atom-scale covalent electrochemical modification of single-layer graphene on SiC substrates by diaryliodonium salts

    DOE PAGES

    Gearba, Raluca I.; Mueller, Kory M.; Veneman, Peter A.; ...

    2015-05-09

    Owing to its high conductivity, graphene holds promise as an electrode for energy devices such as batteries and photovoltaics. However, to this end, the work function and doping levels in graphene need to be precisely tuned. One promising route for modifying graphene’s electronic properties is via controlled covalent electrochemical grafting of molecules. We show that by employing diaryliodonium salts instead of the commonly used diazonium salts, spontaneous functionalization is avoided. This then allows for precise tuning of the grafting density. Moreover, by employing bis(4-nitrophenyl)iodonium(III) tetrafluoroborate (DNP) salt calibration curves, the surface functionalization density (coverage) of glassy carbon was controlled usingmore » cyclic voltammetry in varying salt concentrations. These electro-grafting conditions and calibration curves translated directly over to modifying single layer epitaxial graphene substrates (grown on insulating 6H-SiC (0 0 0 1)). In addition to quantifying the functionalization densities using electrochemical methods, samples with low grafting densities were characterized by low-temperature scanning tunneling microscopy (LT-STM). We show that the use of buffer-layer free graphene substrates is required for clear observation of the nitrophenyl modifications. Furthermore, atomically-resolved STM images of single site modifications were obtained, showing no preferential grafting at defect sites or SiC step edges as supposed previously in the literature. Most of the grafts exhibit threefold symmetry, but occasional extended modifications (larger than 4 nm) were observed as well.« less

  7. Development of printed ITO coatings on PET and PEN foil for flexible organic photodiodes

    NASA Astrophysics Data System (ADS)

    Heusing, S.; Oliveira, P. W.; Kraker, E.; Haase, A.; Palfinger, C.; Veith, M.

    2008-04-01

    ITO (tin doped indium oxide) coatings with a sheet resistance of 2 to 3 kΩ(square) were produced by gravure printing process on PET and PEN foil. The printing paste consisted of ITO nanoparticles which were dispersed in a solvent by using a surfactant. The dispersion was mixed with a binder and a photo initiator before printing. The printed films were hardened under UV-irradiation at low temperatures (< 130°C). The sheet resistance could be decreased by heat treatment at 120°C under forming gas atmosphere (N II/H II) to 1.5 kΩ(square). The transmission of the ITO coated PET and PEN foils is more than 80 % in the visible range. The ITO films were directly used as the bottom electrode in an organic photodiode (OPD). The setup of the OPD originates from the well known Tang photodiode, consisting of a stacked layer of copper phthalocyanine (p-type material) and perylene tetracarboxylic bisbenzimidazole (n-type material). The photodiodes are characterised via current-voltage (I-V) characteristics. The performance of the photodiodes with printed ITO on plastic substrates could be improved by the deposition of a PEDOT/PSS layer (Baytron (R) P) on the ITO coated foils and was then comparable to the performance of photodiodes with semi-transparent gold as anode on PET substrates. These results demonstrate the suitability of the printed ITO layers as anode for organic photodiodes.

  8. Modification of Ti6Al4V Substrates with Well-defined Zwitterionic Polysulfobetaine Brushes for Improved Surface Mineralization

    PubMed Central

    2015-01-01

    Osteoconductive mineral coatings are beneficial for improving the osteointegration of metallic orthopedic/dental implants, but achieving adequate structural integration between the surface minerals and underlying metallic substrates has been a significant challenge. Here, we report covalent grafting of zwitterionic poly(sulfobetaine methacrylate) (pSBMA) brushes on the Ti6Al4V substrates to promote the surface-mineralization of hydroxyapatite with enhanced surface mineral coverage and mineral-substrate interfacial adhesion. We first optimized the atom transfer radical polymerization (ATRP) conditions for synthesizing pSBMA polymers in solution. Well-controlled pSBMA polymers (relative molecular weight up to 26kD, PDI = 1.17) with high conversions were obtained when the ATRP was carried out in trifluoroethanol/ionic liquid system at 60 °C. Applying identical polymerization conditions, surface-initiated atom transfer radical polymerization (SI-ATRP) was carried out to graft zwitterionic pSBMA brushes (PDI < 1.20) from the Ti6Al4V substrates, generating a stable superhydrophilic and low-fouling surface coating without compromising the bulk mechanic property of the Ti6Al4V substrates. The zwitterionic pSBMA surface brushes, capable of attracting both cationic and anionic precursor ions during calcium phosphate apatite mineralization, increased the surface mineral coverage from 32% to 71%, and significantly reinforced the attachment of the apatite crystals on the Ti6Al4V substrate. This facile approach to surface modification of metallic substrates can be exploited to generate multifunctional polymer coatings and improve the performance of metallic implants in skeletal tissue engineering and orthopedic and dental care. PMID:24828749

  9. Recent advances in the ITO/InP solar cell

    NASA Technical Reports Server (NTRS)

    Gessert, T. A.; Li, X.; Wanlass, M. W.; Coutts, T. J.

    1991-01-01

    It was demonstrated that Indium Tin Oxide (ITO)/InP solar cells can now be made on as-received p(-) bulk substrates which are of nearly equal quality to those which could previously only be made on epitaxially grown p(-) InP base layers. Although this advancement is due in part to both increases in substrate quality and a better understanding of back contact formation, it appears that the passivation/compensation effects resulting from having H2 in the sputtering gas tends to reduce significantly the performance differences previously observed between these two substrates. It is shown that since high efficiency ITO/InP cells can be made from as-received substrates, and since the type conversion process is not highly spatially dependent, large area ITO/InP cells (4 sq cm) with efficiencies approaching 17 percent (Global) can be made. Furthermore, the measured open circuit voltages (V sub OC) and quantum efficiencies (QEs) from these large cells suggest that, when they are processed using optimum grid designs, the efficiencies will be nearly equal to that of the smaller cells thus far produced. It has been shown, through comparative experiments involving ITO/InP and IO/InP cells, that Sn may not be the major cause of type conversion of the InP surface and thus further implies that the ITO may not be an essential element in this type of device. Specifically, very efficient photovoltaic solar cells were made by sputtering (Sn free) In2O3 showing that type conversion and subsequent junction formation will occur even in the absence of the sputtered SN species. The result suggests that sputter damage may indeed be the important mechanism(s) of type conversion. Finally, an initial study of the stability of the ITO/InP cell done over the course of about one year has indicated that the J(sub SC) (short circuit current) and the fill factor (FF) are measurably stable within experimental certainty.

  10. Film Properties and Polycrystallization of Organic Dyes on ITOs with Surface Treatment for Organic Light-Emitting Diodes

    NASA Astrophysics Data System (ADS)

    Iwama, Yuki; Mori, Tatsuo; Mizutani, Teruyoshi

    ITO(Indium-Tin-Oxide) has been now widely used as the transparent anode for organic light-emitting devices(OLEDs). We used various methods of ITO surface treatment and examined the effects of them by measuring contact angle and calculating surface energy. We also prepared OLEDs with ITO treated by each method, and estimated their characteristics. The surface of ITO treated by UV-O3 or O2-plasma was more hydrophilic than that treated by only organic rinse or no treatment, and consequently the characteristic of the OLED was improved. We suppose these treatments affect the hole injection from ITO into organic layer, due to ionization potential or surface cleanness. We also investigated time degradation of NPD films on the ITO substrates. The films deposited with high deposition rate porycrystallized faster.

  11. Thermal induced modification of the contact mechanics of adhering liposomes on cationic substrate.

    PubMed

    Chan, Vincent; Wan, Kai Tak

    2002-12-01

    The correlation between the mechanical property and the thermotropic transition of the phospholipid bilayer has been recently demonstrated (Chem. Phys. Lipids 110 (2001) 27). However, the role of thermal induced mechanical responses of phospholipid bilayer on the contact mechanics of liposome adhering on a cationic substrate has not been determined. In this study, confocal-reflectance interference contrast microscopy, phase contrast microscopy and contact mechanics modeling are applied to probe the adhesion mechanisms of liposomes in the presence of electrostatic interactions during the thermotropic transition of the lipid bilayer. When temperature increases from 23 to 49 degrees C at pH 7.4, the degree of liposome deformation (a/R) and adhesion energy of dipalmitoyl-sn-glycero-3-phosphocholine liposome increases by 10% and remains constant, respectively, on 3-amino-propyl-triethoxy-silane (APTES) modified substrate. The extents of increase in these two parameters are highly dependent on the physicochemical properties of the rigid substrate. At pH 4, the adhesion energies above and below the phase transition temperature (T(m)) are increased by one order of magnitude due to the formation of the free silanol groups on APTES substrate. In hypotonic condition, the degree of vesicle deformation remains constant and the adhesion energy reduces by 20% during sample heating. Under all conditions, the adhesion energy of the adhering liposome spans a few orders of magnitude against the increase of liposome size as the surface area to volume ratio is maximized in smallest vesicle.

  12. Agarose-Based Substrate Modification Technique for Chemical and Physical Guiding of Neurons In Vitro.

    PubMed

    Krumpholz, Katharina; Rogal, Julia; El Hasni, Akram; Schnakenberg, Uwe; Bräunig, Peter; Bui-Göbbels, Katrin

    2015-08-26

    A new low cost and highly reproducible technique is presented that provides patterned cell culture substrates. These allow for selective positioning of cells and a chemically and mechanically directed guiding of their extensions. The patterned substrates consist of structured agarose hydrogels molded from reusable silicon micro templates. These templates consist of pins arranged equidistantly in squares, connected by bars, which mold corresponding wells and channels in the nonadhesive agarose hydrogel. Subsequent slice production with a standard vibratome, comprising the described template pattern, completes substrate production. Invertebrate neurons of locusts and pond snails are used for this application as they offer the advantage over vertebrate cells as being very large and suitable for cultivation in low cell density. Their neurons adhere to and grow only on the adhesive areas not covered by the agarose. Agarose slices of 50 μm thickness placed on glass, polystyrene, or MEA surfaces position and immobilize the neurons in the wells, and the channels guide their neurite outgrowth toward neighboring wells. In addition to the application with invertebrate neurons, the technique may also provide the potential for the application of a wide range of cell types. Long-term objective is the achievement of isolated low-density neuronal networks on MEAs or different culture substrates for various network analysis applications.

  13. [Ito hypomelanosis: Four case reports].

    PubMed

    Sagna, S D; Mbonda, P; Ndiaye, M; Sow, A D; Basse, A M; Diop, M S; Diagne, N S; Diop, A G; Kane, A; Ndiaye, M M

    2016-10-01

    Ito hypomelanosis is a rare neurocutaneous condition. We report on four observations in infants aged between 8 and 20 months. They all presented with epilepsy, psychomotor delay, and diffuse hypomelanosis. The electroencephalograms showed diffuse irritative abnormalities. Brain imaging was normal in two infants and showed hemispheric atrophy in another case. Despite antiepileptic treatment and physical therapy, no significant progression was noted and all children continued to have drug-resistant epilepsy and psychomotor delay. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  14. ITOS meteorological satellite system: TIROS M spacecraft (ITOS 1), volume 1

    NASA Technical Reports Server (NTRS)

    1970-01-01

    The ITOS system and mission are described along with the design of the TIROS M spacecraft, and the ITOS ground complex. The command subsystems, and the primary environmental sensor subsystem are discussed.

  15. Supersymmetric Ito equation: Bosonization and exact solutions

    SciTech Connect

    Ren Bo; Yu Jun; Lin Ji

    2013-04-15

    Based on the bosonization approach, the N=1 supersymmetric Ito (sIto) system is changed to a system of coupled bosonic equations. The approach can effectively avoid difficulties caused by intractable fermionic fields which are anticommuting. By solving the coupled bosonic equations, the traveling wave solutions of the sIto system are obtained with the mapping and deformation method. Some novel types of exact solutions for the supersymmetric system are constructed with the solutions and symmetries of the usual Ito equation. In the meanwhile, the similarity reduction solutions of the model are also studied with the Lie point symmetry theory.

  16. Interfacial modification of amorphous substrates for microcrystalline silicon growth with in situ hydrogen plasma pretreatment

    NASA Astrophysics Data System (ADS)

    Park, Young-Bae; Rhee, Shi-Woo; Li, Xiaodong

    2005-10-01

    Microcrystalline silicon (μc-Si:H) films have been deposited onto hydrogenated and amorphous Si-rich silicon nitride and thermal oxide substrates with silane (SiH4)-hydrogen (H2) in remote plasma-enhanced chemical vapor deposition (RPECVD) at 250 °C, and these films have been investigated. It is found that in situ hydrogen plasma pretreatment of the amorphous substrates prior to μc-Si:H deposition is effective in reducing the interfacial amorphous transition region. It is believed that this hydrogen plasma pretreatment gives adsorption and nucleation sites by breaking weak Si-N and Si-Si bonds and also removes native Si-O x and hydrocarbon impurities. In the case of SiNx:H surface, surface roughening from atomic hydrogen etching and surface cleaning effects are greater than those for stable thermal oxide. Surface crystallization at the initial stage of the growth can be obtained on amorphous substrate at low temperature without an a-Si transition layer.

  17. 7 CFR 254.3 - Administration by an ITO.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... FOR INDIAN HOUSEHOLDS IN OKLAHOMA § 254.3 Administration by an ITO. (a) Applicability of part 253. All...) Qualification as an ITO. The ITO of a tribe in Oklahoma must document to the satisfaction of FNS that the ITO meets the definition of an ITO in § 254.2, is organized under the provisions of the Oklahoma Indian...

  18. Surface modification for patterned cell growth on substrates with pronounced topographies using sacrificial photoresist and parylene-C peel-off

    NASA Astrophysics Data System (ADS)

    Larramendy, Florian; Yoshida, Shotaro; Jalabert, Laurent; Takeuchi, Shoji; Paul, Oliver

    2016-09-01

    A range of methods including soft lithography are available for patterning protein layers for cell adhesion on quasi-planar substrates. Suitably structured, these layers favor the geometrically constrained, controlled growth of cells and the development of cellular extensions on them. For this purpose, the ability to control the shape and dimension of cell-adhesive areas with high precision is crucial. For more advanced studies of cell interactions, the surface modification or functionalization of substrates with complex topographies is desirable. This paper describes a simple technique allowing to produce surface modification patterns using delicate molecules such as laminin on substrates exhibiting pronounced topographies with recessed and protruding microstructures. The technique is based on the combination of sacrificial photoresist structures with a connected parylene-C layer. This layer locally adheres to the substrate wherever the substrate needs to be protected against the surface modification. After surface modification, the parylene-C layer is peeled off. Patterns comprising arbitrary networks of modified and unmodified substrate areas can thus be realized. We demonstrate the technique with the guided growth of neuron-like PC12 cells on networks of laminin lines on substrates structured with micropillars and microwells.

  19. Catalyst-free growth of ZnO nanowires on ITO seed/glass by thermal evaporation method: Effects of ITO seed layer thickness

    NASA Astrophysics Data System (ADS)

    Alsultany, Forat H.; Hassan, Z.; Ahmed, Naser M.

    2016-07-01

    A seed/catalyst-free growth of ZnO nanowires (ZnO-NWs) on a glass substrate were successfully fabricated using thermal evaporation technique. These nanowires were grown on ITO seed layers of different thicknesses of 25 and 75 nm, which were deposited on glass substrates by radio frequency (RF) magnetron sputtering. Prior to synthesized ITO nanowires, the sputtered ITO seeds were annealed using the continuous wave (CW) CO2 laser at 450 °C in air for 15 min. The effect of seed layer thickness on the morphological, structural, and optical properties of ZnO-NWs were systematically investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and UV-Vis spectrophotometer.

  20. Catalyst-free growth of ZnO nanowires on ITO seed/glass by thermal evaporation method: Effects of ITO seed layer thickness

    SciTech Connect

    Alsultany, Forat H. Ahmed, Naser M.; Hassan, Z.

    2016-07-19

    A seed/catalyst-free growth of ZnO nanowires (ZnO-NWs) on a glass substrate were successfully fabricated using thermal evaporation technique. These nanowires were grown on ITO seed layers of different thicknesses of 25 and 75 nm, which were deposited on glass substrates by radio frequency (RF) magnetron sputtering. Prior to synthesized ITO nanowires, the sputtered ITO seeds were annealed using the continuous wave (CW) CO2 laser at 450 °C in air for 15 min. The effect of seed layer thickness on the morphological, structural, and optical properties of ZnO-NWs were systematically investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and UV-Vis spectrophotometer.

  1. Highly Stretchable and Flexible Graphene/ITO Hybrid Transparent Electrode.

    PubMed

    Liu, Juhua; Yi, Yaohua; Zhou, Yihua; Cai, Huafei

    2016-12-01

    The flexible hybrid transparent electrode was prepared by a two-step process: graphene film was firstly grown on Cu foil by modified thermal chemical vapor deposition (CVD) and then transferred onto indium tin oxide (ITO) electrode on the polyethylene terephthalate (PET) substrate. The quality of the graphene is characterized by various analytic techniques, including the AFM, SEM, TEM, and Raman spectroscopy. The gradient flux was found to be beneficial to decrease defect. The thickness, morphology, light transmittance, and electromechanical properties of three conductive electrodes were investigated and compared. The outcomes show that the hybrid electrode could resist mechanical force and the results are better than original ITO electrode. It may be a potential trend to apply the graphene to other conducts in the flexible transparent conductive field.

  2. Highly Stretchable and Flexible Graphene/ITO Hybrid Transparent Electrode

    NASA Astrophysics Data System (ADS)

    Liu, Juhua; Yi, Yaohua; Zhou, Yihua; Cai, Huafei

    2016-02-01

    The flexible hybrid transparent electrode was prepared by a two-step process: graphene film was firstly grown on Cu foil by modified thermal chemical vapor deposition (CVD) and then transferred onto indium tin oxide (ITO) electrode on the polyethylene terephthalate (PET) substrate. The quality of the graphene is characterized by various analytic techniques, including the AFM, SEM, TEM, and Raman spectroscopy. The gradient flux was found to be beneficial to decrease defect. The thickness, morphology, light transmittance, and electromechanical properties of three conductive electrodes were investigated and compared. The outcomes show that the hybrid electrode could resist mechanical force and the results are better than original ITO electrode. It may be a potential trend to apply the graphene to other conducts in the flexible transparent conductive field.

  3. Hierarchical zwitterionic modification of a SERS substrate enables real-time drug monitoring in blood plasma

    PubMed Central

    Sun, Fang; Hung, Hsiang-Chieh; Sinclair, Andrew; Zhang, Peng; Bai, Tao; Galvan, Daniel David; Jain, Priyesh; Li, Bowen; Jiang, Shaoyi; Yu, Qiuming

    2016-01-01

    Surface-enhanced Raman spectroscopy (SERS) is an ultrasensitive analytical technique with molecular specificity, making it an ideal candidate for therapeutic drug monitoring (TDM). However, in critical diagnostic media including blood, nonspecific protein adsorption coupled with weak surface affinities and small Raman activities of many analytes hinder the TDM application of SERS. Here we report a hierarchical surface modification strategy, first by coating a gold surface with a self-assembled monolayer (SAM) designed to attract or probe for analytes and then by grafting a non-fouling zwitterionic polymer brush layer to effectively repel protein fouling. We demonstrate how this modification can enable TDM applications by quantitatively and dynamically measuring the concentrations of several analytes—including an anticancer drug (doxorubicin), several TDM-requiring antidepressant and anti-seizure drugs, fructose and blood pH—in undiluted plasma. This hierarchical surface chemistry is widely applicable to many analytes and provides a generalized platform for SERS-based biosensing in complex real-world media. PMID:27834380

  4. Hierarchical zwitterionic modification of a SERS substrate enables real-time drug monitoring in blood plasma

    NASA Astrophysics Data System (ADS)

    Sun, Fang; Hung, Hsiang-Chieh; Sinclair, Andrew; Zhang, Peng; Bai, Tao; Galvan, Daniel David; Jain, Priyesh; Li, Bowen; Jiang, Shaoyi; Yu, Qiuming

    2016-11-01

    Surface-enhanced Raman spectroscopy (SERS) is an ultrasensitive analytical technique with molecular specificity, making it an ideal candidate for therapeutic drug monitoring (TDM). However, in critical diagnostic media including blood, nonspecific protein adsorption coupled with weak surface affinities and small Raman activities of many analytes hinder the TDM application of SERS. Here we report a hierarchical surface modification strategy, first by coating a gold surface with a self-assembled monolayer (SAM) designed to attract or probe for analytes and then by grafting a non-fouling zwitterionic polymer brush layer to effectively repel protein fouling. We demonstrate how this modification can enable TDM applications by quantitatively and dynamically measuring the concentrations of several analytes--including an anticancer drug (doxorubicin), several TDM-requiring antidepressant and anti-seizure drugs, fructose and blood pH--in undiluted plasma. This hierarchical surface chemistry is widely applicable to many analytes and provides a generalized platform for SERS-based biosensing in complex real-world media.

  5. Rectified photocurrent in a planar ITO/graphene/ITO photodetector on SiC by local irradiation of ultraviolet light

    NASA Astrophysics Data System (ADS)

    Yang, Junwei; Guo, Liwei; Huang, Jiao; Mao, Qi; Guo, Yunlong; Jia, Yuping; Peng, Tonghua; Chen, Xiaolong

    2017-10-01

    A rectified photocurrent behaviour is demonstrated in a simple planar structure of ITO-graphene-ITO formed on a SiC substrate when an ultraviolet (UV) light is locally incident on one of the edges between the graphene and ITO electrode. The photocurrent has similar characteristics as those of a vertical structure graphene/semiconductor junction photodiode, but is clearly different from those found in a planar structure metal–graphene–metal device. Furthermore, the device behaves multi-functionally as a photodiode with sensitive UV photodetection capability (responsivity of 11.7 mA W‑1 at 0.3 V) and a self-powered UV photodetector (responsivity of 4.4 mA W‑1 at zero bias). Both features are operative in a wide dynamic range and with a fast speed of response in about gigahertz. The linear I–V behaviour with laser power at forward bias and cutoff at reverse bias leads to a conceptual photodiode, which is compatible with modern semiconductor planar device architecture. This paves a potential way to realize ultrafast graphene planar photodiodes for monolithic integration of graphene-based devices on the same SiC substrate.

  6. Chemical mechanical polishing characteristics of ITO thin film prepared by RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Lee, Kang-Yeon; Choi, Gwon-Woo; Kim, Yong-Jae; Choi, Youn-Ok; Kim, Nam-Oh

    2012-02-01

    Indium-tin-oxide (ITO) thin films have attracted intensive interest because of their unique properties of good conductivity, high optical transmittance over the visible region and easy patterning ability. ITO thin films have found many applications in anti-static coatings, thermal heaters, solar cells, flat panel displays (FPDs), liquid crystal displays (LCDs), electroluminescent devices, sensors and organic light-emitting diodes (OLEDs). ITO thin films are generally fabricated by using various methods, such as spraying, chemical vapor deposition (CVD), evaporation, electron gun deposition, direct current electroplating, high frequency sputtering, and reactive sputtering. In this research, ITO films were grown on glass substrates by using a radio-frequency (RF) magnetron sputtering method. In order to achieve a high transmittance and a low resistivity, we examined the various film deposition conditions, such as substrate temperature, working pressure, annealing temperature, and deposition time. Next, in order to improve the surface quality of the ITO thin films, we performed a chemical mechanical polishing (CMP) with different process parameters and compared the electrical and the optical properties of the polished ITO thin films. The best CMP conditions with a high removal rate, low nonuniformity, low resistivity and high transmittance were as follows: platen speed, head speed, polishing time, and slurry flow rate of 30 rpm, 30 rpm, 60 sec, and 60 ml/min, respectively.

  7. Annealing of indium tin oxide (ITO) coated optical fibers for optical and electrochemical sensing purposes

    NASA Astrophysics Data System (ADS)

    Dominik, Magdalena; Siuzdak, Katarzyna; Niedziałkowski, Paweł; Stranak, Vitezslav; Sezemsky, Petr; Sobaszek, Michał; Bogdanowicz, Robert; Ossowski, Tadeusz; Śmietana, Mateusz

    2016-12-01

    Glass and fiber structures with Indium Tin Oxide (ITO) coating were subjected to annealing in order to identify impact of the thermal treatment on their optical and electrochemical properties. It is shown that the annealing process significantly modifies optical properties and thickness of the films, which are crucial for performance of optical fiber sensors. Moreover, it visibly improves electrochemical activity of ITO on glass slides and thicker (∅=400 μm) ITO-coated fibers, whereas in the case of thinner fibers (∅=125 μm) it could lead to a loss of their electrochemical activity. Depending on the applied substrate and the annealing process, the investigated structures with ITO coating can be further used as fiber-based sensors with integrated opto-electrochemical readout.

  8. Fabrication of Bi-doped In2O3-ITO nanocomposites and their photoluminescence properties

    NASA Astrophysics Data System (ADS)

    Gil Na, Han; Jung, Taek-Kyun; Lee, Ji-Woon; Hyun, Soong-Keun; Kwon, Yong Jung; Mirzaei, Ali; Kim, Tae-Bum; Shin, Young-Chul; Choi, Ho-Joon; Kim, Hyoun Woo; Jin, Changhyun

    2016-09-01

    For the first time, Bi-doped In2O3-indium tin oxide (ITO) nanocomposites were prepared on Si substrates with the assistance of a Au catalyst through the simple gas-phase transport of a mixture of Bi, In, and Sn powders. The square-shaped Bi-doped In2O3-ITO nanostructures were straight, a few hundreds of nanometres in width, and below a few tens of micrometres in length. Electron microscopy, x-ray diffraction, and energy-dispersive x-ray spectroscopy analyses indicated that the Bi-doped In2O3-ITO nanorods were single crystals with a basis of cubic In2O3 structures. The photoluminescence spectra revealed that the Bi-doped In2O3-ITO nanorods had a strong orange emission band centred at approximately 626 nm without any shoulder bands. The enhancement of orange emission might be due to the oxygen deficiencies of structural defects in the nanorods.

  9. Insights into Phosphate Cooperativity and Influence of Substrate Modifications on Binding and Catalysis of Hexameric Purine Nucleoside Phosphorylases

    PubMed Central

    de Giuseppe, Priscila O.; Martins, Nadia H.; Meza, Andreia N.; dos Santos, Camila R.; Pereira, Humberto D’Muniz; Murakami, Mario T.

    2012-01-01

    The hexameric purine nucleoside phosphorylase from Bacillus subtilis (BsPNP233) displays great potential to produce nucleoside analogues in industry and can be exploited in the development of new anti-tumor gene therapies. In order to provide structural basis for enzyme and substrates rational optimization, aiming at those applications, the present work shows a thorough and detailed structural description of the binding mode of substrates and nucleoside analogues to the active site of the hexameric BsPNP233. Here we report the crystal structure of BsPNP233 in the apo form and in complex with 11 ligands, including clinically relevant compounds. The crystal structure of six ligands (adenine, 2′deoxyguanosine, aciclovir, ganciclovir, 8-bromoguanosine, 6-chloroguanosine) in complex with a hexameric PNP are presented for the first time. Our data showed that free bases adopt alternative conformations in the BsPNP233 active site and indicated that binding of the co-substrate (2′deoxy)ribose 1-phosphate might contribute for stabilizing the bases in a favorable orientation for catalysis. The BsPNP233-adenosine complex revealed that a hydrogen bond between the 5′ hydroxyl group of adenosine and Arg43* side chain contributes for the ribosyl radical to adopt an unusual C3’-endo conformation. The structures with 6-chloroguanosine and 8-bromoguanosine pointed out that the Cl6 and Br8 substrate modifications seem to be detrimental for catalysis and can be explored in the design of inhibitors for hexameric PNPs from pathogens. Our data also corroborated the competitive inhibition mechanism of hexameric PNPs by tubercidin and suggested that the acyclic nucleoside ganciclovir is a better inhibitor for hexameric PNPs than aciclovir. Furthermore, comparative structural analyses indicated that the replacement of Ser90 by a threonine in the B. cereus hexameric adenosine phosphorylase (Thr91) is responsible for the lack of negative cooperativity of phosphate binding in this

  10. Insights into phosphate cooperativity and influence of substrate modifications on binding and catalysis of hexameric purine nucleoside phosphorylases.

    PubMed

    de Giuseppe, Priscila O; Martins, Nadia H; Meza, Andreia N; dos Santos, Camila R; Pereira, Humberto D'Muniz; Murakami, Mario T

    2012-01-01

    The hexameric purine nucleoside phosphorylase from Bacillus subtilis (BsPNP233) displays great potential to produce nucleoside analogues in industry and can be exploited in the development of new anti-tumor gene therapies. In order to provide structural basis for enzyme and substrates rational optimization, aiming at those applications, the present work shows a thorough and detailed structural description of the binding mode of substrates and nucleoside analogues to the active site of the hexameric BsPNP233. Here we report the crystal structure of BsPNP233 in the apo form and in complex with 11 ligands, including clinically relevant compounds. The crystal structure of six ligands (adenine, 2'deoxyguanosine, aciclovir, ganciclovir, 8-bromoguanosine, 6-chloroguanosine) in complex with a hexameric PNP are presented for the first time. Our data showed that free bases adopt alternative conformations in the BsPNP233 active site and indicated that binding of the co-substrate (2'deoxy)ribose 1-phosphate might contribute for stabilizing the bases in a favorable orientation for catalysis. The BsPNP233-adenosine complex revealed that a hydrogen bond between the 5' hydroxyl group of adenosine and Arg(43*) side chain contributes for the ribosyl radical to adopt an unusual C3'-endo conformation. The structures with 6-chloroguanosine and 8-bromoguanosine pointed out that the Cl(6) and Br(8) substrate modifications seem to be detrimental for catalysis and can be explored in the design of inhibitors for hexameric PNPs from pathogens. Our data also corroborated the competitive inhibition mechanism of hexameric PNPs by tubercidin and suggested that the acyclic nucleoside ganciclovir is a better inhibitor for hexameric PNPs than aciclovir. Furthermore, comparative structural analyses indicated that the replacement of Ser(90) by a threonine in the B. cereus hexameric adenosine phosphorylase (Thr(91)) is responsible for the lack of negative cooperativity of phosphate binding in this

  11. Fast anodization fabrication of AAO and barrier perforation process on ITO glass.

    PubMed

    Liu, Sida; Xiong, Zuzhou; Zhu, Changqing; Li, Ma; Zheng, Maojun; Shen, Wenzhong

    2014-01-01

    Thin films of porous anodic aluminum oxide (AAO) on tin-doped indium oxide (ITO) substrates were fabricated through evaporation of a 1,000- to 2,000-nm-thick Al, followed by anodization with different durations, electrolytes, and pore widening. A faster method to obtain AAO on ITO substrates has been developed, which with 2.5 vol.% phosphoric acid at a voltage of 195 V at 269 K. It was found that the height of AAO films increased initially and then decreased with the increase of the anodizing time. Especially, the barrier layers can be removed by extending the anodizing duration, which is very useful for obtaining perforation AAO and will broaden the application of AAO on ITO substrates.

  12. Fast anodization fabrication of AAO and barrier perforation process on ITO glass

    PubMed Central

    2014-01-01

    Thin films of porous anodic aluminum oxide (AAO) on tin-doped indium oxide (ITO) substrates were fabricated through evaporation of a 1,000- to 2,000-nm-thick Al, followed by anodization with different durations, electrolytes, and pore widening. A faster method to obtain AAO on ITO substrates has been developed, which with 2.5 vol.% phosphoric acid at a voltage of 195 V at 269 K. It was found that the height of AAO films increased initially and then decreased with the increase of the anodizing time. Especially, the barrier layers can be removed by extending the anodizing duration, which is very useful for obtaining perforation AAO and will broaden the application of AAO on ITO substrates. PMID:24708829

  13. Transparent ITO/Ag-Pd-Cu/ITO multilayer cathode use in inverted organic solar cells

    NASA Astrophysics Data System (ADS)

    Kim, Hyo-Joong; Lee, Hyun Hwi; Kal, Jinha; Hahn, Jungseok; Kim, Han-Ki

    2015-10-01

    The characteristics of transparent ITO/Ag-Pd-Cu (APC)/ITO multilayer cathodes were investigated for use in inverted organic solar cells (IOSCs). The insertion of an APC interlayer into the ITO film effectively led to crystallization of the top ITO layer, unlike that in the Ag interlayer, and resulted in a low sheet resistance of 6.55 Ohm/square and a high optical transmittance of 84.14% without post annealing. In addition, the alloying of the Pd and Cu elements into Ag prevented agglomeration and oxidization of the metal interlayer and led to more stable ITO/APC/ITO films under ambient conditions. The microstructure and interfacial structure of the transparent ITO/APC/ITO cathode in the IOSCs were examined in detail by synchrotron X-ray scattering and high resolution transmission electron microscopy. Furthermore, we suggested a possible mechanism to explain the lower PCE of the IOSCs with an ITO/APC/ITO cathode than that of a reference IOSC with a crystalline ITO cathode using the external quantum efficiency of the IOSCs.

  14. Transparent ITO/Ag-Pd-Cu/ITO multilayer cathode use in inverted organic solar cells

    SciTech Connect

    Kim, Hyo-Joong; Kim, Han-Ki; Lee, Hyun Hwi; Kal, Jinha; Hahn, Jungseok

    2015-10-15

    The characteristics of transparent ITO/Ag-Pd-Cu (APC)/ITO multilayer cathodes were investigated for use in inverted organic solar cells (IOSCs). The insertion of an APC interlayer into the ITO film effectively led to crystallization of the top ITO layer, unlike that in the Ag interlayer, and resulted in a low sheet resistance of 6.55 Ohm/square and a high optical transmittance of 84.14% without post annealing. In addition, the alloying of the Pd and Cu elements into Ag prevented agglomeration and oxidization of the metal interlayer and led to more stable ITO/APC/ITO films under ambient conditions. The microstructure and interfacial structure of the transparent ITO/APC/ITO cathode in the IOSCs were examined in detail by synchrotron X-ray scattering and high resolution transmission electron microscopy. Furthermore, we suggested a possible mechanism to explain the lower PCE of the IOSCs with an ITO/APC/ITO cathode than that of a reference IOSC with a crystalline ITO cathode using the external quantum efficiency of the IOSCs.

  15. Temperature-dependent surface modifications of AISI 316L and AISI 440C stainless steel substrates

    NASA Astrophysics Data System (ADS)

    Gröning, P.; Nowak, S.; Schlapbach, L.

    1991-12-01

    Using X-ray photoelectron spectroscopy (XPS) we have analyzed the surface composition of austenitic AISI 316L and martensitic AISI 440C stainless steels after 1 h annealing in high vacuum at temperatures between 25 and 1000°C. On both steels we have observed, in the temperature range between 350 and 850°C, strong chromium (Cr), manganese (Mn) and silicon (Si) diffusion from the bulk to the surface. The composition of the forming surface layer (thickness about 50 Å) was strongly temperature-dependent and completely different from the bulk. We conclude that the well known difference in the quality of the adhesion of hard PVD coatings on stainless steels can be related to the surface composition of the steel substrate.

  16. Modification of substrate specificity in single point mutants of Agrobacterium tumefaciens type II NADH dehydrogenase.

    PubMed

    Desplats, C; Beyly, A; Cuiné, S; Bernard, L; Cournac, L; Peltier, G

    2007-08-21

    Type II NADH dehydrogenases (NDH-2) are monomeric flavoenzymes catalyzing electron transfer from NADH to quinones. While most NDH-2 preferentially oxidize NADH, some of these enzymes have been reported to efficiently oxidize NADPH. With the aim to modify the NADPH vs NADH specificity of the relatively NADH specific Agrobacterium tumefaciens NDH-2, two conserved residues (E and A) of the substrate binding domain were, respectively, mutated to Q and S. We show that when E was replaced by Q at position 203 the enzyme was able to oxidize NADPH as efficiently as NADH. Growth on a minimal medium of an Escherichia coli double mutant lacking both NDH-1 and NDH-2 was restored more efficiently when mutated proteins able to oxidize NADPH were expressed. The biotechnological interest of expressing such modified enzymes in photosynthetic organisms is discussed.

  17. Modification of the substrate specificity of porcine pepsin for the enzymatic production of bovine hide gelatin.

    PubMed Central

    Galea, C. A.; Dalrymple, B. P.; Kuypers, R.; Blakeley, R.

    2000-01-01

    The substrate specificity of porcine pepsin has been altered by site-directed mutagenesis in an attempt to selectively cleave bovine hide collagen at only a few sites, similar to cathepsin D, for the production of high quality gelatin. Kinetic parameters were determined using chromogenic peptide substrates based on the sequence Lys-Pro-Xaa-Yaa-Phe*Nph-Arg-Leu (where Xaa is Ile or Pro, Yaa is Glu. Leu, Gln or Lys, Nph is p-nitrophenylalanine, and * is the site of cleavage). Substitution of Thr222 and Glu287 within the S2 subsite of pepsin by Val and Met, respectively, produced a double mutant with a two- to fourfold higher kcat/Km, compared with wild-type pepsin, for the chromogenic peptides with residues Leu, Gln, and Glu at position P2 (Yaa). The results suggest that the functional group of the P2 side chain may be exposed to solvent, while the aliphatic portion interacts with hydrophobic residues comprising S2. Wild-type pepsin cleaved a peptide corresponding to the carboxy-terminal telopeptide region of bovine type I collagen alpha1 chain, SGGYDLSFLPQPPQE, predominantly at three sites (Asp-Leu, Leu-Ser, and Phe-Leu) and at a significantly lower rate at Ser-Phe. However, Thr222Val/Glu287Met cleaved site Ser-Phe at a rate 20-fold higher than the wild-type. Significantly, enzymes containing the double substitution Phe111Thr/Leu112Phe cleaved this peptide predominantly at one site Leu-Ser (similar to cathepsin D) and at a rate 23-fold higher than the wild-type. These mutants can potentially enhance the rate of solubilization of bovine hide collagen under conditions mild enough to maintain the triple helix structure and hence minimize the rate of subsequent denaturation and proteolytic cleavage. PMID:11106168

  18. The influence of surface modification on bacterial adhesion to titanium-based substrates.

    PubMed

    Lorenzetti, Martina; Dogša, Iztok; Stošicki, Tjaša; Stopar, David; Kalin, Mitjan; Kobe, Spomenka; Novak, Saša

    2015-01-28

    This study examines bacterial adhesion on titanium-substrates used for bone implants. Adhesion is the most critical phase of bacterial colonization on medical devices. The surface of titanium was modified by hydrothermal treatment (HT) to synthesize nanostructured TiO2-anatase coatings, which were previously proven to improve corrosion resistance, affect the plasma protein adsorption, and enhance osteogenesis. The affinity of the anatase coatings toward bacterial attachment was studied by using a green fluorescent protein-expressing Escherichia coli (gfp-E. coli) strain in connection with surface photoactivation by UV irradiation. We also analyzed the effects of surface topography, roughness, charge, and wettability. The results suggested the dominant effects of the macroscopic surface topography, as well as microasperity at the surface roughness scale, which were produced during titanium machining, HT treatment, or both. Macroscopic grooves provided a preferential site for bacteria deposit within the valleys, while the microscopic roughness of the valleys determined the actual interaction surface between bacterium and substrate, resulting in an "interlocking" effect and undesired high bacterial adhesion on nontreated titanium. In the case of TiO2-coated samples, the nanocrystals reduced the width between the microasperities and thus added nanoroughness features. These factors decreased the contact area between the bacterium and the coating, with consequent lower bacterial adhesion (up to 50% less) in comparison to the nontreated titanium. On the other hand, the pronounced hydrophilicity of one of the HT-coated discs after pre-irradiation seemed to enhance the attachment of bacteria, although the increase was not statistically significant (p > 0.05). This observation may be explained by the acquired similar degree of wetting between gfp-E. coli and the coating. No correlation was found between the bacterial adhesion and the ζ-values of the samples in PBS, so the

  19. Effects of the pulse duration in laser modification of nano-sized WTi film on Si substrate

    NASA Astrophysics Data System (ADS)

    Petrović, Suzana; Peruško, D.; Milovanović, D.; Kovač, J.; Čekada, M.; Panjan, P.; Gaković, B.; Trtica, M.

    2010-07-01

    A study of morphological and composition changes of the WTi/Si system induced by nanosecond and picosecond laser pulses is presented. A 190 nm thick WTi film was deposited on a silicon substrate of n-type (100). The pulsed laser systems used were: nanosecond TEA CO2 laser (emission, 10.6 µm pulse FWHM; pulse duration 120 ns) and picosecond Nd:YAG laser (emission, 532 nm pulse FWHM; pulse duration 40 ps). During experiments the used fluences (Φ) had similar values, Φ1 = 20 J cm - 2 in case of the TEA CO2 laser and Φ2 = 16 J cm - 2 for the Nd:YAG laser. The laser-induced morphological and composition modifications showed a dependence on pulse duration. Generally, the following morphological changes were observed: (i) ablation/exfoliation of the WTi thin film, (ii) appearance of hydrodynamic features such as resolidified material, and (iii) formation of nano-sized grains and globules. Overall morphological modifications were more pronounced after the picosecond laser action. The surface composition analysis showed a quite different distribution of sample components depending on the pulse duration. Formation of the silicon dioxide (SiO2) was recorded only in the case of irradiation of the WTi/Si system by picosecond laser pulses.

  20. Microstructure and dielectric properties of cellulose acetate-ZnO/ITO composite films based on water hyacinth

    NASA Astrophysics Data System (ADS)

    Diantoro, M.; Mustikasari, A. A.; Wijayanti, N.; Yogihati, C.; Taufiq, A.

    2017-05-01

    The electrical properties of Cellulose Acetate (CA), especially extracted from water hyacinth, is rarely informed. CA is generally more stable compared to its cellulose. It has a good potential for electronic application with specific modifications such as inducing metal oxide. A combination of intrinsic properties of Zinc Oxide (ZnO) and CA is expected as a great potential for electrical and optical applications. CA-ZnO/ITO composite film was investigated in relation with its structure, dielectric constant, and the effect of light intensity on their dielectric constant. CA-ZnO composite films were prepared with different mass of ZnO i.e. 0; 0,02; 0,04; 0,06 and 0,08 grams. CA-ZnO solution was synthesized via the mixing method with PEG:DMF solvents by using a magnetic hotplate stirrer with the rotation rate of 1500 rpm at 80°C. The CA-ZnO solution was then deposited onto ITO/glass substrate by using spin coating technique. The CA-ZnO/ITO films were annealed at 160°C to remove the remaining solvents. The effects of ZnO composition on the structure (crystallinity and morphology) and dielectric constant properties were investigated by using X-Ray Diffractometer, Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, and LCR meter. It was shown that cellulose can be isolated from water hyacinth with the yield of 67,72 % by Chesson method and can further be transformed into CA. The X-ray diffraction pattern showed that there are 2 phases formed i.e. CA and ZnO. Furthermore, greater ZnO amount increased the crystallinity of composite films. The CA-ZnO films exhibit porous films with ZnO distributed on the CA surface films. Therefore, ZnO increases the dielectric constant of CA-ZnO composite films.

  1. Pulsed modification of germanium films on silicon, sapphire, and quartz substrates: Structure and optical properties

    SciTech Connect

    Novikov, H. A.; Batalov, R. I. Bayazitov, R. M.; Faizrakhmanov, I. A.; Lyadov, N. M.; Shustov, V. A.; Galkin, K. N.; Galkin, N. G.; Chernev, I. M.; Ivlev, G. D.; Prokop’ev, S. L.; Gaiduk, P. I.

    2015-06-15

    The structural and optical properties of thin Ge films deposited onto semiconducting and insulating substrates and modified by pulsed laser radiation are studied. The films are deposited by the sputtering of a Ge target with a low-energy Xe{sup +} ion beam. Crystallization of the films is conducted by their exposure to nanosecond ruby laser radiation pulses (λ = 0.694 μm) with the energy density W = 0.2−1.4 J cm{sup −2}. During pulsed laser treatment, the irradiated area is probed with quasi-cw (quasi-continuous-wave) laser radiation (λ = 0.532 and 1.064 μm), with the reflectance recorded R(t). Experimental data on the lifetime of the Ge melt are compared with the results of calculation, and good agreement between them is demonstrated. Through the use of a number of techniques, the dependences of the composition of the films, their crystal structure, the level of strains, and the reflectance and transmittance on the conditions of deposition and annealing are established.

  2. Effective surface modification by chemical solution deposition for flexible metal substrates

    NASA Astrophysics Data System (ADS)

    Du, Wei; Bai, Yue-Ling; Wang, Jing; Fang, Jianhui; Fan, Feng; Liu, Zhiyong; Guo, Yanqun; Bai, Chuanyi; Cai, Chuanbing

    2017-03-01

    Solution deposition planarization (SDP) was used to modify the flexible metal substrates for high temperature superconductor (HTS) tapes to ensure an available and effective surface for subsequent growth of buffer films. The surface morphologies with different tape speeds and coating layers were systematically investigated. 16 layers SDP-films decreased the surface roughness (RMS) from 11.74 to 0.788 nm for Hastelloy C-276 and 12 layers SDP-films decreased the RMS from 20.93 to 0.903 nm for SUS 304. Follow-up study confirmed that the low value of RMS (<1 nm) and high reflectivity of SDP-films exhibit superior characteristics for ion beam-assisted deposited (IBAD)-MgO, sputtered LaMnO3 films and YBCO films. A 10 m sample verified the stability of SDP-films on Hastelloy. The similar result for achieved SDP-films on SUS 304 (I cAVG  =  110.1 A) and Hastelloy (I cAVG  =  124.5 A) revealed the stainless steel has potential application value for coated conductor, which further reduced the cost of raw materials.

  3. Low temperature and self catalytic growth of ultrafine ITO nanowires by electron beam evaporation method and their optical and electrical properties

    SciTech Connect

    Kumar, R. Rakesh; Rao, K. Narasimha; Rajanna, K.; Phani, A.R.

    2014-04-01

    Highlights: • ITO nanowires were grown by e-beam evaporation method. • ITO nanowires growth done at low substrate temperature of 350 °C. • Nanowires growth was carried out without use of catalyst and reactive oxygen gas. • Nanowires growth proceeds via self catalytic VLS growth. • Grown nanowires have diameter 10–20 nm and length 1–4 μm long. • ITO nanowire films have shown good antireflection property. - Abstract: We report the self catalytic growth of Sn-doped indium oxide (ITO) nanowires (NWs) over a large area glass and silicon substrates by electron beam evaporation method at low substrate temperatures of 250–400 °C. The ITO NWs growth was carried out without using an additional reactive oxygen gas and a metal catalyst particle. Ultrafine diameter (∼10–15 nm) and micron long ITO NWs growth was observed in a temperature window of 300–400 °C. Transmission electron microscope studies confirmed single crystalline nature of the NWs and energy dispersive spectroscopy studies on the NWs confirmed that the NWs growth proceeds via self catalytic vapor-liquid-solid (VLS) growth mechanism. ITO nanowire films grown on glass substrates at a substrate temperature of 300–400 °C have shown ∼2–6% reflection and ∼70–85% transmission in the visible region. Effect of deposition parameters was systematically investigated. The large area growth of ITO nanowire films would find potential applications in the optoelectronic devices.

  4. ZnS nanoparticles electrodeposited onto ITO electrode as a platform for fabrication of enzyme-based biosensors of glucose.

    PubMed

    Du, Jian; Yu, Xiuping; Wu, Ying; Di, Junwei

    2013-05-01

    The electrochemical and photoelectrochemical biosensors based on glucose oxidase (GOD) and ZnS nanoparticles modified indium tin oxide (ITO) electrode were investigated. The ZnS nanoparticles were electrodeposited directly on the surface of ITO electrode. The enzyme was immobilized on ZnS/ITO electrode surface by sol-gel method to fabricate glucose biosensor. GOD could electrocatalyze the reduction of dissolved oxygen, which resulted in a great increase of the reduction peak current. The reduction peak current decreased linearly with the addition of glucose, which could be used for glucose detection. Moreover, ZnS nanoparticles deposited on ITO electrode surface showed good photocurrent response under illumination. A photoelectrochemical biosensor for the detection of glucose was also developed by monitoring the decreases in the cathodic peak photocurrent. The results indicated that ZnS nanoparticles deposited on ITO substrate were a good candidate material for the immobilization of enzyme in glucose biosensor construction.

  5. A simple two-step method to fabricate highly transparent ITO/polymer nanocomposite films

    NASA Astrophysics Data System (ADS)

    Liu, Haitao; Zeng, Xiaofei; Kong, Xiangrong; Bian, Shuguang; Chen, Jianfeng

    2012-09-01

    Transparent functional indium tin oxide (ITO)/polymer nanocomposite films were fabricated via a simple approach with two steps. Firstly, the functional monodisperse ITO nanoparticles were synthesized via a facile nonaqueous solvothermal method using bifunctional chemical agent (N-methyl-pyrrolidone, NMP) as the reaction solvent and surface modifier. Secondly, the ITO/acrylics polyurethane (PUA) nanocomposite films were fabricated by a simple sol-solution mixing method without any further surface modification step as often employed traditionally. Flower-like ITO nanoclusters with about 45 nm in diameter were mono-dispersed in ethyl acetate and each nanocluster was assembled by nearly spherical nanoparticles with primary size of 7-9 nm in diameter. The ITO nanoclusters exhibited an excellent dispersibility in polymer matrix of PUA, remaining their original size without any further agglomeration. When the loading content of ITO nanoclusters reached to 5 wt%, the transparent functional nanocomposite film featured a high transparency more than 85% in the visible light region (at 550 nm), meanwhile cutting off near-infrared radiation about 50% at 1500 nm and blocking UV ray about 45% at 350 nm. It could be potential for transparent functional coating materials applications.

  6. Nanopillar ITO electrodes via argon plasma etching

    SciTech Connect

    Van Dijken, Jaron G.; Brett, Michael J.

    2012-07-15

    The authors demonstrate the formation of vertically aligned indium tin oxide (ITO) nanopillars by exposing planar ITO films to Ar plasma, the conditions of which determine the size, spacing, and aspect ratio of the pillars. Annealing in air and forming gas is used to recover and optimize the optical transmittance and electrical conductivity of the nanopillar films. The final product is an ITO film whose superior optical transmittance and strong electrical conductivity combine with its robust columnar morphology and processing scalability to make it suitable for use in highly absorbing organic solar cells.

  7. Catalytic wateroxidation on derivatized nanoITO

    SciTech Connect

    Chen, Zuofeng; Concepcion, Javier J; Hull, Jonathan F; Hoertz, Paul G.; Meyer, Thomas J.

    2010-06-22

    Electrocatalytic water oxidation occurs on high surface area, nanocrystalline ITO (nanoITO) surface-derivatized by phosphonate-binding of the catalyst [Ru(Mebimpy)(4,4'-((HO)2OPCH2)2bpy)(OH2)]2+ (Mebimpy is 2,6-bis(1-methylbenzimidazol-2-yl)pyridine; bpy is 2,2'-bipyridine). With nanoITO, spectral data can be acquired on electrochemically generated intermediates and voltammograms monitored spectrophotometrically.

  8. Impact of Substrate Modification by Catheter Ablation on Implantable Cardioverter-Defibrillator Interventions in Patients With Unstable Ventricular Arrhythmias and Coronary Artery Disease: Results From the Multicenter Randomized Controlled SMS (Substrate Modification Study).

    PubMed

    Kuck, Karl-Heinz; Tilz, Roland Richard; Deneke, Thomas; Hoffmann, Boris A; Ventura, Rodolfo; Hansen, Peter Steen; Zarse, Markus; Hohnloser, Stefan H; Kautzner, Josef; Willems, Stephan

    2017-03-01

    The implantable cardioverter-defibrillator (ICD) is the standard therapy to prevent sudden cardiac death in patients with coronary artery disease and unstable ventricular tachyarrhythmias. The prospective multinational SMS (Substrate Modification Study) was designed to assess whether prophylactic ablation of the arrhythmogenic substrate reduces or prevents the recurrence of ventricular tachycardia/ventricular fibrillation in such patients. Of 111 patients included in an intention-to-treat analysis, 54 were randomly assigned catheter ablation plus ICD implantation (ablation group: 68±8 years; 47 men), whereas 57 were assigned ICD implantation without catheter ablation (ICD-only group: 66±8 years; 46 men). Primary study end point was the time to first recurrence of ventricular tachycardia/ventricular fibrillation. ICD episodes were assessed and verified by an independent board. Patients were followed up for 2.3±1.1 years. The primary end point was reached by 25 ablation patients and 26 ICD-only patients. Two-year event-free survival was estimated at 49.0% (95% confidence interval, 33.3%-62.9%) in the former and 52.4% (36.7%-65.9%) in the latter groups. Comparison of episode incidence revealed no significant difference in the primary end point (P=0.84). In an Andersen-Gill regression model with multiple end point recurrences, the difference between the study arms significantly favored catheter ablation for both the primary end point and all but one of the predefined subgroups of detected arrhythmia events. SMS failed to meet the primary end point of time to first ventricular tachycardia/ventricular fibrillation recurrence. However, catheter ablation did reduce the total number of ICD interventions during the duration of follow-up. https://clinicaltrials.gov. Unique identifier: NCT00170287. © 2017 American Heart Association, Inc.

  9. Controllably annealed CuO-nanoparticle modified ITO electrodes: Characterisation and electrochemical studies

    NASA Astrophysics Data System (ADS)

    Wang, Tong; Su, Wen; Fu, Yingyi; Hu, Jingbo

    2016-12-01

    In this paper, we report a facile and controllable two-step approach to produce indium tin oxide electrodes modified by copper(II) oxide nanoparticles (CuO/ITO) through ion implantation and annealing methods. After annealing treatment, the surface morphology of the CuO/ITO substrate changed remarkably and exhibited highly electroactive sites and a high specific surface area. The effects of annealing treatment on the synthesis of CuO/ITO were discussed based on various instruments' characterisations, and the possible mechanism by which CuO nanoparticles were generated was also proposed in this work. Cyclic voltammetric results indicated that CuO/ITO electrodes exhibited effective catalytic responses toward glucose in alkaline solution. Under optimal experimental conditions, the proposed CuO/ITO electrode showed sensitivity of 450.2 μA cm-2 mM-1 with a linear range of up to ∼4.4 mM and a detection limit of 0.7 μM (S/N = 3). Moreover, CuO/ITO exhibited good poison resistance, reproducibility, and stability properties.

  10. Hypomelanosis of Ito with triphalangeal thumbs.

    PubMed Central

    Kukolich, M K; Althaus, B W; Freeman, M V; Lewandowski, R C

    1980-01-01

    A black female with abnormal skin pigmentation, similar to that seen in hypomelanosis of Ito, and triphalangeal thumbs is presented. This association has not previously been reported. Images PMID:7381873

  11. Hypomelanosis of Ito associated with precocious puberty.

    PubMed

    Rutland, Beth M; Edgar, Mark A; Horenstein, Marcelo G

    2006-01-01

    Hypomelanosis of Ito has been associated with precocious puberty in two cases. This study reports a third case involving a female with hypomelanosis of Ito including severe mental retardation and seizure disorder with autonomic symptoms (gastroesophageal reflux and asthma). At age 5 she developed vaginal discharge, thelarche, and adrenarche. Soon after, she died of pneumonia stemming from her neurologic deficits. A postmortem examination revealed normal gonads and endocrine organs. The breasts and vulva were prematurely developed. Central nervous system findings included megalencephaly, neuronal eosinophilic inclusions, leptomeningeal neuroglial heterotopias, and cortical dysplasia. Both previously reported cases of hypomelanosis of Ito associated with precocious puberty had abnormal gonads and responded to cyproterone acetate therapy, indicating a peripheral mechanism of precocious puberty (gonadotrophin-independent). The current case, which was autopsied, lacks significant gonadal pathology, and has extensive neurologic involvement that suggests that a central mechanism of precocious puberty (gonadotrophin-dependent) can also be associated with hypomelanosis of Ito.

  12. Roll-to-roll cohesive, coated, flexible, high-efficiency polymer light-emitting diodes utilizing ITO-free polymer anodes.

    PubMed

    Shin, Seongbeom; Yang, Minyang; Guo, L Jay; Youn, Hongseok

    2013-12-09

    This paper reports solution-processed, high-efficiency polymer light-emitting diodes fabricated by a new type of roll-to-roll coating method under ambient air conditions. A noble roll-to-roll cohesive coating system utilizes only natural gravity and the surface tension of the solution to flow out from the capillary to the surface of the substrate. Because this mechanism uses a minimally cohesive solution, the roll-to-roll cohesive coating can effectively realize an ultra-thin film thickness for the electron injection layer. In addition, the roll-to-roll cohesive coating enables the fabrication of a thicker polymer anode film more than 250 nm at one time by modification of the surface energy and without wasting the solution. It is observed that the standard sheet resistance deviation of the polymer anode is only 2.32 Ω/□ over 50 000 bending cycles. The standard sheet resistance deviation of the polymer anode in the different bending angles (0 to 180°) is 0.313 Ω/□, but the case of the ITO-PET is 104.93 Ω/□. The average surface roughness of the polymer anode measured by atomic force microscopy is only 1.06 nm. Because the surface of the polymer anode has a better quality, the leakage current of the polymer light-emitting diodes (PLEDs) using the polymer anode is much lower than that using the ITO-PET substrate. The luminous power efficiency of the two devices is 4.13 lm/W for the polymer anode and 3.21 lm/W for the ITO-PET. Consequently, the PLEDs made by using the polymer anode exhibited 28% enhanced performance because the polymer anode represents not only a higher transparency than the ITO-PET in the wavelength of 560 nm but also greatly reduced roughness. The optimized the maximum current efficiency and power efficiency of the device show around 6.1 cd/A and 5.1 lm/W, respectively, which is comparable to the case of using the ITO-glass.

  13. Super Smooth Modification of Al2O3 Ceramic Substrate by High Temperature Glaze of CaO-Al2O3-SiO2 System

    NASA Astrophysics Data System (ADS)

    Zhang, Jihua; Zhen, Shanxue; Yang, Lijun; Lou, Feizhi; Chen, Hongwei; Yang, Chuanren

    2011-01-01

    The rough surface of ceramic substrate is an obstacle for the scale down of line-width for thin film passive integrated devices (PID). In this paper, a modification method for Al2O3 ceramic substrate with super smooth in surface was proposed. Coating a layer of CaO-Al2O3-SiO2 (CAS) glass was performed to flat the rough surface of alumina substrate by sol-gel method. It was found that addition of 0.06% V2O5 can inhibit the recrystallization of the glaze. The root-mean-square (RMS) roughness of the glazed substrates reached a surprising flatness as small as 0.5 nm, and its melting temperature is higher than 1300 °C. This substrate with super flatness and high temperature endurance may be promising for high performance thin film devices.

  14. ITO with embedded silver grids as transparent conductive electrodes for large area organic solar cells.

    PubMed

    Patil, Bhushan R; Mirsafaei, Mina; Cielecki, Paweł Piotr; Cauduro, André Luis Fernandes; Fiutowski, Jacek; Rubahn, Horst-Günter; Madsen, Morten

    2017-10-06

    In this work, development of semi-transparent electrodes for efficient large area organic solar cells (OSCs) has been demonstrated. Electron beam evaporated silver grids were embedded in commercially available ITO coatings on glass, through a standard negative photolithography process, in order to improve the conductivity of planar ITO substrates. The fabricated electrodes with embedded line and square patterned Ag grids reduced the sheet resistance of ITO by 25% and 40%, respectively, showing optical transmittance drops of less than 6% within the complete visible light spectrum for both patterns. Solution processed bulk heterojunction OSCs based on PTB7:[70]PCBM were fabricated on top of these electrodes with cell areas of 4.38 cm(2), and the performance of these OSCs was compared to reference cells fabricated on pure ITO electrodes. The Fill Factor (FF) of the large-scale OSCs fabricated on ITO with embedded Ag grids was enhanced by 18% for the line grids pattern and 30% for the square grids pattern compared to that of the reference OSCs. The increase in the FF was directly correlated to the decrease in the series resistance of the OSCs. The maximum power conversion efficiency (PCE) of the OSCs was measured to be 4.34%, which is 23% higher than the PCE of the reference OSCs. As the presented method does not involve high temperature processing, it could be considered a general approach for development of large area organic electronics on solvent resistant, flexible substrates.

  15. ITO with embedded silver grids as transparent conductive electrodes for large area organic solar cells

    NASA Astrophysics Data System (ADS)

    Patil, Bhushan R.; Mirsafaei, Mina; Piotr Cielecki, Paweł; Fernandes Cauduro, André Luis; Fiutowski, Jacek; Rubahn, Horst-Günter; Madsen, Morten

    2017-10-01

    In this work, development of semi-transparent electrodes for efficient large area organic solar cells (OSCs) has been demonstrated. Electron beam evaporated silver grids were embedded in commercially available ITO coatings on glass, through a standard negative photolithography process, in order to improve the conductivity of planar ITO substrates. The fabricated electrodes with embedded line and square patterned Ag grids reduced the sheet resistance of ITO by 25% and 40%, respectively, showing optical transmittance drops of less than 6% within the complete visible light spectrum for both patterns. Solution processed bulk heterojunction OSCs based on PTB7:[70]PCBM were fabricated on top of these electrodes with cell areas of 4.38 cm2, and the performance of these OSCs was compared to reference cells fabricated on pure ITO electrodes. The Fill Factor (FF) of the large-scale OSCs fabricated on ITO with embedded Ag grids was enhanced by 18% for the line grids pattern and 30% for the square grids pattern compared to that of the reference OSCs. The increase in the FF was directly correlated to the decrease in the series resistance of the OSCs. The maximum power conversion efficiency (PCE) of the OSCs was measured to be 4.34%, which is 23% higher than the PCE of the reference OSCs. As the presented method does not involve high temperature processing, it could be considered a general approach for development of large area organic electronics on solvent resistant, flexible substrates.

  16. Effects of electron irradiation during the growth of ITO films by an using RF sputtering system

    NASA Astrophysics Data System (ADS)

    Yoon, Young Joon; Cho, Sung Hwan; Kim, Bongho

    2016-10-01

    We perform electron irradiation during the radio-frequency (RF) sputtering process to realize the growth of a transparent oxide thin film, indium tin oxide (ITO), to achieve a high transparency and a low resistivity. Using an electron gun attached to the sputtering system, we simultaneously accelerate a large number of electrons onto the substrate along with the sputtered ITO atoms by using a negative bias of up to 1.5 kV. As the electron-beam voltage increased, the preferred orientation of the ITO film changed from the (222) plane to the (400) plane, and the film showed a flake-type surface morphology. Sputtered ITO atoms in the electron-assisted sputtering (EAS) process showed sufficient mobility because of the kinetic effect of continuous electron irradiation without the need for an additional substrate heating process. The ITO films grown using the EAS process had a minimum resistivity value of 1.46×10-4 Ωcm under an electron irradiation condition of 1.5 kV and showed a transmittance of 95% at 550 nm.

  17. [Coating modification of anthracite substrates in vertical-flow constructed wetlands by LDHs synthesized from different metal compounds and the nitrogen removal efficiencies].

    PubMed

    Zhang, Xiang-Ling; Guo, Lu; Chen, Jun-Jie; Liu, Xiao-Ting; Xu, Lu; Chen, Qiao-Zhen; Wang, Xiao-Xiao

    2014-08-01

    As one kind of vertical-flow constructed wetlands substrates, anthracite was selected in this experiment. LDHs (layered double hydroxides) were synthesized in alkaline conditions by co-precipitation of different kinds of metal compounds, such as CaCl2, ZnCl2, MgCl2, FeCl3, AlCl3, CoCl3. The synthesized LDHs were in-situ coated onto the surface of anthracite substrate to achieve the aim of modification. Simulated test columns were constructed to study the nitrogen removal efficiency of the urban sewage using the original anthracite substrates and 9 kinds of modified anthracite substrates. The results showed that: LDHs synthesized by all the 9 different kinds of methods could effectively modify the anthracite substrate by in-situ coating. With Mg2+ involved in the synthesis of modified substrates, good TN and ammonia nitrogen removal efficiencies were observed. The modified anthracite substrates coated with MgCo-LDHs had the optimal performance with average TN and ammonia nitrogen removal efficiencies of higher than 80% and 85%, respectively. The ammonia nitrogen removal efficiencies by the modified anthracite substrates coated by LDHs reacted with Mg2+ and Fe3+ were also high. The ammonia nitrogen removal efficiencies by modified anthracite substrates coated with CaFe-LDHs and MgFe-LDHs were higher than 85%.

  18. Atrial Substrate Modification in Atrial Fibrillation: Targeting GP or CFAE? Evidence from Meta-Analysis of Clinical Trials

    PubMed Central

    Qin, Mu; Liu, Xu; Wu, Shao-Hui; Zhang, Xiao-Dong

    2016-01-01

    Several clinically relevant outcomes post atrial substrate modification in patients with atrial fibrillation (AF) have not been systematically analyzed among published studies on adjunctive cardiac ganglionated plexi (GP) or complex fractionated atrial electograms (CFAE) ablation vs. pulmonary vein isolation (PVI) alone. Out of 176 reports identified, the present meta-analysis included 14 randomized and non-randomized controlled trials (1613 patients) meeting inclusion criteria. Addition of GP ablation to PVI significantly increased freedom from atrial tachyarrhythmia in short- (OR: 1.72; P = 0.003) and long-term (OR: 2.0, P = 0.0006) follow-up, while adjunctive CFAE ablation did not after one or repeat procedure (P<0.05). The percentage of atrial tachycardia or atrial flutter (AT/AFL) after one procedure was higher for CFAE than GP ablation. In sub-analysis of non-paroxysmal AF, relative to PVI alone, adjunctive GP but not CFAE ablation significantly increased sinus rhythm maintenance (OR: 1.88, P = 0.01; and OR:1.24, P = 0.18, respectively). Meta regression analysis of the 14 studies indicated that sample size was significant source of heterogeneity either in outcomes after one or repeat procedure. In conclusion, in patients with AF, adjunctive GP but not CFAE ablation appeared to significantly add to the beneficial effects on sinus rhythm maintenance of PVI ablation alone; and CFAE ablation was associated with higher incidence of subsequent AT/AFL. PMID:27764185

  19. Atrial Substrate Modification in Atrial Fibrillation: Targeting GP or CFAE? Evidence from Meta-Analysis of Clinical Trials.

    PubMed

    Qin, Mu; Liu, Xu; Wu, Shao-Hui; Zhang, Xiao-Dong

    2016-01-01

    Several clinically relevant outcomes post atrial substrate modification in patients with atrial fibrillation (AF) have not been systematically analyzed among published studies on adjunctive cardiac ganglionated plexi (GP) or complex fractionated atrial electograms (CFAE) ablation vs. pulmonary vein isolation (PVI) alone. Out of 176 reports identified, the present meta-analysis included 14 randomized and non-randomized controlled trials (1613 patients) meeting inclusion criteria. Addition of GP ablation to PVI significantly increased freedom from atrial tachyarrhythmia in short- (OR: 1.72; P = 0.003) and long-term (OR: 2.0, P = 0.0006) follow-up, while adjunctive CFAE ablation did not after one or repeat procedure (P<0.05). The percentage of atrial tachycardia or atrial flutter (AT/AFL) after one procedure was higher for CFAE than GP ablation. In sub-analysis of non-paroxysmal AF, relative to PVI alone, adjunctive GP but not CFAE ablation significantly increased sinus rhythm maintenance (OR: 1.88, P = 0.01; and OR:1.24, P = 0.18, respectively). Meta regression analysis of the 14 studies indicated that sample size was significant source of heterogeneity either in outcomes after one or repeat procedure. In conclusion, in patients with AF, adjunctive GP but not CFAE ablation appeared to significantly add to the beneficial effects on sinus rhythm maintenance of PVI ablation alone; and CFAE ablation was associated with higher incidence of subsequent AT/AFL.

  20. Preparation and modification of VO2 thin film on R-sapphire substrate by rapid thermal process

    NASA Astrophysics Data System (ADS)

    Zhu, Nai-Wei; Hu, Ming; Xia, Xiao-Xu; Wei, Xiao-Ying; Liang, Ji-Ran

    2014-04-01

    The VO2 thin film with high performance of metal-insulator transition (MIT) is prepared on R-sapphire substrate for the first time by magnetron sputtering with rapid thermal process (RTP). The electrical characteristic and THz transmittance of MIT in VO2 film are studied by four-point probe method and THz time domain spectrum (THz-TDS). X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and search engine marketing (SEM) are employed to analyze the crystalline structure, valence state, surface morphology of the film. Results indicate that the properties of VO2 film which is oxidized from the metal vanadium film in oxygen atmosphere are improved with a follow-up RTP modification in nitrogen atmosphere. The crystallization and components of VO2 film are improved and the film becomes compact and uniform. A better phase transition performance is shown that the resistance changes nearly 3 orders of magnitude with a 2-°C hysteresis width and the THz transmittances are reduced by 64% and 60% in thermal and optical excitation respectively.

  1. Increased efficiency with surface texturing in ITO/InP solar cells

    NASA Technical Reports Server (NTRS)

    Jenkins, Phillip; Landis, Geoffrey A.; Fatemi, Navid; Li, Xiaonan; Scheiman, David; Bailey, Sheila

    1992-01-01

    Optimization of an InP solar cell with a V-grooved surface is discussed. Total internal reflection in the coverglass reduces surface reflection and can recover light reflected from the front metallization. Results from the first ITO/InP solar cells on low-angle V-grooved substrates are presented, showing a 5.8 percent increase in current.

  2. Increased efficiency with surface texturing in ITO/InP solar cells

    NASA Technical Reports Server (NTRS)

    Jenkins, Phillip; Landis, Geoffrey A.; Fatemi, Navid; Li, Xiaonan; Scheiman, David; Bailey, Sheila

    1992-01-01

    Optimization of an InP solar cell with a V-grooved surface is discussed. Total internal reflection in the coverglass reduces surface reflection and can recover light reflected from the front metallization. Results from the first ITO/InP solar cells on low-angle V-grooved substrates are presented, showing a 5.8 percent increase in current.

  3. Characteristics of Indium Tin Oxide (ITO) Nanoparticles Recovered by Lift-off Method from TFT-LCD Panel Scraps

    PubMed Central

    Choi, Dongchul; Hong, Sung-Jei; Son, Yongkeun

    2014-01-01

    In this study, indium-tin-oxide (ITO) nanoparticles were simply recovered from the thin film transistor-liquid crystal display (TFT-LCD) panel scraps by means of lift-off method. This can be done by dissolving color filter (CF) layer which is located between ITO layer and glass substrate. In this way the ITO layer was easily lifted off the glass substrate of the panel scrap without panel crushing. Over 90% of the ITO on the TFT-LCD panel was recovered by using this method. After separating, the ITO was obtained as particle form and their characteristics were investigated. The recovered product appeared as aggregates of particles less than 100 nm in size. The weight ratio of In/Sn is very close to 91/9. XRD analysis showed that the ITO nanoparticles have well crystallized structures with (222) preferred orientation even after recovery. The method described in this paper could be applied to the industrial recovery business for large size LCD scraps from TV easily without crushing the glass substrate. PMID:28788267

  4. Enhancing light reflective properties on ITO glass by plasmonic effect of silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Zhang, Dezhong; Tang, Yang

    The preparation of well-defined silver (Ag) nanoparticle arrays is reported in this paper. Ag nanoparticles are electrodeposited on Indium tin oxide (ITO) coated glass substrates at 30 °C. The size, shape and periodicity of the Ag nanoparticle arrays are well-controlled. We study the effect of particle size and interparticle distance on reflection enhancement. The sample at the deposition potential of -0.2 V for an electrodeposition time of 3600 s exhibits an enhancement of 28% in weighted reflection in contrast with bare ITO glass. This study reports the high reflection of Ag nanoparticle arrays by electrodeposition method might be application to large-scale photovoltaic devices.

  5. Substrate modification by adding ablation of localized complex fractionated electrograms after stepwise linear ablation in persistent atrial fibrillation.

    PubMed

    Nakahara, Shiro; Kamijima, Tohru; Hori, Yuichi; Tsukada, Naofumi; Okano, Akiko; Takayanagi, Kan

    2014-03-01

    Linear left atrial (LA) ablation in patients with persistent atrial fibrillation (PsAF) resulting in the elimination of most complex fractionated electrogram (CFE) sites has been demonstrated. This study was designed to evaluate the impact of a localized CFE ablation in addition to a representative linear LA ablation in patients with PsAF. A total of 40 consecutive patients with PsAF underwent construction of CFE and dominant frequency (DF) maps using NavX. A stepwise linear ablation including at the PV antra, septum, roof, mitral annulus, and ridge of the appendage was performed followed by additional ablation of localized CFEs detected by an automatic algorithm. A significant reduction in the continuous CFE burden (<50 ms) after the linear ablation (69 vs. 21 %; P < 0.0001) was confirmed, and localized CFEs (40-120 ms) were observed with a significant predilection for the anterior (30 %), posterior (30 %), and inferior LA (38 %) regions (P < 0.01). Comparing the localized CFEs with higher frequency sources, 45 % (70/156) of the localized CFE sites included continuous CFE regions, and 59 % (92/156) of those sites overlapped with the high-DF sites (>8 Hz). Additional localized CFE-targeted ablation further terminated PsAF in 20 % of the patients and further increased the mean CFE cycle length (110 ± 31 to 125 ± 39 ms; P = 0.0033) and decreased the DF (6.0 ± 0.8 to 5.7 ± 0.7 Hz; P = 0.0013) within the CS. The presence of localized CFE sites with a predilection for particular LA regions after a representative linear LA ablation could provide the optimal sites for selective substrate modification of the atrial fibrillation substrate in patients with PsAF.

  6. Influence of substrate modification and C-terminal truncation on the active site structure of substrate-bound heme oxygenase from Neisseriae meningitidis; A 1H NMR study†

    PubMed Central

    Peng, Dungeng; Satterlee, James D.; Ma, Li-Hua; Dallas, Jerry L.; Smith, Kevin M.; Zhang, Xuhong; Sato, Michihiko; La Mar, Gerd N.

    2011-01-01

    Heme oxygenase, HO, from the pathogenic bacterium N. meningitidis, NmHO, which secures host iron, shares many properties with mammalian HOs, but also exhibits some key differences. The crystal structure appears more compact and the crystal-undetected C-terminus interacts with substrate in solution. The unique nature of substrate-protein, specifically pyrrole-I/II-helix-2, peripheral interactions in NmHO are probed by 2D 1H NMR to reveal unique structural features controlling substrate orientation. The thermodynamics of substrate orientational isomerism are mapped for substrates with individual vinyl → methyl → hydrogen substitutions and with enzyme C-terminal deletions. NmHO exhibits significantly stronger orientational preference, reflecting much stronger and selective pyrrole-I/II interactions with the protein matrix, than in mammalian HOs. Thus, replacing bulky vinyls with hydrogens results in a 180° rotation of substrate about the α,γ-meso axis in the active site. A "collapse" of the substrate pocket as substrate size decreases is reflected in movement of helix-2 toward the substrate as indicated by significant and selective increased NOESY cross peak intensity, increase in steric Fe-CN tilt reflected in the orientation of the major magnetic axis, and decrease in steric constraints controlling the rate of aromatic ring reorientation. The active site of NmHO appears "stressed" for native protohemin and its "collapse" upon replacing vinyls by hydrogen leads to a factor ~102 increase in substrate affinity. Interaction of the C-terminus with the active site destabilizes the crystallographic protohemin orientation by ~0.7 kcal/mol, which is consistent with optimizing the His207-Asp27 H-bond. Implications of the active site "stress" for product release are discussed. PMID:21870860

  7. Biochemical characterization of USP7 reveals post-translational modification sites and structural requirements for substrate processing and subcellular localization.

    PubMed

    Fernández-Montalván, Amaury; Bouwmeester, Tewis; Joberty, Gerard; Mader, Robert; Mahnke, Marion; Pierrat, Benoit; Schlaeppi, Jean-Marc; Worpenberg, Susanne; Gerhartz, Bernd

    2007-08-01

    Ubiquitin specific protease 7 (USP7) belongs to the family of deubiquitinating enzymes. Among other functions, USP7 is involved in the regulation of stress response pathways, epigenetic silencing and the progress of infections by DNA viruses. USP7 is a 130-kDa protein with a cysteine peptidase core, N- and C-terminal domains required for protein-protein interactions. In the present study, recombinant USP7 full length, along with several variants corresponding to domain deletions, were expressed in different hosts in order to analyze post-translational modifications, oligomerization state, enzymatic properties and subcellular localization patterns of the enzyme. USP7 is phosphorylated at S18 and S963, and ubiquitinated at K869 in mammalian cells. In in vitro activity assays, N- and C-terminal truncations affected the catalytic efficiency of the enzyme different. Both the protease core alone and in combination with the N-terminal domain are over 100-fold less active than the full length enzyme, whereas a construct including the C-terminal region displays a rather small decrease in catalytic efficiency. Limited proteolysis experiments revealed that USP7 variants containing the C-terminal domain interact more tightly with ubiquitin. Besides playing an important role in substrate recognition and processing, this region might be involved in enzyme dimerization. USP7 constructs lacking the N-terminal domain failed to localize in the cell nucleus, but no nuclear localization signal could be mapped within the enzyme's first 70 amino acids. Instead, the tumor necrosis factor receptor associated factor-like region (amino acids 70-205) was sufficient to achieve the nuclear localization of the enzyme, suggesting that interaction partners might be required for USP7 nuclear import.

  8. DbPTM 3.0: an informative resource for investigating substrate site specificity and functional association of protein post-translational modifications.

    PubMed

    Lu, Cheng-Tsung; Huang, Kai-Yao; Su, Min-Gang; Lee, Tzong-Yi; Bretaña, Neil Arvin; Chang, Wen-Chi; Chen, Yi-Ju; Chen, Yu-Ju; Huang, Hsien-Da

    2013-01-01

    Protein modification is an extremely important post-translational regulation that adjusts the physical and chemical properties, conformation, stability and activity of a protein; thus altering protein function. Due to the high throughput of mass spectrometry (MS)-based methods in identifying site-specific post-translational modifications (PTMs), dbPTM (http://dbPTM.mbc.nctu.edu.tw/) is updated to integrate experimental PTMs obtained from public resources as well as manually curated MS/MS peptides associated with PTMs from research articles. Version 3.0 of dbPTM aims to be an informative resource for investigating the substrate specificity of PTM sites and functional association of PTMs between substrates and their interacting proteins. In order to investigate the substrate specificity for modification sites, a newly developed statistical method has been applied to identify the significant substrate motifs for each type of PTMs containing sufficient experimental data. According to the data statistics in dbPTM, >60% of PTM sites are located in the functional domains of proteins. It is known that most PTMs can create binding sites for specific protein-interaction domains that work together for cellular function. Thus, this update integrates protein-protein interaction and domain-domain interaction to determine the functional association of PTM sites located in protein-interacting domains. Additionally, the information of structural topologies on transmembrane (TM) proteins is integrated in dbPTM in order to delineate the structural correlation between the reported PTM sites and TM topologies. To facilitate the investigation of PTMs on TM proteins, the PTM substrate sites and the structural topology are graphically represented. Also, literature information related to PTMs, orthologous conservations and substrate motifs of PTMs are also provided in the resource. Finally, this version features an improved web interface to facilitate convenient access to the resource.

  9. dbPTM 3.0: an informative resource for investigating substrate site specificity and functional association of protein post-translational modifications

    PubMed Central

    Lu, Cheng-Tsung; Huang, Kai-Yao; Su, Min-Gang; Lee, Tzong-Yi; Bretaña, Neil Arvin; Chang, Wen-Chi; Chen, Yi-Ju; Chen, Yu-Ju; Huang, Hsien-Da

    2013-01-01

    Protein modification is an extremely important post-translational regulation that adjusts the physical and chemical properties, conformation, stability and activity of a protein; thus altering protein function. Due to the high throughput of mass spectrometry (MS)-based methods in identifying site-specific post-translational modifications (PTMs), dbPTM (http://dbPTM.mbc.nctu.edu.tw/) is updated to integrate experimental PTMs obtained from public resources as well as manually curated MS/MS peptides associated with PTMs from research articles. Version 3.0 of dbPTM aims to be an informative resource for investigating the substrate specificity of PTM sites and functional association of PTMs between substrates and their interacting proteins. In order to investigate the substrate specificity for modification sites, a newly developed statistical method has been applied to identify the significant substrate motifs for each type of PTMs containing sufficient experimental data. According to the data statistics in dbPTM, >60% of PTM sites are located in the functional domains of proteins. It is known that most PTMs can create binding sites for specific protein-interaction domains that work together for cellular function. Thus, this update integrates protein–protein interaction and domain–domain interaction to determine the functional association of PTM sites located in protein-interacting domains. Additionally, the information of structural topologies on transmembrane (TM) proteins is integrated in dbPTM in order to delineate the structural correlation between the reported PTM sites and TM topologies. To facilitate the investigation of PTMs on TM proteins, the PTM substrate sites and the structural topology are graphically represented. Also, literature information related to PTMs, orthologous conservations and substrate motifs of PTMs are also provided in the resource. Finally, this version features an improved web interface to facilitate convenient access to the resource

  10. Transparent conducting AZO and ITO films produced by pulsed laser ablation at 355 nm

    NASA Astrophysics Data System (ADS)

    Thestrup, B.; Schou, J.

    Thin films of aluminium-doped zinc oxide (AZO) and indium tin oxide (ITO) were deposited on glass substrates by laser ablation in an oxygen environment. The electrical and optical properties of films grown at various oxygen pressures were compared. With no substrate heating, highly transparent and conducting films were obtained with oxygen pressures between 15 and 23 mTorr for both materials. We obtained a specific resistivity of 1.8×10-3 Ωcm for AZO and 1.1×10-3 Ωcm for ITO. By heating the substrate to 160 °C or 200 °C, the resistivity was further reduced to 1.1×10-3 Ωcm for AZO and 3.9×10-4 Ωcm for ITO. The average transmission of visible light (450-750 nm) was between 82% and 98% in most cases. The results suggest that AZO is a promising alternative to ITO.

  11. Electrodeposition of gold nanoparticle arrays on ITO glass as electrode with high electrocatalytic activity

    SciTech Connect

    Zhang, Kui; Wei, Juan; Zhu, Houjuan; Ma, Fang; Wang, Suhua

    2013-03-15

    Highlights: ► Electrodeposition of gold nanoparticle arrays on ITO glass as catalytic-electrodes. ► The sizes and densities of the gold nanoparticles can be easily controlled. ► Such arrays on ITO glass shows high electrocatalytic activity and good stability. - Abstract: Herein, we reported a templateless, surfactantless, and simple electrochemical method to directly fabricate gold nanoparticle (AuNP) arrays on indium tin oxide (ITO) glass substrates as effective electrocatalytic electrodes. The as-prepared AuNP arrays have been characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), etc. AuNPs with small sizes (<20 nm) were uniformly deposited on the ITO glass under constant current densities, and particle densities can be adjusted by varying the applied charges. The resultant AuNP array electrode showed higher catalytic activity and good stability toward electro-oxidation of ascorbic acid compared with other electrodes, such as bare ITO electrode, bare glassy carbon electrode and bulk gold film electrode.

  12. A transparent flexible z-axis sensitive multi-touch panel based on colloidal ITO nanocrystals.

    PubMed

    Sangeetha, N M; Gauvin, M; Decorde, N; Delpech, F; Fazzini, P F; Viallet, B; Viau, G; Grisolia, J; Ressier, L

    2015-08-07

    Bottom-up fabrication of a flexible multi-touch panel prototype based on transparent colloidal indium tin oxide (ITO) nanocrystal (NC) films is presented. A series of 7% Sn(4+) doped ITO NCs protected by oleate, octanoate and butanoate ligands are synthesized and characterized by a battery of techniques including, high resolution transmission electron microscopy, X-ray diffraction, (1)H, (13)C and (119)Sn nuclear magnetic resonance spectroscopy, and the related diffusion ordered spectroscopy. Electrical resistivities of transparent films of these NCs assembled on flexible polyethylene terephthalate substrates by convective self-assembly from their suspension in toluene decrease with the ligand length, from 220 × 10(3) for oleate ITO to 13 × 10(3)Ω cm for butanoate ITO NC films. A highly transparent, flexible touch panel based on a matrix of strain gauges derived from the least resistive film of 17 nm butanoate ITO NCs sensitively detects the lateral position (x, y) of the touch as well as its intensity over the z-axis. Being compatible with a stylus or bare/gloved finger, a larger version of this module may be readily implemented in upcoming flexible screens, enabling navigation capabilities over all three axes, a feature highly desired by the display industry.

  13. In situ Crystallization of RF sputtered ITO thin films: A comparison with annealed samples

    SciTech Connect

    John, K. Aijo; Manju, T.

    2014-01-28

    Tin doped Indium Oxide (ITO) is a wide band gap semiconductor with high conductivity and transparency in the visible region of the solar spectrum. One of the most popular and exploited applications of ITO is the realization of the transparent conductive layers needed for the electrodes of light sensitive devices, such as photovoltaic cells. The thermal energy for the crystallization of ITO films is very low (150°C). The crystallization can be achieved by the continuous energetic bombardment of the ions in the sputtering chamber without annealing or substrate heating. The accumulated energy will ensure the thermal energy necessary for the crystallization. With the help of sufficiently high sputtering power and sufficient duration, crystallized ITO films can be produced without annealing. In this report, a comparison of the conductivity and transparency of ITO films under two crystallization conditions ((1) crystallization of the sputtered films by annealing; (2) in situ crystallization of the films by providing high sputtering power and long sputtering duration) will be presented.

  14. Conduction noise absorption by ITO thin films attached to microstrip line utilizing Ohmic loss

    SciTech Connect

    Kim, Sun-Hong; Kim, Sung-Soo

    2010-07-15

    For the aim of wide-band noise absorbers with a special design for low frequency performance, this study proposes conductive indium-tin oxide (ITO) thin films as the absorbent materials in microstrip line. ITO thin films were deposited on the polyimide film substrates by rf magnetron cosputtering of In{sub 2}O{sub 3} and Sn targets. The deposited ITO films show a typical value of electrical resistivity ({approx}10{sup -4} {Omega} m) and sheet resistance can be controlled in the range of 20-230 {Omega} by variation in film thickness. Microstrip line with characteristic impedance of 50 {Omega} was used for determining their noise absorbing properties. It is found that there is an optimum sheet resistance of ITO films for the maximum power absorption. Reflection parameter (S{sub 11}) is increased with decrease in sheet resistance due to impedance mismatch. On the while, transmission parameter (S{sub 21}) is decreased with decrease in sheet resistance due to larger Ohmic loss of the ITO films. Experimental results and computational prediction show that the optimum sheet resistance is about 100 {Omega}. For this film, greater power absorption is predicted in the lower frequency region than ferrite thin films of high magnetic loss, which indicates that Ohmic loss is the predominant loss parameter for power absorption in the low frequency range.

  15. A transparent flexible z-axis sensitive multi-touch panel based on colloidal ITO nanocrystals

    NASA Astrophysics Data System (ADS)

    Sangeetha, N. M.; Gauvin, M.; Decorde, N.; Delpech, F.; Fazzini, P. F.; Viallet, B.; Viau, G.; Grisolia, J.; Ressier, L.

    2015-07-01

    Bottom-up fabrication of a flexible multi-touch panel prototype based on transparent colloidal indium tin oxide (ITO) nanocrystal (NC) films is presented. A series of 7% Sn4+ doped ITO NCs protected by oleate, octanoate and butanoate ligands are synthesized and characterized by a battery of techniques including, high resolution transmission electron microscopy, X-ray diffraction, 1H, 13C and 119Sn nuclear magnetic resonance spectroscopy, and the related diffusion ordered spectroscopy. Electrical resistivities of transparent films of these NCs assembled on flexible polyethylene terephthalate substrates by convective self-assembly from their suspension in toluene decrease with the ligand length, from 220 × 103 for oleate ITO to 13 × 103 Ω cm for butanoate ITO NC films. A highly transparent, flexible touch panel based on a matrix of strain gauges derived from the least resistive film of 17 nm butanoate ITO NCs sensitively detects the lateral position (x, y) of the touch as well as its intensity over the z-axis. Being compatible with a stylus or bare/gloved finger, a larger version of this module may be readily implemented in upcoming flexible screens, enabling navigation capabilities over all three axes, a feature highly desired by the display industry.Bottom-up fabrication of a flexible multi-touch panel prototype based on transparent colloidal indium tin oxide (ITO) nanocrystal (NC) films is presented. A series of 7% Sn4+ doped ITO NCs protected by oleate, octanoate and butanoate ligands are synthesized and characterized by a battery of techniques including, high resolution transmission electron microscopy, X-ray diffraction, 1H, 13C and 119Sn nuclear magnetic resonance spectroscopy, and the related diffusion ordered spectroscopy. Electrical resistivities of transparent films of these NCs assembled on flexible polyethylene terephthalate substrates by convective self-assembly from their suspension in toluene decrease with the ligand length, from 220 × 103 for

  16. Influence of dielectric substrate modification and deposition temperature on structure and morphology of CuPc thin films: X-ray reflectivity and angle dependent NEXAFS study

    NASA Astrophysics Data System (ADS)

    Sinha, Sumona; Wang, C.-H.; Mukherjee, M.

    2017-09-01

    The performances of organic thin film transistor devices are significantly linked with the structural properties at organic semiconductor/dielectric interface. The changes in internal structure, molecular ordering and morphology of 20 nm thick CuPc thin films have been investigated by modifying surface of the dielectric substrate with various organic buffer layers at different deposition temperatures. CuPc films are prepared on bare and modified SiO2 substrates at three deposition temperatures. Dielectric surface modification and deposition temperature modify the CuPc /dielectric interfaces accordingly and growth of subsequent CuPc layer. The internal structure, ordering and morphology of CuPc film strongly depends on the behavior of the dielectric layers at various temperatures as well as the diffusion of CuPc molecules. The XRR results reveal that the thickness and ordering of periodic part of CuPc film is varied with dielectric substrate modification as well as deposition temperature. The periodicity of CuPc molecules in the film is always obtained in its α-form. In addition, the angle dependent NEXAFS data determine the angle of CuPc molecular orientation in the range 64° to 71° in the range of 40° to 120 °C deposition temperature, independent of surface modification. The results pave the way for the design and realization of CuPc based thin film transistor devices.

  17. Novel Protein Substrates of the Phospho-Form Modification System in Neisseria gonorrhoeae and Their Connection to O-Linked Protein Glycosylation

    PubMed Central

    Anonsen, Jan Haug; Egge-Jacobsen, Wolfgang; Aas, Finn Erik; Børud, Bente; Koomey, Michael

    2012-01-01

    The zwitterionic phospho-form moieties phosphoethanolamine (PE) and phosphocholine (PC) are important components of bacterial membranes and cell surfaces. The major type IV pilus subunit protein of Neisseria gonorrhoeae, PilE, undergoes posttranslational modifications with these moieties via the activity of the pilin phospho-form transferase PptA. A number of observations relating to colocalization of phospho-form and O-linked glycan attachment sites in PilE suggested that these modifications might be either functionally or mechanistically linked or interact directly or indirectly. Moreover, it was unknown whether the phenomenon of phospho-form modification was solely dedicated to PilE or if other neisserial protein targets might exist. In light of these concerns, we screened for evidence of phospho-form modification on other membrane glycoproteins targeted by the broad-spectrum O-linked glycosylation system. In this way, two periplasmic lipoproteins, NGO1043 and NGO1237, were identified as substrates for PE addition. As seen previously for PilE, sites of PE modifications were clustered with those of glycan attachment. In the case of NGO1043, evidence for at least six serine phospho-form attachment sites was found, and further analyses revealed that at least two of these serines were also attachment sites for glycan. Finally, mutations altering glycosylation status led to the presence of pptA-dependent PC modifications on both proteins. Together, these results reinforce the associations established in PilE and provide evidence for dynamic interplay between phospho-form modification and O-linked glycosylation. The observations also suggest that phospho-form modifications likely contribute biologically at both intracellular and extracellular levels. PMID:22083701

  18. Comparative study of ITO and TiN fabricated by low-temperature RF biased sputtering

    SciTech Connect

    Simon, Daniel K. Schenk, Tony; Dirnstorfer, Ingo; Fengler, Franz P. G.; Jordan, Paul M.; Krause, Andreas; Tröger, David; Mikolajick, Thomas

    2016-03-15

    Radio frequency (RF) biasing induced by a second plasma source at the substrate is applied to low-temperature sputtering processes for indium tin oxide (ITO) and titanium nitride (TiN) thin films. Investigations on crystal structure and surface morphology show that RF-biased substrate plasma processes result in a changed growth regime with different grain sizes and orientations than those produced by processes without a substrate bias. The influence of the RF bias is shown comparatively for reactive RF-sputtered ITO and reactive direct-current-sputtered TiN. The ITO layers exhibit an improved electrical resistivity of 0.5 mΩ cm and an optical absorption coefficient of 0.5 × 10{sup 4 }cm{sup −1} without substrate heating. Room-temperature sputtered TiN layers are deposited that possess a resistivity (0.1 mΩ cm) of 3 orders of magnitude lower than, and a density (5.4 g/cm{sup 3}) up to 45% greater than, those obtained from layers grown using the standard process without a substrate plasma.

  19. Directed modification of the Aspergillus usamii β-mannanase to improve its substrate affinity by in silico design and site-directed mutagenesis.

    PubMed

    Li, Jianfang; Wei, Xihuan; Tang, Cunduo; Wang, Junqing; Zhao, Mei; Pang, Qingfeng; Wu, Minchen

    2014-04-01

    β-Mannanases (EC 3.2.1.78) can catalyze the cleavage of internal β-1,4-D-mannosidic linkages of mannan backbones, and they have found applications in food, feed, pulp and paper, oil, pharmaceutical and textile industries. Suitable amino acid substitution can promote access to the substrate-binding groove and maintain the substrate therein, which probably improves the substrate affinity and, thus, increases catalytic efficiency of the enzyme. In this study, to improve the substrate affinity of AuMan5A, a glycoside hydrolase (GH) family 5 β-mannanase from Aspergillus usamii, had its directed modification conducted by in silico design, and followed by site-directed mutagenesis. The mutant genes, Auman5A (Y111F) and Auman5A (Y115F), were constructed by megaprimer PCR, respectively. Then, Auman5A and its mutant genes were expressed in Pichia pastoris GS115 successfully. The specific activities of purified recombinant β-mannanases (reAuMan5A, reAuMan5A(Y111F) and reAuMan5A(Y115F)) towards locust bean gum were 152.5, 199.6 and 218.9 U mg(-1), respectively. The two mutants were found to be similar to reAuMan5A regarding temperature and pH characteristics. Nevertheless, the K m values of reAuMan5A(Y111F) and reAuMan5A(Y115F), towards guar gum, decreased to 2.95 ± 0.22 and 2.39 ± 0.33 mg ml(-1) from 4.49 ± 0.07 mg ml(-1) of reAuMan5A, which would make reAuMan5A(Y111F) and reAuMan5A(Y115F) promising candidates for industrial processes. Structural analysis showed that the two mutants increased their affinity by decreasing the steric conflicts with those more complicated substrates. The results suggested that subtle conformational modification in the substrate-binding groove could substantially alter the substrate affinity of AuMan5A. This study laid a solid foundation for the directed modification of substrate affinities of β-mannanases and other enzymes.

  20. Photosynthetic reaction centers/ITO hybrid nanostructure.

    PubMed

    Szabó, Tibor; Bencsik, Gábor; Magyar, Melinda; Visy, Csaba; Gingl, Zoltán; Nagy, Krisztina; Váró, György; Hajdu, Kata; Kozák, Gábor; Nagy, László

    2013-03-01

    Photosynthetic reaction center proteins purified from Rhodobacter sphaeroides purple bacterium were deposited on the surface of indium tin oxide (ITO), a transparent conductive oxide, and the photochemical/-physical properties of the composite were investigated. The kinetics of the light induced absorption change indicated that the RC was active in the composite and there was an interaction between the protein cofactors and the ITO. The electrochromic response of the bacteriopheophytine absorption at 771 nm showed an increased electric field perturbation around this chromophore on the surface of ITO compared to the one measured in solution. This absorption change is associated with the charge-compensating relaxation events inside the protein. Similar life time, but smaller magnitude of this absorption change was measured on the surface of borosilicate glass. The light induced change in the conductivity of the composite as a function of the concentration showed the typical sigmoid saturation characteristics unlike if the photochemically inactive chlorophyll was layered on the ITO. In this later case the light induced change in the conductivity was oppositely proportional to the chlorophyll concentration due to the thermal dissipation of the excitation energy. The sensitivity of the measurement is very high; few picomole RC can change the light induced resistance of the composite. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Label-free optical biosensor based on localized surface plasmon resonance of twin-linked gold nanoparticles electrodeposited on ITO glass.

    PubMed

    Deng, Jiajia; Song, Yan; Wang, Yuan; Di, Junwei

    2010-10-15

    A simple low-cost electrochemical approach has been used to directly deposit twin-linked gold nanoparticles (TGNPs) onto transparent indium tin oxide (ITO) coated film glass. The as-prepared TGNPs have a transverse localized surface plasmon resonance (LSPR) band at 540 nm and a longitudinal LSPR band at about 710 nm. The longitudinal LSPR band of TGNPs exhibits higher refractive index sensitivity (245 nm/RIU) than its transverse LSPR band. The resulting "clean" surface of the TGNPs is easy applied to the further modification. The subsequent bioconjugation of TGNP films with goat anti-mouse-immunoglobulin G (anti-m-IgG) is successfully employed for the detection of mouse-immunoglobulin G (m-IgG) in a model based on the specific binding affinity between the antigen and antibody. The spectrophotometric sensor shows concentration-dependent binding for m-IgG. This study reveals a simple and sensitive method to fabricate a label-free optical biosensor based on longitudinal LSPR band of TGNPs on ITO substrate. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Identification of the Major Site of O-Linked β-N-Acetylglucosamine Modification in the C Terminus of Insulin Receptor Substrate-1*

    PubMed Central

    Ball, Lauren E.; Berkaw, Mary N.; Buse, Maria G.

    2008-01-01

    Signal transduction from the insulin receptor to downstream effectors is attenuated by phosphorylation at a number of Ser/Thr residues of insulin receptor substrate-1 (IRS-1) resulting in resistance to insulin action, the hallmark of type II diabetes. Ser/Thr residues can also be reversibly glycosylated by O-linked β-N-acetylglucosamine (O-GlcNAc) monosaccharide, a dynamic posttranslational modification that offers an alternative means of protein regulation to phosphorylation. To identify sites of O-GlcNAc modification in IRS-1, recombinant rat IRS-1 isolated from HEK293 cells was analyzed by two complementary mass spectrometric methods. Using data-dependent neutral loss MS3 mass spectrometry, MS/MS data were scanned for peptides that exhibited a neutral loss corresponding to the mass of N-acetylglucosamine upon dissociation in an ion trap. This methodology provided sequence coverage of 84% of the protein, permitted identification of a novel site of phosphorylation at Thr-1045, and facilitated the detection of an O-GlcNAc-modified peptide of IRS-1 at residues 1027−1073. The level of O-GlcNAc modification of this peptide increased when cells were grown under conditions of high glucose with or without chronic insulin stimulation or in the presence of an inhibitor of the O-GlcNAcase enzyme. To map the exact site of O-GlcNAc modification, IRS-1 peptides were chemically derivatized with dithiothreitol following β-elimination and Michael addition prior to LC-MS/MS. This approach revealed Ser-1036 as the site of O-GlcNAc modification. Site-directed mutagenesis and Western blotting with an anti-O-GlcNAc antibody suggested that Ser-1036 is the major site of O-GlcNAc modification of IRS-1. Identification of this site will facilitate exploring the biological significance of the O-GlcNAc modification. PMID:16244361

  3. Initial stages of ITO/Si interface formation: In situ x-ray photoelectron spectroscopy measurements upon magnetron sputtering and atomistic modelling using density functional theory

    SciTech Connect

    Løvvik, O. M.; Diplas, S.; Ulyashin, A.; Romanyuk, A.

    2014-02-28

    Initial stages of indium tin oxide (ITO) growth on a polished Si substrate upon magnetron sputtering were studied experimentally using in-situ x-ray photoelectron spectroscopy measurements. The presence of pure indium and tin, as well as Si bonded to oxygen at the ITO/Si interface were observed. The experimental observations were compared with several atomistic models of ITO/Si interfaces. A periodic model of the ITO/Si interface was constructed, giving detailed information about the local environment at the interface. Molecular dynamics based on density functional theory was performed, showing how metal-oxygen bonds are broken on behalf of silicon-oxygen bonds. These theoretical results support and provide an explanation for the present as well as previous ex-situ and in-situ experimental observations pointing to the creation of metallic In and Sn along with the growth of SiO{sub x} at the ITO/Si interface.

  4. Anodization of Ti thin film deposited on ITO.

    PubMed

    Sadek, Abu Z; Zheng, Haidong; Latham, Kay; Wlodarski, Wojtek; Kalantar-Zadeh, Kourosh

    2009-01-06

    We have investigated several key aspects for the self-organization of nanotubes in RF sputtered titanium (Ti) thin films formed by the anodization process in fluoride-ion-containing neutral electrolytes. Ti films were deposited on indium tin oxide (ITO) glass substrates at room temperature and 300 degrees C, and then anodized. The films were studied using scanning electron microscopy (SEM), X-ray diffraction (XRD), and UV-vis spectrometry before and after anodization. It was observed that anodization of high temperature deposited films resulted in nanotube type structures with diameters in the range of 10-45 nm for an applied voltage of 5-20 V. In addition, the anatase form of TiO(2) is formed during the anodization process which is also confirmed using photocurrent measurements. However, the anodization of room temperature deposited Ti films resulted in irregular pores or holes.

  5. Effect of Aluminum Substrate Surface Modification on Wettability and Freezing Delay of Water Droplet at Subzero Temperatures.

    PubMed

    Rahimi, Maral; Afshari, Alireza; Thormann, Esben

    2016-05-04

    In this study, we have investigated the freezing delay of a water droplet on precooled substrates of an aluminum alloy that is commonly used for heat-exchanger fins. The surfaces of the substrates were modified to obtain surfaces with different hydrophilicity/hydrophobicity and different surface chemistry but without significantly modifying the surface topography. The freezing delays and water contact angles were measured as a function of the substrate temperature and the results were compared to the predictions of the heterogeneous ice nucleation theory. Although the trends for each sample followed the trend in this theory, the differences in the extents of freezing delays were in apparent disagreement with the predictions. Concretely, a slightly hydrophilic substrate modified by (3-aminopropyl) triethoxysilane (APTES) showed longer freezing delays than both more hydrophilic and more hydrophobic substrates. We suggest that this is because this particular surface chemistry prevents ice formation at the interface of the substrate, prior to the deposition of the water droplet. On the basis of our results, we suggest that not only wettability and topography but also the concrete surface chemistry plays a significant role in the kinetics of the ice formation process when a water droplet is placed on a precooled substrate.

  6. Electrical circuit model of ITO/AZO/Ge photodetector.

    PubMed

    Patel, Malkeshkumar; Kim, Joondong

    2017-10-01

    In this data article, ITO/AZO/Ge photodetector was investigated for electrical circuit model. Due to the double (ITO and AZO) transparent metal-oxide films (DOI:10.1016/j.mssp.2016.03.007) (Yun et al., 2016) [1], the Ge heterojunction device has a better interface quality due to the AZO layer with a low electrical resistance due to the ITO layer (Yun et al., 2015) [2]. The electrical and interfacial benefitted ITO/AZO/Ge heterojunction shows the quality Schottky junction. In order to investigate the device, the ITO/AZO/Ge heterojunction was analyzed by R-C circuit model using the impedance spectroscopy.

  7. Characteristics of organic light-emitting diodes with conducting polymer anodes on plastic substrates

    NASA Astrophysics Data System (ADS)

    Huh, Jin Woo; Kim, Young Min; Park, Young Wook; Choi, Jin Hwan; Lee, Jin Woo; Lee, Jong Woo; Yang, Jae Woong; Ju, Sung Hoo; Paek, Kyeong Kap; Ju, Byeong Kwon

    2008-02-01

    The fabrication of conducting polymer films by a screen-printing method and characterization of an organic light-emitting diode (OLED) implemented using these films as an anode on plastic substrates are reported. Organic transparent electrode materials containing poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(styrenesulfonic acid) (PSS) (PEDOT:PSS) were used after the modification by a unique nanoparticle binder design. The electro-optical properties as well as mechanical stabilities of these films were measured. The OLED performances when employing these films were comparable to that of OLEDs using indium tin oxide (ITO) despite their relatively poor conductivity. An external quantum efficiency of the OLED using this anode is ˜3.5%, which is about twice as that of OLEDs using ITO. These results show that the organic transparent electrode of a conducting polymer film patterned by the screen-printing method is a potential candidate for an electrode of the flexible OLED.

  8. Mechanical Properties of ZTO, ITO, and a-Si:H Multilayer Films for Flexible Thin Film Solar Cells

    PubMed Central

    Hengst, Claudia; Menzel, Siegfried B; Rane, Gayatri K; Smirnov, Vladimir; Wilken, Karen; Leszczynska, Barbara; Fischer, Dustin; Prager, Nicole

    2017-01-01

    The behavior of bi- and trilayer coating systems for flexible a-Si:H based solar cells consisting of a barrier, an electrode, and an absorption layer is studied under mechanical load. First, the film morphology, stress, Young’s modulus, and crack onset strain (COS) were analyzed for single film coatings of various thickness on polyethylene terephthalate (PET) substrates. In order to demonstrate the role of the microstructure of a single film on the mechanical behavior of the whole multilayer coating, two sets of InSnOx (indium tin oxide, ITO) conductive coatings were prepared. Whereas a characteristic grain–subgrain structure was observed in ITO-1 films, grain growth was suppressed in ITO-2 films. ITO-1 bilayer coatings showed two-step failure under tensile load with cracks propagating along the ITO-1/a-Si:H-interface, whereas channeling cracks in comparable bi- and trilayers based on amorphous ITO-2 run through all constituent layers. A two-step failure is preferable from an application point of view, as it may lead to only a degradation of the performance instead of the ultimate failure of the device. Hence, the results demonstrate the importance of a fine-tuning of film microstructure not only for excellent electrical properties, but also for a high mechanical performance of flexible devices (e.g., a-Si:H based solar cells) during fabrication in a roll-to-roll process or under service. PMID:28772609

  9. Mechanical Properties of ZTO, ITO, and a-Si:H Multilayer Films for Flexible Thin Film Solar Cells.

    PubMed

    Hengst, Claudia; Menzel, Siegfried B; Rane, Gayatri K; Smirnov, Vladimir; Wilken, Karen; Leszczynska, Barbara; Fischer, Dustin; Prager, Nicole

    2017-03-01

    The behavior of bi- and trilayer coating systems for flexible a-Si:H based solar cells consisting of a barrier, an electrode, and an absorption layer is studied under mechanical load. First, the film morphology, stress, Young's modulus, and crack onset strain (COS) were analyzed for single film coatings of various thickness on polyethylene terephthalate (PET) substrates. In order to demonstrate the role of the microstructure of a single film on the mechanical behavior of the whole multilayer coating, two sets of InSnOx (indium tin oxide, ITO) conductive coatings were prepared. Whereas a characteristic grain-subgrain structure was observed in ITO-1 films, grain growth was suppressed in ITO-2 films. ITO-1 bilayer coatings showed two-step failure under tensile load with cracks propagating along the ITO-1/a-Si:H-interface, whereas channeling cracks in comparable bi- and trilayers based on amorphous ITO-2 run through all constituent layers. A two-step failure is preferable from an application point of view, as it may lead to only a degradation of the performance instead of the ultimate failure of the device. Hence, the results demonstrate the importance of a fine-tuning of film microstructure not only for excellent electrical properties, but also for a high mechanical performance of flexible devices (e.g., a-Si:H based solar cells) during fabrication in a roll-to-roll process or under service.

  10. Electrical and optical properties of near UV transparent conductive ITO/Ga2O3 multilayer films deposited by RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Kwan; Lee, Ji-Myon

    2016-10-01

    Ga2O3/ITO co-sputtering and alternating multilayer films were deposited on the Corning glass substrates by radio frequency magnetron technique at room temperature. We investigated the effects of the thickness and period of Ga2O3 interlayer on the microstructure. We also elucidated the electrical and the optical properties of Ga2O3/indium tin oxide (ITO) multilayer films and co-sputtered the Ga2O3/ITO mixed films (co-IGTO). One-period Ga2O3/ITO films, which exhibited the lowest sheet resistance of 58.6 Ω/sq and the highest transmittance of 80.94% at a wavelength of 380 nm, were deposited on the Corning glass. The sheet resistance of co-sputtered Ga2O3/ITO film was rapidly increased to 189.2 Ω/sq., while the Hall mobility of the same film was rapidly decreased to 12.53 cm2/(V s). Although the carrier concentration of the multilayer films was lower than that of the ITO single layer, the figure of merit of the Ga2O3/ITO one-period alternating multilayer films was higher than those of single ITO and co-IGTO films.

  11. Plasmonic ITO-free polymer solar cell.

    PubMed

    Lin, Ming-Yi; Kang, Yu Ling; Chen, Yu-Cheng; Tsai, Tsung-Han; Lin, Shih-Chieh; Huang, Yi-Hsiang; Chen, Yi-Jiun; Lu, Chun-Yang; Lin, Hoang Yan; Wang, Lon A; Wu, Chung-Chih; Lee, Si-Chen

    2014-03-10

    The aluminum and sliver multilayered nano-grating structure is fabricated by laser interference lithography and the intervals between nanoslits is filled with modified PEDOT:PSS. The grating structured transparent electrode functions as the anti-reflection layer which not only decreases the reflected light but also increases the absorption of the active layer. The performances of P3HT:PC₆₁BM solar cells are studied experimentally and theoretically in detail. The field intensities of the transverse magnetic (TM) and transverse electrical (TE) waves distributed in the active layer are simulated by rigorous coupled wave analysis (RCWA). The power conversion efficiency of the plasmonic ITO-free polymer solar cell can reach 3.64% which is higher than ITO based polymer solar cell with efficiency of 3.45%.

  12. HYPOMELANOSIS OF ITO: A CASE REPORT

    PubMed Central

    Gupta, Monisha; Gupta, Vinay

    2002-01-01

    A twelve year old female child presented with learning disability. Detailed physical examination revealed anomalies involving the nervous and musculoskeletal system. In addition she had linear and whorled. hypopigmented lesions along the lines of Blaschko distributed over the upper limb, trunk and face on the left side of the body. She fulfilled the diagnostic criteria for Hypomelanosis of Ito, even in the absence of chromosomal studies and advanced histopathological studies. PMID:21206591

  13. Surface modification of a-plane sapphire substrates and its effect on crystal orientation of ZnTe layer

    NASA Astrophysics Data System (ADS)

    Nakasu, Taizo; Sun, Wei-Che; Kobayashi, Masakazu

    2017-01-01

    Domain structures of ZnTe layers grown on a-plane sapphire substrates were investigated by changing the crystallographic properties of the surface and interface. Pole figure images were obtained and we investigated the domain structure in the grown film and the orientation relationships between films and substrates. It was confirmed that two kinds of {111} domains were oriented by annealing the buffer layer at 350 °C, while the (100) domain was obtained by annealing the buffer layer at 300 °C. From the results of the rocking curve measurement, the introduction of a step-terrace surface through the high-temperature treatment of the substrate resulted in an improved crystallographic quality. However, it did not affect the domain structure in the layer. The introduction of an off-angle on the substrate surface resulted in the formation of a single (111) domain layer. These crystallographic features were mainly affected by the surface atom arrangement of the sapphire substrate and its chemical nature.

  14. c-Myc Alters Substrate Utilization and O-GlcNAc Protein Posttranslational Modifications without Altering Cardiac Function during Early Aortic Constriction

    PubMed Central

    Ledee, Dolena; Smith, Lincoln; Bruce, Margaret; Kajimoto, Masaki; Isern, Nancy; Portman, Michael A.; Olson, Aaron K.

    2015-01-01

    Hypertrophic stimuli cause transcription of the proto-oncogene c-Myc (Myc). Prior work showed that myocardial knockout of c-Myc (Myc) attenuated hypertrophy and decreased expression of metabolic genes after aortic constriction. Accordingly, we assessed the interplay between Myc, substrate oxidation and cardiac function during early pressure overload hypertrophy. Mice with cardiac specific, inducible Myc knockout (MycKO-TAC) and non-transgenic littermates (Cont-TAC) were subjected to transverse aortic constriction (TAC; n = 7/group). Additional groups underwent sham surgery (Cont-Sham and MycKO-Sham, n = 5 per group). After two weeks, function was measured in isolated working hearts along with substrate fractional contributions to the citric acid cycle by using perfusate with 13C labeled mixed fatty acids, lactate, ketone bodies and unlabeled glucose and insulin. Cardiac function was similar between groups after TAC although +dP/dT and -dP/dT trended towards improvement in MycKO-TAC versus Cont-TAC. In sham hearts, Myc knockout did not affect cardiac function or substrate preferences for the citric acid cycle. However, Myc knockout altered fractional contributions during TAC. The unlabeled fractional contribution increased in MycKO-TAC versus Cont-TAC, whereas ketone and free fatty acid fractional contributions decreased. Additionally, protein posttranslational modifications by O-GlcNAc were significantly greater in Cont-TAC versus both Cont-Sham and MycKO-TAC. In conclusion, Myc alters substrate preferences for the citric acid cycle during early pressure overload hypertrophy without negatively affecting cardiac function. Myc also affects protein posttranslational modifications by O-GlcNAc during hypertrophy, which may regulate Myc-induced metabolic changes. PMID:26266538

  15. c-Myc alters substrate utilization and O-GlcNAc protein posttranslational modifications without altering cardiac function during early aortic constriction

    DOE PAGES

    Ledee, Dolena; Smith, Lincoln; Bruce, Margaret; ...

    2015-08-12

    Pressure overload cardiac hypertrophy alters substrate metabolism. Prior work showed that myocardial inactivation of c-Myc (Myc) attenuated hypertrophy and decreased expression of metabolic genes after aortic constriction. Accordingly, we hypothesize that Myc regulates substrate preferences for the citric acid cycle during pressure overload hypertrophy from transverse aortic constriction (TAC) and that these metabolic changes impact cardiac function and growth. To test this hypothesis, we subjected mice with cardiac specific, inducible Myc inactivation (MycKO-TAC) and non-transgenic littermates (Cont-TAC) to transverse aortic constriction (TAC; n=7/group). A separate group underwent sham surgery (Sham, n=5). After two weeks, function was measured in isolated workingmore » hearts along with substrate fractional contributions to the citric acid cycle by using perfusate with 13C labeled mixed fatty acids, lactate, ketone bodies and unlabeled glucose and insulin. Cardiac function was similar between groups after TAC although +dP/dT and -dP/dT trended towards improvement in MycKO-TAC versus Cont-TAC. Compared to Sham, Cont-TAC had increased free fatty acid fractional contribution with a concurrent decrease in unlabeled (predominately glucose) contribution. The changes in free fatty acid and unlabeled fractional contributions were abrogated by Myc inactivation during TAC (MycKO-TAC). Additionally, protein posttranslational modification by O-GlcNAc was significantly greater in Cont-TAC versus both Sham and MycKO-TAC. Lastly, Myc alters substrate preferences for the citric acid cycle during early pressure overload hypertrophy without negatively affecting cardiac function. Myc also affects protein posttranslational modifications by O-GlcNAc during hypertrophy.« less

  16. c-Myc alters substrate utilization and O-GlcNAc protein posttranslational modifications without altering cardiac function during early aortic constriction

    SciTech Connect

    Ledee, Dolena; Smith, Lincoln; Bruce, Margaret; Kajimoto, Masaki; Isern, Nancy; Portman, Michael A.; Olson, Aaron K.; Bertrand, Luc

    2015-08-12

    Pressure overload cardiac hypertrophy alters substrate metabolism. Prior work showed that myocardial inactivation of c-Myc (Myc) attenuated hypertrophy and decreased expression of metabolic genes after aortic constriction. Accordingly, we hypothesize that Myc regulates substrate preferences for the citric acid cycle during pressure overload hypertrophy from transverse aortic constriction (TAC) and that these metabolic changes impact cardiac function and growth. To test this hypothesis, we subjected mice with cardiac specific, inducible Myc inactivation (MycKO-TAC) and non-transgenic littermates (Cont-TAC) to transverse aortic constriction (TAC; n=7/group). A separate group underwent sham surgery (Sham, n=5). After two weeks, function was measured in isolated working hearts along with substrate fractional contributions to the citric acid cycle by using perfusate with 13C labeled mixed fatty acids, lactate, ketone bodies and unlabeled glucose and insulin. Cardiac function was similar between groups after TAC although +dP/dT and -dP/dT trended towards improvement in MycKO-TAC versus Cont-TAC. Compared to Sham, Cont-TAC had increased free fatty acid fractional contribution with a concurrent decrease in unlabeled (predominately glucose) contribution. The changes in free fatty acid and unlabeled fractional contributions were abrogated by Myc inactivation during TAC (MycKO-TAC). Additionally, protein posttranslational modification by O-GlcNAc was significantly greater in Cont-TAC versus both Sham and MycKO-TAC. Lastly, Myc alters substrate preferences for the citric acid cycle during early pressure overload hypertrophy without negatively affecting cardiac function. Myc also affects protein posttranslational modifications by O-GlcNAc during hypertrophy.

  17. Sensitivity of CuS and CuS/ITO EGFETs implemented as pH sensors

    NASA Astrophysics Data System (ADS)

    Sabah, Fayroz A.; Ahmed, Naser M.; Hassan, Z.; Al-Hardan, Naif H.

    2016-09-01

    Several studies have been performed on the use of ITO as an extended gate of field effect transistor. Studies have also been done on the effects of using ITO as a substrate to improve the sensitivity of SnO2 membrane. In this research, the ITO was used as a substrate for the synthesis of CuS thin films to determine its potential to improve sensitivity and any possible application as pH sensors. The CuS thin film was prepared from copper chloride and sodium thiosulfate via spray pyrolysis deposition using de-ionized water as a solvent. The sensitivity of the CuS/ITO membrane was measured and comparatively analyzed against that of CuS membrane. Structural and morphological properties were investigated for both as-deposit thin films. The membranes were then deployed as pH sensors and their sensitivities measured. The results confirmed that CuS/ITO membrane had much better sensitivity (37 µA/pH and 37 mV/pH) compared to CuS membrane (8 µA/pH and 7.5 mV/pH).

  18. Interface modification and material synthesis of organic light-emitting diodes using plasma technology

    NASA Astrophysics Data System (ADS)

    Liang, Rongqing; Ou, Qiongrong; Yang, Cheng; He, Kongduo; Yang, Xilu; Zhong, Shaofeng; plasma application Team

    2015-09-01

    Organic light-emitting diodes (OLEDs), due to their unique properties of solution processability, compatibility with flexible substrates and with large-scale printing technology, attract huge interest in the field of lighting. The integration of plasma technology into OLEDs provides a new route to improve their performance. Here we demonstrate the modification of indium-tin-oxide (ITO) work function by plasma treatment, synthesis of thermally activated delayed fluorescence (TADF) materials using plasma grafting (polymerisation), and multi-layer solution processing achieved by plasma cross-linking.

  19. Modification of fluorous substrates with oligo(ethylene glycol) via "click" chemistry for long-term resistance of cell adhesion.

    PubMed

    Contreras-Caceres, Rafael; Santos, Catherine M; Li, Siheng; Kumar, Amit; Zhu, Zhiling; Kolar, Satya S; Casado-Rodriguez, Miguel A; Huang, Yongkai; McDermott, Alison; Lopez-Romero, Juan Manuel; Cai, Chengzhi

    2015-11-15

    In this work perfluorinated substrates fabricated from SiO2 glass slides are modified with oligo(ethylene glycol) (OEG) units for long-term resistance of cell adhesion purposes, based on fluorous interactions and click chemistry. Specifically, fluorous substrates, prepared by treatment of glass slides with 1H, 1H, 2H, 2H-perfluorodecyltrimethoxysilane (FAS17), were coated with ethynyl-OEG-C8F17, followed by covalent attachment of an azido-OEG via copper-catalyzed azide-alkyne cycloaddition (CuAAC) "click" reaction. We demonstrate that the resultant surface avoid fibrinogen adsorption and resisted cell adhesion for over 14days. X-ray photoemission spectroscopy (XPS) analysis and contact angle goniometry measurements confirm the presence of the OEG molecules on the fluorous substrates. Bright field optical images show total absence of 3T3 fibroblast cells on the OEG modified fluorinated substrate for 1 and 5days, and a remarkably decrease of cell adhesion at 14days.

  20. ITO nanoparticles reused from ITO scraps and their applications to sputtering target for transparent conductive electrode layer

    NASA Astrophysics Data System (ADS)

    Hong, Sung-Jei; Song, Sang-Hyun; Kim, Byeong Jun; Lee, Jae-Yong; Kim, Young-Sung

    2017-09-01

    In this study, ITO nanoparticles (ITO-NPs) were reused from ITO target scraps to synthesize low cost ITO-NPs and to apply to make sputtering target for transparent conductive electrodes (TCEs). By controlling heat-treatment temperature as 980 °C, we achieved reused ITO-NPs having Brunauer, Emmett and Teller specific surface area (BET SSA) and average particle size 8.05 m2/g and 103.8 nm, respectively. The BET SSA decreases along with increasing heat-treatment temperature. The ITO-NPs were grown as round mound shape, and highly crystallized to (222) preferred orientations. Also, applying the reused ITO-NPs, we achieved an ITO target of which density was 99.6%. Using the ITO target, we achieved high quality TCE layer of which sheet resistance and optical transmittance at 550 nm were 29.5 Ω/sq. and 82.3%. Thus, it was confirmed that the reused ITO-NPs was feasible to sputtering target for TCEs layer.

  1. ITO nanoparticles reused from ITO scraps and their applications to sputtering target for transparent conductive electrode layer.

    PubMed

    Hong, Sung-Jei; Song, Sang-Hyun; Kim, Byeong Jun; Lee, Jae-Yong; Kim, Young-Sung

    2017-01-01

    In this study, ITO nanoparticles (ITO-NPs) were reused from ITO target scraps to synthesize low cost ITO-NPs and to apply to make sputtering target for transparent conductive electrodes (TCEs). By controlling heat-treatment temperature as 980 °C, we achieved reused ITO-NPs having Brunauer, Emmett and Teller specific surface area (BET SSA) and average particle size 8.05 m(2)/g and 103.8 nm, respectively. The BET SSA decreases along with increasing heat-treatment temperature. The ITO-NPs were grown as round mound shape, and highly crystallized to (222) preferred orientations. Also, applying the reused ITO-NPs, we achieved an ITO target of which density was 99.6%. Using the ITO target, we achieved high quality TCE layer of which sheet resistance and optical transmittance at 550 nm were 29.5 Ω/sq. and 82.3%. Thus, it was confirmed that the reused ITO-NPs was feasible to sputtering target for TCEs layer.

  2. Differential responses of rabbit ventricular and atrial transient outward current (Ito) to the Ito modulator NS5806.

    PubMed

    Cheng, Hongwei; Cannell, Mark B; Hancox, Jules C

    2017-03-01

    Transient outward potassium current (Ito) in the heart underlies phase 1 repolarization of cardiac action potentials and thereby affects excitation-contraction coupling. Small molecule activators of Ito may therefore offer novel treatments for cardiac dysfunction, including heart failure and atrial fibrillation. NS5806 has been identified as a prototypic activator of canine Ito This study investigated, for the first time, actions of NS5806 on rabbit atrial and ventricular Ito Whole cell patch-clamp recordings of Ito and action potentials were made at physiological temperature from rabbit ventricular and atrial myocytes. 10 μmol/L NS5806 increased ventricular Ito with a leftward shift in Ito activation and accelerated restitution. At higher concentrations, stimulation of Ito was followed by inhibition. The EC50 for stimulation was 1.6 μmol/L and inhibition had an IC50 of 40.7 μmol/L. NS5806 only inhibited atrial Ito (IC50 of 18 μmol/L) and produced a modest leftward shifts in Ito activation and inactivation, without an effect on restitution. 10 μmol/L NS5806 shortened ventricular action potential duration (APD) at APD20-APD90 but prolonged atrial APD NS5806 also reduced atrial AP upstroke and amplitude, consistent with an additional atrio-selective effect on Na(+) channels. In contrast to NS5806, flecainide, which discriminates between Kv1.4 and 4.x channels, produced similar levels of inhibition of ventricular and atrial Ito NS5806 discriminates between rabbit ventricular and atrial Ito, with mixed activator and inhibitor actions on the former and inhibitor actions against the later. NS5806 may be of significant value for pharmacological interrogation of regional differences in native cardiac Ito. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  3. ITOS D AND E system design report, volume 1

    NASA Technical Reports Server (NTRS)

    1970-01-01

    The configuration and functions of the ITOS D and E system are described. The system will expand the operational capability of the basic TIROS M/ITOS system. The ITOS D and E mission will utilize the capabilities of the two-stage DSV 3N-6 Delta launch vehicle to place the ITOS D and E spacecraft into a circular, near-polar, sun synchronous orbit at 790 nautical miles altitude. The ITOS D and E will provide the following primary data: (1) visible daytime observations of cloud cover, (2) daytime and nighttime observations of cloud cover as detected from radiance in infrared spectrum, and (3) vertical temperature profile of the atmosphere on a global basis for data processing. In addition, the ITOS D and E system will provide secondary data comprising solar proton density measurements obtained throughout the orbit.

  4. Probing the promiscuous active site of myo-inositol dehydrogenase using synthetic substrates, homology modeling, and active site modification.

    PubMed

    Daniellou, Richard; Zheng, Hongyan; Langill, David M; Sanders, David A R; Palmer, David R J

    2007-06-26

    The active site of myo-inositol dehydrogenase (IDH, EC 1.1.1.18) from Bacillus subtilis recognizes a variety of mono- and disaccharides, as well as 1l-4-O-substituted inositol derivatives. It catalyzes the NAD+-dependent oxidation of the axial alcohol of these substrates with comparable kinetic constants. We have found that 4-O-p-toluenesulfonyl-myo-inositol does not act as a substrate for IDH, in contrast to structurally similar compounds such as those bearing substituted benzyl substituents in the same position. X-ray crystallographic analysis of 4-O-p-toluenesulfonyl-myo-inositol and 4-O-(2-naphthyl)methyl-myo-inositol, which is a substrate for IDH, shows a distinct difference in the preferred conformation of the aryl substituent. Conformational analysis of known substrates of IDH suggests that this conformational difference may account for the difference in reactivity of 4-O-p-toluenesulfonyl-myo-inositol in the presence of IDH. A sequence alignment of IDH with the homologous glucose-fructose oxidoreductase allowed the construction of an homology model of inositol dehydrogenase, to which NADH and 4-O-benzyl-scyllo-inosose were docked and the active site energy minimized. The active site model is consistent with all experimental results and suggests that a conserved tyrosine-glycine-tyrosine motif forms the hydrophobic pocket adjoining the site of inositol recognition. Y233F and Y235F retain activity, while Y233R and Y235R do not. A histidine-aspartate pair, H176 and D172, are proposed to act as a dyad in which H176 is the active site acid/base. The enzyme is inactivated by diethyl pyrocarbonate, and the mutants H176A and D172N show a marked loss of activity. Kinetic isotope effect experiments with D172N indicate that chemistry is rate-determining for this mutant.

  5. Insights into the Activity and Substrate Binding of Xylella fastidiosa Polygalacturonase by Modification of a Unique QMK Amino Acid Motif Using Protein Chimeras

    PubMed Central

    Warren, Jeremy G.; Lincoln, James E.; Kirkpatrick, Bruce C.

    2015-01-01

    Polygalacturonases (EC 3.2.1.15) catalyze the random hydrolysis of 1, 4-alpha-D-galactosiduronic linkages in pectate and other galacturonans. Xylella fastidiosa possesses a single polygalacturonase gene, pglA (PD1485), and X. fastidiosa mutants deficient in the production of polygalacturonase are non-pathogenic and show a compromised ability to systemically infect grapevines. These results suggested that grapevines expressing sufficient amounts of an inhibitor of X. fastidiosa polygalacturonase might be protected from disease. Previous work in our laboratory and others have tried without success to produce soluble active X. fastidiosa polygalacturonase for use in inhibition assays. In this study, we created two enzymatically active X. fastidiosa / A. vitis polygalacturonase chimeras, AX1A and AX2A to explore the functionality of X. fastidiosa polygalacturonase in vitro. The AX1A chimera was constructed to specifically test if recombinant chimeric protein, produced in Escherichia coli, is soluble and if the X. fastidiosa polygalacturonase catalytic amino acids are able to hydrolyze polygalacturonic acid. The AX2A chimera was constructed to evaluate the ability of a unique QMK motif of X. fastidiosa polygalacturonase, most polygalacturonases have a R(I/L)K motif, to bind to and allow the hydrolysis of polygalacturonic acid. Furthermore, the AX2A chimera was also used to explore what effect modification of the QMK motif of X. fastidiosa polygalacturonase to a conserved RIK motif has on enzymatic activity. These experiments showed that both the AX1A and AX2A polygalacturonase chimeras were soluble and able to hydrolyze the polygalacturonic acid substrate. Additionally, the modification of the QMK motif to the conserved RIK motif eliminated hydrolytic activity, suggesting that the QMK motif is important for the activity of X. fastidiosa polygalacturonase. This result suggests X. fastidiosa polygalacturonase may preferentially hydrolyze a different pectic substrate or

  6. Insights into the Activity and Substrate Binding of Xylella fastidiosa Polygalacturonase by Modification of a Unique QMK Amino Acid Motif Using Protein Chimeras.

    PubMed

    Warren, Jeremy G; Lincoln, James E; Kirkpatrick, Bruce C

    2015-01-01

    Polygalacturonases (EC 3.2.1.15) catalyze the random hydrolysis of 1, 4-alpha-D-galactosiduronic linkages in pectate and other galacturonans. Xylella fastidiosa possesses a single polygalacturonase gene, pglA (PD1485), and X. fastidiosa mutants deficient in the production of polygalacturonase are non-pathogenic and show a compromised ability to systemically infect grapevines. These results suggested that grapevines expressing sufficient amounts of an inhibitor of X. fastidiosa polygalacturonase might be protected from disease. Previous work in our laboratory and others have tried without success to produce soluble active X. fastidiosa polygalacturonase for use in inhibition assays. In this study, we created two enzymatically active X. fastidiosa / A. vitis polygalacturonase chimeras, AX1A and AX2A to explore the functionality of X. fastidiosa polygalacturonase in vitro. The AX1A chimera was constructed to specifically test if recombinant chimeric protein, produced in Escherichia coli, is soluble and if the X. fastidiosa polygalacturonase catalytic amino acids are able to hydrolyze polygalacturonic acid. The AX2A chimera was constructed to evaluate the ability of a unique QMK motif of X. fastidiosa polygalacturonase, most polygalacturonases have a R(I/L)K motif, to bind to and allow the hydrolysis of polygalacturonic acid. Furthermore, the AX2A chimera was also used to explore what effect modification of the QMK motif of X. fastidiosa polygalacturonase to a conserved RIK motif has on enzymatic activity. These experiments showed that both the AX1A and AX2A polygalacturonase chimeras were soluble and able to hydrolyze the polygalacturonic acid substrate. Additionally, the modification of the QMK motif to the conserved RIK motif eliminated hydrolytic activity, suggesting that the QMK motif is important for the activity of X. fastidiosa polygalacturonase. This result suggests X. fastidiosa polygalacturonase may preferentially hydrolyze a different pectic substrate or

  7. Surface modification of titanium substrates with silver nanoparticles embedded sulfhydrylated chitosan/gelatin polyelectrolyte multilayer films for antibacterial application.

    PubMed

    Li, Wen; Xu, Dawei; Hu, Yan; Cai, Kaiyong; Lin, Yingcheng

    2014-06-01

    To develop Ti implants with potent antibacterial activity, a novel "sandwich-type" structure of sulfhydrylated chitosan (Chi-SH)/gelatin (Gel) polyelectrolyte multilayer films embedding silver (Ag) nanoparticles was coated onto titanium substrate using a spin-assisted layer-by-layer assembly technique. Ag ions would be enriched in the polyelectrolyte multilayer films via the specific interactions between Ag ions and -HS groups in Chi-HS, thus leading to the formation of Ag nanoparticles in situ by photo-catalytic reaction (ultraviolet irradiation). Contact angle measurement and field emission scanning electron microscopy equipped with energy dispersive X-ray spectroscopy were employed to monitor the construction of Ag-containing multilayer on titanium surface, respectively. The functional multilayered films on titanium substrate [Ti/PEI/(Gel/Chi-SH/Ag) n /Gel] could efficiently inhibit the growth and activity of Bacillus subtitles and Escherichia coli onto titanium surface. Moreover, studies in vitro confirmed that Ti substrates coating with functional multilayer films remained the biological functions of osteoblasts, which was reflected by cell morphology, cell viability and ALP activity measurements. This study provides a simple, versatile and generalized methodology to design functional titanium implants with good cyto-compatibility and antibacterial activity for potential clinical applications.

  8. Satellite technology. [Landsat 1 and ITOS

    NASA Technical Reports Server (NTRS)

    Branchflower, G. A.

    1974-01-01

    An exposure to satellite design and fabrication techniques used in unmanned satellite programs is provided. Spacecraft configurations of the earth resources technology satellite (ERTS) and the improved ITOS operational satellite, which are typical of the construction and layout techniques presently in use, are discussed. Support and service subsystems are described taking the ERTS subsystems as representative. The subsystems explained comprise: power, attitude control, orbit adjustment, wideband telemetry, tracking-telemetry-command, auxiliary processing, electrical integration, and spaceborne recording devices. A number of photographs, renditions and diagrams illustrates the text.

  9. ITO-MgF2 Film Development for PowerSphere Polymer Surface Protection

    NASA Technical Reports Server (NTRS)

    Hambourger, Paul D.; Kerslake, Thomas W.; Waters, Deborah L.

    2004-01-01

    Multi-kilogram class microsatellites with a PowerSphere electric power system are attractive for fulfilling a variety of potential NASA missions. However, PowerSphere polymer surfaces must be coated with a film that has suitable electrical sheet resistivity for electrostatic discharge control, be resistant to atomic oxygen attack, be transparent to ultraviolet light for composite structure curing and resist ultraviolet light induced darkening for efficient photovoltaic cell operation. In addition, the film must be tolerant of polymer layer folding associated with launch stowage of PowerSphere inflatable structures. An excellent film material candidate to meet these requirements is co-sputtered, indium oxide (In2O3) - tin oxide (SnO2), known as 'ITO', and magnesium fluoride (MgF2). While basic ITO-MgF2 film properties have been the subject of research over the last decade, further research is required in the areas of film durability for space-inflatable applications and precise film property control for large scale commercial production. In this paper, the authors present film durability results for a folded polymer substrate and film resistance to vacuum UV darkening. The authors discuss methods and results in the area of film sheet resistivity measurement and active control, particularly dual-channel, plasma emission line measurement of ITO and MgF2 plasma sources. ITO-MgF2 film polymer coupon preparation is described as well as film deposition equipment, procedures and film characterization. Durability testing methods are also described. The pre- and post-test condition of the films is assessed microscopically and electrically. Results show that an approx. 500A ITO-18vol% MgF2 film is a promising candidate to protect PowerSphere polymer surfaces for Earth orbit missions. Preliminary data also indicate that in situ film measurement methods are promising for active film resistivity control in future large scale production. Future film research plans are also

  10. Monitoring of dopamine release in single cell using ultrasensitive ITO microsensors modified with carbon nanotubes.

    PubMed

    Shi, Bao-Xian; Wang, Yu; Zhang, Kai; Lam, Tin-Lun; Chan, Helen Lai-Wa

    2011-02-15

    The study of single cell dynamics has been greatly adapted in biological and medical research and applications. In this work a novel microfluidic electrochemical sensor with carbon nanotubes (CNTs) modified indium tin oxide (ITO) microelectrode was developed for single cells release monitoring. The sensitivity of the electrochemical sensor after CNTs surface modification was improved by 2.5-3 orders of magnitude. The developed CNTs modified ITO sensor was successfully employed to monitor the dopamine release from single living rat pheochromocytoma (PC 12) cells. Its ultrahigh sensitivity, transparency and need for fewer agents enable this smart electrochemical sensor to become a powerful tool in recording dynamic release from various living tissues and organs optically and electrically.

  11. Studies on Ferromagnetic and Photoluminescence Properties of ITO and Cu-Doped ITO Nanoparticles Synthesized by Solid State Reaction

    NASA Astrophysics Data System (ADS)

    Babu, S. Harinath; Kaleemulla, S.; Rao, N. Madhusudhana; Krishnamoorthi, C.

    2016-11-01

    Cubic structured indium-tin-oxide (ITO) and copper-doped ITO nanoparticles were synthesized by solid state reaction. The structure, morphology, chemical, magnetic, and photoluminescence properties of the synthesized nanoparticles were studied by x-ray diffraction, field emission scanning electron microscopy, x-ray photoelectron spectroscopy, vibrating sample magnetometry, and photoluminescence spectrophotometry, respectively. Magnetic studies confirmed that the ITO nanoparticles were ferromagnetic at room temperature (300 K) and at 100 K, and it was believed that the observed ferromagnetism may be due to oxygen vacancies and defects present in the system. No hysteresis loop was observed in copper-doped ITO nanoparticles at room temperature and 100 K. The ITO and Cu-doped ITO nanoparticles exhibited two broad emission peaks in the visible region of the electromagnetic spectrum.

  12. Surface modification of amorphous substrates by disulfide derivatives: A photo-assisted route to direct functionalization of chalcogenide glasses

    NASA Astrophysics Data System (ADS)

    Amalric, Julien; Marchand-Brynaert, Jacqueline

    2011-12-01

    A novel route for chalcogenide glass surface modification is disclosed. The formation of an organic monolayer from disulfide derivatives is studied on two different glasses of formula GexAsySez by water contact angle measurement, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy in attenuated total reflection mode (FTIR-ATR). The potential anchoring group is the disulfide functionality. Since thioctic acid derivatives absorb around 335 nm, an irradiation step is included, in order to favor S-S disruption. Three types of disulfide compounds are grafted onto small glass breaks for contact angle and XPS analyses. The results show effective changes of surface state. According to contact angle measurement, the deposited organic layer functionalized by a small polyethylene glycol chain leads to a more hydrophilic surface, long alkyl chain or a perfluorinated carbon chain leads to a more hydrophobic surface. XPS shows the presence at the surface of an organic layer with sulfur and ethylene oxide chains, or augmentation of organic carbons or fluorine and Csbnd F bonds. The photo-assisted grafting of the disulfides onto an ATR prism made of chalcogenide glass shows that this surface modification process does not affect infrared transparency, despite UV treatment, and accurate structural analysis can be performed.

  13. Modification of bovine heart succinate dehydrogenase with ethoxyformic anhydride and rose bengal: evidence for essential histidyl residues protectable by substrates.

    PubMed

    Hederstedt, L; Hatefi, Y

    1986-06-01

    Purified and membrane-bound succinate dehydrogenase (SDH) from bovine heart mitochondria was inhibited by the histidine-modifying reagents ethoxyformic anhydride (EFA) and Rose Bengal in the presence of light. Succinate and competitive inhibitors protected against inhibition, and decreased the number of histidyl residues modified by EFA. The essential residue modified by EFA was not the essential thiol of SDH, but modification of the essential thiol abolished the protective effect of malonate against inhibition of SDH by EFA. The EFA inhibition was reversed by hydroxylamine nearly completely when the inhibition was less than or equal to 35%, and only partially when the inhibition was more extensive. The uv spectrum of EFA-modified SDH before and after hydroxylamine treatment suggested that extensive inhibition of SDH with EFA may result in ethoxyformylation at both imidazole nitrogens of histidyl residues. Such a modification is not reversed by hydroxylamine. Succinate dehydrogenases and fumarate reductases from several different sources have similar compositions, and the two enzymes from Escherichia coli have considerable homology in the amino acid composition of their respective flavoprotein and iron-sulfur protein subunits. In the former, there is a short stretch containing conserved histidine, cysteine, and arginine residues. These residues, if also conserved in the bovine enzyme, may be the essential active site residues suggested by this work (histidine) and previously (cysteine, arginine).

  14. A Sensitive Microplate Assay for Lipase Activity Measurement Using Olive Oil Emulsion Substrate: Modification of the Copper Soap Colorimetric Method.

    PubMed

    Mustafa, Ahmad; Karmali, Amin; Abdelmoez, Wael

    2016-01-01

    The present work involves a sensitive high-throughput microtiter plate based colorimetric assay for estimating lipase activity using cupric acetate pyridine reagent (CAPR). In the first approach, three factors two levels factorial design methodology was used to evaluate the interactive effect of different parameters on the sensitivity of the assay method. The optimization study revealed that the optimum CAPR concentration was 7.5% w/v, the optimum solvent was heptane and the optimum CAPR pH was 6. In the second approach, the optimized colorimetric microplate assay was used to measure lipase activity based on enzymatic hydrolysis of olive oil emulsion substrate at 37°C and 150 rpm. The emulsion substrates were formulated by using olive oil, triton X-100 (10% v/v in pH 8) and sodium phosphate buffer of pH 8 in ratio of 1:1:1 in the case of Candida sp. lipase. While in the case of immobilized lipozyme RMIM, The emulsion substrates were formulated by using olive oil, triton X-100 (1% v/v in pH 8) and sodium phosphate buffer of pH 8 in ratio of 2:1:1. Absorbance was measured at 655 nm. The stability of this assay (in terms of colored heptane phase absorbance readings) retained more than 92.5% after 24 h at 4°C compared to the absorbance readings measured at zero time. In comparison with other lipase assay methods, beside the developed sensitivity, the reproducibility and the lower limit of detection (LOD) of the proposed method, it permits analyzing of 96 samples at one time in a 96-well microplate. Furthermore, it consumes small quantities of chemicals and unit operations.

  15. Electrochemically-deposited ZnO nanorods arrays on ITO seeding layers

    NASA Astrophysics Data System (ADS)

    Petrov, M.; Lovchinov, K.; Nichev, H.; Dimova-Malinovska, D.

    2016-03-01

    In this paper, results are reported from the study of the structural and optical properties of ZnO nanostructured arrays with nanorods (NRs) grown electrochemically on ITO seeding layers with two different thicknesses deposited on a glass substrate. The properties are compared of the ZnO NRs grown on ITO seeding layers with resistivity 6.4 × 10-4 Ω cm, sheet resistance 80 Ω/□ and 8 Ω/□ and different ITO thicknesses - 80 and 800 nm, respectively. The optical spectra of reflectance, transmittance, diffused reflection and diffused transmission and the haze ratio in transmission and reflection of the samples carried out before and after ZnO NRs deposition are compared and discussed. The structures' properties are studied by scanning electron microscopy (SEM). The ZnO NRs arrays with increased values of diffused transmission and reflection compared to the seeding layer substrates can be used in thin-film solar cells for increasing the light trapping.

  16. Degradation-by-design: Surface modification with functional substrates that enhance the enzymatic degradation of carbon nanotubes.

    PubMed

    Sureshbabu, Adukamparai Rajukrishnan; Kurapati, Rajendra; Russier, Julie; Ménard-Moyon, Cécilia; Bartolini, Isacco; Meneghetti, Moreno; Kostarelos, Kostas; Bianco, Alberto

    2015-12-01

    Biodegradation of carbon-based nanomaterials has been pursued intensively in the last few years, as one of the most crucial issues for the design of safe, clinically relevant conjugates for biomedical applications. In this paper it is demonstrated that specific functional molecules can enhance the catalytic activity of horseradish peroxidase (HRP) and xanthine oxidase (XO) for the degradation of carbon nanotubes. Two different azido coumarins and one cathecol derivative are linked to multi-walled carbon nanotubes (MWCNTs). These molecules are good reducing substrates and strong redox mediators to enhance the catalytic activity of HRP. XO, known to metabolize various molecules mainly in the mammalian liver, including human, was instead used to test the biodegradability of MWCNTs modified with an azido purine. The products of the biodegradation process are characterized by transmission electron microscopy and Raman spectroscopy. The results indicate that coumarin and catechol moieties have enhanced the biodegradation of MWCNTs compared to oxidized nanotubes, likely due to the capacity of these substrates to better interact with and activate HRP. Although azido purine-MWCNTs are degraded less effectively by XO than oxidized nanotubes, the data uncover the importance of XO in the biodegradation of carbon-nanomaterials leading to their better surface engineering for biomedical applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Large-area flexible monolithic ITO/WO3/Nb2O5/NiVOχ/ITO electrochromic devices prepared by using magnetron sputter deposition

    NASA Astrophysics Data System (ADS)

    Tang, Chien-Jen; Ye, Jia-Ming; Yang, Yueh-Ting; He, Ju-Liang

    2016-05-01

    Electrochromic devices (ECDs) have been applied in smart windows to control the transmission of sunlight in green buildings, saving up to 40-50% electricity consumption and ultimately reducing carbon dioxide emissions. However, the high manufacturing costs and difficulty of transportation of conventional massive large area ECDs has limited widespread applications. A unique design replacing the glass substrate commonly used in the ECD windows with inexpensive, light-weight and flexible polymeric substrate materials would accelerate EC adoption allowing them to be supplemented for regular windows without altering window construction. In this study, an ITO/WO3/Nb2O5/NiVOχ/ITO all-solid-state monolithic ECD with an effective area of 24 cm × 18 cm is successfully integrated on a PET substrate by using magnetron sputter deposition. The electrochromic performance and bending durability of the resultant material are also investigated. The experimental results indicate that the ultimate response times for the prepared ECD is 6 s for coloring at an applied voltage of -3 V and 5 s for bleaching at an applied voltage of +3 V, respectively. The optical transmittances for the bleached and colored state at a wavelength of 633 nm are 53% and 11%, respectively. The prepared ECD can sustain over 8000 repeated coloring and bleaching cycles, as well as tolerate a bending radius of curvature of 7.5 cm.

  18. Gradual thickness change of CuPc on MoOx on Oxygen Plasma Treated ITO

    NASA Astrophysics Data System (ADS)

    Wang, Chenggong; Irfan, Irfan; Gao, Yongli

    2012-02-01

    The thickness dependence of copper phthalocyanine (CuPc) interlayer on molybdenum trioxide (MoO3) and conducting indium tin oxide (ITO) has been investigated with ultraviolet photoemission spectroscopy (UPS). We also investigated the air exposure effect on the CuPc/MoO3/ITO interlayers. It was found that the MoO3 interlayer substantially increased the substrate work function (WF). With the deposition of CuPc the WF decreased and saturated at the thickness of 80 å. We also found that 3x10^6 Langmuir (L) air exposure decreased both the MoO3 WF and the interface dipole between CuPc/MoO3 interface.

  19. Nanostructured Ultrathin Carbazole Polymer Layers for Improved Hole-Transport and Injection Properties on ITO

    NASA Astrophysics Data System (ADS)

    Advincula, Rigoberto

    2010-03-01

    This talk will focus on strategies to modify Indium Tin Oxide (ITO) surfaces, an important substrate for display and photovoltaic devices using macromolecular grafting, layer-by-layer, and electrodeposition methods of carbazole derivatives. An important consequence is the improved morphology of rough ITO surfaces and better interfacial adhesion. This involves the use of surface initiated polymerization (SIP) to directly modify and graft carbazole containing layers. Alternatively, layer-by-layer deposition of hole-transport and injecting layers allow for controlled layer thickness and layer ordering. Lastly, the use of electropolymerizable conjugated polymer network precursors allow for a highly cross-linked films with improved stability and charge carrier transport. The use of surface sensitive analytical methods is key to defining structure-property relationships. Several device configurations and performance will be described.

  20. Study of low resistivity and high work function ITO films prepared by oxygen flow rates and N2O plasma treatment for amorphous/crystalline silicon heterojunction solar cells.

    PubMed

    Hussain, Shahzada Qamar; Oh, Woong-Kyo; Kim, Sunbo; Ahn, Shihyun; Le, Anh Huy Tuan; Park, Hyeongsik; Lee, Youngseok; Dao, Vinh Ai; Velumani, S; Yi, Junsin

    2014-12-01

    Pulsed DC magnetron sputtered indium tin oxide (ITO) films deposited on glass substrates with lowest resistivity of 2.62 x 10(-4) Ω x cm and high transmittance of about 89% in the visible wavelength region. We report the enhancement of ITO work function (Φ(ITO)) by the variation of oxygen (O2) flow rate and N2O surface plasma treatment. The Φ(ITO) increased from 4.43 to 4.56 eV with the increase in O2 flow rate from 0 to 4 sccm while surface treatment of N2O plasma further enhanced the ITO work function to 4.65 eV. The crystallinity of the ITO films improved with increasing O2 flow rate, as revealed by XRD analysis. The ITO work function was increased by the interfacial dipole resulting from the surface rich in O- ions and by the dipole moment formed at the ITO surface during N2O plasma treatment. The ITO films with high work functions can be used to modify the front barrier height in heterojunction with intrinsic thin layer (HIT) solar cells.

  1. A facile strategy for the modification of polyethylene substrates with non-fouling, bioactive poly(poly(ethylene glycol) methacrylate) brushes.

    PubMed

    Lavanant, Laurent; Pullin, Brian; Hubbell, Jeffrey A; Klok, Harm-Anton

    2010-01-11

    This manuscript reports a facile strategy for the modification of polyethylene, a widely used biomaterial, with a thin non-biofouling coating that can act as a platform to introduce biochemical cues to control and direct, e.g., cell adhesion and proliferation. The non-biofouling coating is produced, following a two-step strategy involving photobromination of the polyethylene substrate followed by surface-initiated ATRP of poly(ethylene glycol) methacrylate. The resulting coatings, which are referred to as polymer brushes, are robust and withstand prolonged exposure to aqueous ethanol and phosphate buffered saline and also do not show any signs of detachment or degradation in the in vivo studies over a period of 10 d. Functionalization of these polymer brush coatings with extracellular matrix derived peptide sequences, promotes adhesion and spreading of endothelial cells.

  2. Flexible CuS nanotubes-ITO film Schottky junction solar cells with enhanced light harvesting by using an Ag mirror.

    PubMed

    Wu, Chunyan; Zhang, Zihan; Wu, Yiliang; Lv, Peng; Nie, Biao; Luo, Linbao; Wang, Li; Hu, Jigang; Jie, Jiansheng

    2013-02-01

    Here we report the fabrication of a novel photovoltaic device based on CuS nanotubes (CuSNTs) and indium tin oxide (ITO) Schottky junctions. Large-quantity synthesis of CuSNTs was accomplished via a solution-based sacrificial template method under moderate conditions, while ITO Schottky contacts were fabricated via micro-fabrication and pulsed laser deposition (PLD). Upon light illumination, CuSNTs-ITO Schottky junctions exhibited pronounced photovoltaic behavior, giving rise to a power conversion efficiency of 1.17% on a conventional SiO(2)/Si substrate. Furthermore, by utilizing PET as the substrate, transparent and flexible CuSNTs-ITO solar cells were constructed and showed performance close to their device counterparts on a rigid substrate. Notably, it was found that the flexible devices were robust against tensile strain and could stand a bending angle up to ∼95°. To enhance the light absorption of the devices, an Ag mirror layer was deposited on the rear side of the PET substrate so as to allow multiple reflection and absorption of the incident light. As a result, the flexible devices showed a substantial performance improvement, yielding an efficiency of ∼2%. Our results demonstrate that low-cost and environmentally friendly CuSNTs-ITO solar cells are promising candidates for new-generation photovoltaic devices.

  3. Fabrication of three-dimensional hybrid nanostructure-embedded ITO and its application as a transparent electrode for high-efficiency solution processable organic photovoltaic devices.

    PubMed

    Kim, Jeong Won; Jeon, Hwan-Jin; Lee, Chang-Lyoul; Ahn, Chi Won

    2017-03-02

    Well-aligned, high-resolution (10 nm), three-dimensional (3D) hybrid nanostructures consisting of patterned cylinders and Au islands were fabricated on ITO substrates using an ion bombardment process and a tilted deposition process. The fabricated 3D hybrid nanostructure-embedded ITO maintained its excellent electrical and optical properties after applying a surface-structuring process. The solution processable organic photovoltaic device (SP-OPV) employing a 3D hybrid nanostructure-embedded ITO as the anode displayed a 10% enhancement in the photovoltaic performance compared to the photovoltaic device prepared using a flat ITO electrode, due to the improved charge collection (extraction and transport) efficiency as well as light absorbance by the photo-active layer.

  4. Improving wettability of photo-resistive film surface with plasma surface modification for coplanar copper pillar plating of IC substrates

    NASA Astrophysics Data System (ADS)

    Xiang, Jing; Wang, Chong; Chen, Yuanming; Wang, Shouxu; Hong, Yan; Zhang, Huaiwu; Gong, Lijun; He, Wei

    2017-07-01

    The wettability of the photo-resistive film (PF) surfaces undergoing different pretreatments including the O2sbnd CF4 low-pressure plasma (OCLP) and air plasma (AP), is investigated by water contact angle measurement instrument (WCAMI) before the bottom-up copper pillar plating. Chemical groups analysis performed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectra (XPS) shows that after the OCLP and wash treatment, the wettability of PF surface is attenuated, because embedded fluorine and decreased oxygen content both enhance hydrophobicity. Compared with OCLP treatment, the PF surface treatment by non-toxic air plasma displays features of Csbnd O, Osbnd Cdbnd O, Cdbnd O and sbnd NO2 by AIR-FTIR and XPS, and a promoted wettability by WCAM. Under the identical electroplating condition, the surface with a better wettability allows electrolyte to spontaneously soak all the places of vias, resulting in improved copper pillar uniformity. Statistical analysis of metallographic data shows that more coplanar and flat copper pillars are achieved with the PF treatment of air plasma. Such modified copper-pillar-plating technology meets the requirement of accurate impedance, the high density interconnection for IC substrates.

  5. Surface-initiated ATRP modification of tissue culture substrates: poly(glycerol monomethacrylate) as an antifouling surface.

    PubMed

    Patrucco, Elena; Ouasti, Sihem; Vo, Cong Duan; De Leonardis, Piero; Pollicino, Antonino; Armes, Steve P; Scandola, Mariastella; Tirelli, Nicola

    2009-11-09

    Surface-initiated atom transfer radical polymerization (SI-ATRP) can be used to produce conformal coatings of controlled thickness on virtually any surface, providing to it specific physico-chemical and biological properties. Here we have tackled the problem of modulating cell adhesion on typical culture substrates; tissue culture polystyrene (TCPS) offers a number of favorable properties (optical transparency, chemical stability, sterilizability, availability in a wide variety of shapes) but somehow limited biological function. A fine tuning of cell adhesion can, on the contrary, allow better control cell phenotype during cell expansion or, by using responsive polymers, allow attachment/detachment cycles with reduced cell damage. Here we have optimized a procedure of TCPS surface oxidation to allow the adsorption of cationic macroinitiators and the successive growth of surface-born polymer chains, producing films with controlled thickness. We have specifically focused our attention on the preparation of films containing poly(glycerol monomethacrylate) (PGMMA), showing that PGMMA is nontoxic but nonadhesive to cells, possibly providing "stealth" surfaces. Cell adhesion can be reinstated by copolymerizing GMMA with other monomers: films containing N,N-dimethylamino ethyl methacrylate (DMAEMA; in the surface-grown films this monomer is substantially hydrophobic at physiological pH) together with GMMA provided cell attachment and spreading to comparable to TCPS. Last, cell circularity was here shown to be a valid reporter for the assessment of cell spreading.

  6. Low-temperature fabrication of VO2 thin film on ITO glass with a Mott transition

    NASA Astrophysics Data System (ADS)

    Lin, Tiegui; Wang, Langping; Wang, Xiaofeng; Zhang, Yufen

    2016-09-01

    Polycrystalline Vanadium dioxide (VO2) thin film can be fabricated on glass substrates by high power impulse magnetron sputtering at a relative high temperature. In order to apply an effective bias voltage on substrate and control the energy of the ions impinged to the substrate, conductive indium-tin oxide (ITO) glass was used as the substrate. UV-visible-near IR transmittance spectra and X-ray diffraction (XRD) patterns of the as-deposited films exhibited that M-VO2 thin film with a metal-insulator transition temperature of 37∘C was fabricated successfully at 300∘C with a bias voltage of -200V, and the calculated average crystalline size of this film was about 12nm. XRD patterns at varied temperatures showed that the structural change of MIT of the VO2 thin film was suppressed during the phase transition process, and a pure Mott transition was obtained.

  7. Highly flexible, hybrid-structured indium tin oxides for transparent electrodes on polymer substrates

    SciTech Connect

    Triambulo, Ross E.; Kim, Jung-Hoon; Park, Jin-Woo; Na, Min-Young; Chang, Hye-Jung

    2013-06-17

    We developed highly flexible, hybrid-structured crystalline indium tin oxide (ITO) for use as transparent electrodes on polymer substrates by embedding Ag nanoparticles (AgNPs) into the substrate. The hybrid ITO consists of domains in one orientation grown on the AgNPs and a matrix of the other orientation. The domains are stronger than the matrix and function as barriers to crack propagation. As a result, both the critical bending radius (r{sub c}) (under which the resistivity change ({Delta}{rho}) is less than a given value) and the change in {Delta}{rho} with decreasing r significantly decreased in the hybrid ITO compared with homogenous ITO.

  8. Microstructure, ferromagnetic and photoluminescence properties of ITO and Cr doped ITO nanoparticles using solid state reaction

    NASA Astrophysics Data System (ADS)

    Babu, S. Harinath; Kaleemulla, S.; Rao, N. Madhusudhana; Rao, G. Venugopal; Krishnamoorthi, C.

    2016-11-01

    Indium-tin-oxide (ITO) (In0.95Sn0.05)2O3 and Cr doped indium-tin-oxide (In0.90Sn0.05Cr0.05)2O3 nanoparticles were prepared using simple low cost solid state reaction method and characterized by different techniques to study their structural, optical and magnetic properties. Microstructures, surface morphology, crystallite size of the nanoparticles were studied using X-ray diffractometer (XRD), field emission scanning electron microscope (FE-SEM). From these methods it was found that the particles were about 45 nm. Chemical composition and valence states of the nanoparticles were studied using energy dispersive analysis of X-rays (EDAX) and X-ray photoelectron spectroscopy (XPS). From these techniques it was observed that the elements of indium, tin, chromium and oxygen were present in the system in appropriate ratios and they were in +3, +4, +3 and -2 oxidation states. Raman studies confirmed that the nanoparticle were free from unintentional impurities. Two broad emission peaks were observed at 330 nm and 460 nm when excited wavelength of 300 nm. Magnetic studies were carried out at 300 K and 100 K using vibrating sample magnetometer (VSM) and found that the ITO nanoparticles were ferromagnetic at 100 K and 300 K. Where-as the room temperature ferromagnetism completely disappeared in Cr doped ITO nanoparticles at 100 K and 300 K.

  9. Evaporation-Driven Deposition of ITO Thin Films from Aqueous Solutions with Low-Speed Dip-Coating Technique.

    PubMed

    Ito, Takashi; Uchiyama, Hiroaki; Kozuka, Hiromitsu

    2017-05-30

    We suggest a novel wet coating process for preparing indium tin oxide (ITO) films from simple solutions containing only metal salts and water via evaporation-driven film deposition during low-speed dip coating. Homogeneous ITO precursor films were deposited on silica glass substrates from the aqueous solutions containing In(NO3)3·3H2O and SnCl4·5H2O by dip coating at substrate withdrawal speeds of 0.20-0.50 cm min(-1) and then crystallized by the heat treatment at 500-800 °C for 10-60 min under N2 gas flow of 0.5 L min(-1). The ITO films heated at 600 °C for 30 min had a high optical transparency in the visible range and a good electrical conductivity. Multiple-coating ITO films obtained with five-times dip coating exhibited the lowest sheet (ρS) and volume (ρV) resistivities of 188 Ω sq(-1) and 4.23 × 10(-3) Ω cm, respectively.

  10. Energy-Level Alignment of a Hole-Transport Organic Layer and ITO: Toward Applications for Organic Electronic Devices.

    PubMed

    Arnoux, Quentin; Boucly, Anthony; Barth, Vincent; Benbalagh, Rabah; Cossaro, Albano; Floreano, Luca; Silly, Mathieu; Sirotti, Fausto; Derat, Etienne; Carniato, Stéphane; Bournel, Fabrice; Gallet, Jean-Jacques; Fichou, Denis; Tortech, Ludovic; Rochet, François

    2017-09-13

    2,2',6,6'-Tetraphenyl-4,4'-dipyranylidene (DIPO-Ph4) was grown by vacuum deposition on an indium tin oxide (ITO) substrate. The films were characterized by atomic force microscopy as well as synchrotron radiation UV and X-ray photoelectron spectroscopy to gain an insight into the material growth and to better understand the electronic properties of the ITO/DIPO-Ph4 interface. To interpret our spectroscopic data, we consider the formation of cationic DIPO-Ph4 at the ITO interface owing to a charge transfer from the organic layer to the substrate. Ionization energy DFT calculations of the neutral and cationic species substantiate this hypothesis. Finally, we present the energetic diagram of the ITO/DIPO-Ph4 system, and we discuss the application of this interface in various technologically relevant systems, as a hole-injector in OLEDs or as a hole-collector interfacial layer adjacent to the prototypical OPV layer P3HT:PCBM.

  11. Fabrication and characterization of a CuO/ITO heterojunction with a graphene transparent electrode

    NASA Astrophysics Data System (ADS)

    Mageshwari, K.; Han, Sanghoo; Park, Jinsub

    2016-05-01

    In this paper, we investigate the electrical properties of a CuO-ITO heterojunction diode with the use of a graphene transparent electrode by current-voltage (I-V) characteristics. CuO thin films were deposited onto an ITO substrate by a simple sol-gel spin coating method and annealed at 500 °C. The x-ray diffraction pattern of the CuO thin films revealed the polycrystalline nature of CuO and exhibited a monoclinic crystal structure. FESEM images showed a uniform and densely packed particulate morphology. The optical band gap of CuO thin films estimated using UV-vis absorption spectra was found to be 2.50 eV. The I-V characteristics of the fabricated CuO-ITO heterojunction showed a well-defined rectifying behavior with improved electrical properties after the insertion of graphene. The electronic parameters of the heterostructure such as barrier height, ideality factor and series resistance were determined from the I-V measurements, and the possible current transport mechanism was discussed.

  12. Gravure printing of transparent conducting ITO coatings for display applications

    NASA Astrophysics Data System (ADS)

    Puetz, Joerg; Heusing, Sabine; de Haro Moro, Marcos; Ahlstedt, C. Mikael; Aegerter, Michel A.

    2005-09-01

    Transparent conducting coatings and patterns of ITO (indium tin oxide) were deposited by a direct gravure printing on PET foils using nanoparticle-based UV-curable inks. Solid areas with thicknesses ranging between 300 and >1000 nm were obtained by varying the ink composition (e.g. ITO content, solvents) and fundamental parameters of the printing plate such as the line density. The best ITO coating patterns showed a sheet resistance of 3 to 10 kΩ□ and a transmission of up to 88 % with a haze of less than 1 %. One of the most crucial steps during film formation is the drying of the wet film as it changes the rheology and polarity of the ink and in consequence decisively influences the film formation. Typical fields of application of the gravure-printed ITO patterned electrodes include smart windows, flexible displays and printed electronics.

  13. Ammonia plasma modification towards a rapid and low temperature approach for tuning electrical conductivity of ZnO nanowires on flexible substrates.

    PubMed

    Ong, Wei Li; Zhang, Chun; Ho, Ghim Wei

    2011-10-05

    Though the fabrication of ZnO nanostructures is economical and low temperature, the lack of a facile, reliable and low temperature methodology to tune its electrical conductivity has prevented it from competing with other semiconductors. Here, we carried out surface modification of ZnO nanowires using ammonia plasma with no heat treatment, and studied their electrical properties over an extended time frame of more than a year. The fabrication of flexible devices was demonstrated via various methods of transferring and aligning as-synthesized ZnO nanowires onto plastic substrates. Hall measurements of the plasma modified ZnO nanowires revealed p-type conductivity. The N1s peak was present in the X-ray photoelectron spectrum of the surface modified ZnO, showing the presence of ammonia complexes. Low temperature photoluminescence showed evidence of acceptor-bound exciton emission. The resulting electrical devices, a chemical sensor and p-n homojunction, show the tunable electrical response of the surface modified ZnO nanowires.

  14. Mask-assisted electron radiation grafting for localized through-volume modification of porous substrates: influence of electron energy on spatial resolution

    NASA Astrophysics Data System (ADS)

    Forner-Cuenca, A.; Manzi-Orezzoli, V.; Kristiansen, P. M.; Gubler, L.; Schmidt, T. J.; Boillat, P.

    2017-06-01

    The spatial resolution aspects of the local modification of porous materials by electron induced graft-polymerization were studied by a combination of experiments and numerical simulations. Using blocking masks, only selected regions of the material were exposed to radiation and subsequently grafted. The main focus of this study is the application to gas diffusion layers, a carbonaceous 200 μm thick porous substrate widely used in fuel cells, with the goal of improving water management by locally tuning the wettability. The comparison of experiments performed with different electron energies and corresponding simulations shows good agreement, identifying the energy threshold necessary to graft through the material to be approximately 150 keV. The impact of electron energy on spatial resolution was studied, showing that the blurring effects due to electron scattering reach a maximum at around 200 keV and are reduced at higher electron energies. Finally, the numerical simulations were used to define the conditions necessary to selectively graft only parts of bi-layer fuel cell materials.

  15. Ito equations out of domino cellular automaton with efficiency parameters

    NASA Astrophysics Data System (ADS)

    Czechowski, Zbigniew; Białecki, Mariusz

    2012-06-01

    Ito equations are derived for simple stochastic cellular automaton with parameters describing efficiencies for avalanche triggering and cell occupation. Analytical results are compared with the numerical one obtained from the histogram method. Good agreement for various parameters supports the wide applicability of the Ito equation as a macroscopic model of some cellular automata and complex natural phenomena which manifest random energy release. Also, the paper is an example of effectiveness of histogram procedure as an adequate method of nonlinear modeling of time series.

  16. Multifractal analysis of time series generated by discrete Ito equations

    SciTech Connect

    Telesca, Luciano; Czechowski, Zbigniew; Lovallo, Michele

    2015-06-15

    In this study, we show that discrete Ito equations with short-tail Gaussian marginal distribution function generate multifractal time series. The multifractality is due to the nonlinear correlations, which are hidden in Markov processes and are generated by the interrelation between the drift and the multiplicative stochastic forces in the Ito equation. A link between the range of the generalized Hurst exponents and the mean of the squares of all averaged net forces is suggested.

  17. Size- and Density-Controllable Fabrication of the Platinum Nanoparticle/ITO Electrode by Pulse Potential Electrodeposition for Ammonia Oxidation.

    PubMed

    Li, Siyuan; Chen, Haiyan; Liu, Jie; Deng, Yida; Han, Xiaopeng; Hu, Wenbin; Zhong, Cheng

    2017-08-23

    Pulse potential electrodeposition was successfully utilized to electrochemically fabricate platinum (Pt) nanoparticles on indium tin oxide (ITO) conductive glass substrates for catalysis toward ammonia electro-oxidation. The effect of deposition parameters (lower potential El, lower potential duration tl, and upper potential duration tu) on the size and number density of Pt nanoparticles was investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrocatalytic activity of the Pt nanoparticle/ITO electrode for ammonia oxidation was characterized by the cyclic voltammetry (CV) method. The results showed that lower El and longer tl accelerate the formation of Pt nuclei while longer tu favors the growth of grain size to some extent, as El mainly tunes electrochemical overpotential while tl and tu affect the activation and mass transfer process. By the tuning of the deposition parameters, Pt nanoparticle/ITO electrodes with a polycrystalline nature and 5 nm-scale primary particles, could be easily modified in Pt particle size and number density. Furthermore, the Pt nanoparticle/ITO electrode shows high mass specific catalytic activity (MA) toward ammonia oxidation (1.65 mC μg(-1)), much higher than that of the commercial Pt/C electrode (0.32 mC μg(-1)). Additionally, the high catalytic performance results not only from the nanosize effect of Pt nanoparticles, but also from the special morphology formed during the electrodeposition process.

  18. Metal-free molecular junctions on ITO via amino-silane binding-towards optoelectronic molecular junctions.

    PubMed

    Sergani, S; Furmansky, Y; Visoly-Fisher, I

    2013-11-15

    Light control over currents in molecular junctions is desirable as a non-contact input with high spectral and spatial resolution provided by the photonic input and the molecular electronics element, respectively. Expanding the study of molecular junctions to non-metallic transparent substrates, such as indium tin oxide (ITO), is vital for the observation of molecular optoelectronic effects. Non-metallic electrodes are expected to decrease the probability of quenching of molecular photo-excited states, light-induced plasmonic effects, or significant electrode expansion under visible light. We have developed micron-sized, metal free, optically addressable ITO molecular junctions with a conductive polymer serving as the counter-electrode. The electrical transport was shown to be dominated by the nature of the self-assembled monolayer (SAM). The use of amino-silane (APTMS) as the chemical binding scheme to ITO was found to be significant in determining the transport properties of the junctions. APTMS allows high junction yields and the formation of dense molecular layers preventing electrical short. However, polar amino-silane binding to the ITO significantly decreased the conductance compared to thiol-bound SAMs, and caused tilted geometry and disorder in the molecular layer. As the effect of the molecular structure on transport properties is clearly observed in our junctions, such metal-free junctions are suitable for characterizing the optoelectronic properties of molecular junctions.

  19. Metal-free molecular junctions on ITO via amino-silane binding—towards optoelectronic molecular junctions

    NASA Astrophysics Data System (ADS)

    Sergani, S.; Furmansky, Y.; Visoly-Fisher, I.

    2013-11-01

    Light control over currents in molecular junctions is desirable as a non-contact input with high spectral and spatial resolution provided by the photonic input and the molecular electronics element, respectively. Expanding the study of molecular junctions to non-metallic transparent substrates, such as indium tin oxide (ITO), is vital for the observation of molecular optoelectronic effects. Non-metallic electrodes are expected to decrease the probability of quenching of molecular photo-excited states, light-induced plasmonic effects, or significant electrode expansion under visible light. We have developed micron-sized, metal free, optically addressable ITO molecular junctions with a conductive polymer serving as the counter-electrode. The electrical transport was shown to be dominated by the nature of the self-assembled monolayer (SAM). The use of amino-silane (APTMS) as the chemical binding scheme to ITO was found to be significant in determining the transport properties of the junctions. APTMS allows high junction yields and the formation of dense molecular layers preventing electrical short. However, polar amino-silane binding to the ITO significantly decreased the conductance compared to thiol-bound SAMs, and caused tilted geometry and disorder in the molecular layer. As the effect of the molecular structure on transport properties is clearly observed in our junctions, such metal-free junctions are suitable for characterizing the optoelectronic properties of molecular junctions.

  20. ITO-Free Solution-Processed Flexible Electrochromic Devices Based on PEDOT:PSS as Transparent Conducting Electrode.

    PubMed

    Singh, Rekha; Tharion, Joseph; Murugan, Sengottaiyan; Kumar, Anil

    2017-06-14

    Electrochromic devices (ECDs) are emerging as novel technology for various applications ranging from commercialized smart window glasses, goggles, and autodimming rear view mirrors to uncommon yet more sophisticated applications such as infrared camouflage in military and thermal control in space satellites. The development of low-power, lightweight, inexpensive, and flexible devices is the need of the hour. In this respect, utilizing PEDOT:PSS as transparent conducting electrode (TCE) to replace indium tin oxide (ITO) and metal based TCEs for ECDs is a promising solution for the aforementioned requirements. In this work we have demonstrated the performance of PEDOT:PSS films coated on flexible substrates, treated with PTSA-DMSO, as TCEs for ECD applications and their comparison with that of ITO based ECDs. The PEDOT:PSS based flexible TCEs used in this study have conductivity of 1400-1500 S·cm(-1) and figure of merit (FoM) of 70-77. The process of increasing the conductivity of PEDOT:PSS films also led to the broadening of the conducting potential window (CPW), which is important for electrochemical applications of PEDOT:PSS when used as a stand-alone electrode. More than achieving a comparable electrochromic contrast, switching time, and coloration efficiency with respect to the ITO based ECDs, PEDOT:PSS devices also had the added advantage of good mechanical flexibility. These devices demonstrated superior stability during electrochemical cycling and multiple mechanical bending tests, making them an inexpensive alternative to the costly ITO based ECD technology.

  1. Direct laser patterning of transparent ITO-Ag-ITO multilayer anodes for organic solar cells

    NASA Astrophysics Data System (ADS)

    Kim, Hyo-Joong; Seo, Ki-Won; Kim, Yong Hyeon; Choi, Jiyeon; Kim, Han-Ki

    2015-02-01

    Direct laser patterning of transparent ITO-Ag-ITO (IAI) multilayer anodes is investigated using a femtosecond fiber laser for application in organic solar cells (OSC) fabrication. By adjusting laser fluence and scan speed, we successfully patterned the IAI multilayer anode without changing the electrical or optical properties. At an optimized laser fluence of 0.6 J/cm2 and a scan speed of 200 mm/s, the patterned IAI multilayer was electrically isolated with a clean edge. The metallic Ag interlayer of the IAI multilayer plays an important role in direct laser patterning because it absorbed the laser and increases the maximum temperature in the IAI multilayer. In addition, the Ag layer could effectively decrease the temperature of the IAI multilayer after irradiation of laser. The OSC fabricated on the laser patterned IAI multilayer showed power conversion efficiencies of 3.12% (Ag 8 nm) and 2.85% (Ag 12 nm). Successful operation of the OSC indicates that direct laser patterning of IAI multilayer anodes is a promising, simple patterning technology for fabrication of IAI-based OSCs.

  2. Catalyst-free growth of ZnO nanowires on ITO seed layer/glass by thermal evaporation method: Effects of ITO seed layer laser annealing temperature

    NASA Astrophysics Data System (ADS)

    Alsultany, Forat H.; Hassan, Z.; Ahmed, Naser M.

    2016-04-01

    Novel catalyst-free growth of ZnO nanowires (ZnO-NWs) on ITO seeds/glass substrate by thermal evaporation method, and effects of continuous wave CO2 laser thermal annealed seed layer on the morphology and properties of ZnO-NWs growth were investigated. The effects of sputtered ITO seed layer laser annealing temperature on the morphological, structural, and optical properties of ZnO-NWs was systematically investigated at temperatures 250, 350, and 450 °C, respectively. The surface morphology and structure of the seeds and the products of ZnO-NWs were characterized in detail by using field emission scanning electron microscopy, atomic force microscopy, and X-ray diffraction. Optical properties were further examined through photoluminescence, and UV-Vis spectrophotometer. A growth mechanism was proposed on the basis of obtained results. The results showed that the nanowires were strongly dependent on the seed layer annealing temperatures, which played an important role in nucleation and dissimilar growth of the nanowires with varying sizes and geometric shapes.

  3. A forming-free bipolar resistive switching behavior based on ITO/V2O5/ITO structure

    NASA Astrophysics Data System (ADS)

    Wan, Zhenni; Darling, Robert B.; Majumdar, Arka; Anantram, M. P.

    2017-07-01

    Forming-free bipolar resistive switching behavior in an ITO/V2O5/ITO structure is observed. While the bottom ITO layer functions as a common ground electrode, the top ITO layer is an active element and used as an oxygen reservoir, with an additional metal electrode patterned on its top for making contact. In contrast to typical metal/transition metal oxide/metal based resistive memories, our device exhibits a low resistance state in its virgin state and is switched to a high resistance state when a forward bias of ˜+2.5 V is applied. The device can be reset to its original state at a reverse bias of ˜-1.5 V. A noticeable decrease in switching voltage with a reduced top contact area is observed, indicating a strong electric field enhanced switching mechanism. Different from the widely seen conductive filament mechanism in bipolar switching, we explain the switching behavior by the migration of oxygen ions at the top ITO/V2O5 interface. When oxygen ions are extracted to the ITO side, an interfacial layer with reduced oxidation states is formed and acts as a Schottky barrier that suppresses the current through the whole device. The results suggest future applications in low power, high speed integrated non-volatile memories.

  4. Ubiquitin modifications

    PubMed Central

    Swatek, Kirby N; Komander, David

    2016-01-01

    Protein ubiquitination is a dynamic multifaceted post-translational modification involved in nearly all aspects of eukaryotic biology. Once attached to a substrate, the 76-amino acid protein ubiquitin is subjected to further modifications, creating a multitude of distinct signals with distinct cellular outcomes, referred to as the 'ubiquitin code'. Ubiquitin can be ubiquitinated on seven lysine (Lys) residues or on the N-terminus, leading to polyubiquitin chains that can encompass complex topologies. Alternatively or in addition, ubiquitin Lys residues can be modified by ubiquitin-like molecules (such as SUMO or NEDD8). Finally, ubiquitin can also be acetylated on Lys, or phosphorylated on Ser, Thr or Tyr residues, and each modification has the potential to dramatically alter the signaling outcome. While the number of distinctly modified ubiquitin species in cells is mind-boggling, much progress has been made to characterize the roles of distinct ubiquitin modifications, and many enzymes and receptors have been identified that create, recognize or remove these ubiquitin modifications. We here provide an overview of the various ubiquitin modifications present in cells, and highlight recent progress on ubiquitin chain biology. We then discuss the recent findings in the field of ubiquitin acetylation and phosphorylation, with a focus on Ser65-phosphorylation and its role in mitophagy and Parkin activation. PMID:27012465

  5. Highly flexible InSnO electrodes on thin colourless polyimide substrate for high-performance flexible CH3NH3PbI3 perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Park, Jeong-Il; Heo, Jin Hyuck; Park, Sung-Hyun; Hong, Ki Il; Jeong, Hak Gee; Im, Sang Hyuk; Kim, Han-Ki

    2017-02-01

    We fabricated high-performance flexible CH3NH3PbI3 (MAPbI3) perovskite solar cells with a power conversion efficiency of 15.5% on roll-to-roll sputtered ITO films on 60 μm-thick colourless polyimide (CPI) substrate. Due to the thermal stability of the CPI substrate, an ITO/CPI sample subjected to rapid thermal annealing at 300 °C showed a low sheet resistance of 57.8 Ω/square and high transmittance of 83.6%, which are better values than those of an ITO/PET sample. Outer and inner bending tests demonstrated that the mechanical flexibility of the ITO/CPI was superior to that of the conventional ITO/PET sample owing to the thinness of the CPI substrate. In addition, due to its good mechanical flexibility, the ITO/CPI showed no change in resistance after 10,000 cycle outer and inner dynamic fatigue tests. Flexible perovskite solar cells with the structure of Au/PTAA/MAPbI3/ZnO/ITO/CPI showed a high power conversion efficiency of 15.5%. The successful operation of these flexible perovskite solar cells on ITO/CPI substrate indicated that the ITO film on thermally stable CPI substrate is a promising of flexible substrate for high-temperature processing, a finding likely to advance the commercialization of cost-efficient flexible perovskite solar cells.

  6. On-chip nanostructuring and impedance trimming of transparent and flexible ITO electrodes by laser induced coherent sub-20 nm cuts

    NASA Astrophysics Data System (ADS)

    Afshar, Maziar; Leber, Moritz; Poppendieck, Wigand; König, Karsten; Seidel, Helmut; Feili, Dara

    2016-01-01

    In this work, the effect of laser-induced nanostructuring of transparent indium tin oxide (ITO) electrodes on flexible glass is investigated. Multi-electrode arrays (MEA) for electrical and optical characterization of biological cells were fabricated using standard MEMS technologies. Optimal sputter parameters concerning oxygen flow, sputter power and ambient pressure for ITO layers with both good optical and electrical properties were determined. Afterwards, coherent sub-20 nm wide and 150 nm deep nanocuts of many micrometers in length were generated within the ITO electrodes by a sub-15 femtosecond (fs) pulsed laser. The influence of laser processing on the electrical and optical properties of electrodes was investigated. The electrochemical impedance of the manufactured electrodes was measured before and after laser modification using electrochemical impedance spectroscopy. A small reduction in electrode impedance was observed. These nanostructured electrodes show also polarizing effects by the visible spectrum.

  7. High transmittance hetero junctions based on n-ITO/p-CuO bilayer thin films

    NASA Astrophysics Data System (ADS)

    Jaya, T. P.; Pradyumnan, P. P.

    2016-12-01

    Oxide based bilayered n-ITO/p-CuO crystalline diodes were fabricated by plasma vapor deposition using radio frequency magnetron sputtering. The p-n hetero junction diodes were highly transparent in the visible region and exhibits rectifying I-V characteristics. The substrate temperature during fabrication of p-layer CuO was found to have a profound influence on I-V characteristics. The films deposited at substrate temperature of 150 °C and 230 °C exhibited diode ideality factors of (η value) 1.731 and 1.862 respectively. This high ideality factor, combined with an optical transparency of above 70% suggests the potential use of these bi-layers in optoelectronic applications.

  8. ZnSe/ITO thin films: candidate for CdTe solar cell window layer

    NASA Astrophysics Data System (ADS)

    Khurram, A. A.; Imran, M.; Khan, Nawazish A.; Nasir Mehmood, M.

    2017-09-01

    The crystal structure, electrical and optical properties of ZnSe thin films deposited on an In2O3:Sn (ITO) substrate are evaluated for their suitability as the window layer of CdTe thin film solar cells. ZnSe thin films of 80, 90, and 100 nm thickness were deposited by a physical vapor deposition method on Indium tin oxide coated glass substrates. The lattice parameters are increased to 5.834 Å when the film thickness was 100 nm, which is close to that of CdS. The crystallite size is decreased with the increase of film thickness. The optical transmission analysis shows that the energy gap for the sample with the highest thickness has also increased and is very close to 2.7 eV. The photo decay is also studied as a function of ZnSe film thickness.

  9. Fabrication of printed ITO sensor for the ammonia hydroxide detection

    NASA Astrophysics Data System (ADS)

    Lee, Seok-hwan; Koo, Jieun; Jung, Soohoon; Lee, Moonjin; Jung, Jung-Yeul; Chang, Jiho

    2015-07-01

    Monitoring the hazardous and noxious substances (HNS) is a very important issue for mitigating the influence of catastrophic accidents in ocean and coastal areas. However, research on the HNS sensor is just in the beginning stage. In this study, we proposed a new HNS sensor using a printed ITO layer. We carried out a series of experiments of detecting the NH4OH and seawater solution to investigate the feasibility as a HNS sensor. The resistance of ITO layer dropped abruptly when it soaked into the solutions. The resistance change (δR) was linearly correlated with the NH4OH concentration of the solution, also it can be classified into two states; one is the transition stage, the other is the stabilized stage. The former is considered to be caused by the large capacitance of the electrical double layer (EDL) on the ITO surface. Also, the ITO layer showed considerable chemical stability within our experimental condition. In this paper, we have investigated the feasibility of printed ITO layer as a sensitive and cheap HNS sensor.

  10. Enhanced Performance of Photoelectrochemical Water Splitting with ITO@α-Fe2O3 Core-Shell Nanowire Array as Photoanode.

    PubMed

    Yang, Jie; Bao, Chunxiong; Yu, Tao; Hu, Yingfei; Luo, Wenjun; Zhu, Weidong; Fu, Gao; Li, Zhaosheng; Gao, Hao; Li, Faming; Zou, Zhigang

    2015-12-09

    Hematite (α-Fe2O3) is one of the most promising candidates for photoelectrodes in photoelectrochemical water splitting system. However, the low visible light absorption coefficient and short hole diffusion length of pure α-Fe2O3 limits the performance of α-Fe2O3 photoelectrodes in water splitting. Herein, to overcome these drawbacks, single-crystalline tin-doped indium oxide (ITO) nanowire core and α-Fe2O3 nanocrystal shell (ITO@α-Fe2O3) electrodes were fabricated by covering the chemical vapor deposited ITO nanowire array with compact thin α-Fe2O3 nanocrystal film using chemical bath deposition (CBD) method. The J-V curves and IPCE of ITO@α-Fe2O3 core-shell nanowire array electrode showed nearly twice as high performance as those of the α-Fe2O3 on planar Pt-coated silicon wafers (Pt/Si) and on planar ITO substrates, which was considered to be attributed to more efficient hole collection and more loading of α-Fe2O3 nanocrystals in the core-shell structure than planar structure. Electrochemical impedance spectra (EIS) characterization demonstrated a low interface resistance between α-Fe2O3 and ITO nanowire arrays, which benefits from the well contact between the core and shell. The stability test indicated that the prepared ITO@α-Fe2O3 core-shell nanowire array electrode was stable under AM1.5 illumination during the test period of 40,000 s.

  11. Fabrication of ITO/Ag3SbS3/CdX (X = S, Se) thin film heterojunctions for photo-sensing applications

    NASA Astrophysics Data System (ADS)

    Daniel, T.; Henry, J.; Mohanraj, K.; Sivakumar, G.

    2016-11-01

    Thin film heterojunctions of Ag3SbS3/CdX (X = S, Se) are deposited on a glass substrate coated with SnO2:In (ITO). The films were characterized by x-ray diffraction (XRD), atomic force microscopy (AFM), UV-visible spectroscopy, photoluminescence spectroscopy, field emission scanning electron microscopy and I-V analysis. XRD reveals the monoclinic structure of Ag3SbS3 and a fcc structure for both CdS and CdSe thin films. The AFM images clearly show the distinct morphological features (nanopyramids, wedge-shaped and rectangular nanorod-like grains). From the I-V studies, under illumination, an ITO/Ag3SbS3/CdS heterojunction produces a higher photocurrent (12.4 mA) than that an ITO/Ag3SbS3/CdSe heterojunction (1.34 mA).

  12. Patterning ITO by Template-Assisted Colloidal-Lithography for Enhancing Power Conversion Efficiency in Organic Photovoltaic.

    PubMed

    Lee, Jin-Su; Yu, Jung-Hun; Hwang, Ki-Hwan; Nam, Sang-Hun; Boo, Jin-Hyo; Yun, Sang H

    2016-05-01

    Highly structured interfaces are very desirable in organic photovoltaic solar cells (OPVs), in order to enhance power conversion efficiency (PCE) by decreasing of the transport path for excited charge carriers in the absorber and increasing the optical path length for photon absorption. Many complicated, high-cost lithographic methods have been attempted to modify the surface of the absorber or substrate. However, solution-based colloidal-lithography processes are scalable and cost-effective, but generally result in non-uniform structured surfaces. In this report, we demonstrated an optimized silica-templated colloidal lithographical approach to create a well-defined and controlled transparent ITO layer for enhancing power conversion efficiency (PCE). Additionally, morphological effects of the patterned ITO on optical properties and PCE were analyzed in detail.

  13. Effect of organic solar cells using various power O2 plasma treatments on the indium tin oxide substrate.

    PubMed

    Ke, Jhong-Ciao; Wang, Yeong-Her; Chen, Kan-Lin; Huang, Chien-Jung

    2016-03-01

    The effect of organic solar cells (OSCs) by using different power O2 plasma treatments on indium tin oxide (ITO) substrate was studied. The power of O2 plasma treatment on ITO substrate was varied from 20W to 80W, and the power conversion efficiency of device was improved from 1.18% to 1.93% at 20W O2 plasma treatment. The function of O2 plasma treatment on ITO substrate was to remove the surface impurity and to improve the work function of ITO, which can reduce the energy offset between the ITO and SubPc layer and depress the leakage current of device, leading to the shunt resistance increased from 897 to 1100Ωcm(2). The surface roughness of ITO decreased from 3.81 to 3.33nm and the work function of ITO increased from 4.75 to 5.2eV after 20W O2 plasma treatment on ITO substrate. As a result, the open circuit voltage and the fill factor were improved from 0.46 to 0.70V and from 0.56 to 0.61, respectively. However, the series resistance of device was dramatically increased as the power of O2 plasma treatment exceeds 40W, leading to the efficiency reduction. The result is attributed to the variation of oxygen vacancies in ITO film after the 60, 80W O2 plasma treatment. As a consequence, the power of O2 plasma treatment on ITO substrate for the OSCs application should be controlled below 40W to avoid affecting the electricity of ITO film. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. ITO-free large-area organic light-emitting diodes with an integrated metal grid.

    PubMed

    Choi, Seungkeun; Kim, Sung-Jin; Fuentes-Hernandez, Canek; Kippelen, Bernard

    2011-07-04

    We report on ITO-free large-area organic light-emitting diodes (OLEDs) fabricated on glass substrates comprising α-NPD as a hole transport layer (HTL) and coevaporated CBP:Ir(ppy)(3) as the emission layer. Indium-tin-oxide (ITO) was replaced with a conductive polymer electrode and an electroplated thick metal grid was used to improve the homogeneity of the potential distribution over the transparent polymer electrode. An electrical model of a metal grid integrated OLED shows the benefits of the use of metal grids in terms of improving the uniformity of the light emitted as the area of the OLED increases as well as the conductivity of the transparent electrode decreases. By integrating metal grids with polymer electrodes, the luminance increases more than 24% at 6 V and 45% at 7 V compared to the polymer electrode devices without a metal grid. This implies that a lower voltage can be applied to achieve the same luminance, hence lowering the power consumption. Furthermore, metal grid integrated OLEDs exhibited less variation in light emission compared to devices without a metal grid.

  15. Palatization in Japanese Mimetics: Response to Mester and Ito.

    ERIC Educational Resources Information Center

    Schourup, Lawrence; Tamori, Ikuhiro

    1992-01-01

    Mester and Ito's evidence for the phonological theory of Restricted Underspecification (RU) is refuted. Attention is focused on reduplicated forms; and it is concluded that, if there is only a rough and sporadic sound-syllable meaning association with palatization, the argument for RU is untenable. (12 references) (LB)

  16. 7 CFR 254.3 - Administration by an ITO.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false Administration by an ITO. 254.3 Section 254.3 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL REGULATIONS AND POLICIES-FOOD DISTRIBUTION ADMINISTRATION OF THE FOOD DISTRIBUTION PROGRAM FOR INDIAN HOUSEHOLDS IN OKLAHOMA §...

  17. NonMarkov Ito Processes with 1- state memory

    NASA Astrophysics Data System (ADS)

    McCauley, Joseph L.

    2010-08-01

    A Markov process, by definition, cannot depend on any previous state other than the last observed state. An Ito process implies the Fokker-Planck and Kolmogorov backward time partial differential eqns. for transition densities, which in turn imply the Chapman-Kolmogorov eqn., but without requiring the Markov condition. We present a class of Ito process superficially resembling Markov processes, but with 1-state memory. In finance, such processes would obey the efficient market hypothesis up through the level of pair correlations. These stochastic processes have been mislabeled in recent literature as 'nonlinear Markov processes'. Inspired by Doob and Feller, who pointed out that the ChapmanKolmogorov eqn. is not restricted to Markov processes, we exhibit a Gaussian Ito transition density with 1-state memory in the drift coefficient that satisfies both of Kolmogorov's partial differential eqns. and also the Chapman-Kolmogorov eqn. In addition, we show that three of the examples from McKean's seminal 1966 paper are also nonMarkov Ito processes. Last, we show that the transition density of the generalized Black-Scholes type partial differential eqn. describes a martingale, and satisfies the ChapmanKolmogorov eqn. This leads to the shortest-known proof that the Green function of the Black-Scholes eqn. with variable diffusion coefficient provides the so-called martingale measure of option pricing.

  18. 7 CFR 254.4 - Application by an ITO.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL REGULATIONS AND POLICIES-FOOD DISTRIBUTION ADMINISTRATION OF THE FOOD DISTRIBUTION PROGRAM FOR INDIAN HOUSEHOLDS IN OKLAHOMA § 254.4 Application by an ITO. (a) Application to FNS Regional Office....

  19. 7 CFR 254.3 - Administration by an ITO.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL REGULATIONS AND POLICIES-FOOD DISTRIBUTION ADMINISTRATION OF THE FOOD DISTRIBUTION PROGRAM FOR INDIAN HOUSEHOLDS IN OKLAHOMA § 254.3 Administration by an ITO. (a) Applicability of part 253....

  20. 7 CFR 254.3 - Administration by an ITO.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL REGULATIONS AND POLICIES-FOOD DISTRIBUTION ADMINISTRATION OF THE FOOD DISTRIBUTION PROGRAM FOR INDIAN HOUSEHOLDS IN OKLAHOMA § 254.3 Administration by an ITO. (a) Applicability of part 253....

  1. 7 CFR 254.4 - Application by an ITO.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL REGULATIONS AND POLICIES-FOOD DISTRIBUTION ADMINISTRATION OF THE FOOD DISTRIBUTION PROGRAM FOR INDIAN HOUSEHOLDS IN OKLAHOMA § 254.4 Application by an ITO. (a) Application to FNS Regional Office....

  2. 7 CFR 254.3 - Administration by an ITO.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL REGULATIONS AND POLICIES-FOOD DISTRIBUTION ADMINISTRATION OF THE FOOD DISTRIBUTION PROGRAM FOR INDIAN HOUSEHOLDS IN OKLAHOMA § 254.3 Administration by an ITO. (a) Applicability of part 253....

  3. 7 CFR 254.4 - Application by an ITO.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL REGULATIONS AND POLICIES-FOOD DISTRIBUTION ADMINISTRATION OF THE FOOD DISTRIBUTION PROGRAM FOR INDIAN HOUSEHOLDS IN OKLAHOMA § 254.4 Application by an ITO. (a) Application to FNS Regional Office....

  4. 7 CFR 254.4 - Application by an ITO.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL REGULATIONS AND POLICIES-FOOD DISTRIBUTION ADMINISTRATION OF THE FOOD DISTRIBUTION PROGRAM FOR INDIAN HOUSEHOLDS IN OKLAHOMA § 254.4 Application by an ITO. (a) Application to FNS Regional Office....

  5. 7 CFR 254.4 - Application by an ITO.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE GENERAL REGULATIONS AND POLICIES-FOOD DISTRIBUTION ADMINISTRATION OF THE FOOD DISTRIBUTION PROGRAM FOR INDIAN HOUSEHOLDS IN OKLAHOMA § 254.4 Application by an ITO. (a) Application to FNS Regional Office....

  6. Effective Passivation and Tunneling Hybrid a-SiOx(In) Layer in ITO/n-Si Heterojunction Photovoltaic Device.

    PubMed

    Gao, Ming; Wan, Yazhou; Li, Yong; Han, Baichao; Song, Wenlei; Xu, Fei; Zhao, Lei; Ma, Zhongquan

    2017-05-24

    In this article, using controllable magnetron sputtering of indium tin oxide (ITO) materials on single crystal silicon at 100 °C, the optoelectronic heterojunction frame of ITO/a-SiOx(In)/n-Si is simply fabricated for the purpose of realizing passivation contact and hole tunneling. It is found that the gradation profile of indium (In) element together with silicon oxide (SiOx/In) within the ultrathin boundary zone between ITO and n-Si occurs and is characterized by X-ray photoelectron spectroscopy with the ion milling technique. The atomistic morphology and physical phase of the interfacial layer has been observed with a high-resolution transmission electron microscope. X-ray diffraction, Hall effect measurement, and optical transmittance with Tauc plot have been applied to the microstructure and property analyses of ITO thin films, respectively. The polycrystalline and amorphous phases have been verified for ITO films and SiOx(In) hybrid layer, respectively. For the quantum transport, both direct and defect-assisted tunneling of photogenerated holes through the a-SiOx(In) layer is confirmed. Besides, there is a gap state correlative to the indium composition and located at Ev + 4.60 eV in the ternary hybrid a-SiOx(In) layer that is predicted by density functional theory of first-principles calculation, which acts as an "extended delocalized state" for direct tunneling of the photogenerated holes. The reasonable built-in potential (Vbi = 0.66 V) and optimally controlled ternary hybrid a-SiOx(In) layer (about 1.4 nm) result in that the device exhibits excellent PV performance, with an open-circuit voltage of 0.540 V, a short-circuit current density of 30.5 mA/cm(2), a high fill factor of 74.2%, and a conversion efficiency of 12.2%, under the AM 1.5 illumination. The work function difference between ITO (5.06 eV) and n-Si (4.31 eV) is determined by ultraviolet photoemission spectroscopy and ascribed to the essence of the built-in-field of the PV device. In addition

  7. Nd:YVO4 laser direct ablation of indium tin oxide films deposited on glass and polyethylene terephthalate substrates.

    PubMed

    Wang, Jian-Xun; Kwon, Sang Jik; Han, Jae-Hee; Cho, Eou Sik

    2013-09-01

    A Q-switched diode-pumped neodymium-doped yttrium vanadate (Nd:YVO4, lambda = 1064 nm) laser was applied to obtain the indium tin oxide (ITO) patterns on flexible polyethylene terephthalate (PET) substrate by a direct etching method. After the ITO films were deposited on a soda-lime glass and PET substrate, laser ablations were carried out on the ITO films for various conditions and the laser ablated results on the ITO films were investigated and analyzed considering the effects of substrates on the laser etching. The laser ablated widths on ITO deposited on glass were found to be much narrower than those on ITO deposited on PET substrate, especially, at a higher scanning speed of laser beam such as 1000 mm/s and 2000 mm/s. As the thermal conductivity of glass substrate is about 7.5 times higher than that of PET, more thermal energy would be spread and transferred to lateral direction in the ITO film in case of PET substrate.

  8. In situ electro-mechanical experiments and mechanics modeling of tensile cracking in indium tin oxide thin films on polyimide substrates

    NASA Astrophysics Data System (ADS)

    Peng, Cheng; Jia, Zheng; Bianculli, Dan; Li, Teng; Lou, Jun

    2011-05-01

    Indium tin oxide (ITO) thin films supported by polymer substrates have been widely used as transparent electrodes/interconnects in flexible electronics. Understanding the electro-mechanical behaviors of such material system is crucial for reliable operation of flexible devices under large deformation. In this paper, we performed in situ mechanical and electrical tests of ITO thin films with two different thicknesses (200 and 80 nm) deposited on polyimide substrates inside a scanning electron microscope. The crack initiation and propagation, crack density evolution and the corresponding electrical resistance variation were systematically investigated. It was found that cracks initiated at a higher tensile strain level and saturated with a higher density in thinner ITO films. Integrated with a coherently formulated mechanics model, the cohesive toughness and fracture strength of ITO thin films and the ITO/polyimide interfacial toughness were quantitatively determined. The experimentally observed thickness dependence of the saturated crack density in ITO thin films was also quantitatively verified by the model.

  9. SHI Induced Modifications in CdS/CuInSe{sub 2} Thin Film: XRD Analysis

    SciTech Connect

    Joshi, Rajesh A.; Taur, Vidya S.; Sharma, Ramphal; Ghule, Anil V.

    2011-07-15

    CuInSe{sub 2}(CIS nanostructured) thin films were prepared by ion exchange method at room temperature on ITO coated glass substrates in an alkaline medium. The as prepared thin films were irradiated by 120 MeV Au{sup 9+} swift heavy ion (SHI) at 5x10{sup 11} and 5x10{sup 12} ions/cm{sup 2} fluence respectively. To study the effect of irradiation, the pristine and irradiated nanostructured thin films were characterized by X ray Diffraction (XRD) and analyzed the improvement in crystalline quality and crystallite size. The observed structural modifications discussed considering the high electronic energy deposition by 120 MeV gold heavy (Au{sup 9+}) ions in CuInSe{sub 2} thin films.

  10. Fine characterization of ITO layers by spectroscopic ellipsometry

    NASA Astrophysics Data System (ADS)

    Boher, Pierre; Defranoux, Christophe; Piel, Jean-Philippe; Stehle, Jean-Louis P.; Suzuki, Y.

    1996-08-01

    Indium tin oxide films (ITO) are characterized precisely by spectroscopic ellipsometry which determines not only the thickness of the layers but also the optical indices in a large spectral range. The quality of the ITO films is checked by the transparency of the layers in the visible range 0.4 to 0.6 micrometers . Indeed, target degradation is detected by the occurrence of an absorption band in this region. The electrical conductivity of the layer can also be deduced by the Drude model applied to the absorption in the infrared region. Moreover, spectroscopic ellipsometry can give all these information on all the surface of the panels, checking at the same time the homogeneity and the stability of the deposition process. Different experimental examples will be presented and discussed.

  11. High substrate specificity factor ribulose bisphosphate carboxylase/oxygenase from eukaryotic marine algae and properties of recombinant cyanobacterial RubiSCO containing "algal" residue modifications.

    PubMed

    Read, B A; Tabita, F R

    1994-07-01

    Marine algae play an important role in removing carbon dioxide from the atmosphere. In this investigation, we have determined the substrate specificity factor of ribulose 1,5-bisphosphate carboxylase/oxygenase from several marine chromophytic and rhodophytic algae. The enzymes were purified to homogeneity and all possessed significantly higher substrate specificity factors than the enzymes from terrestrial plants, green algae, or bacteria. There are substantial differences in the sequence in a helix 6 of the large subunit of these enzymes, which is intriguing since residues of this region had been previously shown to influence the ability of ribulose bisphosphate carboxylase to discriminate between CO2 and O2, presumably by influencing the adjacent flexible loop 6 region. Sequence divergence at this and other key regions might contribute to the substantial differences in the substrate specificity factor of the chromophyte/rhodophyte enzyme. Initial studies on probing the basis for the high substrate specificity factor employed single amino acid substitutions in the recombinant cyanobacterial ribulose bisphosphate carboxylase. Residues in the vicinity of loop 6 were changed to reflect the corresponding residues in the chromophyte/rhodophyte large subunit. Some changes in the substrate specificity factor were noted, as were alterations in other important kinetic parameters. Since marine algae show little evidence of photorespiratory metabolism, the high substrate specificity of ribulose bisphosphate carboxylase is consistent with the physiology of these organisms. The results of this study provide further evidence that the properties of this enzyme may evolve or change according to the environment in which the host organism is found.

  12. Hypomelanosis of Ito and multiple naevoid hypertrichosis: rare cutaneous mosaicism.

    PubMed

    Khurana, Ananta; Singal, Archana; Pandhi, Deepika

    2014-05-01

    Hypomelanosis of Ito and naevoid hypertrichosis are both uncommon disorders and their coexistence in the same patient is rarely described. Most previously reported patients, in addition to cutaneous lesions, had multiple neurological, musculoskeletal and other organ system involvements. We present the case of a 3-year-old girl with these two naevoid disorders at sites completely exclusive of each other and without any severe associated defects.

  13. [Tree pollen dispersion in Ito City, Shizuoka Prefecture].

    PubMed

    Fujii, Mayumi; Okazaki, Kenji; Makiyama, Kiyoshi; Hisamatsu, Kenichi

    2013-11-01

    The authors investigated the atmospheric tree pollen dispersion in Ito City, Shizuoka Prefecture for 12 years for the purpose of the prophylaxis and treatment of pollinosis. We set up a Durham sampler on the rooftop of the three-story building in Ito City, and counted atmospheric pollen grouping first, Taxodiaceae and Cupressaceae; second, Pinaceae and Podocarpaceae; third, Betulaceae and Ulmaceae; last, Fagaceae. The counts of atmospheric tree pollen on season and the weather from January to June were treated statistically and analyzed on the computer program Microsoft Excel. Each average and SD of total pollen count was, in order, 7079±6503 count/cm(2), 502±146 count/cm(2), 891±480 count/cm(2), 906±481 count/cm(2). The last summer weather correlates to the atmospheric pollen count of Taxodiaceae, Cupressaceae, Betulaceace and Ulmaceae. The atmospheric pollen count of Taxodiaceae and Cupressaceae in spring is influenced by the weather; their atmospheric pollen count is reduced by a heavy rain or a heavy snow out of season. The atmospheric pollen count of Pinaceae, Podocarpaceae and Fagaceae does not relate to the weather. As a result of having examined the relations between the count of the atmospheric pollen and the weather in Ito City, I recognized relations in Taxodiaceae, Cupressaceae, Pinaceae and Podocarpaceae, but there were not the relations of intentionality in Betulaceae, Ulmaceae and Fagaceae.

  14. A three-dimensional metal grid mesh as a practical alternative to ITO.

    PubMed

    Jang, Sungwoo; Jung, Woo-Bin; Kim, Choelgyu; Won, Phillip; Lee, Sang-Gil; Cho, Kyeong Min; Jin, Ming Liang; An, Cheng Jin; Jeon, Hwan-Jin; Ko, Seung Hwan; Kim, Taek-Soo; Jung, Hee-Tae

    2016-08-07

    The development of a practical alternative to indium tin oxide (ITO) is one of the most important issues in flexible optoelectronics. In spite of recent progress in this field, existing approaches to prepare transparent electrodes do not satisfy all of their essential requirements. Here, we present a new substrate-embedded tall (∼350 nm) and thin (∼30 nm) three-dimensional (3D) metal grid mesh structure with a large area, which is prepared via secondary sputtering. This structure satisfies most of the essential requirements of transparent electrodes for practical applications in future opto-electronics: excellent optoelectronic performance (a sheet resistance of 9.8 Ω□(-1) with a transmittance of 85.2%), high stretchability (no significant change in resistance for applied strains <15%), a sub-micrometer mesh period, a flat surface (a root mean square roughness of approximately 5 nm), no haze (approximately 0.5%), and strong adhesion to polymer substrates (it survives attempted detachment with 3M Scotch tape). Such outstanding properties are attributed to the unique substrate-embedded 3D structure of the electrode, which can be obtained with a high aspect ratio and in high resolution over large areas with a simple process. As a demonstration of its suitability for practical applications, our transparent electrode was successfully tested in a flexible touch screen panel. We believe that our approach opens up new practical applications in wearable electronics.

  15. Micropatterning of mammalian cells on indium tin oxide substrates using ion implantation.

    PubMed

    Hwang, In-Tae; Ahn, Mi-Young; Jung, Chan-Hee; Choi, Jae-Hak; Shin, Kwanwoo

    2013-05-01

    In this study, a simple surface patterning method to create micropatterns of mammalian cells on indium tin oxide (ITO) substrates was developed using ion implantation. Thin polystyrene (PS) films spin-coated on an ITO glass was selectively implanted with accelerated proton ions through a pattern mask and then developed to generate PS micropatterns. Well-organized negative PS patterns were generated on the ITO glass. The results of the in vitro cell culture on the PS-patterned ITO glass with two types of cancer cell lines revealed the formation of well-defined cell patterns through a selective cell adhesion and proliferation only onto the ITO regions separated by PS regions. This facile method for cell patterning may be used to create a desired platform for cellular device applications, such as biosensors and cell microarrays.

  16. MOCVD Growth of High-Quality and Density-Tunable GaAs Nanowires on ITO Catalyzed by Au Nanoparticles Deposited by Centrifugation.

    PubMed

    Wu, Dan; Tang, Xiaohong; Yoon, Ho Sup; Wang, Kai; Olivier, Aurelien; Li, Xianqiang

    2015-12-01

    High-quality and density-tunable GaAs nanowires (NWs) are directly grown on indium tin oxide (ITO) using Au nanoparticles (NPs) as catalysts by metal organic chemical vapor deposition (MOCVD). Au catalysts were deposited on ITO glass substrate using a centrifugal method. Compared with the droplet-only method, high-area density Au NPs were uniformly distributed on ITO. Tunable area density was realized through variation of the centrifugation time, and the highest area densities were obtained as high as 490 and 120 NP/μm(2) for 10- and 20-nm diameters of Au NPs, respectively. Based on the vapor-liquid-solid growth mechanism, the growth rates of GaAs NWs at 430 °C were 18.2 and 21.5 nm/s for the highest area density obtained of 10- and 20-nm Au NP-catalyzed NWs. The growth rate of the GaAs NWs was reduced with the increase of the NW density due to the competition of precursor materials. High crystal quality of the NWs was also obtained with no observable planar defects. 10-nm Au NP-induced NWs exhibit wurtzite structure whereas zinc-blende is observed for 20-nm NW samples. Controllable density and high crystal quality of the GaAs NWs on ITO demonstrate their potential application in hybrid a solar cell.

  17. Preparation of ZnO nanorods on conductive PET-ITO-Ag fibers

    NASA Astrophysics Data System (ADS)

    Li, Yiwen; Ji, Shuai; Chen, Yuanyu; Zhang, Hong; Gong, Yumei; Guo, Jing

    2016-12-01

    We studied the vertical ZnO nanorods grown on conductive conventional polyethylene terephthalate (PET) fibers which are prepared by electroless silver depositing on tin-doped indium oxide (ITO) coated PET fibers through an efficient and low-cost green approach. The PET fibers were firstly functionalized with a layer of ITO gel synthesized through a sol-gel process at rather low temperature, simply by immersing the fibers into ITO sol for several minutes followed by gelation at 120 °C. Once the ITO gel layer surface was activated by SnCl2, a continuous, uniform, and compact layer of silver was carried out on the surface of the PET-ITO fibers through electroless plating operation at room temperature. The as-prepared PET-ITO-Ag fibers had good electrical conductivity, with surface resistivity as low as 0.23 mΩ cm. The overall procedure is simple, efficient, nontoxic, and controllable. The conductive PET-ITO-Ag fiber was used successfully as a flexible basal material to plant vertical ZnO nanorods through controlling the seeding and growth processes. The morphology of the PET-ITO, PET-ITO-Ag, and PET-ITO-Ag-ZnO fibers were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Undergone the whole process, although the tensile strength of the fiber decreased slightly, they may still exert their applications in flexible electronic such as photovoltaic and piezoelectric devices.

  18. Pulsed laser deposition of ITO/AZO transparent contact layers for GaN LED applications.

    PubMed

    Ou, Sin Liang; Wuu, Dong Sing; Liu, Shu Ping; Fu, Yu Chuan; Huang, Shih Cheng; Horng, Ray Hua

    2011-08-15

    In this study, indium-tin oxide (ITO)/Al-doped zinc oxide (AZO) composite films were fabricated by pulsed laser deposition and used as transparent contact layers (TCLs) in GaN-based blue light emitting diodes (LEDs). The ITO/AZO TCLs were composed of the thin ITO (50 nm) films and AZO films with various thicknesses from 200 to 1000 nm. Conventional LED with ITO (200 nm) TCL prepared by E-beam evaporation was fabricated and characterized for comparison. From the transmittance spectra, the ITO/AZO films exhibited high transparency above 90% at wavelength of 465 nm. The sheet resistance of ITO/AZO TCL decreased as the AZO thickness increased, which could be attributed to the increase in a carrier concentration, leading to a decrease in the forward bias of LED. The LEDs with ITO/AZO composite TCLs showed better light extraction as compared to LED with ITO TCL in compliance with simulation. When an injection current of 20 mA was applied, the output power for LEDs fabricated with ITO/AZO TCLs had 45%, 63%, and 71% enhancement as compared with those fabricated using ITO (200 nm) TCL for the AZO thicknesses of 200, 460, and 1000 nm, respectively.

  19. The Study of Simulated Space Radiation Environment Effect on Conductive Properties of ITO Thermal Control Materials

    NASA Astrophysics Data System (ADS)

    Wei-Quan, Feng; Chun-Qing, Zhao; Zi-Cai, Shen; Yi-Gang, Ding; Fan, Zhang; Yu-Ming, Liu; Hui-Qi, Zheng; Xue, Zhao

    In order to prevent detrimental effects of ESD caused by differential surface charging of spacecraft under space environments, an ITO transparent conductive coating is often deposited on the thermal control materials outside spacecraft. Since the ITO coating is exposed in space environment, the environment effects on electrical property of ITO coatings concern designers of spacecraft deeply. This paper introduces ground tests to simulate space radiation environmental effects on conductive property of ITO coating. Samples are made of ITO/OSR, ITO/Kapton/Al and ITO/FEP/Ag thermal control coatings. Simulated space radiation environment conditions are NUV of 500ESH, 40 keV electron of 2 × 1016 е/cm2, 40 keV proton of 2.5 × 1015 p/cm2. Conductive property is surface resistivity measured in-situ in vacuum. Test results proved that the surface resistivity for all ITO coatings have a sudden decrease in the beginning of environment test. The reasons for it may be the oxygen vacancies caused by vacuum and decayed RIC caused by radiation. Degradation in conductive properties caused by irradiation were found. ITO/FEP/Ag exhibits more degradation than other two kinds. The conductive property of ITO/kapton/Al is stable for vacuum irradiation. The analysis of SEM and XPS found more crackers and less Sn and In concentration after irradiation which may be the reason for conductive property degradation.

  20. Experimental investigation of metallic thin film modification of nickel substrates for chemical vapor deposition growth of single layer graphene at low temperature

    NASA Astrophysics Data System (ADS)

    Aminalragia Giamini, Sigiava; Marquez-Velasco, Jose; Sakellis, Ilias; Tsipas, Polychronis; Kelaidis, Nikolaos; Tsoutsou, Dimitra; Boukos, Nikolaos; Kantarelou, Vasiliki; Xenogiannopoulou, Evangelia; Speliotis, Thanassis; Aretouli, Kleopatra; Kordas, George; Dimoulas, Athanasios

    2016-11-01

    Lowering the growth temperature of single layer graphene by chemical vapor deposition (CVD) is important for its real-life application and mass production. Doing this without compromising quality requires advances in catalytic substrates. It is shown in this work that deposition of Zn and Bi metals modify the surface of nickel suppressing the uncontrollable growth of multiple layers of graphene. As a result, single layer graphene is obtained by CVD at 600 °C with minimum amount of defects, showing substantial improvement over bare Ni. In contrast, Cu, and Mo suppress graphene growth. We also show that graphene grown with our method has a defect density that is strongly dependent on the roughness of the original nickel foil. Good quality or highly defective holey single layer graphene can be grown at will by selecting a smooth or rough foil substrate respectively.

  1. Effect of pyrolytic temperature on the properties of TiO2/ITO films for hydrogen sensing.

    PubMed

    Vijayalakshmi, K; Jereil, S David; Karthick, K

    2015-03-05

    Titanium dioxide (TiO2) thin films were prepared on ITO (222) coated glass substrates by spray pyrolysis technique. The influence of substrate temperature on the orientation, phase, vibrational bands and band gap energy of TiO2 films were discussed. The X-ray diffraction patterns of the films revealed preferentially oriented (101) TiO2 anatase phase at the substrate temperature of 300°C and 350°C. Fourier transform infrared spectra of the films showed the significant sharpening of absorption band at ∼645cm(-1) with increase in substrate temperature, which clearly indicates the formation of anatase phase dependent on substrate temperature. Fourier Raman Spectra of the films showed the significant presence of long range order anatase TiO2 phase. The optical measurements of the film prepared at different substrate temperatures revealed the direct band gap of 3.15-3.63eV and indirect band gap of 3.48-3.73eV, characteristic of TiO2 anatase phase. To understand the enhancement of sensing performances of TiO2 films with substrate temperature, the gas sensing mechanism of the films towards 400sccm of hydrogen at room temperature was studied and discussed.

  2. Modification of the wettability of a polymeric substrate by pH effect. Determination of the surface acid dissociation constant by contact angle measurements.

    PubMed

    Badre, Chantal; Mayaffre, Alain; Letellier, Pierre; Turmine, Mireille

    2006-09-26

    The wetting properties of a substrate can be changed by chemical reaction. Here, we studied simple materials with acid-base properties, by preparing poly(vinyl chloride) films containing lauric acid. These substrates constitute simple polymeric surfaces the wettability of which can be easily controlled by the acid-base equilibrium. The roughness of the material was then varied by adding Aerosil (hydrophobic fumed silica). We then studied the wettability of these materials toward aqueous buffer solutions between pH 2 and 12 from contact angle measurements. The variation of the contact angle of a droplet of buffer solution with the pH of the solution was described by a simple thermodynamic model requiring only two parameters. Thus, we could characterize the acid polymer by an effective surface acid dissociation constant the value of which was consistent with those obtained with a similar surface. We showed that the behavior of any substrate could be described even if the surface geometry was not well-known.

  3. Structure, stability and electrochromic properties of polyaniline film covalently bonded to indium tin oxide substrate

    NASA Astrophysics Data System (ADS)

    Zhang, Wenzhi; Ju, Wenxing; Wu, Xinming; Wang, Yan; Wang, Qiguan; Zhou, Hongwei; Wang, Sumin; Hu, Chenglong

    2016-03-01

    Indium tin oxide (ITO) substrate was modified with 4-aminobenzylphosphonic acid (ABPA), and then the polyaniline (PANI) film covalently bonded to ITO substrate was prepared by the chemical oxidation polymerization. X-ray photoelectron spectroscopy (XPS), attenuated total reflection infrared (ATR-IR) spectroscopy, and atomic force microscopy (AFM) measurements demonstrated that chemical binding was formed between PANI and ABPA-modified ITO surface, and the maximum thickness of PANI layer is about 30 nm. The adhesive strength of PANI film on ITO substrate was tested by sonication. It was found that the film formed on the modified ITO exhibited a much better stability than that on bare one. Cyclic voltammetry (CV) and UV-vis spectroscopy measurements indicated that the oxidative potentials of PANI film on ABPA-modified ITO substrate were decreased and the film exhibited high electrochemical activities. Moreover, the optical contrast increased from 0.58 for PANI film (without ultrasound) to 1.06 for PANI film (after ultrasound for 60 min), which had an over 83% enhancement. The coloration time was 20.8 s, while the bleaching time was 19.5 s. The increase of electrochromic switching time was due to the lower ion diffusion coefficient of the large cation of (C4H9)4N+ under the positive and negative potentials as comparison with the small Li+ ion.

  4. Dealloying Ag-Al alloy to prepare nanoporous silver as a substrate for surface-enhanced Raman scattering: effects of structural evolution and surface modification.

    PubMed

    Qiu, Huajun; Zhang, Zhonghua; Huang, Xirong; Qu, Yinbo

    2011-08-01

    Sensitive detection of molecules by using the surface-enhanced Raman scattering (SERS) technique depends on the nanostructured metallic substrate and many efforts have been devoted to the preparation of SERS substrates with high sensitivity, stability, and reproducibility. Herein, we report on the fabrication of stable monolithic nanoporous silver (NPS) by chemical dealloying of Ag-Al precursor alloys with an emphasis on the effect of structural evolution on SERS signals. It was found that the dealloying conditions had great influence on the morphology (the ligament/pore size) and the crystallization status, which determined the SERS signal of rhodamine 6G on the NPS. NPS with small pores, low residual Al, and perfect crystallization gave high SERS signals. A high enhancement factor of 7.5 × 10(5) was observed on bare NPS obtained by dealloying Ag(30)Al(70) in 2.5 wt % HCl at room temperature followed by 15 min aging at around 85 °C. After coating Ag nanoparticles on the NPS surface, the enhancement factor increased to 1.6 × 10(8) owing to strong near-field coupling between the ligaments and nanoparticles.

  5. The effect of substrate temperature on the microstructural, electrical and optical properties of Sn-doped indium oxide thin films

    NASA Astrophysics Data System (ADS)

    Raoufi, Davood; Taherniya, Atefeh

    2015-06-01

    In this work, Sn doping In2O3 (ITO) thin films with a thickness of 200 nm were deposited on glass substrates by electron beam evaporation (EBE) method at different substrate temperatures. The crystal structure of these films was studied by X-ray diffraction technique. The sheet resistance was measured by a four-point probe. Van der Pauw method was used to measure carrier density and mobility of ITO films. The optical transmittance spectra were recorded in the wavelength region of 300-800 nm. Scanning electron microscope (SEM) has been used for the surface morphology analysis. The prepared ITO films exhibited body-centered cubic (BCC) structure with preferred orientation of growth along the (2 2 2) crystalline plane. The grain size of the films increases by rising the substrate temperature. Transparency of the films, over the visible light region, is increased with increasing the substrate temperature. It is found that the electrical properties of ITO films are significantly affected by substrate temperature. The electrical resistivity decreases with increasing substrate temperature, whereas the carrier density and mobility are enhanced with an increase in substrate temperature. The evaluated values of energy band gap Eg for ITO films were increase from 3.84 eV to 3.91 eV with increasing the substrate temperatures from 200 °C to 500 °C. The SEM micrographs of the films revealed a homogeneous growth without perceptible cracks with particles which are well covered on the substrate.

  6. Artificially MoO3 graded ITO anodes for acidic buffer layer free organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Lee, Hye-Min; Kim, Seok-Soon; Kim, Han-Ki

    2016-02-01

    We report characteristics of MoO3 graded ITO anodes prepared by a RF/DC graded sputtering for acidic poly(3,4-ethylene dioxylene thiophene):poly(styrene sulfonic acid) (PEDOT:PSS)-free organic solar cells (OSCs). Graded sputtering of the MoO3 buffer layer on top of the ITO layer produced MoO3 graded ITO anodes with a sheet resistance of 12.67 Ω/square, a resistivity of 2.54 × 10-4 Ω cm, and an optical transmittance of 86.78%, all of which were comparable to a conventional ITO anode. In addition, the MoO3 graded ITO electrode showed a greater work function of 4.92 eV than that (4.6 eV) of an ITO anode, which is beneficial for hole extraction from an organic active layer. Due to the high work function of MoO3 graded ITO electrodes, the acidic PEDOT:PSS-free OSCs fabricated on the MoO3 graded ITO electrode exhibited a power conversion efficiency 3.60% greater than that of a PEDOT:PSS-free OSC on the conventional ITO anode. The successful operation of PEDOT:PSS-free OSCs indicates simpler fabrication steps for cost-effective OSCs and elimination of interfacial reactions caused by the acidic PEDOT:PSS layer for reliable OSCs.

  7. Optimizing ITO for incorporation into multilayer thin film stacks for visible and NIR applications

    NASA Astrophysics Data System (ADS)

    Roschuk, Tyler; Taddeo, David; Levita, Zachary; Morrish, Alan; Brown, Douglas

    2017-05-01

    Indium Tin Oxide, ITO, is the industry standard for transparent conductive coatings. As such, the common metrics for characterizing ITO performance are its transmission and conductivity/resistivity (or sheet resistance). In spite of its recurrent use in a broad range of technological applications, the performance of ITO itself is highly variable, depending on the method of deposition and chamber conditions, and a single well defined set of properties does not exist. This poses particular challenges for the incorporation of ITO in complex optical multilayer stacks while trying to maintain electronic performance. Complicating matters further, ITO suffers increased absorption losses in the NIR - making the ability to incorporate ITO into anti-reflective stacks crucial to optimizing overall optical performance when ITO is used in real world applications. In this work, we discuss the use of ITO in multilayer thin film stacks for applications from the visible to the NIR. In the NIR, we discuss methods to analyze and fine tune the film properties to account for, and minimize, losses due to absorption and to optimize the overall transmission of the multilayer stacks. The ability to obtain high transmission while maintaining good electrical properties, specifically low resistivity, is demonstrated. Trade-offs between transmission and conductivity with variation of process parameters are discussed in light of optimizing the performance of the final optical stack and not just with consideration to the ITO film itself.

  8. Quantum conversion enhancement with TiO(x) compact layers for ITO-plastic-film-based low-temperature-processed dye-sensitized photoelectrodes.

    PubMed

    Morita, Saori; Ikegami, Masashi; Wei, Tzu-Chien; Miyasaka, Tsutomu

    2014-04-14

    A plastic substrate-based dye-sensitized photoelectrode was fabricated with a thin mesoporous titania film prepared on a TiO(x)-coated indium tin oxide-polyethylene naphthalate (ITO-PEN) substrate by a low-temperature process. The 3.5 μm-thick titania film sensitized with an indoline dye (D205) yielded a power conversion efficiency of 5.2%, with the internal quantum efficiency reaching 100%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Retinoblastoma Presenting in a Child with Hypomelanosis of Ito

    PubMed Central

    El-Sawy, Tarek; He, Lingmin; Chiang, Michael F; Anyane-Yeboa, Kwame; Morel, Kimberly D; Folberg, Robert; Marr, Brian P; Abramson, David

    2011-01-01

    Purpose: To describe a case of a child with a known history of pigmentary mosaicism suggestive of Hypomelanosis of Ito presenting with unilateral leukocoria, who was ultimately diagnosed with retinoblastoma. Methods: A report of a 16-month-old girl with pigmentary mosaicism and unilateral retinoblastoma. Results: A previously healthy 16-month-old girl with a diagnosis of a mosaic hypopigmentation at the age of 6 months based on a linear and whorled pattern of skin hypopigmentation along the lines of Blaschko, presented with unilateral strabismus, leukocoria, retinal detachment, and sub-retinal exudation. Hypomelanosis of Ito and other similar neurocutaneous syndromes are known to be associated with abnormal retinal pigmentation, vascular abnormalities, and retinal detachment. Examination included a fluorescein angiogram, ultrasonography, and an MRI of the brain and orbits that demonstrated features consistent with retinoblastoma. Given these findings and a flat electroretinogram, the eye was enucleated with final pathologic confirmation of retinoblastoma. Conclusions: Previously unreported presentation of unilateral retinoblastoma in a child with pigmentary mosaicism. PMID:22216075

  10. Investigation of ITO free transparent conducting polymer based electrode

    NASA Astrophysics Data System (ADS)

    Sharma, Vikas; Sapna, Sachdev, Kanupriya

    2016-05-01

    The last few decades have seen a significant improvement in organic semiconductor technology related to solar cell, light emitting diode and display panels. The material and structure of the transparent electrode is one of the major concerns for superior performance of devices such as OPV, OLED, touch screen and LCD display. Commonly used ITO is now restricted due to scarcity of indium, its poor mechanical properties and rigidity, and mismatch of energy levels with the active layer. Nowadays DMD (dielectric-metal-dielectric) structure is one of the prominent candidates as alternatives to ITO based electrode. We have used solution based spin coated polymer layer as the dielectric layer with silver thin film embedded in between to make a polymer-metal-polymer (PMP) structure for TCE applications. The PMP structure shows low resistivity (2.3 x 10-4Ω-cm), high carrier concentration (2.9 x 1021 cm-3) and moderate transparency. The multilayer PMP structure is characterized with XRD, AFM and Hall measurement to prove its suitability for opto-electronic device applications.

  11. Investigation of ITO free transparent conducting polymer based electrode

    SciTech Connect

    Sharma, Vikas; Sapna,; Sachdev, Kanupriya

    2016-05-23

    The last few decades have seen a significant improvement in organic semiconductor technology related to solar cell, light emitting diode and display panels. The material and structure of the transparent electrode is one of the major concerns for superior performance of devices such as OPV, OLED, touch screen and LCD display. Commonly used ITO is now restricted due to scarcity of indium, its poor mechanical properties and rigidity, and mismatch of energy levels with the active layer. Nowadays DMD (dielectric-metal-dielectric) structure is one of the prominent candidates as alternatives to ITO based electrode. We have used solution based spin coated polymer layer as the dielectric layer with silver thin film embedded in between to make a polymer-metal-polymer (PMP) structure for TCE applications. The PMP structure shows low resistivity (2.3 x 10{sup −4}Ω-cm), high carrier concentration (2.9 x 10{sup 21} cm{sup −3}) and moderate transparency. The multilayer PMP structure is characterized with XRD, AFM and Hall measurement to prove its suitability for opto-electronic device applications.

  12. (110)-oriented indium tin oxide films grown on m- and r-plane sapphire substrates

    NASA Astrophysics Data System (ADS)

    Chern, Ming-Yau; Lu, Tso-Wen; Xu, Wei-Lun

    2015-04-01

    Indium tin oxide (ITO) thin films have been deposited by pulsed laser deposition on m-plane (100) and r-plane (012) sapphire substrates. For both substrates, the films were grown with their [110] direction perpendicular to the substrate planes under the conditions of high growth temperature and high oxygen pressure. Their in-plane epitaxial relations with the substrates were identified to be ITO[001] ∥ Al2O3[020] and \\text{ITO}[1\\bar{1}0]\\parallel \\text{Al}2\\text{O}3[001] for the m-plane substrate. For the r-plane substrate, two types of lattice matching were observed: one being \\text{ITO}[001]\\parallel \\text{Al}2\\text{O}3[2,1, - 1/2] and \\text{ITO}[1\\bar{1}0]\\parallel \\text{Al}2\\text{O}3[4/3, - 4/3,2/3], the other being \\text{ITO}[001]\\parallel \\text{Al}2\\text{O}3[1, - 1,1/2] and \\text{ITO}[1\\bar{1}0]/\\text{Al}2\\text{O}3[8/3,4/3, - 2/3]. The electrical properties were measured by the Hall effect and van der Pauw methods at room temperature. All of the samples have low electrical resistivity on the order of 3.0 × 10-4 Ω cm, high carrier concentration of about 2.5 × 1020 cm-3, and mobility ranging from 70 to 90 cm2 V-1 s-1.

  13. One-step synthesis of carbon nanosheets converted from a polycyclic compound and their direct use as transparent electrodes of ITO-free organic solar cells.

    PubMed

    Son, Su-Young; Noh, Yong-Jin; Bok, Changsuk; Lee, Sungho; Kim, Byoung Gak; Na, Seok-In; Joh, Han-Ik

    2014-01-21

    Through a catalyst- and transfer-free process, we fabricated indium tin oxide (ITO)-free organic solar cells (OSCs) using a carbon nanosheet (CNS) with properties similar to graphene. The morphological and electrical properties of the CNS derived from a polymer of intrinsic microporosity-1 (PIM-1), which is mainly composed of several aromatic hydrocarbons and cycloalkanes, can be easily controlled by adjusting the polymer concentration. The CNSs, which are prepared by simple spin-coating and heat-treatment on a quartz substrate, are directly used as the electrodes of ITO-free OSCs, showing a high efficiency of approximately 1.922% under 100 mW cm(-2) illumination and air mass 1.5 G conditions. This catalyst- and transfer-free approach is highly desirable for electrodes in organic electronics.

  14. Conditioning-specific reflex modification of the rabbit's nictitating membrane response and heart rate: behavioral rules, neural substrates, and potential applications to posttraumatic stress disorder.

    PubMed

    Burhans, Lauren B; Smith-Bell, Carrie; Schreurs, Bernard G

    2008-12-01

    Interest in classical conditioning is usually focused on anticipatory responses to a stimulus associated with a significant event, and it is assumed that responses to the event itself are reflexive, involuntary, and relatively invariant. However, there is compelling evidence that both the rabbit nictitating membrane response (NMR) and heart rate response (HR), well-known reflexive reactions to aversive events, can change quite dramatically as a function of learning when measured in the absence of the conditioned stimulus. In the case of NMR conditioning, a simple blink is transformed into a larger and more complex response. For HR conditioning, reflexive heart rate acceleration can actually change to heart rate deceleration. In both cases, the reflex comes to resemble the conditioned response and follows some of the same behavioral laws. This change in response to the aversive event itself or weaker forms of that event is called conditioning-specific reflex modification (CRM). CRM may force us to reevaluate the behavioral and neural consequences of classical conditioning and may have important consequences for the treatment of conditions such as posttraumatic stress disorder.

  15. Sintered indium-tin-oxide (ITO) particles: a new pneumotoxic entity.

    PubMed

    Lison, Dominique; Laloy, Julie; Corazzari, Ingrid; Muller, Julie; Rabolli, Virginie; Panin, Nadtha; Huaux, François; Fenoglio, Ivana; Fubini, Bice

    2009-04-01

    Indium-Tin-Oxide (ITO) is a sintered mixture of indium- (In(2)O(3)) and tin-oxide (SnO(2)) in a ratio of 90:10 (wt:wt) that is used for the manufacture of LCD screens and related high technology applications. Interstitial pulmonary diseases have recently been reported in workers from ITO producing plants. The present study was conducted to identify experimentally the exact chemical component responsible for this toxicity and to address possible mechanisms of action. The reactivity of respirable ITO particles was compared with that of its single components alone or their unsintered 90:10 mixture (MIX) both in vivo and in vitro. For all endpoints considered, ITO particles behaved as a specific toxic entity. In vivo, after a single pharyngeal administration (2-20 mg per rat), ITO particles induced a strong inflammatory reaction. At day 3, the inflammatory reaction (cell accumulation, LDH and protein in bronchoalveolar lavage fluid) appeared more marked with ITO particles than with each oxide separately or the MIX. This inflammatory reaction persisted and even worsened after 15 days. After 60 days, this inflammation was still present but no significant fibrotic response was observed. The cytotoxicity of ITO was assessed in vitro in lung epithelial cells (RLE) and macrophages (NR8383 cell line). While ITO particles (up to 200 microg/ml) did not affect epithelial cell integrity (LDH release), a strong cytotoxic response was found in macrophages exposed to ITO, but not to its components alone or mixed. ITO particles also induced an increased frequency of micronuclei in type II pneumocytes in vivo but not in RLE in vitro, suggesting the preponderance of a secondary genotoxic mechanism. To address the possible mechanism of ITO toxicity, reactive oxygen species production was assessed by electron paramagnetic resonance spectrometry in an acellular system. Carbon centered radicals (COO-.) and Fenton-like activity were detected in the presence of ITO particles, not with In(2)O

  16. Biatrial linear ablation in sustained nonpermanent AF: Results of the substrate modification with ablation and antiarrhythmic drugs in nonpermanent atrial fibrillation (SMAN-PAF) trial.

    PubMed

    Wynn, Gareth J; Panikker, Sandeep; Morgan, Maureen; Hall, Mark; Waktare, Johan; Markides, Vias; Hussain, Wajid; Salukhe, Tushar; Modi, Simon; Jarman, Julian; Jones, David G; Snowdon, Richard; Todd, Derick; Wong, Tom; Gupta, Dhiraj

    2016-02-01

    More advanced atrial fibrillation (AF) is associated with lower success rates after pulmonary vein isolation (PVI), and the optimal ablation strategy is uncertain. To assess the impact of additional linear ablation (lines) compared to PVI alone. In this multicenter randomized controlled trial, 122 patients (mean age 61.9 ± 10.5 years; left atrial diameter 43 ± 6 mm) with persistent AF (PeAF) or sustained (>12 hours) paroxysmal AF (SusPAF) with risk factors for atrial substrate were included and followed up for 12 months. Patients were randomized to PVI-only or PVI + lines (left atrial roof line, mitral isthmus line, and tricuspid isthmus line) group. Holter monitoring was performed at 3, 6, and 12 months and according to symptoms. The primary outcome was atrial tachyarrhythmia recurrence lasting ≥30 seconds. Baseline characteristics were comparable between groups; 61% had PeAF and 39% SusPAF. Successful PVI was achieved for 98% of pulmonary veins, and bidirectional block was obtained in 90% of lines. The primary end point occurred in 38% of the PVI + lines group and 32% of the PVI-only group (P = .50), which was consistent in both PeAF (36% vs 28%; P = .45) and SusPAF (42% vs 39%; P = .86). Compared with the PVI-only group, the PVI + lines group had higher procedure duration (209 ± 52 minutes vs 172 ± 44 minutes; P < .001), ablation time (4352 ± 1084 seconds vs 2503 ± 1061 seconds; P < .001), and radiation exposure (Dose-area product 3992 ± 6496 Gy·cm(2) vs 2106 ± 1679 Gy·cm(2); P = .03). Quality of life (disease-specific Atrial Fibrillation Effect on Quality of Life questionnaire and mental component scale of the Short Form 36 Health Survey) improved significantly during the study but did not differ between groups. Adding lines to wide antral PVI in substrate-based AF requires significantly more ablation, increases procedure duration and radiation dose, but provides no additional clinical benefit. Copyright © 2016 Heart Rhythm Society. Published by

  17. Chemical modification of hydroxynitrile lyase by selective reaction of an essential cysteine-SH group with alpha, beta-unsaturated propiophenones as pseudo-substrates.

    PubMed

    Jaenicke, L; Preun, J

    1984-01-16

    3-Oxo-3-phenylpropyne and 3-oxo-3-phenylpropene were synthesized as active-site-directed irreversible inhibitors of the bitter almond hydroxynitrile lyase (EC 4.1.2.10), an FAD-protein. The substrate and competitors (e.g. benzoate) decrease the rate of the inhibitor-mediated deactivation of the enzyme. By excess addition of either one of the two inhibitors, the deactivation process is shown to be pseudo-first order. The reaction with equimolar amounts of 3-oxo-3-phenylpropyne with the enzyme is accompanied by a shift in the ultraviolet spectrum of the inhibitor, allowing direct measurement of the enzyme-inactivation process. The spectral change has second-order kinetics. Incubation with 3-oxo-3-[p-3H]phenylpropyne or 3-oxo-3-[1-14C]phenylpropene shows a one-to-one stoichiometry for the inhibitory-enzyme reaction. Dissociation of the 3-oxo-3[p-3H]phenylpropyne-inactivated holoenzyme with acid ammonium sulfate yields a labeled apoenzyme; the inhibitor does not react with free or enzyme-bound FAD. After boranate reduction and exhaustive hydrolysis of the 3-oxo-3-[1-14C]phenylpropene-inactivated enzyme, a labeled cysteine derivative was isolated which was identified by chromatographic and mass spectroscopic comparison with synthetic references as L-2-amino-4-thia-DL-7-hydroxy-7-phenylhepatanoic acid, the reduced, linear addition product of the inhibitor to a cysteine-SH group.

  18. Stand-Alone Pulmonary Vein Isolation Versus Pulmonary Vein Isolation With Additional Substrate Modification as Index Ablation Procedures in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation: The Randomized Alster-Lost-AF Trial (Ablation at St. Georg Hospital for Long-Standing Persistent Atrial Fibrillation).

    PubMed

    Fink, Thomas; Schlüter, Michael; Heeger, Christian-Hendrik; Lemes, Christine; Maurer, Tilman; Reissmann, Bruno; Riedl, Johannes; Rottner, Laura; Santoro, Francesco; Schmidt, Boris; Wohlmuth, Peter; Mathew, Shibu; Sohns, Christian; Ouyang, Feifan; Metzner, Andreas; Kuck, Karl-Heinz

    2017-07-01

    Pulmonary vein isolation (PVI) for persistent atrial fibrillation is associated with limited success rates and often requires multiple procedures to maintain stable sinus rhythm. In the prospective and randomized Alster-Lost-AF trial (Ablation at St. Georg Hospital for Long-Standing Persistent Atrial Fibrillation), we sought to assess, in patients with symptomatic persistent or long-standing persistent atrial fibrillation, the outcomes of initial ablative strategies comprising either stand-alone PVI (PVI-only approach) or a stepwise approach of PVI followed by complex fractionated atrial electrogram ablation and linear ablation (Substrate-modification approach). Patients were randomized 1:1 to stand-alone PVI or PVI plus substrate modification. The primary study end point was freedom from recurrence of any atrial tachyarrhythmia, outside a 90-day blanking period, at 12 months. A total of 124 patients were enrolled, with 118 patients included in the analysis (61 in the PVI-only group, 57 in the Substrate-modification group). Atrial tachyarrhythmias recurred in 28 PVI-only group patients and 24 Substrate-modification group patients, for 1-year freedom from tachyarrhythmia recurrence after a single ablation procedure of 54% (95% confidence interval, 43%-68%) in the PVI-only and 57% (95% confidence interval, 46%-72%) in the Substrate-modification group (P=0.86). Twenty-four patients in the PVI-only group (39%) and 18 in the Substrate-modification group (32%) were without arrhythmia recurrence and off antiarrhythmic drug therapy at the end of the 12-month follow-up. In patients with persistent and long-standing persistent atrial fibrillation, no significant difference was observed in 12-month freedom from atrial tachyarrhythmias between an index ablative approach of stand-alone PVI and a stepwise approach of PVI plus complex fractionated atrial electrogram and linear ablation. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00820625. © 2017 American Heart

  19. A three-dimensional metal grid mesh as a practical alternative to ITO

    NASA Astrophysics Data System (ADS)

    Jang, Sungwoo; Jung, Woo-Bin; Kim, Choelgyu; Won, Phillip; Lee, Sang-Gil; Cho, Kyeong Min; Jin, Ming Liang; An, Cheng Jin; Jeon, Hwan-Jin; Ko, Seung Hwan; Kim, Taek-Soo; Jung, Hee-Tae

    2016-07-01

    The development of a practical alternative to indium tin oxide (ITO) is one of the most important issues in flexible optoelectronics. In spite of recent progress in this field, existing approaches to prepare transparent electrodes do not satisfy all of their essential requirements. Here, we present a new substrate-embedded tall (~350 nm) and thin (~30 nm) three-dimensional (3D) metal grid mesh structure with a large area, which is prepared via secondary sputtering. This structure satisfies most of the essential requirements of transparent electrodes for practical applications in future opto-electronics: excellent optoelectronic performance (a sheet resistance of 9.8 Ω □-1 with a transmittance of 85.2%), high stretchability (no significant change in resistance for applied strains <15%), a sub-micrometer mesh period, a flat surface (a root mean square roughness of approximately 5 nm), no haze (approximately 0.5%), and strong adhesion to polymer substrates (it survives attempted detachment with 3M Scotch tape). Such outstanding properties are attributed to the unique substrate-embedded 3D structure of the electrode, which can be obtained with a high aspect ratio and in high resolution over large areas with a simple process. As a demonstration of its suitability for practical applications, our transparent electrode was successfully tested in a flexible touch screen panel. We believe that our approach opens up new practical applications in wearable electronics.The development of a practical alternative to indium tin oxide (ITO) is one of the most important issues in flexible optoelectronics. In spite of recent progress in this field, existing approaches to prepare transparent electrodes do not satisfy all of their essential requirements. Here, we present a new substrate-embedded tall (~350 nm) and thin (~30 nm) three-dimensional (3D) metal grid mesh structure with a large area, which is prepared via secondary sputtering. This structure satisfies most of the essential

  20. One-step synthesis of carbon nanosheets converted from a polycyclic compound and their direct use as transparent electrodes of ITO-free organic solar cells

    NASA Astrophysics Data System (ADS)

    Son, Su-Young; Noh, Yong-Jin; Bok, Changsuk; Lee, Sungho; Kim, Byoung Gak; Na, Seok-In; Joh, Han-Ik

    2013-12-01

    Through a catalyst- and transfer-free process, we fabricated indium tin oxide (ITO)-free organic solar cells (OSCs) using a carbon nanosheet (CNS) with properties similar to graphene. The morphological and electrical properties of the CNS derived from a polymer of intrinsic microporosity-1 (PIM-1), which is mainly composed of several aromatic hydrocarbons and cycloalkanes, can be easily controlled by adjusting the polymer concentration. The CNSs, which are prepared by simple spin-coating and heat-treatment on a quartz substrate, are directly used as the electrodes of ITO-free OSCs, showing a high efficiency of approximately 1.922% under 100 mW cm-2 illumination and air mass 1.5 G conditions. This catalyst- and transfer-free approach is highly desirable for electrodes in organic electronics.Through a catalyst- and transfer-free process, we fabricated indium tin oxide (ITO)-free organic solar cells (OSCs) using a carbon nanosheet (CNS) with properties similar to graphene. The morphological and electrical properties of the CNS derived from a polymer of intrinsic microporosity-1 (PIM-1), which is mainly composed of several aromatic hydrocarbons and cycloalkanes, can be easily controlled by adjusting the polymer concentration. The CNSs, which are prepared by simple spin-coating and heat-treatment on a quartz substrate, are directly used as the electrodes of ITO-free OSCs, showing a high efficiency of approximately 1.922% under 100 mW cm-2 illumination and air mass 1.5 G conditions. This catalyst- and transfer-free approach is highly desirable for electrodes in organic electronics. Electronic supplementary information (ESI) available: Detailed experimental methods; chemical structure and 1H NMR spectra; AFM images; TGA spectra; shunt and series resistances; Raman spectra and optical images; atomic contents of the CNSs. See DOI: 10.1039/c3nr04828d

  1. Modification of Titanium Substrates with Chimeric Peptides Comprising Antimicrobial and Titanium-Binding Motifs Connected by Linkers To Inhibit Biofilm Formation.

    PubMed

    Liu, Zihao; Ma, Shiqing; Duan, Shun; Xuliang, Deng; Sun, Yingchun; Zhang, Xi; Xu, Xinhua; Guan, Binbin; Wang, Chao; Hu, Meilin; Qi, Xingying; Zhang, Xu; Gao, Ping

    2016-03-02

    Bacterial adhesion and biofilm formation are the primary causes of implant-associated infection, which is difficult to eliminate and may induce failure in dental implants. Chimeric peptides with both binding and antimicrobial motifs may provide a promising alternative to inhibit biofilm formation on titanium surfaces. In this study, chimeric peptides were designed by connecting an antimicrobial motif (JH8194: KRLFRRWQWRMKKY) with a binding motif (minTBP-1: RKLPDA) directly or via flexible/rigid linkers to modify Ti surfaces. We evaluated the binding behavior of peptides using quartz crystal microbalance (QCM) and atomic force microscopy (AFM) techniques and investigated the effect of the modification of titanium surfaces with these peptides on the bioactivity of Streptococcus gordonii (S. gordonii) and Streptococcus sanguis (S. sanguis). Compared with the flexible linker (GGGGS), the rigid linker (PAPAP) significantly increased the adsorption of the chimeric peptide on titanium surfaces (p < 0.05). Concentration-dependent adsorption is consistent with a single Langmuir model, whereas time-dependent adsorption is in line with a two-domain Langmuir model. Additionally, the chimeric peptide with the rigid linker exhibited more effective antimicrobial ability than the peptide with the flexible linker. This finding was ascribed to the ability of the rigid linker to separate functional domains and reduce their interference to the maximum extent. Consequently, the performance of chimeric peptides with specific titanium-binding motifs and antimicrobial motifs against bacteria can be optimized by the proper selection of linkers. This rational design of chimeric peptides provides a promising alternative to inhibit the formation of biofilms on titanium surfaces with the potential to prevent peri-implantitis and peri-implant mucositis.

  2. Fabrication and characterization of ITO/silicon SIS solar cells. Final report, October 1, 1978-April 30, 1980

    SciTech Connect

    DuBow, J. B.

    1980-06-01

    The objectives of this research were to optimize the performance of ITO/polycrystalline silicon solar cells, identify performance limitations, identify major stability problems which would inhibit terrestrial application of these devices, evaluate the impact of indium supply and price on terrestrial applications, and evaluate the economic viability of ITO sputter deposited solar cells. These goals were successfully achieved during the course of this multipronged effort. Both area scaling with efficiency maintenance were achieved by process modifications including surface preparation and in-situ passivation techniques. Indium tin oxide on Wacker polycrystalline silicon solar cells were fabricated which achieved 13.7% efficiency for 11 cm/sup 2/ devices. Typical open circuit voltages were 0.525 volts, short circuit currents, 34 mA/cm/sup 2/, and fill factors of 0.75. In the course of this project, three device measurement techniques which assisted in improving cell efficiency and which have broad applicability to all photovoltaic devices were introduced. These were automated admittance and surface state analysis, noise spectral density analysis, and automated I-V and C-V analysis. These measurements were combined with Auger/ESCA, EBIC and flying spot scanner, and other measurement techniques to identify grain boundaries, intragrain defects, edge leakage, and interface losses which were subsequently alleviated through process improvements. It is concluded from this work that prototype production of cells and modules based on this technology would be warranted in the near term.

  3. Dual enzyme mimicry exhibited by ITO nanocubes and their application in spectrophotometric and electrochemical sensing.

    PubMed

    Aneesh, K; Vusa, Chiranjeevi Srinivasa Rao; Berchmans, Sheela

    2016-06-20

    The dual enzyme mimicry (peroxidase/catalase-like activities) exhibited by ITO nanocubes (ITO NCs) was investigated by spectrophotometric and electrochemical methods. The peroxidase mimic was successfully applied for the electrochemical detection of H2O2 and spectrophotometric biosensing of glucose. Further, the detection could be extended to the detection of glucose in real samples.

  4. Comparative study of ITO and FTO thin films grown by spray pyrolysis

    SciTech Connect

    Ait Aouaj, M.; Diaz, R.; Belayachi, A.; Rueda, F.; Abd-Lefdil, M.

    2009-07-01

    Tin doped indium oxide (ITO) and fluorine doped tin oxide (FTO) thin films have been prepared by one step spray pyrolysis. Both film types grown at 400 deg. C present a single phase, ITO has cubic structure and preferred orientation (4 0 0) while FTO exhibits a tetragonal structure. Scanning electron micrographs showed homogeneous surfaces with average grain size around 257 and 190 nm for ITO and FTO respectively. The optical properties have been studied in several ITO and FTO samples by transmittance and reflectance measurements. The transmittance in the visible zone is higher in ITO than in FTO layers with a comparable thickness, while the reflectance in the infrared zone is higher in FTO in comparison with ITO. The best electrical resistivity values, deduced from optical measurements, were 8 x 10{sup -4} and 6 x 10{sup -4} {Omega} cm for ITO (6% of Sn) and FTO (2.5% of F) respectively. The figure of merit reached a maximum value of 2.15 x 10{sup -3} {Omega}{sup -1} for ITO higher than 0.55 x 10{sup -3} {Omega}{sup -1} for FTO.

  5. Understanding the molecular-level chemistry of water plasmas and the effects of surface modification and deposition on a selection of oxide substrates

    NASA Astrophysics Data System (ADS)

    Trevino, Kristina J.

    2011-12-01

    This dissertation first examines electrical discharges used to study wastewater samples for contaminant detection and abatement. Two different water samples contaminated with differing concentrations of either methanol (MeOH) or methyl tert-butyl ether (MTBE) were used to follow breakdown mechanisms. Emission from CO* was used to monitor the contaminant and for molecular breakdown confirmation through actinometric OES as it can only arise from the carbon-based contaminant in either system. Detection was achieved at concentrations as low as 0.01 ppm, and molecular decomposition was seen at a variety of plasma parameters. This dissertation also explores the vibrational (thetaV), rotational (thetaR) and translational (thetaT) temperatures for a range of diatomic species in different plasma systems. For the majority of the plasma species studied, thetaV are much higher than thetaR and thetaT. This suggests that more energy is partitioned into the vibrational degrees of freedom in our plasmas. The thetaR reported are significantly lower in all the plasma systems studied and this is a result of radical equilibration to the plasma gas temperature. thetaT values show two characteristics; (1) they are less than the thetaV and higher than the theta R and (2) show varying trends with plasma parameters. Radical energetics were examined through comparison of thetaR, thetaT, and thetaV, yielding significant insight on the partitioning of internal and kinetic energies in plasmas. Correlations between energy partitioning results and corresponding radical surface scattering coefficients obtained using our imaging of radicals interacting with surfaces (IRIS) technique are also presented. Another aspect of plasma process chemistry, namely surface modification via plasma treatment, was investigated through characterization of metal oxides (SiOxNy, nat-SiO2, and dep-SiO2) following their exposure to a range of plasma discharges. Here, emphasis was placed on the surface wettability

  6. Carbon nanotube/Prussian blue thin films as cathodes for flexible, transparent and ITO-free potassium secondary battery.

    PubMed

    Nossol, Edson; Souza, Victor H R; Zarbin, Aldo J G

    2016-09-15

    Thin films of either unpurified single-walled carbon nanotubes (SWCNT) or iron-filled multi-walled carbon nanotubes (MWCNT) were deposited through the liquid-liquid interfacial route over plastic substrates, yielding transparent, flexible and ITO-free electrodes. The iron species presented in both electrodes (inside of the MWCNT cavities or outside of the SWCNT bundles, related to the catalyst remaining of the growth process) were employed as reactant to the electrosynthesis of Prussian blue (PB), yielding carbon nanotubes/Prussian blue nanocomposite thin films, which were characterized by Raman spectroscopy, scanning electron microscopy, atomic force microscopy, cyclic voltammetry and galvanostatic charge/discharge measurements. The nanocomposite films were employed as cathodes for flexible, transparent and ITO-free potassium batteries, showing reversible charge/discharge behavior and specific capacitance of 8.3mAhcm(-3) and 2.7mAhcm(-3) for SWCNT/PB and MWCNT/PB, respectively. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Very High Output Thermoelectric Devices Based on ITO Nanocomposites

    NASA Technical Reports Server (NTRS)

    Fralick, Gustave; Gregory, Otto J.

    2009-01-01

    A material having useful thermoelectric properties was synthesized by combining indium-tin-oxide (ITO) with a NiCoCrAlY alloy/alumina cermet. This material had a very large Seebeck coefficient with electromotive-force-versustemperature behavior that is considered to be excellent with respect to utility in thermocouples and other thermoelectric devices. When deposited in thin-film form, ceramic thermocouples offer advantages over precious-metal (based, variously, on platinum or rhodium) thermocouples that are typically used in gas turbines. Ceramic thermocouples exhibit high melting temperatures, chemical stability at high temperatures, and little or no electromigration. Oxide ceramics also resist oxidation better than metal thermocouples, cost substantially less than precious-metal thermocouples, and, unlike precious-metal thermocouples, do not exert catalytic effects.

  8. THE DISPERSION OF HERBACEOUS PLANT POLLEN IN ITO CITY, SHIZUOKA.

    PubMed

    Fujii, Mayumi; Makiyama, Kiyoshi; Okazaki, Kenji; Hisamatsu, Kenichi

    2016-08-01

    Airborne pollen was examined in Ito City, Shizuoka for the purpose of treatment and prophylaxis pollen allergies because the patients with pollen allergy to herbaceous plants have recently increased. Setting up a Durham's sampler, we measured airborne pollen identified and classified: Poaceae, Polygonaceae, Amaranthaceae, Urticaceae, Cannabaceae, Ambrosia and Artemisia indica.We studied whether each airborne pollen count has something to do with weather condition (2004-2015). Average total airborne Poaceae pollen count and standard deviation from January to June was 19.4±5.5 cells/cm(2), average total airborne Polygonaceae pollen count and standard deviation from April to September was 11.6±13.4 cells/cm(2). Airborne Poaceae, Amaranthaceae, Cannabaceae, Uriticaceae. Ambrosia and Artamisia indica pollen count from July to Deccember in order: 34.0±15.5 cells/cm(2), 1.3±1.1 cells/cm(2), 8.7±6.4cells/cm(2), 4.9±6.4 cells/cm(2), 10.5±7.8 cells/cm(2), and 13.6±16.3 cells/cm(2).Cannabaceae admitted that its airborne pollen count has negative correlation to the rainfall.Artemisia indica admitted that its airborne pollen count has negative correlation to the average temperature. Herbaceous plants pollen doesn't cause allergies because it is much less than tree pollen in ItoCity.It is thought that the diversity of the plants keep the people from having a serious allergy to pollen with awarm weather in this area.

  9. Study on CdTe Quantum Dots Electrochemiluminescent Sensor Supported by Carbon Nano-tubes With ITO Basal Electrode

    NASA Astrophysics Data System (ADS)

    Caixia, Yu; Jilin, Yan; Yifeng, Tu

    2011-05-01

    The water soluble CdTe quantum dots (QDs) was synthesized with modified method. Its quantum yield was characterized for higher than 54%. Therefore a novel sensitive electrochemiluminescent (ECL) sensor was constructed based on the modification of composite of CdTe QDs, carbon nanotubes (CNTs) and chitosan (CHIT) on indium tin oxide (ITO) glass. After heat-treatment by infrared radiation, meanwhile with the co-reactant, triethylamine (TEA), the proposed sensor showed excellent anodic ECL efficiency and stability. This ECL sensor responded the dopamine (DA) in a wide linear range from 50 pM to 10 nM with a detection limit of 24 pM due to the quenching effect from DA. The DA contents in practical biological samples of cerebro-spinal fluid were detected with satisfactory recovery of average 95.7%.

  10. Room temperature crystallization of indium tin oxide films on glass and polyethylene terephthalate substrates using rf plasma

    SciTech Connect

    Ohsaki, H.; Suzuki, M.; Shibayama, Y.; Kinbara, A.; Watanabe, T.

    2007-07-15

    The crystallization of amorphous indium tin oxide (ITO) films was achieved by rf (13.56 MHz) plasma treatment. Although the films were crystallized after 2 min, the sample temperature was lower than 90 deg. C without compulsory cooling even after 10 min of treatment and polyethylene terephthalate (PET) substrates had no damage. Plasma-crystallized sputtered ITO films have a bixbite structure and the resistivity reached to 1.6x10{sup -4} {omega}{center_dot}cm. ITO thin films have almost the same resistivity in both cases of PET and glass substrates used and plasma-treated PET ITO films have a bit higher resistivity than that of glass ITO films, while mass spectroscopy measurements indicated that ITO films deposited on PET substrates are expected to include no apparent gas species ejected from PET substrate. It was found that the plasma gas pressure is the key parameter for the effective crystallization and the appropriate gas pressure depends on the plasma gas species.

  11. O2 cluster ion assisted deposition for tin doped indium oxide (ITO) films

    NASA Astrophysics Data System (ADS)

    Matsuo, Jiro; Takaoka, Gikan; Yamada, Isao

    2001-07-01

    B S TO2 Gas Cluster Ion Beam assisted deposition technique has been developed to form ultra high quality tin doped indium-oxide (UHQ-ITO) films. This deposition process uses large cluster ions which can transport thousands of atoms in a ion with very low energy per constituent atom. Interactions between cluster ions and substrate atoms occur in the near-surface region and cluster ions can deposit their energy with a high density in a very localized surface region. The energetic oxygen clusters collapsed at the surface and reacted with the metal atoms and about 10% of them were incorporated, when the kinetic energy of the cluster ion was above 5 keV. Oxidation reaction can be enhanced by energetic cluster ion bombardment which offers a new technique for ion assisted thin film formation. Very smooth, highly transparent (>80 %) and low resistivity films, were obtained by using a 7 keV oxygen cluster ion beam. In order to realize high throughput for industrial application, a Multi-beam Gas Cluster Ion Beam equipment has been newly developed.

  12. Fabrication of Organic Bulk Heterojunction Solar Cells on Flexible Substrates

    NASA Astrophysics Data System (ADS)

    Calderon, Gabriel; Merced-Sanabria, Milzaida; Carradero-Santiago, Carolyn; Vedrine-Pauléus, Josee

    2015-03-01

    The active layer for the organic solar cells fabricated is composed of P3HT:PCBM, poly(3-hexylthiophene) (P3HT) as electron donor and phenyl-C61-butyric acid methyl ester(PCBM) as electron acceptor. These polymers were used due to their promising characteristics for devices such as bulk heterojunction solar devices. We used polyethylene terephthalate (PET) substrates, a highly flexible plastic, with indium tin oxide (ITO) as the transparent conducting anode for the device, and UV lithography technique to pattern the ITO; this is to facilitate multiple devices on a single substrate. The fabrication process for pattern transfer incorporates developing and etching processes. We diluted the HCl and DI water to etch out the ITO. PEDOT:PSS and active layer of P3HT:PCBM were deposited on (3.0 sq-cm) patterned of ITO/PET by spin coating method. The cathode was thermally evaporated with Al. We characterized the device using a sourcemeter. We also simulated portions of the device using PET on graphene as the substrate.

  13. ICP dry etching ITO to improve the performance of GaN-based LEDs

    NASA Astrophysics Data System (ADS)

    Lili, Meng; Yixin, Chen; Li, Ma; Zike, Liu; Guangdi, Shen

    2011-01-01

    In order to improve the light efficiency of the conventional GaN-based light-emitting diodes (LEDs), the indium tin oxide (ITO) film is introduced as the current spreading layer and the light anti-reflecting layer on the p-GaN surface. There is a big problem with the ITO thin film's corrosion during the electrode preparation. In this paper, at least, the edge of the ITO film was lateral corroded 3.5 μm width, i.e. 6.43%-1/3 of ITO film's area. An optimized simple process, i.e. inductively couple plasma (ICP), was introduced to solve this problem. The ICP process not only prevented the ITO film from lateral corrosion, but also improved the LED's light intensity and device performance. The edge of the ITO film by ICP dry etching is steep, and the areas of ITO film are whole. Compared with the chip by wet etching, the areas of light emission increase by 6.43% at least and the chip's lop values increase by 45.9% at most.

  14. Surface modification in microchip electrophoresis.

    PubMed

    Belder, Detlev; Ludwig, Martin

    2003-11-01

    Different approaches and techniques for surface modification of microfluidic devices applied for microchip electrophoresis are reviewed. The main focus is on the improved electrophoretic separation by reducing analyte-wall interactions and manipulation of electroosmosis. Approaches and methods for permanent and dynamic surface modification of microfluidic devices, manufactured from glass, quartz and also different polymeric substrates, are described.

  15. Investigation of the Magnetic Properties of Ni-implanted ITO Thin Films

    NASA Astrophysics Data System (ADS)

    Ay, Figen; Aktas, Bekir; Khaibullin, Rustem; Nuzhdin, Vladimir; Rameev, Bulat

    Commercially available ITO thin films on fused silica substrates were implanted with 40 keV Ni+ ions to fluences of (0.5,1.0&1.5) ×1017 ions/cm2 at room temperature. XRR measurements show that the thickness of the implanted films (~ 28.5 nm) does not change noticeably with the fluence, while the surface roughness increases essentially. SEM and EDX studies revealed a highly non-uniform distribution of Ni atoms. Room temperature ferromagnetism was observed in the samples with fluences of (1.0&1.5) ×1017 ions/cm2. VSM hysteresis curves and FMR signal point to the formation of a ferromagnetic near-surface layer in the implanted films due to agglomeration of closely-spaced metal Ni nanoparticles. The filling factor of the Ni ferromagnetic phase in the granular magnetic layer was estimated from the FMR results. Super- and para- magnetic phases were observed in the temperature dependence of magnetization by VSM. Superparamagnetic phase is attributed to the Ni nanoparticles located in deeper regions near the film/substrate interface, while paramagnetic phase is related to the impurity centers. For the samples with fluences of (1.0&1.5) ×1017 ions/cm2 average sizes of the superparamagnetic nanoparticles were calculated from the blocking temperatures TB observed in thermo-magnetic dependences. TÜBITAK, Grant No. 114F359 TÜBITAK / RFBR joint project program, Grant No. 213M524 / 14-02-91374-cT-a. RAS Programme No.32.

  16. TiO2-ITO and TiO2-ZnO nanocomposites: application on water treatment

    NASA Astrophysics Data System (ADS)

    Chorfi, H.; Saadoun, M.; Bousselmi, L.; Bessais, B.

    2012-06-01

    One of the most promising ideas to enhance the photocatalytic efficiency of the TiO2 is to couple this photocatalyst with other semiconductors. In this work, we report on the development of photo-catalytic properties of two types of composites based on TiO2 - ITO (Indium Tin Oxide) and TiO2 - ZnO deposited on conventional ceramic substrates. The samples were characterized by X-ray diffraction (XRD) and transmission Electron Microscopy (TEM). The photo-catalytic test was carried out under UV light in order to reduce/oxidize a typical textile dye (Cibacron Yellow). The experiment was carried out in a bench scale reactor using a solution having a known initial dye concentration. After optimization, we found that both nanocomposites exhibit better photocatalytic activity compared to the standard photocatalyst P25 TiO2.

  17. Electrodeposition of Sb2Se3 on indium-doped tin oxides substrate: Nucleation and growth

    NASA Astrophysics Data System (ADS)

    Shi, Xuezhao; zhang, Xin; Tian, Yuan; Shen, Chengmin; Wang, Chunming; Gao, Hong-Jun

    2012-01-01

    The mechanisms related to the initial stages of the nucleation and growth of antimony selenide (Sb2Se3) semiconductor compounds onto the indium-doped tin oxides (ITO) coated glass surface have been investigated using chronoamperometry (CA) technique. The fabrication was conducted from nitric acid bath containing both Sb3+ and SeO2 species at ambient conditions. No underpotential deposition (UPD) of antimony and selenium onto ITO substrate was observed in the investigated systems indicating a weak precursor-substrate interaction. Deposition of antimony and selenium onto ITO substrate occurred with large overvoltage through 3D nucleation and growth mechanism followed by diffusion limited growth. FE-SEM and XRD results show that orthorhombic phase Sb2Se3 particles with their size between 90 and 125 nm were obtained and the atomic ratio for antimony and selenium was 2:2.63 according to the EDX results.

  18. Comparison study of transparent RF-sputtered ITO/AZO and ITO/ZnO bilayers for near UV-OLED applications

    NASA Astrophysics Data System (ADS)

    Rezaie, Mahdiyar Nouri; Manavizadeh, Negin; Abadi, Ehsan Mohammadi Nasr; Nadimi, Ebrahim; Boroumand, Farhad Akbari

    2017-01-01

    Hybrid inorganic/organic light-emitting diodes have attracted much attention in the field of luminescent electronics due to the desired incorporation of high optoelectronic features of inorganic materials with the processability and variety of organic polymers. To generate and emit a near ultraviolet (N-UV) ray, wide band gap semiconductors can be applied in the organic light-emitting diodes (OLEDs). In this paper, zinc oxide (ZnO) and aluminum-doped ZnO (AZO) thin films are deposited by radio frequency (RF) sputtering above the ITO electrode and poly [2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene-vinylene] (MEH-PPV) conjugated polymer is utilized as a complementary p-type semiconductor in OLED structure. The impact of ZnO and AZO thickness on the structural, electrical, optical and morphological properties of ITO/AZO and ITO/ZnO bilayers are scrutinized and compared. Results show that with the enlargement of both ZnO and AZO film thickness, the physical properties are gradually improved resulting in the better quality of transparent conducting thin film. The average electrical resistivity of 8.4 × 10-4 and 1.1 × 10-3 Ω-cm, average sheet resistance of 32.9 and 42.3 Ω/sq, average transmittance of 88.3 and 87.3% and average FOM of 1.0 × 104 and 7.4 × 103 (Ω-cm)-1 are obtained for ITO/AZO and ITO/ZnO bilayers, respectively. Moreover, comparing the results indicates that the strain and the stress within the ITO/AZO bilayer are decreased nearly 19% with respect to ITO/ZnO bilayer which yield higher quality of crystal. Consequently, the physical properties of ITO/AZO bilayer is found to be superior regarding ITO/ZnO bilayer. For fabricated UV-OLEDs, the turn-on voltages, the characteristic energy (Et) and the total concentration of traps (Nt) for the devices with the structures of ITO/ZnO/MEH-PPV/Al and ITO/AZO/MEH-PPV/Al are obtained 12 and 14 V, 0.108 and 0.191 eV, 9.33 × 1016 and 5.22 × 1016 cm-3, respectively. Furthermore, according to the electroluminescence

  19. Effects of vacuum annealing and oxygen ion beam bombarding on the electrical and optical properties of ITO films deposited by E-beam evaporation

    NASA Astrophysics Data System (ADS)

    Pan, Yongqiang; Hang, Lingxia

    2012-10-01

    Tin doped indium oxide (ITO) transparent conductive thin films with composition of 10 wt% SnO2 and 89.8 wt% In2O3 have been deposited by electron beam evaporation technique on K9 glass substrates at room temperature. The post annealing processes are done in vacuum with different annealing temperature at 100, 200, 300 and 350 ° for 1 hour, respectively. The oxygen ion energy is 800 eV; oxygen ion beam bombarding time is 10,20,30,40 and 50min, respectively. The results show that conductivity of ITO thin films are improved by increasing annealing temperature. The resistivity of the ITO thin films decrease from 5.2×10-3Ω •cm at room temperature to 1.3×10-3Ω •cm(350 °C). The transmittance values of all samples in the visible range have been increased. As the oxygen ion beam bombarding time increases the resistivity reduce from 5.2×10-3Ω •cm to 9×10-4Ω •cm, the transmittance value improve from 66% to 82% at 550nm. Finally, the vacuum annealing and oxygen ion beam bombarding are done simultaneously, at temperature of 350 °C for 1 hours, ion bombardment time for 40 min. The resistivity of obtained ITO thin film is 7×10-4Ω •cm. The maximum transmittance value is above 89% in the visible wavelength region.

  20. Martingale integrals over Poissonian processes and the Ito-type equations with white shot noise

    NASA Astrophysics Data System (ADS)

    Zygadło, Ryszard

    2003-10-01

    The construction of the Ito-type stochastic integrals and differential equations for compound Poisson processes is provided. The general martingale and nonanticipating properties of the ordinary (Gaussian) Ito theory are conserved. These properties appear particularly important if the stochastic description has to be proposed according to game theory or the linear relaxation (or the exponential growth) requirements. In contrast to the ordinary Ito theory the (uncorrelated) parametric fluctuation of a definite sign can be still modeled by asymmetric white shot noise, so the general scope of applications is not restricted by the positivity requirements. The possible use of the developed formalism in econophysics is addressed.

  1. Martingale integrals over Poissonian processes and the Ito-type equations with white shot noise.

    PubMed

    Zygadło, Ryszard

    2003-10-01

    The construction of the Ito-type stochastic integrals and differential equations for compound Poisson processes is provided. The general martingale and nonanticipating properties of the ordinary (Gaussian) Ito theory are conserved. These properties appear particularly important if the stochastic description has to be proposed according to game theory or the linear relaxation (or the exponential growth) requirements. In contrast to the ordinary Ito theory the (uncorrelated) parametric fluctuation of a definite sign can be still modeled by asymmetric white shot noise, so the general scope of applications is not restricted by the positivity requirements. The possible use of the developed formalism in econophysics is addressed.

  2. Hemimegalencephaly in a patient with coexisting trisomy 21 and hypomelanosis of Ito.

    PubMed

    Okanari, Kazuo; Miyahara, Hiroaki; Itoh, Masayuki; Takahashi, Akio; Aizaki, Koichi; Nakagawa, Eiji; Otsuki, Taisuke; Izumi, Tatsuro

    2014-03-01

    A male infant with trisomy 21 simultaneously showed clinical features of hypomelanosis of Ito and hemimegalencephaly, with related intractable epileptic seizures. The epileptic seizures were refractory to conventional antiepileptic drugs and persisted until the patient underwent functional hemispherotomy. It is well known that patients with hypomelanosis of Ito may also have cortical dysplasia and hemimegalencephaly and that approximately half of these patients have chromosomal abnormalities. However, to our knowledge, there is no previous report of a patient with trisomy 21 associated with hemimegalencephaly. Here, we describe a rare case of coexisting trisomy 21 and hypomelanosis of Ito, associated with hemimegalencephaly.

  3. Swift heavy ion induced modifications in optical and electrical properties of cadmium selenide thin films

    NASA Astrophysics Data System (ADS)

    Choudhary, Ritika; Chauhan, Rishi Pal

    2017-07-01

    The modification in various properties of thin films using high energetic ion beam is an exciting area of basic and applied research in semiconductors. In the present investigations, cadmium selenide (CdSe) thin films were deposited on ITO substrate using electrodeposition technique. To study the swift heavy ion (SHI) induced effects, the deposited thin films were irradiated with 120 MeV heavy Ag9+ ions using pelletron accelerator facility at IUAC, New Delhi, India. Structural phase transformation in CdSe thin film from metastable cubic phase to stable hexagonal phase was observed after irradiation leading to decrease in the band gap from 2.47 eV to 2.12 eV. The phase transformation was analyzed through X-ray diffraction patterns. During SHI irradiation, Generation of high temperature and pressure by thermal spike along the trajectory of incident ions in the thin films might be responsible for modification in the properties of thin films.[Figure not available: see fulltext.

  4. Laser structuring of conducting films on transparent substrates

    NASA Astrophysics Data System (ADS)

    Račiukaitis, G.; Brikas, M.; Darčianovas, G.; Ruthe, D.; Zimmer, K.

    2007-06-01

    The fast growing market of organic electronics, including organic light-emitting devices (OLED), Solar cells and radio-frequency identification devices (RFID), stimulates development of versatile technologies for patterning the thin-film materials on rigid and flexible substrates. Thin films of the transparent conducting oxides (TCO) are important materials for making transparent contacts, conductors or antennas in such devices. High repetition rate lasers with a short, picosecond pulse duration offer new possibilities for high efficiency structuring of transparent conductors on glass and other substrates. The results of ablation of the indium-tin oxide (ITO) layer on glass and ITO and ZnO layers on polymers with picosecond lasers at various wavelengths are presented. Laser radiation initiated ablation of the material, forming trenches in TCO. UV radiation at the 266 nm provided the widest working window for TCO ablation without damage of the substrate. Subcomponents of the thin-film devices were made in order to test the structuring technology.

  5. Influence of defects and processing parameters on the properties of indium tin oxide films on polyethylene napthalate substrate

    SciTech Connect

    Han, H.; Zoo, Yeongseok; Bhagat, S. K.; Lewis, J. S.; Alford, T. L.

    2007-09-15

    Indium tin oxide (ITO) thin films were deposited on polyethylene napthalate (PEN) by rf sputtering using different rf powers (60 and 120 W) and at different substrate temperatures (room temperature and 100 deg. C). Selected PEN substrates were pretreated using an Ar plasma before ITO sputter deposition. Rutherford backscattering spectrometry was used to determine the oxygen content in the films. Hall effect measurements were used to evaluate the electrical properties. In this paper the influence of defect structure, sputtering conditions, and the effect of annealing on the electrical and optical properties of ITO on PEN have been investigated. Electrical properties such as carrier concentration, mobility, and resistivity of the ITO films varied with rf power and substrate temperature. The electrical and optical properties of the films changed after annealing in air. This study also describes how the as-deposited amorphous ITO changes from amorphous to crystalline as a result of heat treatment, and investigates the effects of Sn defect clustering on electrical and optical properties of the ITO films.

  6. Degradation of Flexible, ITO-Free Oligothiophene Organic Solar Cells.

    PubMed

    Bormann, Ludwig; Nehm, Frederik; Sonntag, Luisa; Chen, Fan-Yu; Selzer, Franz; Müller-Meskamp, Lars; Eychmüller, Alexander; Leo, Karl

    2016-06-15

    We investigate the degradation of organic solar cells based on an oligothiophene (DCV5T-Me) small molecule donor and the acceptor C60. Two different flexible, transparent bottom electrode types are employed: a transparent metal electrode (TME) and silver nanowires (AgNWs). They exhibit high optical transparency up to 86% and a sheet resistance as low as 12Ω/□. Power conversion efficiencies of 7.0%, 5.7%, and 7.2% on TME, AgNWs, and indium tin oxide (ITO, reference) are reached, respectively. The solar cells are protected against moisture ingress utilizing a flexible alumina thin-film, exhibiting water vapor transmission rates down to 3 × 10(-5) g m(-2) day(-1) at 38 °C and 90% relative humidity (RH). Implementation of this ultrabarrier as top and bottom encapsulation enables fabrication of fully flexible devices. A decrease in PCE to 80% of initial values is observed after 1000 ± 50 h on flexible, encapsulated TME but only 20 ± 5 h on AgNWs in a climate of 38 °C/50% RH. Degradation in AgNW-based devices is attributed to electrode decomposition.

  7. ITOS VHRR on-board data compression study

    NASA Technical Reports Server (NTRS)

    Gray, R. M.; Davisson, L. D.

    1975-01-01

    Data compression methods for ITOS VHRR data were studied for a tape recorder record-and playback application. A playback period of 9 minutes was assumed with a nominal 18 minute record period for a 2-to-1 compression ratio. Both analog and digital methods were considered with the conclusion that digital methods should be used. Two system designs were prepared. One is a PCM system and the other is an entropy-coded predictive-quantization, sometimes called entropy-coded DPCM or just DPCM, system. Both systems use data management principles to transmit only the necessary data. Both systems use a medium capacity standard tape recorder from specifications provided by the technical officer. The 10 to the 9th power bit capacity of the recorder is the basic limitation on the compression ratio. Both systems achieve the minimum desired 2 to 1 compression ratio. A slower playback rate can be used with the DPCM system due to a higher compression factor for better link performance at a given CNR in terms of bandwidth utilization and error rate. The report is divided into two parts. The first part summarizes the theoretical conclusions of the second part and presents the system diagrams. The second part is a detailed analysis based upon an empirically derived random process model arrived at from specifications and measured data provided by the technical officer.

  8. Anodic Bonding of Transparent Conductive Oxide Coated Silicon Wafer to Glass Substrate for Solar Cell Applications

    NASA Astrophysics Data System (ADS)

    Yuda, Yohei; Koida, Takashi; Kaneko, Tetsuya; Kondo, Michio

    2013-01-01

    We report on the anodic bonding of Si wafer coated by thin transparent conductive oxide (TCO) with a glass substrate, for the first time. We obtained sufficient bonding strength of as high as 9.5 MPa using a 30-nm-thick indium tin oxide (ITO) layer. We have also found that the ITO sample shows much stronger bonding strength does a sample that with a zinc oxide layer. The bonding mechanism is discussed in terms of the permeation of indium elements into the glass side driven by electric field. Finally we demonstrated a solar cell using this substrate.

  9. Nanocrystalline-CdS thin films grown on flexible PET-substrates by chemical bath deposition

    NASA Astrophysics Data System (ADS)

    Rodríguez-Rosales, K.; Quiñones-Galván, J. G.; Guillén-Cervantes, A.; Campos-González, E.; Santos-Cruz, J.; Mayén-Hernández, S. A.; Arias-Cerón, J. S.; Olvera, M. de la L.; Zelaya-Angel, O.; Hernández-Hernández, L. A.; Contreras-Puente, G.; de Moure-Flores, F.

    2017-07-01

    CdS thin films were grown on flexible PET and PET/ITO substrates by chemical bath deposition varying the deposition time. The structural analysis indicates that CdS films are composed of nano-crystalline and amorphous material. CdS films grown on PET substrates have hexagonal phase, while those grown on PET/ITO substrates have a cubic phase. The bandgap values of CdS films grown on PET substrates are in the range 2.31-2.45 eV, and the E g of CdS films grown on PET/ITO substrates are 2.18-2.42 eV. A strong green photoluminescence emission was observed in all the samples, which is associated to near band edge transitions. CdS films grown on PET/ITO substrates have an additional emission at 2.80 eV, which can be attributed to the presence of nano-crystals, in agreement with TEM analyses.

  10. Ordered Genotypes: An Extended ITO Method and a General Formula for Genetic Covariance

    PubMed Central

    Dai, Feng; Weeks, Daniel E.

    2006-01-01

    Traditionally, the stochastic ITO transition matrices provide a simple general method for obtaining the joint genotype distribution and genotypic correlations between any specified pair of noninbred relatives. The ITO method has been widely used in modern genetic analysis; however, since it was originally derived for unordered genotypes, it is not very useful in some new applications—for example, when one is modeling genomic imprinting and must keep track of the parental origin of alleles. To address these new, emerging problems, here we extend the ITO method to handle ordered genotypes. Our extended method is applied to calculate the covariance in unilineal and bilineal relatives under genomic imprinting, and some generalized linear functions of the transition matrices are given. Since the ITO method is limited to biallelic loci and to unilineal and bilineal relatives, we derive a general formula for calculating the genetic covariance using ordered genotypes for any type of relative pair. PMID:16685653

  11. Research of the applications of ITO in microwave-range surface plasmon waves

    NASA Astrophysics Data System (ADS)

    Lai, Senfeng; Wu, Wen; Gu, Wenhua

    2016-09-01

    Because of the electromagnetic field enhancement effect in subwavelength scale, the surface plasmon wave (SPW) has been widely used in beam forming, bio-prospecting, and subwavelength structure design. But most research work is in the visible light or terahertz frequency band, and the surface plasmonic material (SPM) is usually limited to metals. In the microwave band, complex structures have to be used to achieve the desired subwavelength effects, making use of both metal and dielectric materials. In this paper, we propose the excitation of SPW in the microwave range using a simple structure and the material of indium tin oxide (ITO). By measuring the electric field profile during the propagation process, the excitation of SPW in ITO was verified. At the same time, frequency dependence was seen during the propagation process. Therefore, ITO can be a good SPM in the microwave band, just like metals in the visible light band. Considering the transparent characteristics of ITO, it can have many interesting applications.

  12. Point contact resistive switching memory based on self-formed interface of Al/ITO.

    PubMed

    Li, Qiuhong; Qiu, Linjun; Wei, Xianhua; Dai, Bo; Zeng, Huizhong

    2016-07-07

    Point contact resistive switching random access memory (RRAM) has been achieved by directly sputtering Al electrodes on indium tin oxide (ITO) conductive glasses. The room-temperature deposited Al/ITO shows an asymmetrical bipolar resistive switching (BRS) behavior after a process of initialization which induces a stable high resistive state (HRS). It might be caused by the in-situ formation of an ultra-thin layer (≈4 nm) at the interface. By comparison, the Al/ITO device after vacuum annealed exhibits typical symmetrical BRS without an initiation or electroforming process. This can be ascribed to the ex-situ thickening of the interfacial layer (≈9.2 nm) to achieve the stable HRS after heat treatment. This work suggests that the self-formed interface of active Al electrode/ITO would provide the simplest geometry to construct RRAM.

  13. Efficient inverted polymer solar cells based on conjugated polyelectrolyte and zinc oxide modified ITO electrode

    SciTech Connect

    Yuan, Tao; Zhu, Xiaoguang; Tu, Guoli; Zhou, Lingyu; Zhang, Jian

    2015-02-23

    Efficient inverted polymer solar cells (PSCs) were constructed by utilizing a conjugated polyelectrolyte PF{sub EO}SO{sub 3}Na and zinc oxide to modify the indium tin oxide (ITO) electrode. The ITO electrode modified by PF{sub EO}SO{sub 3}Na and zinc oxide possesses high transparency, increased electron mobility, smoothened surface, and lower work function. PTB7:PC{sub 71}BM inverted PSCs containing the modified ITO electrode achieved a high power conversion efficiency (PCE) of 8.49%, exceeding that of the control device containing a ZnO modified ITO electrode (7.48%). Especially, PCE-10:PC{sub 71}BM inverted polymer solar cells achieved a high PCE up to 9.4%. These results demonstrate a useful approach to improve the performance of inverted polymer solar cells.

  14. Point contact resistive switching memory based on self-formed interface of Al/ITO

    NASA Astrophysics Data System (ADS)

    Li, Qiuhong; Qiu, Linjun; Wei, Xianhua; Dai, Bo; Zeng, Huizhong

    2016-07-01

    Point contact resistive switching random access memory (RRAM) has been achieved by directly sputtering Al electrodes on indium tin oxide (ITO) conductive glasses. The room-temperature deposited Al/ITO shows an asymmetrical bipolar resistive switching (BRS) behavior after a process of initialization which induces a stable high resistive state (HRS). It might be caused by the in-situ formation of an ultra-thin layer (≈4 nm) at the interface. By comparison, the Al/ITO device after vacuum annealed exhibits typical symmetrical BRS without an initiation or electroforming process. This can be ascribed to the ex-situ thickening of the interfacial layer (≈9.2 nm) to achieve the stable HRS after heat treatment. This work suggests that the self-formed interface of active Al electrode/ITO would provide the simplest geometry to construct RRAM.

  15. Development of waterborne oil spill sensor based on printed ITO nanocrystals.

    PubMed

    Koo, Jieun; Jung, Jung-Yeul; Lee, Sangtae; Lee, Moonjin; Chang, Jiho

    2015-09-15

    Oil spill accidents occasionally occur in coastal and ocean environments, and cause critical environmental damage, spoiling the marine habitats and ecosystems. To mitigate the damages, the species and amount of spilled oil should be monitored. In this study, we developed a waterborne oil spill sensor using a printed ITO layer. ITO is a compatible material for salty environments such as oceans because ITO is strong against corrosion. The fabricated sensor was tested using three oils, gasoline, lubricant and diesel, and different oil thicknesses of 0, 5, 10, and 15mm. The results showed that the resistance of the sensor clearly increased with the oil thickness and its electrical resistance. For sustainable sensing applications in marine environments, XRD patterns confirmed that the crystal structure of the ITO sensor did not change and FE-SEM images showed that the surface was clearly maintained after tests.

  16. On reconstruction of the Ito-like equation from persistent time series

    NASA Astrophysics Data System (ADS)

    Czechowski, Zbigniew

    2013-12-01

    The Langevin equation with finite-range persistence was introduced as a macroscopic model of various geophysical phenomena. The modified histogram procedure (MHP) of reconstruction of the equation from time series was proposed. An efficiency of MHP was tested on artificial persistent time series (with short and long-tail distributions) generated by different Ito-like equations. For an exemplary geophysical time series, the appropriate Ito-like equation was reconstructed.

  17. Cooperation of Ito cells and hepatocytes in the deposition of an extracellular matrix in vitro.

    PubMed Central

    Loréal, O.; Levavasseur, F.; Fromaget, C.; Gros, D.; Guillouzo, A.; Clément, B.

    1993-01-01

    Cellular and molecular mechanisms involved in the deposition of extracellular matrix components in both normal and fibrotic liver are still poorly understood. We have investigated the influence of cooperation between Ito cells and hepatocytes in matrix deposition in vitro. Immunoprecipitation of radiolabeled proteins from media of 5-day-old Ito cell primary cultures showed that these cells secreted high levels of the major basement membrane components, ie, collagen IV, laminin, and entactin/nidogen. By immunocytochemistry, precursors of basement membrane components were found intracellularly, but only scarce deposits were seen around the cells. When hepatocytes were added to 2-day-old Ito cell primary cultures, they established close contacts with Ito cells in less than 24 hours and expressed ZO-1, a tight junction-associated protein not detectable in standard hepatocyte culture. Cytochemistry analysis revealed an abundant extracellular matrix deposited over hepatocyte cords and between hepatocytes and Ito cells. Immunocytochemistry studies showed that this matrix contained laminin, fibronectin, and collagens proIII and IV. These data indicate that a high level of matrix protein synthesis by liver cells in vitro is not sufficient to induce extracellular matrix deposition, and that cell-cell interactions are strongly involved in this process. Hepatocyte/Ito cell co-culture, which may reflect the actual situation in vivo, represents a useful tool for studying liver fibrogenesis. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8342601

  18. Retinoic acid modulates rat Ito cell proliferation, collagen, and transforming growth factor beta production.

    PubMed Central

    Davis, B H; Kramer, R T; Davidson, N O

    1990-01-01

    Recent studies suggest that vitamin A plays an inhibitory role with respect to "activation" of the hepatic Ito cell, a likely effector of hepatic fibrogenesis. Ito cell "activation" during fibrogenesis is characterized by a decrease in intracellular vitamin A and an increase in cellular proliferation and collagen production. To explore the hypothesis that retinoids have the capacity to diminish Ito cell activation, cultured Ito cells were exposed to retinoic acid and its effects assessed on three key features: cell proliferation, collagen protein production and mRNA abundance, and transforming growth factor beta protein production. Retinoic acid was 100-1,000X more potent than retinol with respect to inhibition of Ito cell proliferation. Interstitial collagen and transforming growth factor beta production were also reduced by 10(-6) M retinoic acid. The relative abundance of type I collagen mRNA however, was not significantly altered. By contrast, retinoic acid administration to rats caused a marked reduction in the abundance of type I collagen mRNA in both total hepatic and purified Ito cell RNA. The relative abundance of rat hepatic fibronectin or apolipoprotein E mRNA was not significantly altered. These studies demonstrate that retinoic acid can differentially modulate several key features of hepatic fibrogenesis in vitro and in vivo. Images PMID:2254460

  19. SEMICONDUCTOR MATERIALS: Properties of the ITO layer in a novel red light-emitting diode

    NASA Astrophysics Data System (ADS)

    Yonghui, Zhang; Weiling, Guo; Wei, Gao; Chunwei, Li; Tianping, Ding

    2010-04-01

    An optically transparent electrode, indium tin oxide (ITO) film is fabricated by vacuum E-beam evaporation. The thermal annealing effects on the ITO/GaP contact have been investigated by means of the transmission line model method. Under 435 °C, with rapid thermal annealing for 40 s in N2 ambient, the ITO contact resistance reaches the minimized value of 4.3 × 10-3 Ω · cm2. The results from Hall testing and Auger spectra analysis indicate that the main reasons for the change of the contact resistance are the difference in the concentration of carriers and the diffusion of In, Ga, O. Furthermore, the reliability of AlGaInP LEDs with a 300-nm thickness transparent conducting ITO film is studied. The increase of LED chip voltage results from the degradation of ITO film. Moreover the difference between the thermal expansion coefficient of GaP and ITO results in the invalidation of the LED chip.

  20. Using the Photolysis of Chemically Modified Gel Films Preparing ITO Fine Patterned Thin Films

    NASA Astrophysics Data System (ADS)

    Li, Ying; Zhao, Gaoyang; Zhang, Weihua; Chen, Yuanqing

    2006-06-01

    A novel technique for the fabrication of tin-doped indium oxide (ITO) fine patterning in sol-gel technology is presented in this paper. The fabricated ITO fine patterning could be obtained through a process which combines film fabrication with film etching. ITO films have good comprehensive property of visible transmittance and electrical conductivity, consequently they have been extensively used as coating electrodes. Indium nitrate (In(NO3)3.4.5H2O) and stannic chloride (SnCl4.5H2O) were used as starting materials which were modified with benzytone (BzAcH). The chelate complexes containing indium ions were produced during the process which of forming photosensitive ITO/BzAcH gel films through sol-gel technique. It was found that the gel films are sensitive to both the ultraviolet (UV) light irradiation and their solubility on solvents as well. For example, ethanol was reduced remarkably while the UV absorption peak disappeared with the dissociation of the chelate complexes correspondingly by means of UV-vis and IR spectrophotometers. Utilizing these characteristics, a fine pattern was obtained by irradiation of UV light on the ITO/BzAcH gel films through a pattern mask. of the fine patterned ITO films were heat treated at 500 °C for 15 min, the optical, electrical properties and the surface element components were examined by X-ray photoelectron spectroscopy (XPS) spectra in this work.

  1. Characteristics of ZnO Thin Films on Plastic Resin Substrates

    NASA Astrophysics Data System (ADS)

    Inoue, Ryuunosuke; Yoshida, Takamasa; Matuda, Namio; Tamaki, Akira

    ZnO thin films on plastic resin substrates were prepared by RF magnetron sputtering. Substrate used polycarbonate of plastic resin. ZnO thin films changed sputtering time and RF power and produced it. Surface morphology were studied by scanning electron microscopy (SEM) and atomic force mi-croscopy (AFM). Adhesive power of thin films on substrates were studied by peel test. Transparency and surface unevenness of ZnO thin films on plastic resin substrates were able to be improved by lowering RF power. ZnO thin films on plastic resin substrates found that adhesive power was stronger than ITO thin films on plastic resin substrates.

  2. Laser patterning of very thin indium tin oxide thin films on PET substrates

    NASA Astrophysics Data System (ADS)

    McDonnell, C.; Milne, D.; Prieto, C.; Chan, H.; Rostohar, D.; O'Connor, G. M.

    2015-12-01

    This work investigates the film removal properties of 30 nm thick Indium Tin Oxide (ITO) thin films, on flexible polyethylene terephthalate (PET) substrates, using 355, 532 and 1064 nm nanosecond pulses (ns), and 343 and 1064 nm femtosecond pulses. The ablation threshold was found to be dependent on the applied wavelength and pulse duration. The surface topography of the laser induced features were examined using atomic force microscopy across the range of wavelengths and pulse durations. The peak temperature, strain and stress tensors were examined in the film and substrate during laser heating, using finite element computational methods. Selective removal of the thin ITO film from the polymer substrate is possible at all wavelengths except at 266 nm, were damage to substrate is observed. The damage to the substrate results in periodic surface structures (LIPPS) on the exposed PET, with a period of twice the incident wavelength. Fragmented crater edges are observed at all nanosecond pulse durations. Film removal using 1030 nm femtosecond pulses results in clean crater edges, however, minor 5 nm damage to the substrate is also observed. The key results show that film removal for ITO on PET, is through film de-lamination across all wavelengths and pulse durations. Film de-lamination occurs due to thermo-elastic stress at the film substrate interface region, as the polymer substrate expands under heating from direct laser absorption and heat conduction across the film substrate interface.

  3. Behavior modification.

    PubMed

    Pelham, W E; Fabiano, G A

    2000-07-01

    Attention deficit/hyperactivity disorder (ADHD) is a chronic and substantially impairing disorder. This means that treatment must also be chronic and substantial. Behavior Modification, and in many cases, the combination of behavior modification and stimulant medication, is a valid, useful treatment for reducing the pervasive impairment experienced by children with ADHD. Based on the research evidence reviewed, behavior modification should be the first line of treatment for children with ADHD.

  4. Electrochemical detection of vascular endothelial growth factors (VEGFs) using VEGF antibody fragments modified Au NPs/ITO electrode.

    PubMed

    Kim, Gang-Il; Kim, Kyung-Woo; Oh, Min-Kyu; Sung, Yun-Mo

    2010-03-15

    A new electrochemical technique for the detection of vascular endothelial growth factors (VEGFs) as a cancer-related biomarker is presented in this paper. Gold nanoparticles (Au NPs) were self-assembled onto an indium tin oxide (ITO) electrode to prepare a modified sandwich type electrochemical immunoassay platform. VEGF antibodies were cleaved into two half-fragments by 2-mercaptoethylamine-HCl (2-MEA) and the fragments were immobilized onto the Au NP substrates by their thiol groups. Through this strategy, randomly oriented attachment of antibodies was prevented which frequently occurs in a general use of whole antibody and reduces the number of available sites for the attachment of target molecules. VEGF target molecules were applied to the immunoelectrodes and they combined with the antibody fragments covering the Au NP electrode, forming antigen-antibody complexes. Then, ferrocene-tagged antibodies, which release electrons under a proper applied potential, were added to the system and they combined with the VEGF molecules pre-attached to the antibody fragments. The redox current of ferrocene measured by the differential pulse voltammetry (DPV) increased almost linearly from 1.27 x 10(-4) to 4.17 x 10(-4)A according to the increase in the concentration of the VEGF target molecules from 100 to 600 pg/ml. The measured current values represent the concentration of the VEGF since they are proportional to the number of ferrocene molecules which is in turn proportional to the concentration of VEGF target molecules. Using this modified sandwich immunoassay with the Au NP/ITO electrode, VEGFs as low as 100 pg/ml were detected with high specificity.

  5. Optical monitoring of thin film electro-polymerization on surface of ITO-coated lossy-mode resonance sensor

    NASA Astrophysics Data System (ADS)

    Sobaszek, Michał; Dominik, Magdalena; Burnat, Dariusz; Bogdanowicz, Robert; Stranak, Viteszlav; Sezemsky, Petr; Śmietana, Mateusz

    2017-04-01

    This work presents an optical fiber sensors based on lossy-mode resonance (LMR) phenomenon supported by indium tin oxide (ITO) thin overlay for investigation of electro-polymerization effect on ITO's surface. The ITO overlays were deposited on core of polymer-clad silica (PCS) fibers using reactive magnetron sputtering (RMS) method. Since ITO is electrically conductive and electrochemically active it can be used as a working electrode in 3-electrode cyclic voltammetry setup. For fixed potential applied to the electrode current flow decrease with time what corresponds to polymer layer formation on the ITO surface. Since LMR phenomenon depends on optical properties in proximity of the ITO surface, polymer layer formation can be monitored optically in real time. The electrodeposition process has been performed with Isatin which is a strong endogenous neurochemical regulator in humans as it is a metabolic derivative of adrenaline. It was found that optical detection of Isatin is possible in the proposed configuration.

  6. Parametrization of optical properties of indium-tin-oxide thin films by spectroscopic ellipsometry: Substrate interfacial reactivity

    NASA Astrophysics Data System (ADS)

    Losurdo, M.; Giangregorio, M.; Capezzuto, P.; Bruno, G.; de Rosa, R.; Roca, F.; Summonte, C.; Plá, J.; Rizzoli, R.

    2002-01-01

    Indium-tin-oxide (ITO) films deposited by sputtering and e-gun evaporation on both transparent (Corning glass) and opaque (c-Si, c-Si/SiO2) substrates and in c-Si/a-Si:H/ITO heterostructures have been analyzed by spectroscopic ellipsometry (SE) in the range 1.5-5.0 eV. Taking the SE advantage of being applicable to absorbent substrate, ellipsometry is used to determine the spectra of the refractive index and extinction coefficient of the ITO films. The effect of the substrate surface on the ITO optical properties is focused and discussed. To this aim, a parametrized equation combining the Drude model, which considers the free-carrier response at the infrared end, and a double Lorentzian oscillator, which takes into account the interband transition contribution at the UV end, is used to model the ITO optical properties in the useful UV-visible range, whatever the substrate and deposition technique. Ellipsometric analysis is corroborated by sheet resistance measurements.

  7. Electron beam induced damage in ITO coated Kapton. [Indium Tin Oxide

    NASA Technical Reports Server (NTRS)

    Krainsky, I.; Gordon, W. L.; Hoffman, R. W.

    1981-01-01

    Data for the stability of thin conductive indium tin oxide films on 0.003 inch thick Kapton substrates during exposure of the surface to electron beams are reported. The electron beam energy was 3 keV and the diameter was about 0.8 mm. Thermal effects and surface modifications are considered. For primary current greater than 0.6 microamperes, an obvious dark discoloration with diameter approximately that of the beam was produced. The structure of the discolored region was studied with the scanning electron microscope, and the findings are stated. Surface modifications were explored by AES, obtaining spectra and secondary emission coefficient as a function of time for different beam intensities. In all cases beam exposure results in a decrease of the secondary yield but because of thermal effects this change, as well as composition changes, cannot be directly interpreted in terms of electron beam dosage.

  8. Electron beam induced damage in ITO coated Kapton. [Indium Tin Oxide

    NASA Technical Reports Server (NTRS)

    Krainsky, I.; Gordon, W. L.; Hoffman, R. W.

    1981-01-01

    Data for the stability of thin conductive indium tin oxide films on 0.003 inch thick Kapton substrates during exposure of the surface to electron beams are reported. The electron beam energy was 3 keV and the diameter was about 0.8 mm. Thermal effects and surface modifications are considered. For primary current greater than 0.6 microamperes, an obvious dark discoloration with diameter approximately that of the beam was produced. The structure of the discolored region was studied with the scanning electron microscope, and the findings are stated. Surface modifications were explored by AES, obtaining spectra and secondary emission coefficient as a function of time for different beam intensities. In all cases beam exposure results in a decrease of the secondary yield but because of thermal effects this change, as well as composition changes, cannot be directly interpreted in terms of electron beam dosage.

  9. Surface modification of Ca-α-SiAlON: Eu2+ phosphor particles by SiO2 coating and fabrication of its deposit by electrophoretic deposition (EPD) process

    NASA Astrophysics Data System (ADS)

    Zhang, Chenning; Uchikoshi, Tetsuo; Kitabatake, Takuya; Sakka, Yoshio; Hirosaki, Naoto

    2013-09-01

    Ca-α-SiAlON: Eu2+ phosphor powder was modified with a SiO2 coating by the adsorption, hydrolysis, and polymerization of the TEOS precursor. Through the modification for the surface defects of the particles by the SiO2 coating, the photoluminescence (PL) emission could be significantly strengthened in the SiO2-coated Ca-α-SiAlON: Eu2+ powder. The electrophoretic deposition (EPD) technique was employed to fabricate the deposit layer on ITO glass using the SiO2 coated phosphor powder. The prepared deposit exhibited a uniform surface morphology with strong adhesion to the substrate. The SiO2-coated Ca-α-SiAlON: Eu2+ powder indicates a potential application when used in pseudo white light-emitting diodes (LEDs) devices.

  10. Ferromagnetism of manganese-doped indium tin oxide films deposited on polyethylene naphthalate substrates

    SciTech Connect

    Nakamura, Toshihiro; Isozaki, Shinichi; Tanabe, Kohei; Tachibana, Kunihide

    2009-04-01

    Mn-doped indium tin oxide (ITO) films were deposited on polyethylene naphthalate (PEN) substrates using radio-frequency magnetron sputtering. The magnetic, electrical, and optical properties of the films deposited on PEN substrates were investigated by comparing with the properties of films grown on glass substrates at the same growth conditions. Thin films on PEN substrates exhibited low electrical resistivity of the order of 10{sup -4} {omega} cm and high optical transmittance between 75% and 90% in the visible region. Ferromagnetic hysteresis loops were observed at room temperature for the samples grown on PEN substrates. Mn-doped ITO films can be one of the most promising candidates of transparent ferromagnetic materials for flexible spintronic devices.

  11. High quality nitrogen-doped zinc oxide thin films grown on ITO by sol-gel method

    NASA Astrophysics Data System (ADS)

    Pathak, Trilok Kumar; Kumar, Vinod; Purohit, L. P.

    2015-11-01

    Highly transparent N-doped ZnO thin films were deposited on ITO coated corning glass substrate by sol-gel method. Ammonium nitrate was used as a dopant source of N with varying the doping concentration 0, 0.5, 1.0, 2.0 and 3.0 at%. The DSC analysis of prepared NZO sols is observed a phase transition at 150 °C. X-ray diffraction pattern showed the preferred (002) peak of ZnO, which was deteriorated with increased N concentrations. The transmittance of NZO thin films was observed to be ~88%. The bandgap of NZO thin films increased from 3.28 to 3.70 eV with increased N concentration from 0 to 3 at%. The maximum carrier concentration 8.36×1017 cm-3 and minimum resistivity 1.64 Ω cm was observed for 3 at% N doped ZnO thin films deposited on glass substrate. These highly transparent ZnO thin films can be used as a window layer in solar cells and optoelectronic devices.

  12. Characterization of ITO/CdO/glass thin films evaporated by electron beam technique

    PubMed Central

    Abdel-Hafez Mohamed, Hussein; Mahmoud Ali, Hazem

    2008-01-01

    A thin buffer layer of cadmium oxide (CdO) was used to enhance the optical and electrical properties of indium tin oxide (ITO) films prepared by an electron-beam evaporation technique. The effects of the thickness and heat treatment of the CdO layer on the structural, optical and electrical properties of ITO films were carried out. It was found that the CdO layer with a thickness of 25 nm results in an optimum transmittance of 70% in the visible region and an optimum resistivity of 5.1×10−3 Ω cm at room temperature. The effect of heat treatment on the CdO buffer layer with a thickness of 25 nm was considered to improve the optoelectronic properties of the formed ITO films. With increasing annealing temperature, the crystallinity of ITO films seemed to improve, enhancing some physical properties, such as film transmittance and conductivity. ITO films deposited onto a CdO buffer layer heated at 450 °C showed a maximum transmittance of 91% in the visible and near-infrared regions of the spectrum associated with the highest optical energy gap of 3.61 eV and electrical resistivity of 4.45×10−4 Ω cm at room temperature. Other optical parameters, such as refractive index, extinction coefficient, dielectric constant, dispersion energy, single effective oscillator energy, packing density and free carrier concentration, were also studied. PMID:27877991

  13. UV light emitting transparent conducting tin-doped indium oxide (ITO) nanowires.

    PubMed

    Gao, J; Chen, R; Li, D H; Jiang, L; Ye, J C; Ma, X C; Chen, X D; Xiong, Q H; Sun, H D; Wu, T

    2011-05-13

    Multifunctional single crystalline tin-doped indium oxide (ITO) nanowires with tuned Sn doping levels are synthesized via a vapor transport method. The Sn concentration in the nanowires can reach 6.4 at.% at a synthesis temperature of 840 °C, significantly exceeding the Sn solubility in ITO bulks grown at comparable temperatures, which we attribute to the unique feature of the vapor-liquid-solid growth. As a promising transparent conducting oxide nanomaterial, layers of these ITO nanowires exhibit a sheet resistance as low as 6.4 Ω/[Symbol: see text] and measurements on individual nanowires give a resistivity of 2.4 × 10(-4) Ω cm with an electron density up to 2.6 × 10(20) cm(-3), while the optical transmittance in the visible regime can reach ∼ 80%. Under the ultraviolet excitation the ITO nanowire samples emit blue light, which can be ascribed to transitions related to defect levels. Furthermore, a room temperature ultraviolet light emission is observed in these ITO nanowires for the first time, and the exciton-related radiative process is identified by using temperature-dependent photoluminescence measurements.

  14. Differential calcineurin/NFATc3 activity contributes to the Ito transmural gradient in the mouse heart.

    PubMed

    Rossow, Charles F; Dilly, Keith W; Santana, Luis F

    2006-05-26

    Kv4 channels are differentially expressed across the mouse left ventricular free wall. Accordingly, the transient outward K+ current (Ito), which is produced by Kv4 channels, is greater in left ventricular epicardial (EPI) than in endocardial (ENDO) cells. However, the mechanisms underlying heterogeneous Kv4 expression in the heart are unclear. Here, we tested the hypothesis that differential [Ca2+]i and calcineurin/NFATc3 signaling in EPI and ENDO cells contributes to the gradient of Ito function in the mouse left ventricle. In support of this hypothesis, we found that [Ca2+]i, calcineurin, and NFAT activity were greater in ENDO than in EPI myocytes. However, the amplitude of Ito was the same in ENDO and EPI cells when [Ca2+]i, calcineurin, and NFAT activity were equalized. Consistent with this, we observed complete loss of Ito and Kv4 heterogeneity in NFATc3-null mice. Interestingly, Kv4.3, Kv4.2, and KChIP2 genes had different apparent thresholds for NFATc3-dependent suppression and were ordered as Kv4.3 approximately KChIP2>Kv4.2. Based on these data, we conclude that calcineurin and NFATc3 constitute a Ca(2+)-driven signaling module that contributes to the nonuniform distribution of Kv4 expression, and hence Ito function, in the mouse left ventricle.

  15. Improved ITOS attitude control system with Hall generator brushless motor and earth-splitting technique

    NASA Technical Reports Server (NTRS)

    Peacock, W. M.

    1971-01-01

    The ITOS with an improved attitude control system is described. A Hall generator brushless dc torque motor will replace the brush dc torque motor on ITOS-I and ITOS-A (NOAA-1). The four attitude horizon sensors will be replaced with two CO2 sensors for better horizon definition. An earth horizon splitting technique will be used to keep the earth facing side of the satellite toward earth even if the desired circular orbit is not achieved. The external appearance of the pitch control subsystem differs from TIROS-M (ITOS-1) and ITOS-A (NOAA-1) in that two instead of one pitch control electronics (PCE) boxes are used. Two instead of four horizon sensors will be used and one instead of two mirrors will be used for sensor scanning. The brushless motor will eliminate the requirement for brushes, strain gages and the telemetry for the brush wear. A single rotating flywheel, supported by a single bearing provides the gyroscopic stability and the required momentum interchange to keep one side of the satellite facing the earth. Magnetic torquing against the earth's magnetic field eliminates the requirement for expendable propellants which would limit satellite life in orbit.

  16. General observation of the memory effect in metal-insulator-ITO structures due to indium diffusion

    NASA Astrophysics Data System (ADS)

    Wu, Xiaojing; Xu, Huihua; Wang, Yu; Rogach, Andrey L.; Shen, Yingzhong; Zhao, Ni

    2015-07-01

    Resistive random access memory (RRAM) devices based on metal oxides, organic molecules and inorganic nanocrystals (NCs) have been studied extensively in recent years. Different memory switching mechanisms have been proposed and shown to be closely related to the device architectures. In this work, we demonstrate that the use of an ITO/active layer/InGa structure can yield nonvolatile resistive memory behavior in a variety of active materials, including polymers, organic small molecules, and colloidal NCs. Through the electrode material and thickness-dependent study, we show that the ON state of the devices is associated with filamentary conduction induced by indium diffusion from the ITO electrode, occurring mostly within around 40-50 nm from the ITO/active layer interface. A negative differential resistance (NDR) regime is observed during transition from the ON to OFF state, and is explained by the space charge limited current (SCLC) effect due to hole injection at the ITO/active layer interface. Our study reveals the impact of indium diffusion at the ITO/active layer interface, an important factor that should be taken into consideration when designing thin printed RRAM devices.

  17. Hypomelanosis of Ito with a trisomy 2 mosaicism: a case report

    PubMed Central

    2014-01-01

    Introduction Hypomelanosis of Ito is a rare neurocutaneous disorder, characterized by streaks and swirls of hypopigmentation following the lines of Blaschko that may be associated to systemic abnormalities involving the central nervous system and musculoskeletal system. Despite the preponderance of reported sporadic hypomelanosis of Ito, few reports of familial hypomelanosis of Ito have been described. Case presentation A 6-month-old Caucasian girl presented with unilateral areas of hypomelanosis distributed on the left half of her body and her father presented with similar mosaic hypopigmented lesions on his upper chest. Whereas both blood karyotypes obtained from peripheral lymphocyte cultures were normal, a 16% trisomy 2 mosaicism was found in cultured skinfibroblasts derived from a hypopigmented skin area of her father. Conclusions Familial cases of hypomelanosis of Ito are very rare and can occur in patients without systemic involvement. Hypomelanosis of Ito constitutes a non-specific diagnostic definition including different clinical entities with a wide phenotypic variability, either sporadic or familial. Unfortunately, a large number of cases remain misdiagnosed due to both diagnostic challenges and controversial issues on cutaneous biopsies in the pediatric population. PMID:25301139

  18. Involvement of flocculin in negative potential-applied ITO electrode adhesion of yeast cells

    PubMed Central

    Koyama, Sumihiro; Tsubouchi, Taishi; Usui, Keiko; Uematsu, Katsuyuki; Tame, Akihiro; Nogi, Yuichi; Ohta, Yukari; Hatada, Yuji; Kato, Chiaki; Miwa, Tetsuya; Toyofuku, Takashi; Nagahama, Takehiko; Konishi, Masaaki; Nagano, Yuriko; Abe, Fumiyoshi

    2015-01-01

    The purpose of this study was to develop novel methods for attachment and cultivation of specifically positioned single yeast cells on a microelectrode surface with the application of a weak electrical potential. Saccharomyces cerevisiae diploid strains attached to an indium tin oxide/glass (ITO) electrode to which a negative potential between −0.2 and −0.4 V vs. Ag/AgCl was applied, while they did not adhere to a gallium-doped zinc oxide/glass electrode surface. The yeast cells attached to the negative potential-applied ITO electrodes showed normal cell proliferation. We found that the flocculin FLO10 gene-disrupted diploid BY4743 mutant strain (flo10Δ /flo10Δ) almost completely lost the ability to adhere to the negative potential-applied ITO electrode. Our results indicate that the mechanisms of diploid BY4743 S. cerevisiae adhesion involve interaction between the negative potential-applied ITO electrode and the Flo10 protein on the cell wall surface. A combination of micropatterning techniques of living single yeast cell on the ITO electrode and omics technologies holds potential of novel, highly parallelized, microchip-based single-cell analysis that will contribute to new screening concepts and applications. PMID:26187908

  19. Fatigue properties of Graphene interconnects on flexible substrates

    NASA Astrophysics Data System (ADS)

    Paradee, Gary

    This thesis represents the first determination of the fatigue behavior of Graphene as interconnect material electronic components on flexible substrates. The potential application of this interconnect material is for displays on flexible substrates where fatigue resistance is required due to the stress placed on the interconnect during mechanical bending. As the display is cyclically deformed (fatigued) during normal operation, cracks in the interconnect layer initiate and propagate leading to the lineout failure condition. The major contribution of this work is to show that Graphene is a superior interconnect material to the present state of the art Indium Tin Oxide (ITO) due to its electrical, optical and mechanical properties. The experimental approach in this thesis is based on Graphene samples which were fabricated on Silicon Nitrite (Si3N4)/Polyethylene Naphthalate (PEN) substrates. For comparison, both patterned and uniform ITO films ITO films on Si3N4/PEN were fabricated. The results of the in-depth characterization of Graphene are reported and based on Atomic Force Microscopy (AFM), Raman Spectroscopy and Scanning Electron Microscopy (SEM) are reported. The fatigue characteristics of ITO were determined at stress amplitudes ranging from 2000 MPa to 400 MPa up to 5000 cycles. The fatigue characteristics of Graphene were determined at stress amplitudes ranging from 80 GPa to 40 GPa up to 5000 cycles. The fatigue S-N curves were determined and showed that Graphene's endurance limit is 40 GPa. Beyond the endurance limit, there is no observable high cycle or low cycle fatigue indication for Graphene on a flexible substrate such as PEN. The microstructural analysis by SEM and AFM did not reveal normal fatigue crack growth and propagation. This thesis presents the first comprehensive behavior of Graphene in a bending fatigue stress environment present in numerous flexible electronic applications. The design and stress environments for safe operation has been

  20. Deposition of tetraferrocenylporphyrins on ITO surfaces for photo-catalytic O2 activation.

    PubMed

    Sabuzi, F; Tiravia, M; Vecchi, A; Gatto, E; Venanzi, M; Floris, B; Conte, V; Galloni, P

    2016-10-07

    Tetraferrocenylporphyrins (TFcPs) are a class of compounds where the porphyrin macrocycle is functionalized with a ferrocenyl group at each of the four meso positions. TFcPs exhibit interesting electrochemical properties, mostly due to electronic communication between the ferrocenyl substituents and the porphyrin core. This leads to their capability to release and accept multiple electrons at distinct potentials through reversible and well distinguished processes. Synthesis of substituted-tetraferrocenylporphyrins containing a carboxylic acid functionality allowed to prepare well packed thin layers of TFcP on ITO electrodes using different deposition techniques. In this context, self-assembled monolayers (SAMs) and Langmuir-Blodgett mono- and multilayers (LBs) of TFcPs have been prepared on ITO surfaces. TFcP-functionalized ITO electrodes showed very high stability, and their application in photocatalytic oxygen activation has been tested.

  1. Low-Work-Function, ITO-Free Transparent Cathodes for Inverted Polymer Solar Cells.

    PubMed

    Xue, Zhichao; Liu, Xingyuan; Lv, Ying; Zhang, Nan; Guo, Xiaoyang

    2015-09-16

    A low-work-function, indium tin oxide (ITO)-free transparent cathode having a tin oxide (SnOX)/Ag/SnOX/bismuth oxide (Bi2O3) (SASB) structure is developed without using annealing treatment. This represents the first time that Bi2O3 has been introduced to lower the work function of transparent electrodes. The SASB transparent cathode exhibits excellent photoelectric properties with a maximum transmittance of ∼88%, a low sheet resistance of ∼9.0 Ω·sq(-1), and a suitable work function of 4.22 eV that matches the lowest unoccupied molecular orbital level of the acceptor for exacting electrons efficiently. The power conversion efficiency of the polymer solar cell with the SASB electrode is 6.21%, which is comparable to that of ITO-based devices. The results indicate that SASB is a good alternative to ITO as transparent cathodes in optoelectronic devices.

  2. Multifractal analysis of visibility graph-based Ito-related connectivity time series.

    PubMed

    Czechowski, Zbigniew; Lovallo, Michele; Telesca, Luciano

    2016-02-01

    In this study, we investigate multifractal properties of connectivity time series resulting from the visibility graph applied to normally distributed time series generated by the Ito equations with multiplicative power-law noise. We show that multifractality of the connectivity time series (i.e., the series of numbers of links outgoing any node) increases with the exponent of the power-law noise. The multifractality of the connectivity time series could be due to the width of connectivity degree distribution that can be related to the exit time of the associated Ito time series. Furthermore, the connectivity time series are characterized by persistence, although the original Ito time series are random; this is due to the procedure of visibility graph that, connecting the values of the time series, generates persistence but destroys most of the nonlinear correlations. Moreover, the visibility graph is sensitive for detecting wide "depressions" in input time series.

  3. Durability of ITO-MgF2 Films for Space-Inflatable Polymer Structures

    NASA Technical Reports Server (NTRS)

    Kerslake, Thomas W.; Waters, Deborah L.; Schieman, David A.; Hambourger, Paul D.

    2003-01-01

    This paper presents results from ITO-MgF2 film durability evaluations that included tape peel, fold, thermal cycle, and AO exposure testing. Polymer coupon preparation is described as well as ITO-MgF2 film deposition equipment, procedures and film characterization. Durability testing methods are also described. The pre- and post-test condition of the films is assessed visually, microscopically, and electrically. Results show that at 500 ITO - 9 vol% MgF2 film is suitable to protect polymer surfaces, such as those used in space-inflatable structures of the PowerSphere microsatellite concept, during a 1-year Earth orbiting mission. Future plans for ground-based and orbital testing of this film are also discussed.

  4. Electrochemical and Optical Evaluation of Noble Metal-and Carbon-ITO Hybrid Optically Transparent Electrodes

    SciTech Connect

    Zudans, Imants; Paddock, Jean R.; Kuramitz, Hideki; Maghasi, Anne T.; Wansapura, Chamika M.; Conklin, Sean D.; Kaval, Necati; Shtoyko, Tanya; Monk, David J.; Bryan, Samuel A.; Hubler, Timothy L.; Richardson, John N.; Seliskar, Carl J.; Heineman, William R.

    2004-04-15

    Optically transparent hybrid electrodes were constructed by sputtering or thermally evaporating layers of varying thickness of Au, Pd, Pt, or C onto an existing conductive indium-tin oxide (ITO) layer on glass. These electrodes were characterized using UV-Vis spectroscopy and cyclic voltammetry; redox probes examined were potassium ferricyanide, tris-(2, 2'-bipyridyl)ruthenium(II) chloride, hydroquinone, and para-aminophenol (PAP). Each type of hybrid was evaluated and compared with other hybrids, as well as with bare ITO electrodes and commercially available Au, Pt, and glassy carbon disk electrodes. Our results indicated that these hybrid electrodes are reasonably robust, easy to prepare, and extend the capabilities of bare ITO surfaces with respect to the electrochemical response (especially for organic redox probes), while giving up little in the way of optical transparency. Because of these characteristics, hybrid electrodes should be especially suited to many spectroelectrochemical applications.

  5. Application of argon atmospheric cold plasma for indium tin oxide (ITO) based diodes

    NASA Astrophysics Data System (ADS)

    Akbari Nia, S.; Jalili, Y. Seyed; Salar Elahi, A.

    2017-09-01

    Transparent Conductive Oxide (TCO) layers due to transparency, high conductivity and hole injection capability have attracted a lot of attention. One of these layers is Indium Tin Oxide (ITO). ITO due to low resistance, transparency in the visible spectrum and its proper work function is widely used in the manufacture of organic light emitting diodes and solar cells. One way for improving the ITO surface is plasma treatment. In this paper, changes in surface morphology, by applying argon atmospheric pressure cold plasma, was studied through Atomic Force Microscopic (AFM) image analysis and Fourier Transform Infrared Spectroscopy (FTIR) analysis. FTIR analysis showed functional groups were not added or removed, but chemical bond angle and bonds strength on the surface were changed and also AFM images showed that surface roughness was increased. These factors lead to the production of diodes with enhanced Ohmic contact and injection mechanism which are more appropriate in industrial applications.

  6. Ground radiation tests and flight atomic oxygen tests of ITO protective coatings for Galileo Spacecraft

    NASA Technical Reports Server (NTRS)

    Bouquet, Frank L.; Maag, Carl R.

    1986-01-01

    Radiation simulation tests (protons and electrons) were performed along with atomic oxygen flight tests aboard the Shuttle to space qualify the surface protective coatings. The results, which contributed to the selection of indium-tin-oxide (ITO) coated polyester as the material for the thermal blankets of the Galileo Spacecraft, are given here. Two candidate materials, polyester and Fluorglas, were radiation-tested to determine changes at simulated Jovian radiation levels. The polyester exhibited a smaller weight loss (2.8) than the Fluorglas (8.8 percent). Other changes of polyester are given. During low-earth orbit, prior to transit to Jupiter, the thermal blankets would be exposed to atomic oxygen. Samples of uncoated and ITO-coated polyesters were flown on the Shuttle. Qualitative results are given which indicated that the ITO coating protected the underlying polyester.

  7. Total Hemi-overgrowth in Pigmentary Mosaicism of the (Hypomelanosis of) Ito Type: Eight Case Reports.

    PubMed

    Pavone, Vito; Signorelli, Salvatore Santo; Praticò, Andrea Domenico; Corsello, Giovanni; Savasta, Salvatore; Falsaperla, Raffaele; Pavone, Piero; Sessa, Giuseppe; Ruggieri, Martino; Ba, Martino Ruggieri

    2016-03-01

    Pigmentary mosaicism of the (hypomelanosis of) Ito type is an umbrella term, which includes phenotypes characterized by mosaic hypopigmentation in the form of streaks, whorls, patchy, or more bizarre skin configurations (running along the lines of Blaschko): these cutaneous patterns can manifest as an isolated skin disorder (pigmentary mosaicism of the Ito type) or as a complex malformation syndrome in association with extracutaneous anomalies (most often of the musculoskeletal and/or nervous systems) (hypomelanosis of Ito). Affected individuals are anecdotally reported to have also partial or total body hemi-overgrowth (HOG), which often causes moderate to severe complications.We studied the occurrence and features of HOG in the 114 children and adults with mosaic pigmentary disorders of the Ito type diagnosed and followed up (from 2 to 22 years; average follow-up 16 years) at our Institutions.Eight patients (5 M, 3 F; aged 4 to 25 years; median age 16 years) out of the 114 analyzed (7%) fulfilled the criteria for unilateral HOG, with differences in diameter ranging from 0.4 to 4.0 cm (upper limbs) and 1.0 to 9.0 cm (lower limbs). Moreover, among these 8 patients, 5/8 filled in the 75th to 90th percentile for height; 6/8 had associated kyphoscoliosis; and 5/8 showed cognitive delays. No tumour complications were recorded. Overall, 6/8 HOG patients presented with additional (extracutaneous) syndromic manifestations, apart from the HOG (ie, with a clinical phenotype of hypomelanosis of Ito).The present study, which includes children and adults with the longest follow-up so far recorded, confirms the association between pigmentary mosaicism of the Ito type and HOG lowering previous estimates (7% vs 16%) for HOG in the context of mosaic hypopigmentation. A careful examination, looking at subtle to moderate asymmetries and associated complications within the spectrum of these mosaic pigmentary disorders, is recommended.

  8. Pilot production of 4 sq cm ITO/InP photovoltaic solar cells

    NASA Technical Reports Server (NTRS)

    Gessert, T. A.; Li, X.; Coutts, T. J.; Tzafaras, N.

    1991-01-01

    Experimental results of a pilot production of 32 4-sq cm indium tin oxide (ITO)InP space solar cells are presented. The discussion includes analysis of the device performance of the best cells produced as well as the performance range of all production cells. The experience gained from the production is discussed, indicating other issues that may be encountered when large-scale productions are initiated. Available data on a 4-sq cm ITO/InP cell that was flown on the UoSAT-5 satellite is reported.

  9. The effect of neutron radiation on the photoelectric parameters of ITO-GaSe structures

    SciTech Connect

    Kovalyuk, Z. D. Litovchenko, P. G.; Politanska, O. A.; Sydor, O. N.; Katerynchuk, V. N.; Lastovetsky, V. F.; Litovchenko, O. P.; Dubovoy, V. K.; Polivtsev, L. A.

    2007-05-15

    The effect of 1-MeV neutrons on the photoelectric parameters of ITO-GaSe heterostructures was studied. It is shown that the observed variations in the current-voltage characteristics are caused by the effect of penetrating radiation on both components of the structure, which brings about an increase in the resistance of the heterostructures. The presence of exciton fine structure in the photosensitivity spectra after irradiation indicates that GaSe retains high structural quality notwithstanding the introduced radiation defects. The results obtained are accounted for by spatial redistribution of doping impurity in GaSe and structural changes in the ITO films.

  10. Electrochromic properties of NiOx:H films deposited by DC magnetron sputtering for ITO/NiOx:H/ZrO2/WO3/ITO device

    NASA Astrophysics Data System (ADS)

    Dong, Dongmei; Wang, Wenwen; Dong, Guobo; Zhou, Yuliang; Wu, Zhonghou; Wang, Mei; Liu, Famin; Diao, Xungang

    2015-12-01

    NiOx:H thin films were deposited on ITO-coated glass by DC reactive magnetron sputtering at room temperature. The effects of the hydrogen content on the structure, morphologies, electrochemical properties, the stoichiometry and chemical states of NiOx:H thin films were systematically studied. In X-ray diffraction and atomic force microscopy analysis, the crystallinity of the films tends to be weakened when the flow amount ratio of Ar:O2:H2 equals 19:1:3 and as confirmed in electrochemical analysis, such relatively weak crystallinity is the main contributing factor to ion transportation. X-ray photoelectron spectroscopy reveals that the increase of the hydrogen contents results in a relatively lower binding energy exhibited in the Ni 2p spectra. The proportion of Ni2O3 in NiOx:H films increases from 22% at bleached state to 33% at colored state. A monolithic all-thin-film inorganic electrochromic device was fabricated with complementary configuration as ITO/NiOx:H/ZrO2/WO3/ITO. The electrochromic device with optimized NiOx:H thin films acting both as ion storage layer and proton-providing source displays high modulation efficiency of 68% at a fixed wavelength 550 nm.

  11. RNA modification in Cajal bodies.

    PubMed

    Meier, U Thomas

    2016-10-24

    Aside from nucleoli, Cajal bodies (CBs) are the best-characterized organelles of mammalian cell nuclei. Like nucleoli, CBs concentrate ribonucleoproteins (RNPs), in particular, spliceosomal small nuclear RNPs (snRNPs) and small nucleolar RNPs (snoRNPs). In one of the best-defined functions of CBs, most of the snoRNPs are involved in site-specific modification of snRNAs. The two major modifications are pseudouridylation and 2'-O-methylation that are guided by the box H/ACA and C/D snoRNPs, respectively. This review details the modifications, their function, the mechanism of modification, and the machineries involved. We dissect the different classes of noncoding RNAs that meet in CBs, guides and substrates. Open questions and conundrums, often raised and appearing due to experimental limitations, are pointed out and discussed. The emphasis of the review is on mammalian CBs and their function in modification of noncoding RNAs.

  12. Laser Direct Ablation of Indium Tin Oxide Films on Both Sides of Various Substrates.

    PubMed

    Oh, Gi Taek; Kwon, Sang Jik; Han, Jae-Hee; Cho, Eou Sik

    2015-03-01

    We demonstrate ablation of indium tin oxide (ITO) films onto both glass and polyethylene terephthalate (PET) substrates, using a Q-switched diode-pumped neodymium-doped yttrium vanadate laser (Nd:YVO4, λ = 1064 nm) incident on both the front and back sides of the substrate. From scanning electron microscope (SEM) images and depth profile data, ITO patterns that were laser-ablated onto glass from the back side showed a larger abrupt change in the ablated line width than those ablated from the front. However, there were only slight differences in ablated line widths due to the direction of the incident laser beam. We provide a possible explanation in terms of several factors: dispersion of laser beam energy through the substrate, overlapping of each laser beam spot due to scanning speed, and the thickness of glass and PET substrates.

  13. 32 CFR 728.44 - Members of security assistance training programs, foreign military sales, and their ITO...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., foreign military sales, and their ITO authorized dependents. 728.44 Section 728.44 National Defense... PERSONS AT NAVY MEDICAL DEPARTMENT FACILITIES Members of Foreign Military Services and Their Dependents § 728.44 Members of security assistance training programs, foreign military sales, and their ITO...

  14. 32 CFR 728.44 - Members of security assistance training programs, foreign military sales, and their ITO...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., foreign military sales, and their ITO authorized dependents. 728.44 Section 728.44 National Defense... PERSONS AT NAVY MEDICAL DEPARTMENT FACILITIES Members of Foreign Military Services and Their Dependents § 728.44 Members of security assistance training programs, foreign military sales, and their ITO...

  15. 32 CFR 728.44 - Members of security assistance training programs, foreign military sales, and their ITO...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., foreign military sales, and their ITO authorized dependents. 728.44 Section 728.44 National Defense... PERSONS AT NAVY MEDICAL DEPARTMENT FACILITIES Members of Foreign Military Services and Their Dependents § 728.44 Members of security assistance training programs, foreign military sales, and their ITO...

  16. A cracked polymer templated metal network as a transparent conducting electrode for ITO-free organic solar cells.

    PubMed

    Rao, K D M; Hunger, Christoph; Gupta, Ritu; Kulkarni, Giridhar U; Thelakkat, Mukundan

    2014-08-07

    We report a highly transparent, low resistance Ag metal network templated by a cracked polymer thin film and its incorporation in an organic solar cell. The performance of this scalable metallic network is comparable to that of conventional ITO electrodes. This is a general approach to replace ITO in diverse thin film devices.

  17. High quality non-rectifying contact of ITO with both Ni and n-type GaAs

    NASA Astrophysics Data System (ADS)

    Qingsong, Wang; Masao, Ikeda; Ming, Tan; Pan, Dai; Yuanyuan, Wu; Shulong, Lu; Hui, Yang

    2015-05-01

    We report the specific contact resistance for ITO with both metal and a semiconductor. Good quality ITO was deposited by electron beam evaporation with the resistivity of 2.32 × 10-4 Ω·cm and an averaged transmittance of 92.8% in the visible light region. The circular transmission line model (c-TLM) method was used to evaluate and compare the properties of the ITO/metal and ITO/semiconductor ohmic contacts. The lowest specific contact resistance of the ITO/Ni is 2.81 × 10-6 Ω·cm2, while that of ITO/n-GaAs is 7 × 10-5 Ω·cm2. This is the best ohmic contact between ITO and n-GaAs ever reported. These results suggest that good quality ITO has strong potential to be used to realize highly efficient solar cells. Project supported by the National Natural Science Foundation (Nos. 61176128, 61376081), the Knowledge Innovation Project of the CAS (No. Y2BAQ11001), and the SINANO SONY Joint Program (Nos. Y1AAQ11002, Y2AAQ11004).

  18. Tuning the ITO work function by capacitively coupled plasma and its application in inverted organic solar cells

    NASA Astrophysics Data System (ADS)

    Fang, Ming; Zhang, Chunmei; Chen, Qiang

    2016-11-01

    In this paper, we investigated the performance of inverted organic solar cells (OSCs) with plasma-treated indium tin oxide (ITO) as the cathode for omitting an electron transport layer. The Ar plasma was produced by capcitively coupled plasma setup under 20 Pa chamber pressure. For the device with the structure of plasma-treated ITO/P3HT:PCBM/MoO3/Ag, a power conversion efficiency (PCE) of 3.22% was achieved, whereas PCE of 1.13% was recorded from the device fabricated with the pristine ITO. The photovoltaic performance was found to be dependent on the applied power of plasma. After analyzing by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), we concluded that the chemical component variation of ITOs surface resulted in the decrease of ITO work function, which meant that the ITO Fermi level became shallow relative to the vacuum level. The low work function of ITO should be responsible for the improvement of inverted OSCs because of the better energy level alignment between ITO and the photoactive layer.

  19. Application of ITO/Al reflectors for increasing the efficiency of single-crystal silicon solar cells

    SciTech Connect

    Kopach, V. R.; Kirichenko, M. V. Khrypunov, G. S.; Zaitsev, R. V.

    2010-06-15

    It is shown that an increase in the efficiency and manufacturability of single-junction single-crystal silicon photoelectric converters of solar energy requires the use of a back-surface reflector based on conductive transparent indium-tin oxide (ITO) 0.25-2 {mu}m thick. To increase the efficiency and reduce the sensitivity to the angle of light incidence on the photoreceiving surface of multijunction photoelectric converters with vertical diode cells based on single-crystal silicon, ITO/Al reflectors with an ITO layer >1 {mu}m thick along vertical boundaries of diode cells should be fabricated. The experimental study of multijunction photoelectric converters with ITO/Al reflectors at diode cell boundaries shows the necessity of modernizing the used technology of ITO layers to achieve their theoretically calculated thickness.

  20. A novel molecularly imprinted sensor for selectively probing imipramine created on ITO electrodes modified by Au nanoparticles.

    PubMed

    Xu, Xiaoli; Zhou, Guoliang; Li, Huixiang; Liu, Qian; Zhang, Song; Kong, Jilie

    2009-04-15

    A sensitive molecularly imprinted electrochemical sensor was created for selective detection of a tricyclic antidepressant imipramine by combination of Au nanoparticles (Au-NPs) with a thin molecularly imprinted film. The sensor was fabricated onto the indium tin oxide (ITO) electrode via stepwise modification of Au-NPs by self-assembly and a thin film of molecularly imprinted polymers (MIPs) via sol-gel technology. It was observed that the molecularly imprinted film displayed excellent selectivity towards the target molecule imipramine. Meanwhile, the introduced Au-NPs exhibited noticeable catalytic activities towards imipramine oxidation, which remarkably enhanced the sensitivity of the imprinted film. Due to such combination, the as-prepared sensor responded quickly to imipramine, within only 1 min of incubation. The differential voltammetric anodic peak current was linear to the logarithm of imipramine concentration in the range from 5.0x10(-6) to 1.0x10(-3) mol L(-1), and the detection limits obtained was 1.0x10(-9) mol L(-1). This method proposed was successfully applied to the determination of imipramine in drug tablets, and proven to be reliable compared with conventional UV method. These results reveal that such a sensor fulfills the selectivity, sensitivity, speed and simplicity requirements for imipramine detection, and provides possibilities of clinical application in physiological fluids.

  1. Nanostructured Polyaniline Coating on ITO Glass Promotes the Neurite Outgrowth of PC 12 Cells by Electrical Stimulation.

    PubMed

    Wang, Liping; Huang, Qianwei; Wang, Jin-Ye

    2015-11-10

    A conducting polymer polyaniline (PANI) with nanostructure was synthesized on indium tin oxide (ITO) glass. The effect of electrical stimulation on the proliferation and the length of neurites of PC 12 cells was investigated. The dynamic protein adsorption on PANI and ITO surfaces in a cell culture medium was also compared with and without electrical stimulation. The adsorbed proteins were characterized using SDS-PAGE. A PANI coating on ITO surface was shown with 30-50 nm spherical nanostructure. The number of PC 12 cells was significantly greater on the PANI/ITO surface than on ITO and plate surfaces after cell seeding for 24 and 36 h. This result confirmed that the PANI coating is nontoxic to PC 12 cells. The electrical stimulation for 1, 2, and 4 h significantly enhanced the cell numbers for both PANI and ITO conducting surfaces. Moreover, the application of electrical stimulation also improved the neurite outgrowth of PC 12 cells, and the number of PC 12 cells with longer neurite lengths increased obviously under electrical stimulation for the PANI surface. From the mechanism, the adsorption of DMEM proteins was found to be enhanced by electrical stimulation for both PANI/ITO and ITO surfaces. A new band 2 (around 37 kDa) was observed from the collected adsorbed proteins when PC 12 cells were cultured on these surfaces, and culturing PC 12 cells also seemed to increase the amount of band 1 (around 90 kDa). When immersing PANI/ITO and ITO surfaces in a DMEM medium without a cell culture, the number of band 3 (around 70 kDa) and band 4 (around 45 kDa) proteins decreased compared to that of PC 12 cell cultured surfaces. These results are valuable for the design and improvement of the material performance for neural regeneration.

  2. Seropharmalogical effects of Fuzheng Huayu decoction on rat Ito cell morphology and function in culture

    PubMed Central

    Liu, Cheng-Hai; Liu, Cheng; Liu, Ping; Xu, Lie-Ming

    1997-01-01

    AIM: To investigate the mechanisms of anti-liver fibrosis actions of Fuzheng Huayu (FZHY) decoction, which acts to strengthen the body’s resistance and promote blood circulation. METHODS: Ito cells were isolated from rats and cultured. Serum samples were collected from healthy (normal) rats after administration of FZHY decoction and added to the subcultured cells. The effects of FZHY decoction on the Ito cells were investigated by contrast microscopy (to observe cell morphology), [3H]Pro incorporation assay (cell viability), [3H]TdR incorporation and MTT colorimetric assay (cell proliferation), and [3H]Pro incorporation and collagenase digestion (collagen synthesis rate). RESULTS: The rat sera samples from rats treated with FZHY decoction had no influence on Ito cell morphology, but improved cell viability and markedly inhibited cell proliferation and collagen synthesis. The magnitude of these effects showed dependence on treatment dosage and drug concentration in serum. CONCLUSION: The seropharmalogical method can be efficiently used to investigate the pharmacological mechanism of anti-fibrotic traditional Chinese herbs and formulae. Inhibition of Ito cell proliferation and collagen synthesis may be two of the major mechanisms underlying the anti-fibrosis actions of the FZHY decoction. PMID:27053890

  3. Hypomelanosis of Ito associated with mosaicism for trisomy 7 and apparent 'pseudomosaicism' at amniocentesis.

    PubMed Central

    Jenkins, D; Martin, K; Young, I D

    1993-01-01

    We describe a patient with hypomelanosis of Ito (HI) and typical characteristics. Cytogenetic analysis of fibroblast cultures showed mosaicism for trisomy 7. The trisomy cell line was first observed in an amniotic fluid culture and illustrates the problem of distinguishing pseudomosaicism from true mosaicism. Images PMID:8411076

  4. Liver damage with reversible portal hypertension from vitamin A intoxication: demonstration of Ito cells.

    PubMed Central

    Guarascio, P; Portmann, B; Visco, G; Williams, R

    1983-01-01

    A patient with sudden onset of ascites and hepatosplenomegaly made a complete recovery after vitamin A was withdrawn. Fluorescence microscopy on embedded tissue provided a simple method of demonstrating the accumulation of fat storage (Ito) cells in the liver. Images PMID:6863568

  5. Transgenerational Authenticity Measurement: A Comment on Ito et al. (2009).

    PubMed

    Giannini, James; Wick, Daniel T

    2016-08-01

    The authors examined their previously published studies of transgenerational authenticity in a Japanese cohort (Ito, Horikoshi, & Kodama). In the previous paper, the authors addressed semantic and semiotic concerns. In this paper, design flaws and statistical flaws are examined. © The Author(s) 2016.

  6. Performance enhancement of ITO/oxide/semiconductor MOS-structure silicon solar cells with voltage biasing.

    PubMed

    Ho, Wen-Jeng; Huang, Min-Chun; Lee, Yi-Yu; Hou, Zhong-Fu; Liao, Changn-Jyun

    2014-01-01

    In this study, we demonstrate the photovoltaic performance enhancement of a p-n junction silicon solar cell using a transparent-antireflective ITO/oxide film deposited on the spacing of the front-side finger electrodes and with a DC voltage applied on the ITO-electrode. The depletion width of the p-n junction under the ITO-electrode was induced and extended while the absorbed volume and built-in electric field were also increased when the biasing voltage was increased. The photocurrent and conversion efficiency were increased because more photo-carriers are generated in a larger absorbed volume and because the carriers transported and collected more effectively due to higher biasing voltage effects. Compared to a reference solar cell (which was biased at 0 V), a conversion efficiency enhancement of 26.57% (from 12.42% to 15.72%) and short-circuit current density enhancement of 42.43% (from 29.51 to 42.03 mA/cm(2)) were obtained as the proposed MOS-structure solar cell biased at 2.5 V. In addition, the capacitance-volt (C-V) measurement was also used to examine the mechanism of photovoltaic performance enhancement due to the depletion width being enlarged by applying a DC voltage on an ITO-electrode.

  7. Time-resolved UV-visible spectroelectrochemistry using transparent 3D-mesoporous nanocrystalline ITO electrodes.

    PubMed

    Renault, Christophe; Harris, Kenneth D; Brett, Michael J; Balland, Véronique; Limoges, Benoît

    2011-02-14

    Efficient and rapid adsorption of microperoxidase 11 within a highly porous ITO thin film (200 nm) prepared by glancing angle deposition was achieved. Adsorbed redox molecules were reversibly and rapidly reduced throughout the 3D-conductive matrix in ca. 50 ms, allowing the heterogeneous electron transfer rate to be determined by derivative cyclic voltabsorptometry.

  8. Generation of transparent conductive electrodes by laser consolidation of LIFT printed ITO nanoparticle layers

    NASA Astrophysics Data System (ADS)

    Baum, M.; Kim, H.; Alexeev, I.; Piqué, A.; Schmidt, M.

    2013-06-01

    Indium tin oxide (ITO) is one of the few materials available that display a high transparency in the visible wavelength region and at the same time can conduct electrical currents. Thus it is widespread in many optoelectronic applications such as displays or solar cells. Layers of this material are commonly deposited by vacuum deposition methods which are not compatible with inexpensive production methods such as roll-to-roll processing or printed electronics in general. In this work, we demonstrate the generation of arbitrarily shaped ITO layers by laser induced forward transfer of ITO nanoparticles. The transferred particle ink volumes range in the sub picoliter regime. Feature sizes as small as 20 μm are produced without any outward flow or "coffee-stain" effects. Furthermore, the feasibility of excimer laser consolidation of these nanoparticulate layers in ambient air for the generation of dense ITO films is shown. Conductivities of over 4000 Ω-1 m-1 were achieved. The presented methods are a promising alternative for the generation of transparent conducting layers for the inexpensive production of optoelectronics.

  9. Use of Whole Exome Sequencing for the Identification of Ito-Based Arrhythmia Mechanism and Therapy

    PubMed Central

    Sturm, Amy C; Kline, Crystal F; Glynn, Patric; Johnson, Benjamin L; Curran, Jerry; Kilic, Ahmet; Higgins, Robert S D; Binkley, Philip F; Janssen, Paul M L; Weiss, Raul; Raman, Subha V; Fowler, Steven J; Priori, Silvia G; Hund, Thomas J; Carnes, Cynthia A; Mohler, Peter J

    2015-01-01

    Background Identified genetic variants are insufficient to explain all cases of inherited arrhythmia. We tested whether the integration of whole exome sequencing with well-established clinical, translational, and basic science platforms could provide rapid and novel insight into human arrhythmia pathophysiology and disease treatment. Methods and Results We report a proband with recurrent ventricular fibrillation, resistant to standard therapeutic interventions. Using whole-exome sequencing, we identified a variant in a previously unidentified exon of the dipeptidyl aminopeptidase-like protein-6 (DPP6) gene. This variant is the first identified coding mutation in DPP6 and augments cardiac repolarizing current (Ito) causing pathological changes in Ito and action potential morphology. We designed a therapeutic regimen incorporating dalfampridine to target Ito. Dalfampridine, approved for multiple sclerosis, normalized the ECG and reduced arrhythmia burden in the proband by >90-fold. This was combined with cilostazol to accelerate the heart rate to minimize the reverse-rate dependence of augmented Ito. Conclusions We describe a novel arrhythmia mechanism and therapeutic approach to ameliorate the disease. Specifically, we identify the first coding variant of DPP6 in human ventricular fibrillation. These findings illustrate the power of genetic approaches for the elucidation and treatment of disease when carefully integrated with clinical and basic/translational research teams. PMID:26015324

  10. Ru/ITO: a carbon-free cathode for nonaqueous Li-O2 battery.

    PubMed

    Li, Fujun; Tang, Dai-Ming; Chen, Yong; Golberg, Dmitri; Kitaura, Hirokazu; Zhang, Tao; Yamada, Atsuo; Zhou, Haoshen

    2013-10-09

    Ru nanoparticles deposited on a conductive support indium tin oxide (Ru/ITO) were applied as a carbon-free cathode in a nonaqueous Li-O2 battery. The Li-O2 battery with Ru/ITO showed much lower charging overpotentials and better cycling performance at 0.15 mA/cm(2) than those with Super P (SP) and SP loaded with Ru nanoparticles (Ru/SP) as the cathodes. The carbon-free cathode Ru/ITO can effectively reduce formation of Li2CO3 or other Li carbonates in a discharging process, which cannot be completely decomposed upon charging, in comparison with the carbon based cathode. The improved performance of Ru/ITO can be attributed to the superior catalytic activity of Ru nanoparticles toward oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) and the absence of carbon that has been reported to react with Li2O2 to form Li2CO3.

  11. Performance enhancement of ITO/oxide/semiconductor MOS-structure silicon solar cells with voltage biasing

    PubMed Central

    2014-01-01

    In this study, we demonstrate the photovoltaic performance enhancement of a p-n junction silicon solar cell using a transparent-antireflective ITO/oxide film deposited on the spacing of the front-side finger electrodes and with a DC voltage applied on the ITO-electrode. The depletion width of the p-n junction under the ITO-electrode was induced and extended while the absorbed volume and built-in electric field were also increased when the biasing voltage was increased. The photocurrent and conversion efficiency were increased because more photo-carriers are generated in a larger absorbed volume and because the carriers transported and collected more effectively due to higher biasing voltage effects. Compared to a reference solar cell (which was biased at 0 V), a conversion efficiency enhancement of 26.57% (from 12.42% to 15.72%) and short-circuit current density enhancement of 42.43% (from 29.51 to 42.03 mA/cm2) were obtained as the proposed MOS-structure solar cell biased at 2.5 V. In addition, the capacitance-volt (C-V) measurement was also used to examine the mechanism of photovoltaic performance enhancement due to the depletion width being enlarged by applying a DC voltage on an ITO-electrode. PMID:25593550

  12. Power gain assessment of ITO based Transparent Gate Recessed Channel (TGRC) MOSFET for RF/wireless applications

    NASA Astrophysics Data System (ADS)

    Kumar, Ajay; Gupta, Neha; Chaujar, Rishu

    2016-03-01

    In this work, power gain assessment and intrinsic delay of Transparent Gate Recessed Channel (TGRC) MOSFET have been observed for RF applications and the results so obtained have been compared with Conventional Recessed Channel (CRC) MOSFET. Simulation results show that TGRC architecture has significantly improved the power gains in terms of maximum available power gain (Gma), maximum transducer power gain (GMT), maximum stable power gain (Gms) and appreciable reduction in intrinsic delay as compared to CRC-MOSFET owing to indium tin oxide (ITO) in recessed channel as a conducting gate material and thus providing its efficacy for low power switching applications. Further, effect of gate length scaling has also been observed on TGRC MOSFET and it has been found that the cut-off frequency (fT) and maximum oscillator frequency (fMAX) enhances by 66% and 36% respectively as channel length scales down to 20 nm. Further, the effect of negative junction depth, oxide thickness and substrate doping have also been investigated for TGRC-MOSFET. This TCAD assessment has been done at frequencies of several THz which fortify its use for high frequency RF/wireless applications.

  13. Direct transparent electrode patterning on layered GaN substrate by screen printing of indium tin oxide nanoparticle ink for Eu-doped GaN red light-emitting diode

    SciTech Connect

    Kashiwagi, Y. Yamamoto, M.; Saitoh, M.; Takahashi, M.; Ohno, T.; Nakamoto, M.; Koizumi, A.; Fujiwara, Y.; Takemura, Y.; Murahashi, K.; Ohtsuka, K.; Furuta, S.

    2014-12-01

    Transparent electrodes were formed on Eu-doped GaN-based red-light-emitting diode (GaN:Eu LED) substrates by the screen printing of indium tin oxide nanoparticle (ITO np) inks as a wet process. The ITO nps with a mean diameter of 25 nm were synthesized by the controlled thermolysis of a mixture of indium complexes and tin complexes. After the direct screen printing of ITO np inks on GaN:Eu LED substrates and sintering at 850 °C for 10 min under atmospheric conditions, the resistivity of the ITO film was 5.2 mΩ cm. The fabricated LED up to 3 mm square surface emitted red light when the on-voltage was exceeded.

  14. Direct transparent electrode patterning on layered GaN substrate by screen printing of indium tin oxide nanoparticle ink for Eu-doped GaN red light-emitting diode

    NASA Astrophysics Data System (ADS)

    Kashiwagi, Y.; Koizumi, A.; Takemura, Y.; Furuta, S.; Yamamoto, M.; Saitoh, M.; Takahashi, M.; Ohno, T.; Fujiwara, Y.; Murahashi, K.; Ohtsuka, K.; Nakamoto, M.

    2014-12-01

    Transparent electrodes were formed on Eu-doped GaN-based red-light-emitting diode (GaN:Eu LED) substrates by the screen printing of indium tin oxide nanoparticle (ITO np) inks as a wet process. The ITO nps with a mean diameter of 25 nm were synthesized by the controlled thermolysis of a mixture of indium complexes and tin complexes. After the direct screen printing of ITO np inks on GaN:Eu LED substrates and sintering at 850 °C for 10 min under atmospheric conditions, the resistivity of the ITO film was 5.2 mΩ cm. The fabricated LED up to 3 mm square surface emitted red light when the on-voltage was exceeded.

  15. Flexural Capability of Patterned Transparent Conductive Substrate by Performing Electrical Measurements and Stress Simulations

    PubMed Central

    Lee, Chang-Chun; Huang, Pei-Chen; Wang, Ko-Shun

    2016-01-01

    The suitability of stacked thin films for next-generation display technology was analyzed based on their properties and geometrical designs to evaluate the mechanical reliability of transparent conducting thin films utilized in flexural displays. In general, the high bending stress induced by various operation conditions is a major concern regarding the mechanical reliability of indium–tin–oxide (ITO) films deposited on polyethylene terephthalate (PET) substrates; mechanical reliability is commonly used to estimate the flexibility of displays. However, the pattern effect is rarely investigated to estimate the mechanical reliability of ITO/PET films. Thus, this study examined the flexible content of patterned ITO/PET films with two different line widths by conducting bending tests and sheet resistance measurements. Moreover, a stress–strain simulation enabled by finite element analysis was performed on the patterned ITO/PET to explore the stress impact of stacked film structures under various levels of flexural load. Results show that the design of the ITO/PET film can be applied in developing mechanically reliable flexible electronics. PMID:28773969

  16. Effect of substrates on structural, optical, electrical and morphological properties of evaporated polycrystalline CdZnTe thin films

    NASA Astrophysics Data System (ADS)

    Chander, Subhash; Purohit, A.; Patel, S. L.; Dhaka, M. S.

    2017-05-01

    It is well known fact that the physical properties of a thin film could be tuned by substrate during deposition process. Therefore, a study on the effect of substrates on structural and opto-electrical properties and surface morphology of CdZnTe thin films (400 nm) deposited by electron beam evaporation onto commercial glass, indium tin oxide (ITO) and silicon wafer, has been undertaken. The films exhibited zinc-blende structure and grain size as well as other structural parameters (i.e. internal strain, dislocation density, lattice constant) were found to be affected by the nature of substrates. The optical band gap was found in the range 2.06-2.33 eV and depended on the substrates while the electrical conductivity was observed maximum for films on ITO substrate. The surface morphology of films was also found to be uniform and homogeneous.

  17. High efficiency bifacial Cu2ZnSnSe4 thin-film solar cells on transparent conducting oxide glass substrates

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Sik; Kang, Jin-Kyu; Hwang, Dae-Kue

    2016-09-01

    In this work, transparent conducting oxides (TCOs) have been employed as a back contact instead of Mo on Cu2ZnSnSe4 (CZTSe) thin-film solar cells in order to examine the feasibility of bifacial Cu2ZnSn(S,Se)4 (CZTSSe) solar cells based on a vacuum process. It is found that the interfacial reaction between flourine doped tin oxide (FTO) or indium tin oxide (ITO) and the CZTSe precursor is at odds with the conventional CZTSe/Mo reaction. While there is no interfacial reaction on CZTSe/FTO, indium in CZTSe/ITO was significantly diffused into the CZTSe layers; consequently, a SnO2 layer was formed on the ITO substrate. Under bifacial illumination, we achieved a power efficiency of 6.05% and 4.31% for CZTSe/FTO and CZTSe/ITO, respectively.

  18. Laser/plasma chemical processing of substrates

    DOEpatents

    Gee, James M.; Hargis, Jr., Philip J.

    1986-01-01

    A process for the modification of substrate surfaces is described, wherein etching or deposition at a surface occurs only in the presence of both reactive species and a directed beam of coherent light.

  19. ITO-free organic light-emitting diodes with MoO3/Al/MoO3 as semitransparent anode fabricated using thermal deposition method

    NASA Astrophysics Data System (ADS)

    Lu, Hsin-Wei; Huang, Ching-Wen; Kao, Po-Ching; Chu, Sheng-Yuan

    2015-08-01

    In this paper, semitransparent electrodes with the structure substrate/MoO3/Al/MoO3 (OMO) were fabricated via the thermal deposition method for use as the anode in organic light-emitting diodes (OLEDs). The optical transmittance of the metal layer was enhanced by depositing metal oxidation (MoO3) and metal (Al) layers. The optimal thickness of the Al thin films was determined to be 15 nm for high optical transmittance and good electrical conductivity. The optimized films show the typical sheet resistance of 7 Ω/sq and a high transmittance of 70% at 550 nm. The indium-tin-oxide (ITO)-free OLEDs with the fabricated composite anodes on a glass substrate exhibited the high luminance and current efficiency of 21,750 cd/m2 and 3.18 cd/A, respectively. In addition, bending effects on the polyethersulfone (PES) substrate/MoO3/Al/MoO3 and PES substrate/MoO3/Al structures were investigated. Cracks formed on the surface of the samples with a bending radius smaller than or equal to 1 cm. MoO3 covering the Al layer modifies the surface of the electrode and enhances durability. The surface roughness of the bi-layer films was higher than that of the tri-layer films. Therefore, OLEDs with OMO anode outperform those with bi-layer films anode.

  20. Effect of methotrexate therapy in psoriatics on the Ito cells in liver biopsies, assessed by point-counting.

    PubMed Central

    Hopwood, D; Nyfors, A

    1976-01-01

    To evaluate the relationship, both quantitative and qualitative, between the Ito cells and methotrexate (MTX) therapy Ito cells were studied by light microscopy in 1 mum toluidine blue stained sections and by electron microscopy in 24 pairs of Menghini needle biopsies before and after MTX therapy of 24 consenting patients with severe psoriasis. Light microscopy showed a statistically significant increase in pathological findings (P less than 0-05) and in the number of Ito cells and their size (P less than 0-0001) after MTX therapy. It was not possible to show a statistically significant correlation between the increase in the number of Ito cells and the cumulative dose of MTX. Ultrastructural analysis of Ito cells showed no marked difference from pre to post-MTX specimens. The fibrosis and cirrhosis seen after MTX therapy in some liver biopsies from psoriatics and the post-MTX increase in the number of Ito cells direct attention to the possible role of Ito cells as fibroblast precursors. Images PMID:956451

  1. Metal-insulator transition in tin doped indium oxide (ITO) thin films: Quantum correction to the electrical conductivity

    NASA Astrophysics Data System (ADS)

    Kaushik, Deepak Kumar; Kumar, K. Uday; Subrahmanyam, A.

    2017-01-01

    Tin doped indium oxide (ITO) thin films are being used extensively as transparent conductors in several applications. In the present communication, we report the electrical transport in DC magnetron sputtered ITO thin films (prepared at 300 K and subsequently annealed at 673 K in vacuum for 60 minutes) in low temperatures (25-300 K). The low temperature Hall effect and resistivity measurements reveal that the ITO thin films are moderately dis-ordered (kFl˜1; kF is the Fermi wave vector and l is the electron mean free path) and degenerate semiconductors. The transport of charge carriers (electrons) in these disordered ITO thin films takes place via the de-localized states. The disorder effects lead to the well-known `metal-insulator transition' (MIT) which is observed at 110 K in these ITO thin films. The MIT in ITO thin films is explained by the quantum correction to the conductivity (QCC); this approach is based on the inclusion of quantum-mechanical interference effects in Boltzmann's expression of the conductivity of the disordered systems. The insulating behaviour observed in ITO thin films below the MIT temperature is attributed to the combined effect of the weak localization and the electron-electron interactions.

  2. 2,4-dinitrophenol acutely inhibits rabbit atrial Ca2+ -sensitive Cl- current (I(TO2)).

    PubMed

    Ravesloot, J H; Rombouts, E

    2000-10-01

    We investigated the effects of 2,4-dinitrophenol (DNP), the uncoupler of mitochondrial oxidative phosphorylation, on the Ca2+ -sensitive Cl- current component of the transient outward current (I(TO2)). Amphotericin B perforated-patch, whole-cell patch-clamp technique was employed (35 degrees C) using enzymatically isolated single rabbit atrial myocytes. We defined I(TO2) as the amplitude of the 2 mM 4-aminopyridine resistant transient outward current sensitive to anthracene-9-carboxylic acid (A9C). Between +5 and +45 mV, 0.2 mM A9C inhibited I(TO2) by approximately 70% (n = 13). Within 30 s after application of 0.2 mM DNP, both normal I(TO2) transients (n = 8) and the I(TO2) transients that remained after A9C treatment (n = 8) were inhibited completely. In cells expressing I(TO2) (70% of total), DNP also suppressed an A9C-insensitive slow outward current by approximately 40%, but the holding current at -80 mV was unaffected. There was a approximately 2 min latency between inhibitory effects of DNP and subsequent membrane current increase, presumably caused by activation of the ATP-sensitive K+ channels (n = 16). We conclude that DNP acutely inhibits I(TO2) via a mechanism presumably separate from metabolic inhibition.

  3. Influence of Different Sol-gel Spin Coating Speed on Memristive Behaviour of Pt/TiO2/ZnO/ITO Device

    NASA Astrophysics Data System (ADS)

    Kasim, S. M. M.; Shaari, N. A. A.; Bakar, R. A.; Aznilinda, Z.; Mohamad, Zulfakri; Herman, S. H.

    2015-11-01

    Composite titanium dioxide (TiO2) and zinc oxide (ZnO) thin films were deposited on indium tin oxide (ITO) substrates using sol-gel spin coating technique. The electrical and physical characterizations of three different sol-gel spin coating speed were investigated using two-probe current-voltage (I-V) measurement, field emission scanning electron microscopy (FESEM) and surface profiler (SP) respectively. The I-V measurement results showed the pinched hysteresis loop for every single of devices thus indicate that all the devices are memristive. ROFF/RON ratio which was defined from the hysteresis loop of device with higher spin speed was slightly higher compared to others.

  4. KChIP2 genotype dependence of transient outward current (Ito) properties in cardiomyocytes isolated from male and female mice.

    PubMed

    Waldschmidt, Lara; Junkereit, Vera; Bähring, Robert

    2017-01-01

    The transient outward current (Ito) in cardiomyocytes is largely mediated by Kv4 channels associated with Kv Channel Interacting Protein 2 (KChIP2). A knockout model has documented the critical role of KChIP2 in Ito expression. The present study was conducted to characterize in both sexes the dependence of Ito properties, including current magnitude, inactivation kinetics, recovery from inactivation and voltage dependence of inactivation, on the number of functional KChIP2 alleles. For this purpose we performed whole-cell patch-clamp experiments on isolated left ventricular cardiomyocytes from male and female mice which had different KChIP2 genotypes; i.e., wild-type (KChIP2+/+), heterozygous knockout (KChIP2+/-) or complete knockout of KChIP2 (KChIP2-/-). We found in both sexes a KChIP2 gene dosage effect (i.e., a proportionality between number of alleles and phenotype) on Ito magnitude, however, concerning other Ito properties, KChIP2+/- resembled KChIP2+/+. Only in the total absence of KChIP2 (KChIP2-/-) we observed a slowing of Ito kinetics, a slowing of recovery from inactivation and a negative shift of a portion of the voltage dependence of inactivation. In a minor fraction of KChIP2-/- myocytes Ito was completely lost. The distinct KChIP2 genotype dependences of Ito magnitude and inactivation kinetics, respectively, seen in cardiomyocytes were reproduced with two-electrode voltage-clamp experiments on Xenopus oocytes expressing Kv4.2 and different amounts of KChIP2. Our results corroborate the critical role of KChIP2 in controlling Ito properties. They demonstrate that the Kv4.2/KChIP2 interaction in cardiomyocytes is highly dynamic, with a clear KChIP2 gene dosage effect on Kv4 channel surface expression but not on inactivation gating.

  5. KChIP2 genotype dependence of transient outward current (Ito) properties in cardiomyocytes isolated from male and female mice

    PubMed Central

    Waldschmidt, Lara; Junkereit, Vera; Bähring, Robert

    2017-01-01

    The transient outward current (Ito) in cardiomyocytes is largely mediated by Kv4 channels associated with Kv Channel Interacting Protein 2 (KChIP2). A knockout model has documented the critical role of KChIP2 in Ito expression. The present study was conducted to characterize in both sexes the dependence of Ito properties, including current magnitude, inactivation kinetics, recovery from inactivation and voltage dependence of inactivation, on the number of functional KChIP2 alleles. For this purpose we performed whole-cell patch-clamp experiments on isolated left ventricular cardiomyocytes from male and female mice which had different KChIP2 genotypes; i.e., wild-type (KChIP2+/+), heterozygous knockout (KChIP2+/-) or complete knockout of KChIP2 (KChIP2-/-). We found in both sexes a KChIP2 gene dosage effect (i.e., a proportionality between number of alleles and phenotype) on Ito magnitude, however, concerning other Ito properties, KChIP2+/- resembled KChIP2+/+. Only in the total absence of KChIP2 (KChIP2-/-) we observed a slowing of Ito kinetics, a slowing of recovery from inactivation and a negative shift of a portion of the voltage dependence of inactivation. In a minor fraction of KChIP2-/- myocytes Ito was completely lost. The distinct KChIP2 genotype dependences of Ito magnitude and inactivation kinetics, respectively, seen in cardiomyocytes were reproduced with two-electrode voltage-clamp experiments on Xenopus oocytes expressing Kv4.2 and different amounts of KChIP2. Our results corroborate the critical role of KChIP2 in controlling Ito properties. They demonstrate that the Kv4.2/KChIP2 interaction in cardiomyocytes is highly dynamic, with a clear KChIP2 gene dosage effect on Kv4 channel surface expression but not on inactivation gating. PMID:28141821

  6. Effects of Melatonin on Differentiation Potential of Ito Cells in Mice with Induced Fibrosis of the Liver.

    PubMed

    Nalobin, D S; Suprunenko, E A; Golichenkov, V A

    2016-10-01

    We studied the effects of melatonin on differentiation potential of Ito cells during atypical regeneration of mouse liver under conditions of CCl4-induced fibrosis. The dynamics of fibrosis was traced at the histological level and the effects of melatonin on the differentiation potential of mouse Ito cells were evaluated. Melatonin alleviated fibrotic changes in the liver tissue and reduced differentiation of Ito cells into myofibroblasts under conditions of atypical regeneration of the liver in induced fibrosis. The hepatoprotective role of melatonin was shown.

  7. Zero curvature representation, bi-Hamiltonian structure, and an integrable hierarchy for the Zakharov-Ito system

    NASA Astrophysics Data System (ADS)

    Baxter, Mathew; Choudhury, S. Roy; Van Gorder, Robert A.

    2015-06-01

    In the present paper, we present an integrable hierarchy for the Zakharov-Ito system. We first construct the Lenard recursion sequence and zero curvature representation for the Zakharov-Ito system, following Cao's method as significantly generalized by other authors. We then construct the bi-Hamiltonian structures employing variational trace identities but woven together with the Lenard recursion sequences. From this, we are in a position to construct an integrable hierarchy of equations from the Zakharov-Ito system, and we obtain the recursion operator and Poisson brackets for constructing this hierarchy. Finally, we demonstrate that the obtained hierarchy is indeed Liouville integrable.

  8. Electrochemical study of highly durable cathode with Pt supported on ITO-CNT composite for proton exchange membrane fuel cells

    SciTech Connect

    Park, Sehkyu; Shao, Yuyan; Viswanathan, Vilayanur V.; Liu, Jun; Wang, Yong

    2016-10-01

    In this paper, we describe a highly stable cathode containing a Pt catalyst supported on an indium tin oxide (ITO) and carbon nanotube (CNT) composite. The dependence of cathode performance and durability on the ITO content and the diameter of the CNTs were investigated by electrochemical techniques. The cathode with 30 wt% ITO and CNTs with diameters 10–20 nm in the composite offered preferred locations for Pt stabilization and was very resistant to carbon corrosion (i.e., 82.7% ESA retention and 105.7% mass activity retention after an accelerated stress test for 400 h).

  9. ITO-free polymer solar cells with inkjet-printed highly-conductive PEDOT:PSS anode

    NASA Astrophysics Data System (ADS)

    Grimaldi, I. A.; Del Mauro, A. De Girolamo; Diana, R.; Loffredo, F.; Morvillo, P.; Villani, F.; Minarini, C.

    2012-07-01

    Actually the most promising polymer solar cell architecture utilizes ITO as transparent conductve anodic electrode. The limited flexibility of ITO and the increasing cost of indium make this kind of electrode not desirable for realizations of low-cost and flexible solar cells. For this reason, it is necessary to develop low-cost, highly flexible and transparent electrodes that can replace the widely used ITO. In this paper, we investigated a new commercial dispersion of PEDOT:PSS suitably modified with dimethyl sulfoxide in solution in order to obtain a highly transparent and conductive manufactured film (HC-PEDOT:PSS) by inkjet printing.

  10. A sensitive, label-free electrochemical detection of telomerase activity without modification or immobilization.

    PubMed

    Liu, Xu; Wei, Min; Xu, Ensheng; Yang, Haitang; Wei, Wei; Zhang, Yuanjian; Liu, Songqin

    2017-05-15

    Telomerase has become one of the most typical tumor marker because it is closely related to cancers. In this paper, a simple label-free electrochemical detection of telomerase activity by using methylene blue (MB) as a G-quadruplex binding probe was proposed, avoiding commonly used complex label procedures, nano-probe synthesis, complicated electrode modification, probe immobilization or signal amplification. In the presence of telomerase substrate (TS) primer, the binding of MB on primer was weak. When repeats of (TTAGGG) were extended on the TS primer under the action of telomerase, they formed multiple G-quadruplexes with the help of K(+). As a result, a large amount of MB bounded to multiple G-quadruplexes because they have more strong interaction with G-quadruplexes than TS primer. As a result, the diffusion current of MB decreased sharply, which was strongly dependent on the telomerase activity. The DPV current change has a linear correlation with the logarithm of HeLa cell number in the range of 10-10,000 cells, with the detection limit of 3 cells. The high sensitivity was due to the formed multiple G-quadruplexes. Using indium tin oxide (ITO) as working electrode without modification ensured the good reproducibility of the method. The method was also simple, rapid, and has been successfully applied in the telomerase activity detection in urine with good selectivity and reproducibility, which is significant for cancer diagnosis, anticancer drugs screening, and cancer therapy evaluation. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Indium tin oxide-free tandem polymer solar cells on opaque substrates with top illumination.

    PubMed

    Gupta, Dhritiman; Wienk, Martijn M; Janssen, René A J

    2014-08-27

    Top-illuminated, indium tin oxide (ITO)-free, tandem polymer solar cells are fabricated on opaque substrates in an inverted device configuration. In the tandem cell, a wide band gap subcell, consisting of poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT) blended with [70]PCBM is combined with a small band gap subcell consisting of a mixture of poly[{2,5-bis(2-hexyldecyl)-2,3,5,6-tetrahydro-3,6-dioxopyrrolo[3,4-c]pyrrole-1,4-diyl}-alt-{[2,2'-(1,4-phenylene)bisthiophene]-5,5'-diyl}] (PDPPTPT) and [60]PCBM. Compared to the more common bottom-illuminated inverted tandem polymer solar cells on transparent ITO substrates, the front and back cells must be reversed when using opaque substrates and a transparent and conductive top contact must be employed to enable top illumination. A high conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layer in combination with Ag lines surrounding the active area as current collection electrode is used for this purpose. The tandem polymer solar cell on an opaque glass/metal substrate yields a power conversion efficiency of 6.1% when the thicknesses of the photoactive layers are balanced for optimum performance. This is similar to the equivalent inverted tandem device fabricated on a transparent glass/ITO substrate.

  12. Engineering interface-type resistance switching based on forming current compliance in ITO/Ga2O3:ITO/TiN resistance random access memory: Conduction mechanisms, temperature effects, and electrode influence

    NASA Astrophysics Data System (ADS)

    Pan, Chih-Hung; Chang, Ting-Chang; Tsai, Tsung-Ming; Chang, Kuan-Chang; Chen, Po-Hsun; Chang-Chien, Shi-Wang; Chen, Min-Chen; Huang, Hui-Chun; Wu, Huaqiang; Deng, Ning; Qian, He; Sze, Simon M.

    2016-10-01

    In this paper, an ITO/Ga2O3:ITO/TiN structured resistance random access memory is introduced. Either interface or filament conduction mechanism can be induced depending on the forming compliance current, which has not been investigated before. Material analyses and electrical I-V measurements on this ITO/Ga2O3:ITO/TiN have also been carried out. The interface conduction mechanism was confirmed by a size-effect experiment, where resistance varied inversely to via size. In addition, the current fitting results show that Schottky emission dominates the on- and off-state currents. All physical mechanisms of device resistive switching behaviors are explained by our models and also confirmed by I-V characteristics.

  13. A dual-plate ITO-ITO generator-collector microtrench sensor: surface activation, spatial separation and suppression of irreversible oxygen and ascorbate interference.

    PubMed

    Hasnat, Mohammad A; Gross, Andrew J; Dale, Sara E C; Barnes, Edward O; Compton, Richard G; Marken, Frank

    2014-02-07

    Generator-collector electrode systems are based on two independent working electrodes with overlapping diffusion fields where chemically reversible redox processes (oxidation and reduction) are coupled to give amplified current signals. A generator-collector trench electrode system prepared from two tin-doped indium oxide (ITO) electrodes placed vis-à-vis with a 22 μm inter-electrode gap is employed here as a sensor in aqueous media. The reversible 2-electron anthraquinone-2-sulfonate redox system is demonstrated to give well-defined collector responses even in the presence of oxygen due to the irreversible nature of the oxygen reduction. For the oxidation of dopamine on ITO, novel "Piranha-activation" effects are observed and chemically reversible generator-collector feedback conditions are achieved at pH 7, by selecting a more negative collector potential, again eliminating possible oxygen interference. Finally, dopamine oxidation in the presence of ascorbate is demonstrated with the irreversible oxidation of ascorbate at the "mouth" of the trench electrode and chemically reversible oxidation of dopamine in the trench "interior". This spatial separation of chemically reversible and irreversible processes within and outside the trench is discussed as a potential in situ microscale sensing and separation tool.

  14. Mussel-Inspired Modification of Nanofibers for REST siRNA Delivery: Understanding the Effects of Gene-Silencing and Substrate Topography on Human Mesenchymal Stem Cell Neuronal Commitment.

    PubMed

    Low, Wei Ching; Rujitanaroj, Pim-On; Lee, Dong-Keun; Kuang, Jinghao; Messersmith, Phillip B; Chan, Jerry Kok Yen; Chew, Sing Yian

    2015-10-01

    In this study, we promote neuronal differentiation of human mesenchymal stem cells (MSCs) through scaffold-mediated sustained release of siRNA targeting RE-1 silencing transcription factor (REST). Poly (ϵ-caprolactone) nanofibers were surface modified with mussel inspired DOPA-melanin (DM) coating for adsorption of REST siRNA. DM modification increased siRNA-loading efficiency and reduced the initial burst release. Fiber alignment and DM modification enhanced REST knockdown efficiencies. Under non-specific differentiation condition, REST silencing and fiber topography enhanced MSC neuronal markers expressions and reduced glial cell commitment. Such scaffolds may find useful applications in enhancing MSCs neuronal differentiation under non-specific conditions such as an in vivo environment. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. A very dark-and-conductive electrode based on Mo/MoOx/ITO structure

    NASA Astrophysics Data System (ADS)

    Feng, Yuanxiang; Chen, Shuming

    2016-10-01

    A dark and conductive electrode based on Mo/MoOx/ITO structure with low resistivity of 1.93 × 10-4 Ω/cm was fabricated by magnetron sputtering. The demonstrated dark electrode exhibits a low reflectance of 2.4-12.9% within the visible spectral range and average luminous reflectance of 3.3%. To improve the conductivity, pure Mo was first sputtered, followed by depositing a dark and conductive MoOx by introducing O2 flow during Mo sputtering. In order to further reduce the reflectance and set the lowest reflectance at the wavelength of 550 nm, which is most sensitive to human eyes, an ITO phase changing layer was introduced on top of the MoOx. The demonstrated dark and conductive electrode can serve as bottom contact and can potentially replace the circular polarizer for high contrast top-emitting organic light-emitting diodes.

  16. AuNPs modified, disposable, ITO based biosensor: Early diagnosis of heat shock protein 70.

    PubMed

    Sonuç Karaboğa, Münteha Nur; Şimşek, Çiğdem Sayıklı; Sezgintürk, Mustafa Kemal

    2016-10-15

    This paper describes a novel, simple, and disposable immunosensor based on indium-tin oxide (ITO) sheets modified with gold nanoparticles to sensitively analyze heat shock protein 70 (HSP70), a potential biomarker that could be evaluated in diagnosis of some carcinomas. Disposable ITO coated Polyethylene terephthalate (PET) electrodes were used and modified with gold nanoparticles in order to construct the biosensors. Optimization and characterization steps were analyzed by electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Surface morphology of the biosensor was also identified by electrochemical methods, scanning electron microscopy (SEM), and atomic force microscopy (AFM). To interpret binding characterization of HSP70 to anti-HSP70 single frequency impedance method was successfully operated. Moreover, the proposed HSP70 immunosensor acquired good stability, repeatability, and reproducibility. Ultimately, proposed biosensor was introduced to real human serum samples to determine HSP70 sensitively and accurately. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Generation of phase-only holograms by laser ablation of nanoparticulate ITO layers

    NASA Astrophysics Data System (ADS)

    Baum, M.; Strauß, J.; Grüßel, F.; Alexeev, I.; Schmidt, M.

    2014-12-01

    Phase holograms offer great potential e.g. for laser beam shaping and imaging applications. However, the generation of these structures typically requires multi-step processes which tend to be time-consuming and expensive, especially if high-quality structures are required. In this work we demonstrate a flexible and inexpensive method which allows for the production of binary phase-only holograms by laser ablation of ITO nanoparticle layers. Since these layers are ablated free of residues, accurately defined phase shifts can be achieved. While arbitrarily shaped structures can be generated, the ITO layer thickness can be adjusted in order to freely tune the phase shift for the desired wavelength. In the diffraction patterns generated by the holograms we observed an excellent zero order suppression.

  18. Investigation of the surface free energy of the ITO thin films deposited under different working pressure

    SciTech Connect

    Özen, Soner Pat, Suat; Korkmaz, Şadan; Şenay, Volkan

    2016-03-25

    This study discusses the influence of working pressure on the surface energy of the ITO thin films produced by radio frequency magnetron sputtering method. Optical tensiometer (Attension Theta Lite) is used for evaluating wetting behavior of the water droplet on the film surface and Equation of State method was selected to determine surface free energy for this study. Equation of state method does not divide the surface tension into different components such as polar, dispersive, acid-base. It is calculated the surfaces’ free energy measuring the contact angle with a single liquid. The surface free energy value was in the range of 15-31 mN/m. Also, the transmittances were determined in the wavelength range between 200 and 1000 nm using the UNICO 4802 UV-Vis double beam spectrophotometer. Transmittances of the produced ITO thin films are greater than %70 in the visible range.

  19. Structural and morphological properties of ITO thin films grown by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Ghorannevis, Z.; Akbarnejad, E.; Ghoranneviss, M.

    2015-10-01

    Physical properties of transparent and conducting indium tin oxide (ITO) thin films grown by radiofrequency (RF) magnetron sputtering are studied systematically by changing deposition time. The X-ray diffraction (XRD) data indicate polycrystalline thin films with grain orientations predominantly along the (2 2 2) and (4 0 0) directions. From atomic force microscopy (AFM) it is found that by increasing the deposition time, the roughness of the film increases. Scanning electron microscopy (SEM) images show a network of a high-porosity interconnected nanoparticles, which approximately have a pore size ranging between 20 and 30 nm. Optical measurements suggest an average transmission of 80 % for the ITO films. Sheet resistances are investigated using four-point probes, which imply that by increasing the film thickness the resistivities of the films decrease to 2.43 × 10-5 Ω cm.

  20. Optimization of ion-assisted ITO films by design of experiment

    NASA Astrophysics Data System (ADS)

    Schwyn Thöny, Silvia; Buchholz, Jürgen; Waldner, Stephan

    2011-09-01

    In this work we want to demonstrate how the methodology of Design of Experiment (DOE) can be used for the development of ion-assisted ITO films deposited at low temperatures. The optimization method allows us to identify the process parameters, which yield films with high transmittance and low resistivity. The article will show the results obtained for transmittance and resistivity. Furthermore, the dispersion of the refractive index and the extinction coefficient will be determined as well as the surface roughness. In ITO there is a trade-off between transmittance / absorbance and sheet resistance. Virtually absorption free films could be obtained with a resistivity of 3.2 μΩm, whereas the lowest resistivity (2.7 μΩm) yielded a transmittance, which was reduced by a few percent.

  1. Toward Plastic Smart Windows: Optimization of Indium Tin Oxide Electrodes for the Synthesis of Electrochromic Devices on Polycarbonate Substrates.

    PubMed

    Laurenti, Marco; Bianco, Stefano; Castellino, Micaela; Garino, Nadia; Virga, Alessandro; Pirri, Candido F; Mandracci, Pietro

    2016-03-01

    Plastic smart windows are becoming one of the key elements in view of the fabrication of inexpensive, lightweight electrochromic (EC) devices to be integrated in the new generation of high-energy-efficiency buildings and automotive applications. However, fabricating electrochromic devices on polymer substrates requires a reduction of process temperature, so in this work we focus on the development of a completely room-temperature deposition process aimed at the preparation of ITO-coated polycarbonate (PC) structures acting as transparent and conductive plastic supports. Without providing any substrate heating or surface activation pretreatments of the polymer, different deposition conditions are used for growing indium tin oxide (ITO) thin films by the radiofrequency magnetron sputtering technique. According to the characterization results, the set of optimal deposition parameters is selected to deposit ITO electrodes having high optical transmittance in the visible range (∼90%) together with low sheet resistance (∼8 ohm/sq). The as-prepared ITO/PC structures are then successfully tested as conductive supports for the fabrication of plastic smart windows. To this purpose, tungsten trioxide thin films are deposited by the reactive sputtering technique on the ITO/PC structures, and the resulting single electrode EC devices are characterized by chronoamperometric experiments and cyclic voltammetry. The fast switching response between colored and bleached states, together with the stability and reversibility of their electrochromic behavior after several cycling tests, are considered to be representative of the high quality of the EC film but especially of the ITO electrode. Indeed, even if no adhesion promoters, additional surface activation pretreatments, or substrate heating were used to promote the mechanical adhesion among the electrode and the PC surface, the observed EC response confirmed that the developed materials can be successfully employed for the

  2. Electrical stimulation of cultured neurons using a simply patterned indium-tin-oxide (ITO) glass electrode.

    PubMed

    Tanamoto, Ryo; Shindo, Yutaka; Miki, Norihisa; Matsumoto, Yoshinori; Hotta, Kohji; Oka, Kotaro

    2015-09-30

    Indium-tin-oxide (ITO) glass electrodes possess the properties of optical transparency and high electrical conductivity, which enables the electrical stimulation of cultured cells to be performed whilst also measuring the responses with fluorescent imaging techniques. However, the quantitative relationship between the intensity of the stimulating current and the cell response is unclear when using conventional methods that employ a separated configuration of counter and stimulation electrodes. A quantitative electrical current stimulation device without the use of a counter electrode was fabricated. Nerve growth factor (NGF)-induced differentiated PC12 cells were cultured on an ITO single glass electrode, and the Ca(2+) response to electrical stimuli was measured using fluorescent Ca(2+) imaging. ITO electrode devices with a width less than 0.1mm were found to evoke a Ca(2+) response in the PC12 cells. Subsequent variation in the length of the device in the range of 2-10mm was found to have little influence on the efficiency of the electric stimulus. We found that the stimulation of the cells was dependent on the electrical current, when greater than 60 μA, rather than on the Joule heat, regardless of the width and length of the conductive area. Because of the cells directly in contact with the electrode, our device enables to stimulate the cells specifically, comparing with previous devices with the counter electrode. The ITO device without the use of a counter electrode is a useful tool for evaluating the quantitative neural excitability of cultured neurons. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Understanding the Effects of a High Surface Area Nanostructured ITO Electrode on Organic Solar Cell Performance.

    PubMed

    Cao, Bing; He, Xiaoming; Sorge, Jason; Lalany, Abeed; Ahadi, Kaveh; Afshar, Amir; Olsen, Brian C; Hauger, Tate C; Mobarok, Md Hosnay; Li, Peng; Cadien, Kenneth C; Brett, Michael J; Luber, Erik J; Buriak, Jillian M

    2017-10-12

    Organic solar cells (OSCs) are a complex assembly of disparate materials, each with a precise function within the device. Typically, the electrodes are flat, and the device is fabricated through a layering approach of the interfacial layers and photoactive materials. This work explores the integration of high surface area transparent electrodes to investigate the possible role(s) a three-dimensional electrode could take within an OSC, with a BHJ composed of a donor-acceptor combination with a high degree of electron and hole mobility mismatch. Nanotree indium tin oxide (ITO) electrodes were prepared via glancing angle deposition (GLAD), structures that were previously demonstrated to be single-crystalline. A thin layer of zinc oxide was deposited on the ITO nanotrees via atomic layer deposition (ALD), followed by a self-assembled monolayer of C60-based molecules that was bound to the zinc oxide surface through a carboxylic acid group. Infiltration of these functionalized ITO nanotrees with the photoactive layer, the bulk heterojunction (BHJ) comprising PC71BM and a high hole mobility low band gap polymer (PDPPTT-T-TT), led to families of devices that were analyzed for the effect of nanotree height. When the height was varied from 0, to 50 nm, 75 nm, 100, and 120 nm, statistically significant differences of device performance were noted, with the maximum device efficiencies observed with a nanotree height of 75 nm. From analysis of these results, it was found that the intrinsic mobility mismatch between the donor and acceptor phases could be compensated for when the electron collection length was reduced relative to the hole collection length, resulting in more balanced charge extraction, reduced recombination, leading to improved efficiencies. However, as the ITO nanotrees increased in height and branching, the decrease in electron collection length was offset by an increase in hole collection length and potential deleterious electric field redistribution effects

  4. High voltage and efficient bilayer heterojunction solar cells based on an organic-inorganic hybrid perovskite absorber with a low-cost flexible substrate.

    PubMed

    Chiang, Yi-Fang; Jeng, Jun-Yuan; Lee, Mu-Huan; Peng, Shin-Rung; Chen, Peter; Guo, Tzung-Fang; Wen, Ten-Chin; Hsu, Yao-Jane; Hsu, Ching-Ming

    2014-04-07

    A low temperature (<100 °C), flexible solar cell based on an organic-inorganic hybrid CH3NH3PbI3 perovskite-fullerene planar heterojunction (PHJ) is successfully demonstrated. In this manuscript, we study the effects of energy level offset between a solar absorber (organic-inorganic hybrid CH3NH3PbI3 perovskite) and the selective contact materials on the photovoltaic behaviors of the planar organometallic perovskite-fullerene heterojunction solar cells. We find that the difference between the highest occupied molecular orbital (HOMO) level of CH3NH3PbI3 perovskite and the Fermi level of indium-tin-oxide (ITO) dominates the voltage output of the device. ITO films on glass or on the polyethylene terephthalate (PET) flexible substrate with different work functions are investigated to illustrate this phenomenon. The higher work function of the PET/ITO substrate decreases the energy loss of hole transfer from the HOMO of perovskite to ITO and minimizes the energy redundancy of the photovoltage output. The devices using the high work function ITO substrate as contact material show significant open-circuit voltage enhancement (920 mV), with the power conversion efficiency of 4.54%, and these types of extra-thin planar bilayer heterojunction solar cells have the potential advantages of low-cost and lightweight.

  5. Soft chemistry based sponge-like indium tin oxide (ITO) — a prospective component of photoanode for solar cell application

    NASA Astrophysics Data System (ADS)

    Biswas, Prasanta Kumar; Das, Nilanjana

    2015-04-01

    Previously we reported the synthesis of novel organic-inorganic composite indium tin oxide (ITO) foam precursor leading to the formation of "sponge-like" ITO by burning away the organics. This newly made sponge-like ITO possesses relatively high electrical conductivity due to phonon confinement with reasonable pore structure and may have potential application as functional materials in semiconducting dye absorbing layer in dye-sensitized solar cell (DSSC) and also as the receptor of electrons injected from the quantum dots (QDs) of organic-inorganic hybrid QD based solar cell. This report is a short review of "sponge-like" ITO described as a lecture note on its future use as an alternative new prospective material for photoanode of solar cell in the domain of sustainable energy.

  6. Nanosecond laser-induced damage of transparent conducting ITO film at 1064nm

    NASA Astrophysics Data System (ADS)

    Yoo, Jae-Hyuck; Adams, John J.; Menor, Marlon G.; Olson, Tammy Y.; Lee, Jonathan R. I.; Samanta, Amit; Bude, Jeff; Elhadj, Selim

    2016-12-01

    Transparent conducting films with superior laser damage performance have drawn intense interests toward optoelectronic applications under high energy density environment. In order to make optoelectronic applications with high laser damage performance, a fundamental understanding of damage mechanisms of conducting films is crucial. In this study, we performed laser damage experiments on tin-doped indium oxide films (ITO, Bandgap = 4.0 eV) using a nanosecond (ns) pulse laser (1064 nm) and investigated the underlying physical damage mechanisms. Single ns laser pulse irradiation on ITO films resulted in common thermal degradation features such as melting and evaporation although the laser photon energy (1.03 eV, 1064 nm) was smaller than the bandgap. Dominant laser energy absorption of the ITO film is attributed to free carriers due to degenerate doping. Upon multi-pulse irradiation on the film, damage initiation and growth were observed at lower laser influences, where no apparent damage was formed upon single pulse, suggesting a laser-induced incubation effect.

  7. Enlarged read window in the asymmetric ITO/HfOx/TiN complementary resistive switch

    NASA Astrophysics Data System (ADS)

    Zhang, H. Z.; Ang, D. S.; Zhou, Y.; Wang, X. P.

    2017-07-01

    The narrow read-window of most complementary resistive switches proposed to-date poses a significant challenge to array level implementation, as inherent variations in the set and reset voltages result in an unacceptably small read margin. In this work, we present the asymmetrical ITO/HfOx/TiN complementary resistive switch, with a significantly enlarged positive read window of 1.6 V as compared to the much narrower window of 0.5 V of the symmetrical TiN/HfOx/TiN switch. A read margin of 1.1 V is obtained after accounting for statistical variations, representing a significant improvement over the 0.1 V margin of the symmetrical counterpart. Analyses show that the enlarged read window may be ascribed to two important attributes: (1) the stronger affinity of ITO for oxygen, which leads to a reduced positive set voltage and (2) a larger work function of the ITO, resulting in an increase in the positive reset voltage.

  8. Environmentally Friendly Plasma Treated PEDOT:PSS as Electrodes for ITO-free Perovskite Solar Cells.

    PubMed

    Vaagensmith, Bjorn; Reza, Khan Mamun; Hasan, Md Nazmul; Elbohy, Hytham; Adhikari, Nirmal; Dubey, Ashish; Kantack, Nick; Gaml, Eman; Qiao, Qiquan

    2017-09-13

    Solution processed poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) transparent electrodes (TEs) offer great potential as a low cost alternative to expensive indium tin oxide (ITO). However, strong acids are typically used for enhancing the conductivity of PEDOT:PSS TEs, which produces processing complexity and environmental issues. This work presents an environmentally friendly acid free approach to enhance the conductivity of PEDOT:PSS using a light oxygen plasma treatment in addition to solvent blend additives and post treatments. The plasma treatment was found to significantly reduce the sheet resistance of PEDOT:PSS TEs from 85 to as low as 15 Ω sq-1, which translates to the highest reported conductivity of 5012 S/cm for PEDOT:PSS TE. The plasma treated PEDOT:PSS transparent electrode resulted in an ITO-free perovskite solar cell efficiency of 10.5%, which is the highest reported efficiency for ITO-free perovskite solar cells with a PEDOT:PSS electrode that excludes the use of acid treatments. This is the first demonstration of this technology. Moreover, the PEDOT:PSS TEs enabled better charge extraction from the perovskite solar cells and reduced the hysteresis in the current density-voltage (J-V) curves.

  9. Investigation of InGaAsN MSM photodetectors with transparent ITO Schottky contacts

    NASA Astrophysics Data System (ADS)

    Chen, W. C.; Su, Y. K.; Chuang, R. W.; Yu, H. C.; Chen, B. Y.; Hsu, S. H.

    2008-03-01

    Metal-semiconductor-metal photodetectors (MSM-PDs) with transparent ITO contacts were studied. The RF-sputtered ITO layers were formed under various ambient gases Ar, Ar/N2, and Ar/O2. The ITO film fabricated under the Ar/O2 ambient has highest Schottky barrier-height, but the high resistivity limited the photocurrent of the photodetectors. Consequently, using Ar/N2 as the plasma gas would be a suitable choice for MSM-PD application. The photo/dark current ratios of the MSM-PDs were 5, 25 and 12 (measured under 0.2 V) using Ar, Ar/N2 and Ar/O2 as the plasma gases. To further improve the photo/dark current ratio, we fabricated the InGaAN-PDs using metal-insulator-metal-semiconductor (MIMS) structures. The dark current was greatly suppressed by the SiO2 layer, and the highest photo/dark current ratio was 66 under 0.2 V bias.

  10. [Malignant transformation of a nevus of Ito: description of a rare case].

    PubMed

    Martínez-Peñuela, A; Iglesias, M E; Mercado, M R; Martínez-Peñuela, J M

    2011-12-01

    Dermal melanocytosis refers to congenital or acquired lesions characterized by the presence of dendritic cells derived from melanocytes that migrate from the neural crest to the epidermis. The nevus of Ito develops in the territory supplied by the acromioclavicular nerve. Malignant transformation in dermal melanocytosis is extremely rare, with only isolated case reports; only 2 cases of malignant transformation of a nevus of Ito have been reported. We report a very rare case that is the third to be described in the literature. The patient was a 24-year-old man who presented with a subcutaneous nodule that had developed in the anterolateral region of the thorax over the previous 8 months. The nodule was located beneath a faint blue-gray macule with poorly defined borders. Biopsy of the nodule revealed malignant melanoma; biopsies of the adjacent skin lesion showed a diffuse proliferation of scattered melanocytes in a collagen stroma in the reticular dermis. A diagnosis of malignant transformation of a nevus of Ito was made after other possibilities were ruled out.

  11. Interfacial behavior of resistive switching in ITO-PVK-Al WORM memory devices

    NASA Astrophysics Data System (ADS)

    Whitcher, T. J.; Woon, K. L.; Wong, W. S.; Chanlek, N.; Nakajima, H.; Saisopa, T.; Songsiriritthigul, P.

    2016-02-01

    Understanding the mechanism of resistive switching in a memory device is fundamental in order to improve device performance. The mechanism of current switching in a basic organic write-once read-many (WORM) memory device is investigated by determining the energy level alignments of indium tin oxide (ITO), poly(9-vinylcarbazole) (PVK) and aluminum (Al) using x-ray and ultraviolet photoelectron spectroscopy, current-voltage characterization and Auger depth profiling. The current switching mechanism was determined to be controlled by the interface between the ITO and the PVK. The electric field applied across the device causes the ITO from the uneven surface of the anode to form metallic filaments through the PVK, causing a shorting effect within the device leading to increased conduction. This was found to be independent of the PVK thickness, although the switch-on voltage was non-linearly dependent on the thickness. The formation of these filaments also caused the destruction of the interfacial dipole at the PVK-Al interface.

  12. Temperature sensor based on a hybrid ITO-silica resonant cavity

    PubMed Central

    Socorro, Abian B.; Soltani, Soheil; Del Villar, Ignacio; Corres, Jesus M.; Armani, Andrea M.

    2015-01-01

    Integrated optical devices comprised of multiple material systems are able to achieve unique performance characteristics, enabling applications in sensing and in telecommunications. Due to ease of fabrication, the majority of previous work has focused on polymer-dielectric or polymer-semiconductor systems. However, the environmental stability of polymers is limited. In the present work, a hybrid device comprised of an indium tin oxide (ITO) coating on a silicon dioxide toroidal resonant cavity is fabricated. Finite element method simulations of the optical field in the multi-material device are performed, and the optical mode profile is significantly altered by the high index film. The quality factor is also measured and is material loss limited. Additionally, its performance as a temperature sensor is characterized. Due to the high thermo-optic coefficient of ITO and the localization of the optical field in the ITO layer, the hybrid temperature sensor demonstrates a nearly 3-fold improvement in performance over the conventional silica device. PMID:25836065

  13. A self-assembled Ni(cyclam)-BTC network on ITO for an oxygen evolution catalyst in alkaline solution.

    PubMed

    Leem, Yun Jin; Cho, Keumnam; Oh, Kyung Hee; Han, Sung-Hwan; Nam, Ki Min; Chang, Jinho

    2017-03-25

    A self-assembled Ni(cyclam)-BTC film was formed on ITO in an acidic solution. Ni(cyclam)-BTC exhibited an enhanced electro-catalytic property for the oxygen evolution reaction (OER), which was strongly relevant to the Ni(iii)/Ni(iv) redox reaction activated by the potential dynamic process. A possible formation mechanism of Ni(cyclam)-BTC by self-assembly on ITO was also proposed.

  14. Role of the transient outward current (Ito) in shaping canine ventricular action potential – a dynamic clamp study

    PubMed Central

    Sun, Xiaoyin; Wang, Hong-Sheng

    2005-01-01

    Transmural electrical dispersion determines the repolarization sequence across the ventricular wall, and plays an important role in the development of arrhythmias under pathological conditions. While it is clear that the transmural gradient of the transient outward current (Ito) underlies the dramatic difference in phase 1 repolarization across the ventricle, its contribution to the transmural action potential duration (APD) dispersion is not clear. We investigated this problem using the dynamic clamp technique in canine ventricular myocytes. The dynamic clamp allows quantitative ‘insertion’ of simulated conductances in real, biological cells, bridging pure computer modelling and experimental electrophysiology. ‘Insertion’ of an epicardial level of Ito in endocardial cells produced a prominent phase 1 repolarization and a ‘spike-and-dome’ action potential morphology, but did not significantly affect the APD. Increasingly larger Ito densities prolonged, and then dramatically shortened the endocardial APD. We also used the dynamic clamp to subtract, or ‘block’ the native Ito in epicardial cells. Such ‘blockade’ eliminated the epicardial action potential notch, but had no significant effect on the APD. We conclude that Ito, while being a key regulator of phase 1 repolarization, does not significantly affect the APD of canine ventricular myocytes, and that the Ito gradient is not a significant contributor to the transmural APD dispersion in the canine ventricle. By allowing computer simulation on a biological background, the dynamic clamp is a new and effective tool to study the ionic basis of the electrical properties of cardiac cells. PMID:15649977

  15. NFATc3-dependent loss of Ito gradient across the left ventricular wall during chronic β adrenergic stimulation

    PubMed Central

    Rossow, Charles F.; Dilly, Keith W.; Yuan, Can; Nieves-Cintrón, Madeline; Cabarrus, Jennifer L.; Santana, Luis F.

    2009-01-01

    In heart, pore-forming Kv4 α channel subunits underlie the K+ transient outward current (Ito). Expression of Kv4 is greater in left ventricular epicardial (EPI) than in endocardial (ENDO) cells, resulting in larger Ito in EPI than in ENDO cells. In adult ventricular myocytes, the transcription factor NFATc3 suppresses Kv4 expression. NFATc3 activity is higher in ENDO than in EPI cells and this has been proposed to contribute to heterogeneous Kv4 expression across the left ventricular free wall. Here, we tested the hypothesis that regional activation of NFATc3 signaling dissipates the gradient of Ito density across the mouse left ventricle during chronic activation of β adrenergic signaling. [Ca2+]i, calcineurin, and NFAT activity were larger in ENDO than in EPI myocytes. Infusion of the β adrenergic receptor agonist isoproterenol increased [Ca2+]i, calcineurin, and NFAT activity in EPI, but not in ENDO myocytes, leading to equalization of these parameters in EPI and ENDO cells. This was accompanied by dissipation of the transmural gradient in Kv4.2 expression and Ito density. Unlike wild type, ENDO or EPI myocytes from β1 adrenergic receptor-null and NFATc3-null mice did not undergo changes in Ito density during isoproterenol infusion. Collectively, these data suggest that calcineurin and NFATc3 signaling contributes to the loss of heterogeneous Kv4 expression, and hence Ito density, in the mouse left ventricle during chronic β adrenergic stimulation. PMID:19027024

  16. Cleavage of denatured natural collagen type II by neutrophil gelatinase B reveals enzyme specificity, post-translational modifications in the substrate, and the formation of remnant epitopes in rheumatoid arthritis.

    PubMed

    Van den Steen, Philippe E; Proost, Paul; Grillet, Bernard; Brand, David D; Kang, Andrew H; Van Damme, Jo; Opdenakker, Ghislain

    2002-03-01

    During acute inflammation, leukocytes release proteolytic enzymes including matrix metalloproteinases (MMPs), but the physiopathological mechanisms and consequences of this process are not yet fully understood. Neutrophils, the predominant leukocyte type, produce neutrophil collagenase (MMP-8) and gelatinase B (MMP-9) but not the tissue inhibitors of MMPs. After stimulation, these cells also activate MMPs chemically. In arthritic diseases, neutrophils undergo great chemoattraction to the synovium, are activated by interleukin-8, and are stimulated to release gelatinase B in vivo. Production levels and net activities of gelatinase B were found to be absent in degenerative osteoarthritis but significantly increased in rheumatoid arthritis. The cleavage sites in cartilage type II collagen by gelatinase B were determined by a combination of reverse phase high-performance liquid chromatography, Edman degradation, and mass spectrometry analysis. The analysis revealed the site specificity of proline and lysine hydroxylations and O-linked glycosylation, the cleavage specificities by gelatinase B, and the preferential absence and presence of post-translational modifications at P2' and P5', respectively. Furthermore, gelatinase B leaves the immunodominant peptides intact, which are known from studies with (autoreactive) T cells. Lysine hydroxylation was detected at a critical position for T-cell activation. These data lend support to the thesis that extracellular proteolysis and other post-translational modifications of antigenic peptides may be critical in the establishment and perpetuation of autoimmune processes.

  17. Preparation and properties of all-solid-state inorganic thin film glass/ITO/WO3/LiNbO3/NiOx/ITO electrochromic device

    NASA Astrophysics Data System (ADS)

    Wu, Zhonghou; Diao, Xungang; Dong, Guobo

    2016-01-01

    The all-thin-film inorganic electrochromic device (ECD) with LiNbO3 as the ion conductor layer was prepared. The ECD was fabricated monolithically in a same vacuum chamber layer by layer using DC reactive sputtering for WO3, NiOx and ITO, and radio frequency (RF) sputtering for LiNbO3. The properties and performance of WO3 thin film and the ECD were studied through X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible spectrometry. WO3 thin film has more than 60% optical modulation with porous amorphous structure. The visible transmittance modulation of the ECD is more than 65%, and the response time of coloring and bleaching are 45 s and 25 s, respectively.

  18. The investigation of electrodeposited Cu2O/ITO layers by chronocoulometry process: effect of electrical potential

    NASA Astrophysics Data System (ADS)

    Mohra, D.; Benhaliliba, M.; Serin, M.; Khelladi, M. R.; Lahmar, H.; Azizi, A.

    2016-10-01

    The thin films of Cu2O are deposited by electrodeposition technique onto indium tin oxide (ITO)-coated glass substrate at different potentials. The precursor is an aqueous solution which contains respectively 0.05 M of CuSO4 and citric acid at kept temperature of 60 °C and the applied potential varies within the {-0.4 V, -0.7 V} SCE range. Based on the chronocoulometry (CC) process, the electrochemical, structural and optical parameters are determined. We measured the current as function of potential within the {-0.4 V, -0.7 V} range and the higher current is found to be within the {-0.7V, -0.3 V} band. The grain sizes are of 12.12 nm and 35.47 nm according to (110) and (221) orientations respectively. The hightextural coefficient of 0.943 is recorded for the potential -0.7 V The transmittance of 72.25 %, within the visible band, is obtained for the as-grown layer at -0.4 V and the band gap is found to be 2.2 eV for the electrodeposition potential of -0.7 V Project supported the PNR (Nos. 8/U311/R77, U311/R81), the “Agencethematique de rechercheen science ettechnologie” (ATRST), the National Administration of Scientific Research, the CNEPRU of Oran University of Sciences and Technology (No. B00L02UN310220130011), and the Scientific Research Projects Coordination (Nos. 2012-01-01-KAP05, 2012-01-01-KAP06) Yildiz Technical University.

  19. Formation of substrate-based gold nanocage chains through dealloying with nitric acid

    PubMed Central

    Yan, Ziren; Wu, Ying

    2015-01-01

    Summary Metal nanocages have raised great interest because of their new properties and wide applications. Here, we report on the use of galvanic replacement reactions to synthesize substrate-supported Ag–Au nanocages from silver templates electrodeposited on transparent indium tin oxide (ITO) film coated glass. The residual Ag in the composition was dealloyed with 10% nitric acid. It was found that chains of Au nanocages were formed on the substrate surface during dealloying. When the concentration of HNO3 increased to 20%, the structures of nanocages were damaged and formed crescent or semi-circular shapes. The transfer process on the substrate surface was discussed. PMID:26199839

  20. Fabrication of High-Performance Polymer Bulk-Heterojunction Solar Cells by Interfacial Modifications II

    DTIC Science & Technology

    2010-08-25

    Our current result indicated that the inverted light -emitting diodes of modified TiO2/ITO substrate have the higher efficiency and better...emitting diodes (O/PLEDs) has been reported by many researchers, which is intimately associated with the threshold of light emission and the...Delannoy, M. Schott, J. Physique 35 (1974) 577. 56. J. Kalinowski, Organic light emitting diodes : Principles, Characteristics, and Processes, M. Dekker

  1. Kv4.3 is not required for the generation of functional Ito,f channels in adult mouse ventricles

    PubMed Central

    Niwa, Noriko; Wang, Wei; Sha, Qun; Marionneau, Céline; Nerbonne, Jeanne M.

    2008-01-01

    Accumulated evidence suggests that the heteromeric assembly of Kv4.2 and Kv4.3 α subunits underlies the fast transient Kv current (Ito,f) in rodent ventricles. Recent studies, however, demonstrated that the targeted deletion of Kv4.2 results in the complete elimination of Ito,f in adult mouse ventricles, revealing an essential role for the Kv4.2 α subunit in the generation of mouse ventricular Ito,f channels. The present study was undertaken to investigate directly the functional role of Kv4.3 by examining the effects of the targeted disruption of the KCND3 (Kv4.3) locus. Mice lacking Kv4.3 (Kv4.3−/−) appear indistinguishable from wild type control animals, and no structural or functional abnormalities were evident in Kv4.3−/− hearts. Voltage-clamp recordings revealed that functional Ito,f channels are expressed in Kv4.3−/− ventricular myocytes, and that mean Ito,f densities are similar to those recorded from wild type cells. In addition, Ito,f properties (inactivation rates, voltage-dependences of inactivation and rates of recovery from inactivation) in Kv4.3−/− and wild type mouse ventricular myocytes were indistinguishable. Quantitative RT-PCR and Western blot analyses did not reveal any measurable changes in the expression of Kv4.2 or the Kv channel interacting protein (KChIP2) in Kv4.3−/−ventricles. Taken together, the results presented here suggest that, in contrast with Kv4.2, Kv4.3 is not required for the generation of functional mouse ventricular Ito,f channels. PMID:18045613

  2. Influence of sputtering power on the optical properties of ITO thin films

    SciTech Connect

    K, Aijo John; M, Deepak T, Manju; Kumar, Vineetha V.

    2014-10-15

    Tin doped indium oxide films are widely used in transparent conducting coatings such as flat panel displays, crystal displays and in optical devices such as solar cells and organic light emitting diodes due to the high electrical resistivity and optical transparency in the visible region of solar spectrum. The deposition parameters have a commendable influence on the optical and electrical properties of the thin films. In this study, ITO thin films were prepared by RF magnetron sputtering. The properties of the films prepared under varying sputtering power were compared using UV- visible spectrophotometry. Effect of sputtering power on the energy band gap, absorption coefficient and refractive index are investigated.

  3. Lump and lump-soliton solutions to the (2+1) -dimensional Ito equation

    NASA Astrophysics Data System (ADS)

    Yang, Jin-Yun; Ma, Wen-Xiu; Qin, Zhenyun

    2017-06-01

    Based on the Hirota bilinear form of the (2+1) -dimensional Ito equation, one class of lump solutions and two classes of interaction solutions between lumps and line solitons are generated through analysis and symbolic computations with Maple. Analyticity is naturally guaranteed for the presented lump and interaction solutions, and the interaction solutions reduce to lumps (or line solitons) while the hyperbolic-cosine (or the quadratic function) disappears. Three-dimensional plots and contour plots are made for two specific examples of the resulting interaction solutions.

  4. Core-shell ITO/ZnO/CdS/CdTe nanowire solar cells

    NASA Astrophysics Data System (ADS)

    Williams, B. L.; Taylor, A. A.; Mendis, B. G.; Phillips, L.; Bowen, L.; Major, J. D.; Durose, K.

    2014-02-01

    Radial p-n junction nanowire (NW) solar cells with high densities of CdTe NWs coated with indium tin oxide (ITO)/ZnO/CdS triple shells were grown with excellent heterointerfaces. The optical reflectance of the devices was lower than for equivalent planar films by a factor of 100. The best efficiency for the NW solar cells was η = 2.49%, with current transport being dominated by recombination, and the conversion efficiencies being limited by a back contact barrier (ϕB = 0.52 eV) and low shunt resistances (RSH < 500 Ω.cm2).

  5. KChIP2 Attenuates Cardiac Hypertrophy Through Regulation of Ito and Intracellular Calcium Signaling

    PubMed Central

    Jin, Hongwei; Hadri, Lahouaria; Palomeque, Julieta; Morel, Charlotte; Karakikes, Ioannis; Kaprielian, Roger; Hajjar, Roger; Lebeche, Djamel

    2010-01-01

    Recent evidence shows that the auxiliary subunit KChIP2, which assembles with pore-forming Kv4-subunits, represents a new potential regulator of the cardiac calcium-independent transient outward potassium current (Ito) density. In hypertrophy and heart failure, KChIP2 expression has been found to be significantly decreased. Our aim was to examine the role of KChIP2 in cardiac hypertrophy and the effect of restoring its expression on electrical remodeling and cardiac mechanical function using a combination of molecular, biochemical and gene targeting approaches. KChIP2 overexpression through gene transfer of Ad.KChIP2 in neonatal cardiomyocytes resulted in a significant increase in Ito-channel forming Kv4.2 and Kv4.3 protein levels. In vivo gene transfer of KChIP2 in aortic banded adult rats showed that, compared to sham-operated or Ad.β-gal-transduced hearts, KChIP2 significantly attenuated the developed left ventricular hypertrophy, robustly increased Ito densities, shortened action potential duration, and significantly altered myocyte mechanics by shortening contraction amplitudes and maximal rates of contraction and relaxation velocities and decreasing Ca2+ transients. Interestingly, blocking Ito with 4-aminopyridine in KChIP2-overexpressing adult cardiomyocytes significantly increased the Ca2+ transients to control levels. One-day old rat pups intracardially transduced with KChIP2 for two months then subjected to aortic banding for 6–8 weeks (to induce hypertrophy) showed similar echocardiographic, electrical and mechanical remodeling parameters. In addition, in cultured adult cardiomyocytes, KChIP2 overexpression increased the expression of Ca2+-ATPase (SERCA2a) and sodium calcium exchanger but had no effect on ryanodine receptor 2 or phospholamban expression. In neonatal myocytes, KChIP2 notably reversed Ang II-induced hypertrophic changes in protein synthesis and MAP-kinase activation. It also significantly decreased calcineurin expression, NFATc1

  6. Making, testing, applying: some progress in the field of micro-optics at ITO

    NASA Astrophysics Data System (ADS)

    Osten, W.; Baer, G.; Häfner, M.; Lyda, W.; Pruss, C.; Reichle, R.; Schaal, F.

    2013-06-01

    Microoptical components play an increasing role in different technology fields such as medical engineering, materials and information processing, imaging and metrology. But their realization needs the combination of modern design concepts with sophisticated processing technologies, new materials and design tools. Furthermore, the introduction of ambitious processing technologies must be accompanied by effective metrology and inspection tools. Therefore, this paper reports about the technologies for making microoptics at ITO. Because sophisticated measurement tools are an indispensable part of the fabrication process, the paper describes our multi-scale inspection approach for the testing of microstructures on wafer-scale level. Finally, some representative applications of microoptical components for advanced measurement and imaging are explained.

  7. Enhanced light extraction in ITO-free OLEDs using double-sided printed electrodes

    NASA Astrophysics Data System (ADS)

    Reboud, Vincent; Khokhar, Ali Z.; Sepúlveda, Borja; Dudek, Damian; Kehoe, Tim; Cuffe, John; Kehagias, Nikolaos; Lira-Cantu, Mónica; Gadegaard, Nikolaj; Grasso, Valentina; Lambertini, Vito; Sotomayor Torres, Clivia M.

    2012-05-01

    We show how nanoimprint lithographic techniques are particularly suited for the realization of OLED device structures. We tested them to realize nanopatterned metallic electrodes containing photonic crystals to couple the light out and plasmonic crystals showing extraordinary transmission. At similar current densities, a two-fold electroluminescence is achieved with devices having double-sided structured metallic electrodes as compared to a control OLED with an ITO anode. The use of combined nanoimprint lithography processes has the potential to expand the performance range of various organic optoelectronic devices.

  8. Hypomelanosis of Ito and X;autosome translocations: a unifying hypothesis.

    PubMed Central

    Hatchwell, E

    1996-01-01

    Hypomelanosis of Ito is a sporadic multisystem disorder known to be associated in many cases with chromosomal mosaicism. While no particular pattern is generally evident for the specific chromosomes involved in such patients, a subgroup of female patients exists in whom the common factor is the presence of a balanced, constitutional X;autosome translocation, with a cytogenetic breakpoint in the pericentromeric region of the X. It is argued here that the phenotype in these cases results not from the interruption of X linked genes but from the presence of mosaic functional disomy of X sequences above the breakpoint. Images PMID:8728687

  9. Photovoltaic performance of hybrid ITO/PEDOT:PSS/n-SnS/Al solar cell structure

    NASA Astrophysics Data System (ADS)

    Jain, Priyal; Arun, P.

    2016-07-01

    The present paper discusses the performance of ITO/PEDOT:PSS/n-SnS/Al structured solar cells fabricated by thermal evaporation. The performance characterizing parameters such as the open circuit voltage, short circuit current density, series resistance, parallel resistance, ideality factor and the overall efficiency were found to be dependent on the SnS grain size in the nano-meter regime and incident light intensity. The experimental work directly reconfirms the theoretical results and ideas raised in the literature by early researchers.

  10. The Modification of Indium Tin Oxide with Phosphonic Acids: Mechanism of Binding, Tuning of Surface Properties, and Potential for Use in Organic Electronic Applications

    SciTech Connect

    Hotchkiss, Peter J.; Jones, Simon C.; Paniagua, Sergio A.; Sharma, Asha; Kippelen, Bernard; Armstrong, Neal R.; Marder, Seth R.

    2012-03-20

    Transparent metal oxides, in particular, indium tin oxide (ITO), are critical transparent contact materials for applications in next-generation organic electronics, including organic light emitting diodes (OLEDs) and organic photovoltaics (OPVs). Understanding and controlling the surface properties of ITO allows for the molecular engineering of the ITO–organic interface, resulting in fine control of the interfacial chemistries and electronics. In particular, both surface energy matching and work function compatibility at material interfaces can result in marked improvement in OLED and OPV performance. Although there are numerous ways to change the surface properties of ITO, one of the more successful surface modifications is the use of monolayers based on organic molecules with widely variable end functional groups. Phosphonic acids (PAs) are known to bind strongly to metal oxides and form robust monolayers on many different metal oxide materials. They also demonstrate several advantages over other functionalizing moieties such as silanes or carboxylic acids. Most notably, PAs can be stored in ambient conditions without degradation, and the surface modification procedures are typically robust and easy to employ. This Account focuses on our research studying PA binding to ITO, the tunable properties of the resulting surfaces, and subsequent effects on the performance of organic electronic devices. We have used surface characterization techniques such as X-ray photoelectron spectroscopy (XPS) and infrared reflection adsorption spectroscopy (IRRAS) to determine that PAs bind to ITO in a predominantly bidentate fashion (where two of three oxygen atoms from the PA are involved in surface binding). Modification of the functional R-groups on PAs allows us to control and tune the surface energy and work function of the ITO surface. In one study using fluorinated benzyl PAs, we can keep the surface energy of ITO relatively low and constant but tune the surface work

  11. Fabrication of nanostructured transmissive optical devices on ITO-glass with UV1116 photoresist using high-energy electron beam lithography.

    PubMed

    Williams, Calum; Bartholomew, Richard; Rughoobur, Girish; Gordon, George S D; Flewitt, Andrew J; Wilkinson, Timothy D

    2016-12-02

    High-energy electron beam lithography for patterning nanostructures on insulating substrates can be challenging. For high resolution, conventional resists require large exposure doses and for reasonable throughput, using typical beam currents leads to charge dissipation problems. Here, we use UV1116 photoresist (Dow Chemical Company), designed for photolithographic technologies, with a relatively low area dose at a standard operating current (80 kV, 40-50 μC cm(-2), 1 nAs(-1)) to pattern over large areas on commercially coated ITO-glass cover slips. The minimum linewidth fabricated was ∼33 nm with 80 nm spacing; for isolated structures, ∼45 nm structural width with 50 nm separation. Due to the low beam dose, and nA current, throughput is high. This work highlights the use of UV1116 photoresist as an alternative to conventional e-beam resists on insulating substrates. To evaluate suitability, we fabricate a range of transmissive optical devices, that could find application for customized wire-grid polarisers and spectral filters for imaging, which operate based on the excitation of surface plasmon polaritons in nanosized geometries, with arrays encompassing areas ∼0.25 cm(2).

  12. Fabrication of nanostructured transmissive optical devices on ITO-glass with UV1116 photoresist using high-energy electron beam lithography

    NASA Astrophysics Data System (ADS)

    Williams, Calum; Bartholomew, Richard; Rughoobur, Girish; Gordon, George S. D.; Flewitt, Andrew J.; Wilkinson, Timothy D.

    2016-12-01

    High-energy electron beam lithography for patterning nanostructures on insulating substrates can be challenging. For high resolution, conventional resists require large exposure doses and for reasonable throughput, using typical beam currents leads to charge dissipation problems. Here, we use UV1116 photoresist (Dow Chemical Company), designed for photolithographic technologies, with a relatively low area dose at a standard operating current (80 kV, 40-50 μC cm-2, 1 nAs-1) to pattern over large areas on commercially coated ITO-glass cover slips. The minimum linewidth fabricated was ˜33 nm with 80 nm spacing; for isolated structures, ˜45 nm structural width with 50 nm separation. Due to the low beam dose, and nA current, throughput is high. This work highlights the use of UV1116 photoresist as an alternative to conventional e-beam resists on insulating substrates. To evaluate suitability, we fabricate a range of transmissive optical devices, that could find application for customized wire-grid polarisers and spectral filters for imaging, which operate based on the excitation of surface plasmon polaritons in nanosized geometries, with arrays encompassing areas ˜0.25 cm2.

  13. Successful differentiation of neural stem/progenitor cells cultured on electrically adjustable indium tin oxide (ITO) surface.

    PubMed

    Lei, Kin Fong; Lee, I-Chi; Liu, Yung-Chiang; Wu, Yu-Chieh

    2014-12-02

    In order to control differentiation of neural cells and guide the developed neurites to targets, polyelectrolyte multilayer (PEM) films were used because of their capability of modulation of electrical charged characteristics, thickness, and stiffness. In this work, we suggested that indium tin oxide (ITO) is an alternative surface to achieve the above-mentioned objectives. A microfluidic system with four culture chambers was developed and each chamber consisted of parallel ITO surfaces for the application of adjustable electrical field. Neural stem/progenitor cells (NSPCs) were respectively cultured on the ITO surfaces with and without PEM film, constructed by alternate adsorption of poly(L-lysine) (PLL) and poly(L-glutamic acid) (PLGA). Analyses of cell morphology, cytotoxicity, process outgrowth, differentiated cell types, and neuron functionality were compared between both surfaces. In this study, NSPCs successfully differentiated on ITO surface with electrical stimulation. The optimal electrical potential was found to be 80 mV that could stimulate the longest process, i.e., >300 μm, after 3 days culture. Cell differentiation, process development, and functionality of differentiated neuron on ITO surface were shown to be strongly controlled by the electrical stimulation that can be simply adjusted by external equipment. The electrically adjustable cell differentiation reported here could potentially be applied to neurochip for the study of neural signal transmission in a well-constructed network.

  14. Silver Nanowire-Conducting Polymer-ITO Hybrids for Flexible and Transparent Conductive Electrodes with Excellent Durability.

    PubMed

    Yoo, Ji Hoon; Kim, Yunkyung; Han, Mi Kyoung; Choi, Seonghwa; Song, Ki Yong; Chung, Kwang Choon; Kim, Ji Man; Kwak, Jeonghun

    2015-07-29

    Solution-processed silver nanowire (AgNW) films have attracted attention as transparent and conductive electrodes for flexible optoelectronic devices and touch screens, to replace sputtered indium-tin-oxide (ITO) films. However, the mechanical flexibility, environmental durability, and the optical (such as transparency and a haze) and electrical properties of the AgNW films should be improved for their practical application. In this work, high-performance and roll-to-roll processed AgNW-based hybrid electrodes comprising poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PSS) and/or ITO are introduced. The optical and electrical properties of the AgNW films combined with PSS, ITO, or both of them were systematically examined. Among the films, the AgNW-PEDOT:PSS-ITO hybrid film exhibits a high transmittance (88%) and a low sheet resistance (44 Ω sq(-1)) with a small haze (1.9%). Moreover, the hybrid films show excellent durability to a variety of environmental stresses. By virtues of the high performance and durability, it is believed that the AgNW-PEDOT:PSS-ITO hybrid electrodes are highly suitable for practical use.

  15. The utilization of SiNWs/AuNPs-modified indium tin oxide (ITO) in fabrication of electrochemical DNA sensor.

    PubMed

    Rashid, Jahwarhar Izuan Abdul; Yusof, Nor Azah; Abdullah, Jaafar; Hashim, Uda; Hajian, Reza

    2014-12-01

    This work describes the incorporation of SiNWs/AuNPs composite as a sensing material for DNA detection on indium tin-oxide (ITO) coated glass slide. The morphology of SiNWs/AuNPs composite as the modifier layer on ITO was studied by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The morphological studies clearly showed that SiNWs were successfully decorated with 20 nm-AuNPs using self-assembly monolayer (SAM) technique. The effective surface area for SiNWs/AuNPs-modified ITO enhanced about 10 times compared with bare ITO electrode. SiNWs/AuNPs nanocomposite was further explored as a matrix for DNA probe immobilization in detection of dengue virus as a bio-sensing model to evaluate its performance in electrochemical sensors. The hybridization of complementary DNA was monitored by differential pulse voltammetry (DPV) using methylene blue (MB) as the redox indicator. The fabricated biosensor was able to discriminate significantly complementary, non-complementary and single-base mismatch oligonucleotides. The electrochemical biosensor was sensitive to target DNA related to dengue virus in the range of 9.0-178.0 ng/ml with detection limit of 3.5 ng/ml. In addition, SiNWs/AuNPs-modified ITO, regenerated up to 8 times and its stability was up to 10 weeks at 4°C in silica gel. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Surface modification by molecular ions

    SciTech Connect

    Hanley, L.; Schultz, D. G.; Ada, E. T.

    1999-06-10

    There are several advantages in using molecular ions for surface modification. The modification can be confined to the uppermost layer of the surface, the molecular character of the ion can be imparted to the surface, and sputter yields are often higher. These effects are demonstrated by the use of mass selected ion beams incident on well characterized surfaces. Energy transfer is examined by detecting the masses and energies of ions scattered off surfaces and performing molecular dynamics simulations. Surface modification is followed by chemical analysis with x-ray photoelectron spectroscopy and surface mass spectrometry. TRIDYN monte carlo simulations are used to support some of the modification experiments. Energy transfer is examined for Si(CD{sub 3}){sub 3}{sup +} scattered off clean and hexanethiolate covered Au(111). Adsorbate desorption cross sections and substrate damage depths for NH{sub 3}/CO/Ni(111) are compared for 10-1000 eV isobaric atomic and polyatomic ions, Xe{sup +} and SF{sub 5}{sup +}. The surface chemical modification of polystyrene thin films by 10-100 eV SF{sub 5}{sup +} and C{sub 3}F{sub 5}{sup +} ions is also examined.

  17. Enhancement of Characteristics of Transparent Conductive Electrode on Flexible Substrate by Combination of Solution-Based Oxide and Metallic Layers.

    PubMed

    Hong, Sung-Jei; Kim, Yong-Hoon; Cha, Seung-Jae; Kim, Yong-Sung

    2015-10-01

    This study investigates solution-processed transparent conductors with hybrid structure consisting of silver nanowires (AgNWs) and indium-tin-oxide nanoparticles (ITO-NPs) layers fabricated on polymeric flexible polyethylene terephthalate (PET) substrate. The transparent conductors had stacked structures of AgNWs/ITO-NPs on 125-μm-thick PET and ITO-NPs/AgNWs/ITO-NPs on 125-μm-thick PET, 188-μm-thick PET, or 700-μm-thick glass substrate, respectively. Successful integrations were possible on the substrates without any deformation or distortion. Sheet resistance of the triple-layered transparent conductor samples exhibits low values ranging from 22.41 Ω/square to 22.99 Ω/squarer. Also, their optical transmittance exhibits high values ranging from 83.78 to 87.29% at 550 nm. The triple-layered transparent conductor showed a good thermal stability in terms of sheet resistance and optical transmittance against the high-temperature environment up to 250 °C. All the double and triple-layered transparent conductors fabricated on PET and glass substrates are so stable against the accelerated thermal aging from 110 °C to 130 °C, that ΔR/R0 and ΔT(550)/T0(550) values exhibit less than 0.068 and 0.049, respectively. Furthermore, the layers are so flexible that ΔR/R0 of the layers on PET substrates is lower than 0.1 even at 4.0-mm bending. Especially, triple-layered transparent conductor on 125-μm-thick PET substrates exhibits ΔR/R0 value of 0.042 even at 4.0 mm bending. Thus, it can be concluded that the hybrid structures have the advantage of both thermal stability and flexibility for electrical and optical properties of transparent conductive electrode; which makes them highly applicable in flexible electronics.

  18. Flexible, transparent and high-power triboelectric generator with asymmetric graphene/ITO electrodes.

    PubMed

    Song, Xinbo; Chen, Yuanfu; Li, Pingjian; Liu, Jingbo; Qi, Fei; Zheng, Binjie; Zhou, Jinhao; Hao, Xin; Zhang, Wanli

    2016-07-29

    The reported flexible and transparent triboelectric generator (FTTG) can only output ultralow power density (∼2 μW cm(-2)), which has seriously hindered its further development and application. The low power density of FTTG is mainly limited by the transparent material and the electrode structure. Herein, for the first time, a FTTG with a superior power density of 60.7 μW cm(-2) has been fabricated by designing asymmetric electrodes where graphene and indium tin oxide (ITO) act as top and bottom electrodes respectively. Moreover, the performance of FTTG with graphene/ITO (G/I) asymmetric electrodes (GI-FTTG) almost remains unchanged even after 700 cycles, indicating excellent mechanical stability. The excellent performance of GI-FTTG can be attributed to the suitable materials and unique asymmetric electrode structure: the extraordinary flexibility of the graphene top electrode ensures the GI-FTTG excellent mechanical robustness and stability even after longer cycles, and the bottom electrode with very low sheet resistance guarantees lower internal resistance and higher production rate of induction charges to obtain higher output power density. It shows that light-emitting diodes (LED) can be easily powered by GI-FTTG, which demonstrates that the GI-FTTG is very promising for harvesting electrical energy from human activities by using flexible and transparent devices.

  19. Respirable indium exposures, plasma indium, and respiratory health among indium-tin oxide (ITO) workers.

    PubMed

    Cummings, Kristin J; Virji, M Abbas; Park, Ji Young; Stanton, Marcia L; Edwards, Nicole T; Trapnell, Bruce C; Carey, Brenna; Stefaniak, Aleksandr B; Kreiss, Kathleen

    2016-07-01

    Workers manufacturing indium-tin oxide (ITO) are at risk of elevated indium concentration in blood and indium lung disease, but relationships between respirable indium exposures and biomarkers of exposure and disease are unknown. For 87 (93%) current ITO workers, we determined correlations between respirable and plasma indium and evaluated associations between exposures and health outcomes. Current respirable indium exposure ranged from 0.4 to 108 μg/m(3) and cumulative respirable indium exposure from 0.4 to 923 μg-yr/m(3) . Plasma indium better correlated with cumulative (rs  = 0.77) than current exposure (rs  = 0.54) overall and with tenure ≥1.9 years. Higher cumulative respirable indium exposures were associated with more dyspnea, lower spirometric parameters, and higher serum biomarkers of lung disease (KL-6 and SP-D), with significant effects starting at 22 μg-yr/m(3) , reached by 46% of participants. Plasma indium concentration reflected cumulative respirable indium exposure, which was associated with clinical, functional, and serum biomarkers of lung disease. Am. J. Ind. Med. 59:522-531, 2016. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  20. Development of an amperometric sulfite biosensor based on SO(x)/PBNPs/PPY modified ITO electrode.

    PubMed

    Rawal, Rachna; Pundir, C S

    2012-11-01

    A sulfite oxidase (SO(x)) (EC 1.8.3.1) purified from Syzygium cumini leaves was immobilized onto prussian blue nanoparticles/polypyrrole composite (PBNPs/PPY) electrodeposited onto the surface of indium tin oxide (ITO) electrode. An amperometric sulfite biosensor was fabricated using SO(x)/PBNPs/PPY/ITO electrode as working electrode, Ag/AgCl as standard and Pt wire as auxiliary electrode connected through a potentiostat. The working electrode was characterized by Fourier transform infrared (FTIR) spectroscopy, cyclic voltammetry (CV), scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS) before and after immobilization of SO(x). The biosensor showed optimum response within 2s, when operated at 20 mV s⁻¹ in 0.1M Tris-HCl buffer, pH 8.5 and at 35 °C. Linear range and minimum detection limit were 0.5-1000 μM and 0.12 μM (S/N=3) respectively. There was good correlation (r=0.99) between red wine samples sulfite value by standard DTNB method and the present method. The sensor was evaluated with 97% recovery of added sulfite in red wine samples and 2.2% and 4.3% within and between batch coefficients of variation respectively. The sensor was employed for determination of sulfite level in red and white wine samples. The enzyme electrode was used 200 times over a period of 3 months when stored at 4 °C.

  1. Optical and electrochemical properties of ordered macroporous gold array on the ITO surface

    NASA Astrophysics Data System (ADS)

    Lu, Huidan; Liu, Yongping; Han, Guo-Cheng

    2011-06-01

    The electrochemical and optical properties of transparent, two-dimensional macroporous gold film were investigated. Colloidal crystal templates were assembled onto indium-doped tin oxide (ITO) glass surface through vertical depositing method. Following gold electrodeposition, they were removed by dissolution with tetrahydrofuran (THF). The highly ordered macroporous gold array was achieved. It was characterized by scanning electron microscope (SEM) and ultraviolet visible (UV-vis) spectrophotometry. The optical transparency of the gold film was near 25% and fairly constant between 300 and 900 nm. The macroporous gold film electrode was mounted into a thin-layer transmission cell. The electrochemical response was evaluated by thin-layer cyclic voltammograms (CV) of the Fe (CN) 63-/Fe (CN) 64- couple. Thin-layer cell exhibits good shape of waves and nearly symmetric cathodic and anodic waves. E0' value and n of TMPD + rad /TMPD (TMPD is acronyms for N,N,N',N'-tetramethyl-p-phenylenediamine, and TMPD + rad is its mono-cation radical) couple were determined. Furthermore, results demonstrated electrolytic equilibrium was faster reached in macroporous gold film than ITO electrode.

  2. Flexible, transparent and high-power triboelectric generator with asymmetric graphene/ITO electrodes

    NASA Astrophysics Data System (ADS)

    Song, Xinbo; Chen, Yuanfu; Li, Pingjian; Liu, Jingbo; Qi, Fei; Zheng, Binjie; Zhou, Jinhao; Hao, Xin; Zhang, Wanli

    2016-07-01

    The reported flexible and transparent triboelectric generator (FTTG) can only output ultralow power density (˜2 μW cm-2), which has seriously hindered its further development and application. The low power density of FTTG is mainly limited by the transparent material and the electrode structure. Herein, for the first time, a FTTG with a superior power density of 60.7 μW cm-2 has been fabricated by designing asymmetric electrodes where graphene and indium tin oxide (ITO) act as top and bottom electrodes respectively. Moreover, the performance of FTTG with graphene/ITO (G/I) asymmetric electrodes (GI-FTTG) almost remains unchanged even after 700 cycles, indicating excellent mechanical stability. The excellent performance of GI-FTTG can be attributed to the suitable materials and unique asymmetric electrode structure: the extraordinary flexibility of the graphene top electrode ensures the GI-FTTG excellent mechanical robustness and stability even after longer cycles, and the bottom electrode with very low sheet resistance guarantees lower internal resistance and higher production rate of induction charges to obtain higher output power density. It shows that light-emitting diodes (LED) can be easily powered by GI-FTTG, which demonstrates that the GI-FTTG is very promising for harvesting electrical energy from human activities by using flexible and transparent devices.

  3. Mid-infrared surface plasmon polariton chemical sensing on fiber-coupled ITO coated glass.

    PubMed

    Martínez, Javier; Ródenas, Airán; Aguiló, Magdalena; Fernandez, Toney; Solis, Javier; Díaz, Francesc

    2016-06-01

    A novel fiber-coupled indium tin oxide (ITO) coated glass slide sensor for performing surface plasmon polariton chemical monitoring in the ∼3.5  μm mid-infrared (IR) range is reported. Efficient mid-IR fiber coupling is achieved with 3D laser written waveguides, and the coupling of glass waveguide modes to ITO surface plasmon polaritons (SPPs) is driven by the varying phase matching conditions of different aqueous analytes across the anomalous dispersion range determined by their molecular fingerprints. By means of using both a mid-IR fiber supercontinuum source and a diode laser, the excitation of SPPs is demonstrated. The sensor sensitivity is tested by discriminating CH from OH features of ethanol in water solutions, demonstrating an instrumental ethanol limit of detection of 0.02% in a wide concentration range of at least 0%-50%. The efficient optical monitoring of mid-IR SPPs in smart glass could have a broad range of applications in biological and chemical sensing.

  4. Respirable Indium Exposures, Plasma Indium, and Respiratory Health Among Indium-Tin Oxide (ITO) Workers

    PubMed Central

    Cummings, Kristin J.; Virji, M. Abbas; Park, Ji Young; Stanton, Marcia L.; Edwards, Nicole T.; Trapnell, Bruce C.; Carey, Brenna; Stefaniak, Aleksandr B.; Kreiss, Kathleen

    2016-01-01

    Background Workers manufacturing indium-tin oxide (ITO) are at risk of elevated indium concentration in blood and indium lung disease, but relationships between respirable indium exposures and biomarkers of exposure and disease are unknown. Methods For 87 (93%) current ITO workers, we determined correlations between respirable and plasma indium and evaluated associations between exposures and health outcomes. Results Current respirable indium exposure ranged from 0.4 to 108 μg/m3 and cumulative respirable indium exposure from 0.4 to 923 μg-yr/m3. Plasma indium better correlated with cumulative (rs = 0.77) than current exposure (rs = 0.54) overall and with tenure ≥1.9 years. Higher cumulative respirable indium exposures were associated with more dyspnea, lower spirometric parameters, and higher serum biomarkers of lung disease (KL-6 and SP-D), with significant effects starting at 22 μg-yr/m3, reached by 46% of participants. Conclusions Plasma indium concentration reflected cumulative respirable indium exposure, which was associated with clinical, functional, and serum biomarkers of lung disease. PMID:27219296

  5. Laser modification of thermally sprayed coatings

    NASA Astrophysics Data System (ADS)

    Uglov, A. A.; Fomin, A. D.; Naumkin, A. O.; Pekshev, P. Iu.; Smurov, I. Iu.

    1987-08-01

    Experimental results are reported on the modification of thermally sprayed coatings on steels and aluminum alloys using pulsed YAG and CW CO2 lasers. In particular, results obtained for self-fluxing Ni9CrBSi powders, ZRO2 ceramic, and titanium are examined. It is shown that the laser treatment of thermally sprayed coatings significantly improves their physicomechanical properties; it also makes it possible to obtain refractory coatings on low-melting substrates with good coating-substrate adhesion.

  6. Optical properties of local surface plasmon resonance in Ag/ITO sliced nanosphere by the discrete dipole approximation

    NASA Astrophysics Data System (ADS)

    Haiwei, Mu; Jingwei, Lv; Zhaoting, Liu; Shijie, Zheng; Lin, Yang; Tao, Sun; Qiang, Liu; Chao, Liu

    2016-04-01

    Optical properties of localized surface plasmon resonances (LSPR) of Ag/ITO sliced nanosphere have been studied using discrete dipole approximation and plasmon hybridization theory. It is found that different morphologies of sliced nanosphere can induce distinctive features in the extinction spectra. In the meanwhile, gap distances and refractive index of the surrounding medium could modulate the plasmon hybridization and the LSPR shifting. At large separation, the shift of LSPR peaks for the nanosphere sliced in halves consisting of ITO and Ag is small and insensitive to the gap distance in the weak coupling, whereas smaller separation exhibits a distinct red shift. Additionally, multiple resonance peaks are excited for the nanosphere sliced in quarters consisting of ITO and Ag. In this situation, electric field is mainly distributed in the gap region of sliced nanosphere and the central point. These results indicate that different morphologies of sliced nanosphere could create abundant tunable LSPR modes, which provides potential for multiplex optical sensing.

  7. Embedding metal electrodes in thick active layers for ITO-free plasmonic organic solar cells with improved performance.

    PubMed

    Lee, Sangjun; Mason, Daniel R; In, Sungjun; Park, Namkyoo

    2014-06-30

    We propose and numerically investigate the optical performance of a novel plasmonic organic solar cell with metallic nanowire electrodes embedded within the active layer. A significant improvement (~15%) in optical absorption over both a conventional ITO organic solar cell and a conventional plasmonic organic solar cell with top-loaded metallic grating is predicted in the proposed structure. Optimal positioning of the embedded metal electrodes (EME) is shown to preserve the condition for their strong plasmonic coupling with the metallic back-plane, meanwhile halving the hole path length to the anode which allows for a thicker active layer that increases the optical path length of propagating modes. With a smaller sheet resistance than a typical 100 nm thick ITO film transparent electrode, and an increased optical absorption and hole collection efficiency, our EME scheme could be an excellent alternative to ITO organic solar cells.

  8. Modeling of sputtered and electron-beam evaporated multilayer ITO/InP solar cells based on efficiency studies

    NASA Astrophysics Data System (ADS)

    Henry, Jasmine; Livingstone, John

    2001-10-01

    With an energy gap of 1.34 eV, indium phosphide (InP) is an ideal material for solar energy conversion. Much work has been carried out on sputtered indium-tin-oxide (ITO)/InP solar cells but modeling of this structure has long been the subject of debate. The double-layer structure used in this work was originally devised to minimize the surface degradation of InP when exposed to normal heating steps during the fabrication process due to the low congruent temperature of InP. We deposited a thin protective layer of either ITO or indium-tin to protect the front surface of the InP before any heating stages took place. A second layer, ITO, was then deposited to compete the junction. Variation of film deposition conditions, thicknesses and annealing steps worked to improve device performances as well as provide insight into junction mechanisms.

  9. A highly sensitive immunosensor based on ITO thin films covered by a new semi-conductive conjugated polymer for the determination of TNFα in human saliva and serum samples.

    PubMed

    Aydın, Elif Burcu; Aydın, Muhammet; Sezgintürk, Mustafa Kemal

    2017-11-15

    A novel, ultrasensitive impedimetric immunosensor was constructed for the detection of tumor necrosis factor α (TNFα) by using Poly(3-thiophene acetic acid) (P3), a conjugated polymer as an immobilization matrix. The polymer P3 contains a lot of carboxylic acid groups on its surface that provide a larger biorecognition surface. This developed immunosensor was prepared on hydroxy-bearing ITO surface via an ester bond linkage of polymer P3 to immobilize anti-TNF α antibodies. The ITO electrode modification steps and interaction between anti-TNF α antibody and TNF α antigen were monitored by cyclic voltammetry (CV) and by electrochemical impedance spectroscopy (EIS) method. After the analytical parameters optimization, a linear detection response from 0.01pg/mL to 2pg/mL, a limit of detection LOD of 3.7 fg/mL and a limit of quantification (LOQ) of 12.4 fg/mL were achieved, which provided accurate results (relative standard deviation; 4.03%). The characterization of this developed immunosensor was performed by using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), SEM-energy dispersive X-ray (EDX) mapping and atomic force microscopy (AFM). The immunosensor allowed a simple and fast detection of TNF α antigen in human serum and satisfied recoveries (98.69-105.20%) were obtained by using standard addition method. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Interfacial Energy Alignment at the ITO/Ultra-Thin Electron Selective Dielectric Layer Interface and Its Effect on the Efficiency of Bulk-Heterojunction Organic Solar Cells.

    PubMed

    Itoh, Eiji; Goto, Yoshinori; Saka, Yusuke; Fukuda, Katsutoshi

    2016-04-01

    We have investigated the photovoltaic properties of an inverted bulk heterojunction (BHJ) cell in a device with an indium-tin-oxide (ITO)/electron selective layer (ESL)/P3HT:PCBM active layer/MoOx/Ag multilayered structure. The insertion of only single layer of poly(diallyl-dimethyl-ammonium chloride) (PDDA) cationic polymer film (or poly(ethyleneimine) (PEI) polymeric interfacial dipole layer) and titanium oxide nanosheet (TN) films as an ESL effectively improved cell performance. Abnormal S-shaped curves were observed in the inverted BHJ cells owing to the contact resistance across the ITO/active layer interface and the ITO/PDDA/TN/active layer interface. The series resistance across the ITO/ESL interface in the inverted BHJ cell was successfully reduced using an interfacial layer with a positively charged surface potential with respect to ITO base electrode. The positive dipole in PEI and the electronic charge phenomena at the electrophoretic deposited TN (ED-TN) films on ITO contributed to the reduction of the contact resistance at the electrode interface. The surface potential measurement revealed that the energy alignment by the transfer of electronic charges from the ED-TN to the base electrodes. The insertion of the ESL with a large positive surface potential reduced the potential barrier for the electron injection at ITO/TN interface and it improved the photovoltaic properties of the inverted cell with an ITO/TN/active layer/MoOx/Ag structure.

  11. Optical and Electrical Performance of MOS-Structure Silicon Solar Cells with Antireflective Transparent ITO and Plasmonic Indium Nanoparticles under Applied Bias Voltage

    PubMed Central

    Ho, Wen-Jeng; Sue, Ruei-Siang; Lin, Jian-Cheng; Syu, Hong-Jang; Lin, Ching-Fuh

    2016-01-01

    This paper reports impressive improvements in the optical and electrical performance of metal-oxide-semiconductor (MOS)-structure silicon solar cells through the incorporation of plasmonic indium nanoparticles (In-NPs) and an indium-tin-oxide (ITO) electrode with periodic holes (perforations) under applied bias voltage. Samples were prepared using a plain ITO electrode or perforated ITO electrode with and without In-NPs. The samples were characterized according to optical reflectance, dark current voltage, induced capacitance voltage, external quantum efficiency, and photovoltaic current voltage. Our results indicate that induced capacitance voltage and photovoltaic current voltage both depend on bias voltage, regardless of the type of ITO electrode. Under a bias voltage of 4.0 V, MOS cells with perforated ITO and plain ITO, respectively, presented conversion efficiencies of 17.53% and 15.80%. Under a bias voltage of 4.0 V, the inclusion of In-NPs increased the efficiency of cells with perforated ITO and plain ITO to 17.80% and 16.87%, respectively. PMID:28773801

  12. Optical and Electrical Performance of MOS-Structure Silicon Solar Cells with Antireflective Transparent ITO and Plasmonic Indium Nanoparticles under Applied Bias Voltage.

    PubMed

    Ho, Wen-Jeng; Sue, Ruei-Siang; Lin, Jian-Cheng; Syu, Hong-Jang; Lin, Ching-Fuh

    2016-08-10

    This paper reports impressive improvements in the optical and electrical performance of metal-oxide-semiconductor (MOS)-structure silicon solar cells through the incorporation of plasmonic indium nanoparticles (In-NPs) and an indium-tin-oxide (ITO) electrode with periodic holes (perforations) under applied bias voltage. Samples were prepared using a plain ITO electrode or perforated ITO electrode with and without In-NPs. The samples were characterized according to optical reflectance, dark current voltage, induced capacitance voltage, external quantum efficiency, and photovoltaic current voltage. Our results indicate that induced capacitance voltage and photovoltaic current voltage both depend on bias voltage, regardless of the type of ITO electrode. Under a bias voltage of 4.0 V, MOS cells with perforated ITO and plain ITO, respectively, presented conversion efficiencies of 17.53% and 15.80%. Under a bias voltage of 4.0 V, the inclusion of In-NPs increased the efficiency of cells with perforated ITO and plain ITO to 17.80% and 16.87%, respectively.

  13. Posttranslational modification and quality control.

    PubMed

    Wang, Xuejun; Pattison, J Scott; Su, Huabo

    2013-01-18

    Protein quality control functions to minimize the level and toxicity of misfolded proteins in the cell. Protein quality control is performed by intricate collaboration among chaperones and target protein degradation. The latter is performed primarily by the ubiquitin-proteasome system and perhaps autophagy. Terminally misfolded proteins that are not timely removed tend to form aggregates. Their clearance requires macroautophagy. Macroautophagy serves in intracellular quality control also by selectively segregating defective organelles (eg, mitochondria) and targeting them for degradation by the lysosome. Inadequate protein quality control is observed in a large subset of failing human hearts with a variety of causes, and its pathogenic role has been experimentally demonstrated. Multiple posttranslational modifications can occur to substrate proteins and protein quality control machineries, promoting or hindering the removal of the misfolded proteins. This article highlights recent advances in posttranslational modification-mediated regulation of intracellular quality control mechanisms and its known involvement in cardiac pathology.

  14. CdS nanoparticles sensitization of Al-doped ZnO nanorod array thin film with hydrogen treatment as an ITO/FTO-free photoanode for solar water splitting

    PubMed Central

    2012-01-01

    Aluminum-doped zinc oxide (AZO) nanorod array thin film with hydrogen treatment possesses the functions of transparent conducting oxide thin film and 1-D nanostructured semiconductor simultaneously. To enhance the absorption in the visible light region, it is sensitized by cadmium sulfide (CdS) nanoparticles which efficiently increase the absorption around 460 nm. The CdS nanoparticles-sensitized AZO nanorod array thin film with hydrogen treatment exhibits significantly improved photoelectrochemical property. After further heat treatment, a maximum short current density of 5.03 mA cm−2 is obtained under illumination. They not only are much higher than those without CdS nanoparticles sensitization and those without Al-doping and/or hydrogen treatment, but also comparable and even slightly superior to some earlier works for the CdS-sensitized zinc oxide nanorod array thin films with indium tin oxide (ITO) or fluorine-doped tin oxide (FTO) as substrates. This demonstrated successfully that the AZO nanorod array thin film with hydrogen treatment is quite suitable as an ITO/FTO-free photoanode and has great potentials in solar water splitting after sensitization by quantum dots capable of visible light absorption. PMID:23098050

  15. CdS nanoparticles sensitization of Al-doped ZnO nanorod array thin film with hydrogen treatment as an ITO/FTO-free photoanode for solar water splitting.

    PubMed

    Hsu, Chih-Hsiung; Chen, Dong-Hwang

    2012-10-25

    Aluminum-doped zinc oxide (AZO) nanorod array thin film with hydrogen treatment possesses the functions of transparent conducting oxide thin film and 1-D nanostructured semiconductor simultaneously. To enhance the absorption in the visible light region, it is sensitized by cadmium sulfide (CdS) nanoparticles which efficiently increase the absorption around 460 nm. The CdS nanoparticles-sensitized AZO nanorod array thin film with hydrogen treatment exhibits significantly improved photoelectrochemical property. After further heat treatment, a maximum short current density of 5.03 mA cm-2 is obtained under illumination. They not only are much higher than those without CdS nanoparticles sensitization and those without Al-doping and/or hydrogen treatment, but also comparable and even slightly superior to some earlier works for the CdS-sensitized zinc oxide nanorod array thin films with indium tin oxide (ITO) or fluorine-doped tin oxide (FTO) as substrates. This demonstrated successfully that the AZO nanorod array thin film with hydrogen treatment is quite suitable as an ITO/FTO-free photoanode and has great potentials in solar water splitting after sensitization by quantum dots capable of visible light absorption.

  16. Intense deep-blue electroluminescence from ITO/Y₂O₃/Ag structure.

    PubMed

    Yin, Xue; Wang, Shenwei; Li, Ling; Mu, Guangyao; Tang, Ying; Duan, Wubiao; Yi, Lixin

    2015-07-13

    ITO/Y₂O₃/Ag devices were fabricated using Y₂O₃ films as insulator. Four intense and sharp lines with half-peak width of 4 nm were observed for the 293.78 nm InI, 316.10 nm InI, 444.82 nm InII and 403.07 nm InIII transitions. Luminescence mechanism was illustrated by cross-section of the devices based on the analysis of surface morphology. Under the action of strong electric field, the loss of K-shell electrons led to the occurrence of characteristic radiation of indium ions. In addition, the device with turn-on voltage of 10V demonstrates typical I-V diode characteristics. Moreover, Y₂O₃/In₂O₃ multiple films as the insulation layer instead of single Y₂O₃ films was found to improve the device performance with excellent CIE (x, y) coordinates (0.16, 0.03).

  17. ITOS to EDGE "Bridge" Software for Morpheus Lunar/Martian Vehicle

    NASA Technical Reports Server (NTRS)

    Hirsh, Robert; Fuchs, Jordan

    2012-01-01

    My project Involved Improving upon existing software and writing new software for the Project Morpheus Team. Specifically, I created and updated Integrated Test and Operations Systems (ITOS) user Interfaces for on-board Interaction with the vehicle during archive playback as well as live streaming data. These Interfaces are an integral part of the testing and operations for the Morpheus vehicle providing any and all information from the vehicle to evaluate instruments and insure coherence and control of the vehicle during Morpheus missions. I also created a "bridge" program for Interfacing "live" telemetry data with the Engineering DOUG Graphics Engine (EDGE) software for a graphical (standalone or VR dome) view of live Morpheus nights or archive replays, providing graphical representation of vehicle night and movement during subsequent tests and in real missions.

  18. The neurologic aspects of hypomelanosis of Ito: Case report and review of the literature

    PubMed Central

    Hassan, Hamdy H; Hamad, Muddathir H A; Alhumidi, Ahmed

    2014-01-01

    The term hypomelanosis of Ito (HI) is applied to individuals with skin hypopigmentation along the lines of Blaschko. Although it was originally described as a purely cutaneous disease, subsequent studies describing HI reported a 33% to 94% association with multiple extracutaneous manifestations, mostly of the central nervous and musculoskeletal systems. This leads to characterization of HI as a neurocutaneous disorder. We report a 10-year-old boy who presented with constellation of multiple congenital anomalies including facial dysmorphism, skin hypopigmentation, musculoskeletal, and nervous system abnormalities. The latter manifested as hypotonia, generalized seizures, and mild mental retardation. Cranial magnetic resonance imaging revealed normal finding initially, however; follow-up diffusion weighted images were suggestive of a possible iron accumulation. The facial phenotype coupled with the bilateral globus pallidi lesions were never been reported in association with HI. Thus, our patient represents a possible novel example of HI. PMID:27493406

  19. Tunable perfect absorber supported by accumulation electron gas at ITO-dielectric heterointerface

    NASA Astrophysics Data System (ADS)

    Li, Liang; Zhao, Hua; Zhang, Jingwen

    2017-10-01

    Absorption of an photonic configuration with 2D accumulation electron gas is theoretically investigated in the first optical window of biological tissue. The configuration consists of a Bragg mirror, an ITO-dielectric heterostructure and a metal film. Our results show that the configuration can realize perfect absorption (reaches 99.98%) of specific wavelength light at matched electron density of the accumulation electron gas. Moreover, the influences of different parameters on the perfect absorption are investigated, which allows us accurately tune the absorption spectrum of the configuration. In addition, manufacture discrepancies of film thicknesses are simulated through introducing random thickness errors in the configuration. It is found that the discrepancies of film thicknesses dramatically affect the absorption spectrum of the configuration. Fortunately, this manufacture impact can be perfectly remedied by changing the electron density of the accumulation electron gas and the incident angle of light.

  20. Calcium sensitizers isolated from the edible pine mushroom, Tricholoma matsutake (S. Ito & Imai) Sing.

    PubMed

    Hou, Yunlong; Sun, Shichao; Wu, Lijun; Wang, Xiaodan; Li, Ting; Zhang, Minyun; Wang, Jianwei; Wang, Libo

    2013-01-01

    Three lactam compounds were isolated from the fruiting body of Tricholoma matsutake (S. Ito & Imai) Sing., an edible mushroom, and their structures were identified as cyclo-S-proline-R-leucine (1), hexahydro-2H-azepin-2-one (2), and butyl 5-oxo-2-pyrrolidine carboxylate (3) by chemical, physicochemical, and spectral evidence. In in vitro screening tests, compounds 1 and 2 acted as calcium sensitizers in ventricular cells from rat. Further studies on compounds 1 and 2 in ex vivo isolated right atria showed positive inotropic effects without disturbing the spontaneous beating rate. The inotropic effect of compounds 1 and 2 could be greatly abolished by pretreating the myocardium in Ca(2+)-free solution. These findings indicate that compounds 1 and 2 can significantly increase the calcium ion concentration ([Ca2+]i) in myocytes, which is greatly dependent on the influx of extracellular Ca2+.