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Sample records for deposited tin films

  1. Electrochemical deposition of subnanometer Ni films on TiN.

    PubMed

    Vanpaemel, Johannes; Sugiura, Masahito; Cuypers, Daniel; van der Veen, Marleen H; De Gendt, Stefan; Vereecken, Philippe M

    2014-03-01

    In this paper, we show the electrochemical deposition of a subnanometer film of nickel (Ni) on top of titanium nitride (TiN). We exploit the concept of cluster growth inhibition to enhance the nucleation of new nuclei on the TiN substrate. By deliberately using an unbuffered electrolyte solution, the degree of nucleation is enhanced as growth is inhibited more strongly. This results in a very high particle density and therefore an ultralow coalescence thickness. To prevent the termination of Ni deposition that typically occurs in unbuffered solutions, the concentration of Ni(2+) in solution was increased. We have verified with RBS and ICP-MS that the deposition of Ni on the surface in this case did not terminate. Furthermore, annealing experiments were used to visualize the closed nature of the Ni film. The closure of the deposited film was also confirmed by TOF-SIMS measurements and occurs when the film thickness is still in the subnanometer regime. The ultrathin Ni film was found to be an excellent catalyst for carbon nanotube growth on conductive substrates and can also be applied as a seed layer for bulk deposition of a smooth Ni film on TiN. PMID:24520857

  2. Pulsed laser deposition of nanostructured indium-tin-oxide film

    NASA Astrophysics Data System (ADS)

    Yong, Thian Kok; Nee, Chen Hon; Yap, Seong Shan; Siew, Wee Ong; Sáfran, György; Yap, Yoke Kin; Tou, Teck Yong

    2010-08-01

    Effects of O2, N2, Ar and He on the formation of micro- and nanostructured indium tin oxide (ITO) thin films were investigated in pulsed Nd:YAG laser deposition on glass substrate. For O2 and Ar, ITO resistivity of <= 4 × 10-4 Ωcm and optical transmittance of > 90% were obtained with substrate temperature of 250 °C. For N2 and He, low ITO resisitivity could be obtained but with poor optical transmittance. SEM images show nano-structured ITO thin films for all gases, where dense, larger and highly oriented, microcrystalline structures were obtained for deposition in O2 and He, as revealed from the XRD lines. EDX results indicated the inclusion of Ar and N2 at the expense of reduced tin (Sn) content. When the ITO films were applied for fabrication of organic light emitting devices (OLED), only those deposited in Ar and O2 produced comparable performance to single-layer OLED fabricated on the commercial ITO.

  3. Deposition of transparent, conductive tin oxide films on glass using a radio-frequency induction heater.

    PubMed

    Solano, I; Schwoebel, P R

    2009-12-01

    Tin oxide films are often used as transparent, conductive coatings on glass in the scientific research setting. The standard approach of depositing these films in an oven leads to poor visibility of the substrate and thus inhibits the ready formation of uniform, low resistivity films. In this note we describe a simple tin oxide film deposition technique using a radio-frequency induction heater that allows for in situ visualization of the deposition process and resulting film. Uniform films having resistivities as low as 2 mohm cm with transmittances of approximately 85% in the visible light spectrum were readily deposited. PMID:20059179

  4. Fabrication of ion conductive tin oxide-phosphate amorphous thin films by atomic layer deposition

    SciTech Connect

    Park, Suk Won; Jang, Dong Young; Kim, Jun Woo; Shim, Joon Hyung

    2015-07-15

    This work reports the atomic layer deposition (ALD) of tin oxide-phosphate films using tetrakis(dimethylamino)tin and trimethyl phosphate as precursors. The growth rates were 1.23–1.84 Å/cycle depending upon the deposition temperature and precursor combination. The ionic conductivity of the ALD tin oxide-phosphate films was evaluated by cross-plane impedance measurements in the temperature range of 50–300 °C under atmospheric air, with the highest conductivity measured as 1.92 × 10{sup −5} S cm{sup −1} at 300 °C. Furthermore, high-resolution x-ray photoelectron spectroscopy exhibited two O1s peaks that were classified as two subpeaks of hydroxyl ions and oxygen ions, revealing that the quantity of hydroxyl ions in the ALD tin oxide-phosphate films influences their ionic conductivity.

  5. Intrinsic anomalous surface roughening of TiN films deposited by reactive sputtering

    SciTech Connect

    Auger, M. A.; Vazquez, L.; Sanchez, O.; Cuerno, R.; Castro, M.; Jergel, M.

    2006-01-15

    We study surface kinetic roughening of TiN films grown on Si(100) substrates by dc reactive sputtering. The surface morphology of films deposited for different growth times under the same experimental conditions were analyzed by atomic force microscopy. The TiN films exhibit intrinsic anomalous scaling and multiscaling. The film kinetic roughening is characterized by a set of local exponent values {alpha}{sub loc}=1.0 and {beta}{sub loc}=0.39, and global exponent values {alpha}=1.7 and {beta}=0.67, with a coarsening exponent of 1/z=0.39. These properties are correlated to the local height-difference distribution function obeying power-law statistics. We associate this intrinsic anomalous scaling with the instability due to nonlocal shadowing effects that take place during thin-film growth by sputtering.

  6. Novel fabrication of an electrochromic antimony-doped tin oxide film using a nanoparticle deposition system

    NASA Astrophysics Data System (ADS)

    Kim, Hyungsub; Park, Yunchan; Choi, Dahyun; Ahn, Sung-Hoon; Lee, Caroline Sunyong

    2016-07-01

    Novel deposition method of Antimony-doped tin oxide (ATO) thin films was introduced using a nanoparticle deposition system (NPDS) to fabricate an electrochromic (EC) device. NPDS is a dry deposition method that simplifies the ATO deposition process by eliminating the need for solvents or binders. In this study, an ATO EC layer was deposited using NPDS. The surface morphology and electrochemical and optical transmittance properties were characterized. The optical transmittance change in the ATO EC device was ∼35% over the wavelength range of 350-800 nm, and the cyclic transmittance was stable. The ATO film deposited using NPDS, exhibited a coloration efficiency of 15.5 cm2 C-1. Therefore, our results suggest that ATO EC devices can be fabricated using a simple, cost-effective NPDS, which allows nanoparticles to be deposited directly without pre- or post-processing.

  7. Residual stress analysis of TiN film fabricated by plasma immersion ion implantation and deposition process

    NASA Astrophysics Data System (ADS)

    Liu, Hongxi; Xu, Qian; Zhang, Xiaowei; Wang, Chuanqi; Tang, Baoyin

    2013-02-01

    Titanium nitride (TiN) films were fabricated on AISI52100 bearing steel surface employing a hybrid plasma immersion ion implantation and deposition (PIIID) technique. The chemical composition, morphology and microstructure of TiN films were characterized by atomic force microscope (AFM), energy dispersive spectrometer (EDS), scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The residual stress of TiN films under different deposition parameter conditions were measured by means of glazing incidence angle X-ray diffraction (GIXRD) method. The influence of film thickness and X-ray glazing incidence angle on residual stress were investigated. AFM observation reveals that the TiN films have extremely smooth surface, high uniformity and efficiency of space filling over large areas. XRD analysis results indicate that TiN phase exists in the surface modified layer and exhibits a preferred orientation with the (2 0 0) plane. The GIXRD data shows that the residual stress in as-deposited TiN films is compressive stress, and the residual stress value decreases with the film thickness and increases with the glazing incidence angle. The compressive stress reduces from 2.164 GPa to 1.163 GPa, which corresponds to the film thickness from 1.5 μm to 4.5 μm, respectively. Reasonably selecting PIIID process parameters for TiN films fabrication, the residual stress in the film can be controlled effectively.

  8. Physical/chemical properties of tin oxide thin film transistors prepared using plasma-enhanced atomic layer deposition

    SciTech Connect

    Lee, Byung Kook; Jung, Eunae; Kim, Seok Hwan; Moon, Dae Chul; Lee, Sun Sook; Park, Bo Keun; Hwang, Jin Ha; Chung, Taek-Mo; Kim, Chang Gyoun; An, Ki-Seok

    2012-10-15

    Thin film transistors (TFTs) with tin oxide films as the channel layer were fabricated by means of plasma enhanced atomic layer deposition (PE-ALD). The as-deposited tin oxide films show n-type conductivity and a nano-crystalline structure of SnO{sub 2}. Notwithstanding the relatively low deposition temperatures of 70, 100, and 130 °C, the bottom gate tin oxide TFTs show an on/off drain current ratio of 10{sup 6} while the device mobility values were increased from 2.31 cm{sup 2}/V s to 6.24 cm{sup 2}/V s upon increasing the deposition temperature of the tin oxide films.

  9. Nanocharacterization of TiN films obtained by Ion Vapor deposition

    NASA Astrophysics Data System (ADS)

    Lara, O. L.; Jerez, A. M.; Morantes, M. L.; Plata, A.; Torres, Y.; Lasprilla, M.; Zhabon, V.

    2011-01-01

    We evaluate and characterize the surface at the nanoscale level and take into account the temperature variation effect in the process of plasma ion deposition for H13 steel samples coated by Titanium Nitride (TiN). The interferometric microscopy and atomic force microscopy (AFM) were used to measure the film to analyze the variation of structural and morphological properties of nanofilms that depend on the temperature of sustrate.

  10. Structural properties of indium tin oxide thin films by glancing angle deposition method.

    PubMed

    Oh, Gyujin; Kim, Seon Pil; Lee, Kyoung Su; Kim, Eun Kyu

    2013-10-01

    We have studied the structural and optical properties of indium tin oxide (ITO) films deposited on sapphire substrates by electron beam evaporator with glancing angle deposition method. The ITO films were grown with different deposition angles of 0 degrees, 30 degrees, 45 degrees, 60 degrees at fixed deposition rate of 3 angstroms/s and with deposition rates of 2 angstroms/s, 3 angstroms/s, and 4angstroms/s at deposition angle of 45 degrees, respectively. From analysis of ellipsometry measurements, it appears that the void fraction of the films increased and their refractive indices decreased from 2.18 to 1.38 at the wavelength of 500 as increasing the deposition angle. The refractive index in the wavelength ranges of 550 nm-800 nm also depends on the deposition rates. Transmittance of ITO film with 235-nm-thickness grown at 60 degrees was covered about 20-80%, and then it was increased in visible wavelength range with increase of deposition angle. PMID:24245214

  11. Cathodic cage plasma deposition of TiN and TiO{sub 2} thin films on silicon substrates

    SciTech Connect

    Sousa, Romulo R. M. de; Sato, Patricia S.; Nascente, Pedro A. P.; Viana, Bartolomeu C.; Alves, Clodomiro; Nishimoto, Akio

    2015-07-15

    Cathodic cage plasma deposition (CCPD) was used for growing titanium nitride (TiN) and titanium dioxide (TiO{sub 2}) thin films on silicon substrates. The main advantages of the CCPD technique are the uniformity, tridimensionality, and high rate of the film deposition that occurs at higher pressures, lower temperatures, and lower treatment times than those used in conventional nitriding treatments. In this work, the influence of the temperature and gas atmosphere upon the characteristics of the deposited films was investigated. The TiN and TiO{sub 2} thin films were characterized by x-ray diffraction, scanning electron microscopy, and Raman spectroscopy to analyze their chemical, structural, and morphological characteristics, and the combination of these results indicates that the low-cost CCPD technique can be used to produce even and highly crystalline TiN and TiO{sub 2} films.

  12. Ionization potentials of transparent conductive indium tin oxide films covered with a single layer of fluorine-doped tin oxide nanoparticles grown by spray pyrolysis deposition

    SciTech Connect

    Fukano, Tatsuo; Motohiro, Tomoyoshi; Ida, Takashi; Hashizume, Hiroo

    2005-04-15

    Indium tin oxide (ITO) films deposited with single layers of monodispersive fluorine-doped tin oxide (FTO) nanoparticles of several nanometers in size were grown on glass substrates by intermittent spray pyrolysis deposition using conventional atomizers. These films have significantly higher ionization potentials than the bare ITO and FTO films grown using the same technique. The ITO films covered with FTO particles of 7 nm in average size show an ionization potential of 5.01 eV, as compared with {approx}4.76 and {approx}4.64 eV in ITO and FTO films, respectively, which decreases as the FTO particle size increases. The ionization potentials are practically invariant against oxidation and reduction treatments, promising a wide application of the films to transparent conducting oxide electrodes in organic electroluminescent devices and light-emitting devices of high efficiencies.

  13. Ionization potentials of transparent conductive indium tin oxide films covered with a single layer of fluorine-doped tin oxide nanoparticles grown by spray pyrolysis deposition

    NASA Astrophysics Data System (ADS)

    Fukano, Tatsuo; Motohiro, Tomoyoshi; Ida, Takashi; Hashizume, Hiroo

    2005-04-01

    Indium tin oxide (ITO) films deposited with single layers of monodispersive fluorine-doped tin oxide (FTO) nanoparticles of several nanometers in size were grown on glass substrates by intermittent spray pyrolysis deposition using conventional atomizers. These films have significantly higher ionization potentials than the bare ITO and FTO films grown using the same technique. The ITO films covered with FTO particles of 7nm in average size show an ionization potential of 5.01eV, as compared with ˜4.76 and ˜4.64eV in ITO and FTO films, respectively, which decreases as the FTO particle size increases. The ionization potentials are practically invariant against oxidation and reduction treatments, promising a wide application of the films to transparent conducting oxide electrodes in organic electroluminescent devices and light-emitting devices of high efficiencies.

  14. Indium Tin Oxide-Magnesium Fluoride Co-Deposited Films for Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    Dever, Joycer A.; Rutledge, Sharon K.; Hambourger, Paul D.; Bruckner, Eric; Ferrante, Rhea; Pal, Anna Marie; Mayer, Karen; Pietromica, Anthony J.

    1998-01-01

    Highly transparent coatings with a maximum sheet resistivity between 10(exp 8) and 10(exp 9) ohms/square are desired to prevent charging of solar arrays for low Earth polar orbit and geosynchronous orbit missions. Indium tin oxide (ITO) and magnesium fluoride (MgF2) were ion beam sputter co-deposited onto fused silica substrates and were evaluated for transmittance, sheet resistivity and the effects of simulated space environments including atomic oxygen (AO) and vacuum ultraviolet (VUV) radiation. Optical properties and sheet resistivity as a function of MgF2 content in the films will be presented. Films containing 8.4 wt.% MgF2 were found to be highly transparent and provided sheet resistivity in the required range. These films maintained a high transmittance upon exposure to AO and to VUV radiation, although exposure to AO in the presence of charged species and intense electromagnetic radiation caused significant degradation in film transmittance. Sheet resistivity of the as-fabricated films increased with time in ambient conditions. Vacuum beat treatment following film deposition caused a reduction in sheet resistivity. However, following vacuum heat treatment, sheet resistivity values remained stable during storage in ambient conditions.

  15. Tungsten-doped tin oxide thin films prepared by pulsed plasma deposition

    SciTech Connect

    Huang Yanwei; Zhang Qun Li Guifeng; Yang Ming

    2009-05-15

    Transparent conductive oxide tungsten-doped tin oxide thin films were deposited on glass substrates from ceramic targets by the pulsed plasma deposition method. The structural, electrical and optical properties have been investigated as functions of tungsten doping content and oxygen partial pressure. The lowest resistivity of 2.1 x 10{sup -3} {omega}{center_dot}cm was reproducibly obtained, with carrier mobility of 30 cm{sup 2}V{sup -1}s{sup -1} and carrier concentration of 9.6 x 10{sup 19} cm{sup -3} at the oxygen partial pressure of 1.8 Pa. The average optical transmission was in excess of 80% in the visible region from 400 to 700 nm, with the optical band gap ranging from 3.91 to 4.02 eV.

  16. Aqueous phase deposition of dense tin oxide films with nano-structured surfaces

    SciTech Connect

    Masuda, Yoshitake Ohji, Tatsuki; Kato, Kazumi

    2014-06-01

    Dense tin oxide films were successfully fabricated in an aqueous solution. The pH of the solutions was controlled to pH 1.3 by addition of HCl. Precise control of solution condition and crystal growth allowed us to obtain dense tin oxide films. Concave–convex surface of fluorine-doped tin oxide (FTO) substrates was entirely-covered with the continuous films. The films were about 65 nm in thickness and had nano-structured surfaces. Morphology of the films was strikingly different from our previous reported nano-sheet assembled structures. The films were not removed from the substrates by strong water flow or air blow to show strong adhesion strength. The aqueous solution process can be applied to surface coating of various materials such as nano/micro-structured surfaces, particles, fibers, polymers, metals or biomaterials. - Graphical abstract: Dense tin oxide films of 65 nm were successfully fabricated in an aqueous solution. They had nano-structured surfaces. Concave-convex substrates were entirely-covered with the continuous films. - Highlights: • Dense tin oxide films of 65 nm were successfully fabricated in an aqueous solution. • They had nano-structured surfaces. • Concave–convex substrates were entirely-covered with the continuous films.

  17. Deposition Of Transparent Conducting Indium - Tin Oxide Films By Dc Sputtering

    NASA Astrophysics Data System (ADS)

    Bawa, S. S.; Sharma, S. S.; Agnihotry, S. A.; Biradar, A. M.; Chandra, Subhas

    1983-12-01

    Unique d.c. reactive sputtering process using a very thin layer of In/Sn alloy(10 wt% Sn) target, at high power levels hasAbeen used to prepare transparent conducting films of ITO with low resistivity (1.17 x 10 ' ohm.m), high optical transmission (" ¬Âº 95%) and of high infra-red reflectivity (e,J90%) for applications as transparent windows in electro-optical devices and solar energy systems. No post-deposition annealing is required. Substrate heating is accomplished entirely by the ion-bombardment intrinsic to DC sputtering, rather than by using an auxilliary resistance heater. Optical, electrical and structural proper-ties of the films have been studied. The characteristic features of the ITO films are very low resistivity, high carrier density, high mobility, low temperature coefficient of resistivity and smaller grain size in comparison with pure indium oxide films. It was concluded from the thermal stability test that the contribution to the carrier density by tin is only a few percent to that created by oxygen.

  18. Studies on high electronic energy deposition in transparent conducting indium tin oxide thin films

    NASA Astrophysics Data System (ADS)

    Deshpande, N. G.; Gudage, Y. G.; Ghosh, A.; Vyas, J. C.; Singh, F.; Tripathi, A.; Sharma, Ramphal

    2008-02-01

    We have examined the effect of swift heavy ions using 100 MeV Au8+ ions on the electrical properties of transparent, conducting indium tin oxide polycrystalline films with resistivity of 0.58 × 10-4 Ω cm and optical transmission greater than 78% (pristine). We report on the modifications occurring after high electronic energy deposition. With the increase in fluency, x-ray line intensity of the peaks corresponding to the planes (1 1 0), (4 0 0), (4 4 1) increased, while (3 3 1) remained constant. Surface morphological studies showed a pomegranate structure of pristine samples, which was highly disturbed with a high dose of irradiation. For the high dose, there was a formation of small spherical domes uniformly distributed over the entire surface. The transmittance was seen to be decreasing with the increase in ion fluency. At higher doses, the resistivity and photoluminescence intensity was seen to be decreased. In addition, the carrier concentration was seen to be increased, which was in accordance with the decrease in resistivity. The observed modifications after high electronic energy deposition in these films may lead to fruitful device applications.

  19. Thin films of tin(II) sulphide (SnS) by aerosol-assisted chemical vapour deposition (AACVD) using tin(II) dithiocarbamates as single-source precursors

    NASA Astrophysics Data System (ADS)

    Kevin, Punarja; Lewis, David J.; Raftery, James; Azad Malik, M.; O'Brien, Paul

    2015-04-01

    The synthesis of the asymmetric dithiocarbamates of tin(II) with the formula [Sn(S2CNRR')2] (where R=Et, R'=n-Bu (1); R=Me, R'=n-Bu (2); R=R'=Et (3)) and their use for the deposition of SnS thin films by aerosol-assisted chemical vapour deposition (AACVD) is described. The effects of temperature and the concentration of the precursors on deposition were investigated. The stoichiometry of SnS was best at higher concentrations of precursors (250 mM) and at 450 °C. The direct electronic band gap of the SnS produced by this method was estimated from optical absorbance measurements as 1.2 eV. The composition of films was confirmed by powder X-ray diffraction (p-XRD) and energy dispersive analysis of X-rays (EDAX) spectroscopy.

  20. Low temperature deposition of indium tin oxide films by plasma ion-assisted evaporation.

    PubMed

    Füchsel, Kevin; Schulz, Ulrike; Kaiser, Norbert; Tünnermann, Andreas

    2008-05-01

    Coatings of transparent conductive oxides, especially indium tin oxide (ITO), are important in different fields. So far, application of these materials has been limited to substrates with high thermal stability. We describe an improved coating process for ITO based on plasma ion-assisted evaporation at a substrate temperature below 100 degrees C, which is suitable for organic substrates. In characterizing the thin films, we used the classical Drude theory to calculate the resistivity from optical film properties and compared the data with linear four-point measurements. X-ray diffraction spectroscopy was used to determine the structural properties of the thin films. PMID:18449263

  1. Optical properties of undoped and tin-doped nanostructured In2O3 thin films deposited by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Fellahi, Nabil; Addou, Mohammed; Kachouane, Amina; El Jouad, Mohamed; Sofiani, Zouhair

    2016-05-01

    Tin-doped indium oxide (In2O3:Sn) thin films in different concentrations (Sn = 0, 3, 5, 8 at.%) were deposited by reactive chemical pulverisation spray pyrolysis on heated glass substrates at 500 °C. The effect of the tin dopant on the nonlinear optical properties was investigated using X-ray diffraction, transmission, electrical resistivity and third harmonic generation (THG). All films were polycrystalline, and crystallised in a cubic structure with a preferential orientation along the (400) direction. The Sn (5 at.%) doped In2O3 thin films exhibited a lower resistivity of 3 × 10-4 Ω cm, and higher transmission in the visible region of about 94%. Optical parameters, such as the extinction coefficient (k), refractive index (n) and energy band gap (Eg), were also studied to show the composition-dependence of tin-doped indium oxide films. The nonlinear properties of the In2O3:Sn thin films have been found to be influenced by doping concentration, and the best value of χ(3) = 3 × 10-11 (esu) was found for the 5 at.% doped sample. Contribution to the topical issue "Materials for Energy Harvesting, Conversion and Storage (ICOME 2015) - Elected submissions", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  2. Effect of oxygen content on piezoresistivity of indium tin oxide thin films prepared by pulsed laser deposition

    SciTech Connect

    Fang, H.; Miller, T.; Rogers, B.R.; Magruder, R.H. III; Weller, R.A.

    2005-04-15

    The piezoresistivity of thin films of indium tin oxide prepared by pulsed laser deposition has been measured as a function of the O-to-(In+Sn) atom ratio. The oxygen-to-metal atom ratio was determined through Rutherford backscattering spectrometry and x-ray photoelectron spectroscopy analyses. Gauge factors, defined as the fractional change of the film resistance to the applied strain, increase with the film's oxygen content. The deposition under 50 mTorr oxygen pressure resulted in the film with the largest oxygen-to-metal atom ratio, 1.92, and a gauge factor of -14.5. A model based on hopping conduction is proposed. Results from this model are consistent with the sign and magnitude of the observed gauge factors.

  3. Smart Windows, Switchable between Transparent, Mirror, and Black States, Fabricated Using Rough and Smooth Indium Tin Oxide Films Deposited by Spray Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Onodera, Ryou; Seki, Yoshiyuki; Seki, Shigeyuki; Yamada, Katsumi; Sawada, Yutaka; Uchida, Takayuki

    2013-02-01

    Two types of indium-tin oxide films, rough and smooth, with an average grain size of 434 and 71 nm, respectively, were deposited by spray pyrolysis chemical vapor deposition. Using both these films, we fabricated glare tunable transparent electrochemical devices exhibiting reversible optical changes between transparent, mirror, and black states, without any treatments. Under zero bias conditions, the transmittance of the transparent state reached 81.1% at 700 nm. With a bias of -2.5 V, the reflectance of the mirror state reached 82.0% at 700 nm. The total transmittances in the mirror and black state amounted to 0.6% in the visible range.

  4. Growth mechanism and optical properties of Ti thin films deposited onto fluorine-doped tin oxide glass substrate

    SciTech Connect

    Einollahzadeh-Samadi, Motahareh; Dariani, Reza S.

    2015-03-15

    In this work, a detailed study of the influence of the thickness on the morphological and optical properties of titanium (Ti) thin films deposited onto rough fluorine-doped tin oxide glass by d.c. magnetron sputtering is carried out. The films were characterized by several methods for composition, crystallinity, morphology, and optical properties. Regardless of the deposition time, all the studied Ti films of 400, 1500, 2000, and 2500 nm in thickness were single crystalline in the α-Ti phase and also very similar to each other with respect to composition. Using the atomic force microscopy (AFM) technique, the authors analyzed the roughness evolution of the Ti films characteristics as a function of the film thickness. By applying the dynamic scaling theory to the AFM images, a steady growth roughness exponent α = 0.72 ± 0.02 and a dynamic growth roughness exponent β = 0.22 ± 0.02 were determined. The value of α and β are consistent with nonlinear growth model incorporating random deposition with surface diffusion. Finally, measuring the reflection spectra of the samples by a spectrophotometer in the spectral range of 300–1100 nm allowed us to investigate the optical properties. The authors observed the increments of the reflection of Ti films with thickness, which by employing the effective medium approximation theory showed an increase in thickness followed by an increase in the volume fraction of metal.

  5. The Effects of Two Thick Film Deposition Methods on Tin Dioxide Gas Sensor Performance

    PubMed Central

    Bakrania, Smitesh D.; Wooldridge, Margaret S.

    2009-01-01

    This work demonstrates the variability in performance between SnO2 thick film gas sensors prepared using two types of film deposition methods. SnO2 powders were deposited on sensor platforms with and without the use of binders. Three commonly utilized binder recipes were investigated, and a new binder-less deposition procedure was developed and characterized. The binder recipes yielded sensors with poor film uniformity and poor structural integrity, compared to the binder-less deposition method. Sensor performance at a fixed operating temperature of 330 °C for the different film deposition methods was evaluated by exposure to 500 ppm of the target gas carbon monoxide. A consequence of the poor film structure, large variability and poor signal properties were observed with the sensors fabricated using binders. Specifically, the sensors created using the binder recipes yielded sensor responses that varied widely (e.g., S = 5 – 20), often with hysteresis in the sensor signal. Repeatable and high quality performance was observed for the sensors prepared using the binder-less dispersion-drop method with good sensor response upon exposure to 500 ppm CO (S = 4.0) at an operating temperature of 330 °C, low standard deviation to the sensor response (±0.35) and no signal hysteresis. PMID:22399977

  6. 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.

  7. Investigation of thermal and hot-wire chemical vapor deposition copper thin films on TiN substrates using CupraSelect as precursor.

    PubMed

    Papadimitropoulos, G; Davazoglou, D

    2011-09-01

    Copper films were deposited on oxidized Si substrates covered with TiN using a novel chemical vapor deposition reactor in which reactions were assisted by a heated tungsten filament (hot-wire CVD, HWCVD). Liquid at room temperature hexafluoroacetylacetonate Cu(I) trimethylvinylsilane (CupraSelect) was directly injected into the reactor with the aid of a direct-liquid injection (DLI) system using N2 as carrier gas. The deposition rates of HWCVD Cu films obtained on TiN covered substrates were found to increase with filament temperature (65 and 170 degrees C were tested). The resistivities of HWCVD Cu films were found to be higher than for thermally grown films due to the possible presence of impurities into the Cu films from the incomplete dissociation of the precursor and W impurities caused by the presence of the filament. For HWCVD films grown at a filament temperature of 170 degrees C, smaller grains are formed than at 65 degrees C as shown from the taken SEM micrographs. XRD diffractograms taken on Cu films deposited on TiN could not reveal the presence of W compounds originating from the filament because the relative peak was masked by the TiN [112] peak. PMID:22097549

  8. TiN thin film deposition by cathodic cage discharge: effect of cage configuration and active species

    NASA Astrophysics Data System (ADS)

    de Freitas Daudt, N.; Pereira Barbosa, J. C.; Cavalcante Braz, D.; Barbalho Pereira, M.; Alves Junior, C.

    2012-12-01

    Plasma cathodic cage technique was developed recently in order to eliminate phenomena such as edge effects and overheating, which occur during conventional nitriding processes. In this work, the effect of plasma active species and cage configurations during thin film deposition of TiN were studied. This compound was chosen because its properties are very sensitive to slight variations in chemical composition and film thickness, becoming a good monitoring tool in fabrication process control. In order to verify the effect of cage geometry on the discharge and characteristics of the grown film, a cage made of titanium was used with different numbers and distribution of holes. Furthermore, different amounts of hydrogen were added to the Ar + N2 plasma atmosphere. Flow rates of Ar and N2 gas were fixed at 4 and 3 sccm, respectively and flow rates of H2 gas was 0, 1 and 2 sccm. Plasma species, electrical discharge and physical characteristics of the grown film were analyzed by Optical Emission Spectroscopy (OES), Atomic Force Microscopy (AFM), X-Ray Diffraction. It was observed by OES that the luminous intensity associated to Hα species is not proportional to flow rate of H2 gas. Electrical efficiency of the system, crystal structure and topography of the TiN film are strongly influenced by this behavior. For constant flow rate of H2 gas, it was found that with more holes at the top of the cage, deposition rate, crystallinity and roughness are higher, if compared to cages with a small number of holes at the top of cage. On the other hand, the opposite behavior was observed when more holes were located at the sidewall of cage.

  9. 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. PMID:24205645

  10. Effect of thermal processing on silver thin films of varying thickness deposited on zinc oxide and indium tin oxide

    SciTech Connect

    Sivaramakrishnan, K.; Ngo, A. T.; Alford, T. L.; Iyer, S.

    2009-03-15

    Silver films of varying thicknesses (25, 45, and 60 nm) were deposited on indium tin oxide (ITO) on silicon and zinc oxide (ZnO) on silicon. The films were annealed in vacuum for 1 h at different temperatures (300-650 deg. C). Four-point-probe measurements were used to determine the resistivity of the films. All films showed an abrupt change in resistivity beyond an onset temperature that varied with thickness. Rutherford backscattering spectrometry measurements revealed agglomeration of the Ag films upon annealing as being responsible for the resistivity change. X-ray pole figure analysis determined that the annealed films took on a preferential <111> texturing; however, the degree of texturing was significantly higher in Ag/ZnO/Si than in Ag/ITO/Si samples. This observation was accounted for by interface energy minimization. Atomic force microscopy (AFM) measurements revealed an increasing surface roughness of the annealed films with temperature. The resistivity behavior was explained by the counterbalancing effects of increasing crystallinity and surface roughness. Average surface roughness obtained from the AFM measurements were also used to model the agglomeration of Ag based on Ostwald ripening theory.

  11. Influence of a TiN interlayer on the microstructure and mechanical properties of hydroxyapatite films grown by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Nelea, Valentin D.; Ristoscu, Carmen; Colis, Silviu; Arens, Simona; Pelletier, Herve; Mihailescu, Ion N.; Mille, Pierre

    2001-04-01

    Crystalline hydroxyapatite (HA) thin films grown on metallic substrates is the best choice for bone restoration. This is due to the good biological compatibility of the hydroxyapatite material combined with the good mechanical characteristics of the substrates. We deposit HA thin films by Pulsed Laser Deposition (PLD) in vacuum at room temperature using a KrF* excimer laser ((lambda) equals 248 nm, (tau) FWHM >= 20 ns). The depositions were performed directly on Ti-5Al-2.5Fe or on substrates previously coated with a TiN buffer layer. The HA deposited structures were characterized by complementary techniques: GIXRD, SEM, TEM, SAED, EDS and nanoindentation. Properties of the HA films grown with and without the TiN buffer were discussed in term of microstructure and mechanical behavior. The films with interlayer preserve the stoichiometry, are completely recrystallized and present better mechanical characteristics as compared with those without buffer.

  12. Surface modification of cadmium sulfide thin film honey comb nanostructures: Effect of in situ tin doping using chemical bath deposition

    NASA Astrophysics Data System (ADS)

    Wilson, K. C.; Basheer Ahamed, M.

    2016-01-01

    Even though nanostructures possess large surface to volume ratio compared to their thin film counterpart, the complicated procedure that demands for the deposition on a substrate kept them back foot in device fabrication techniques. In this work, a honey comb like cadmium sulfide (CdS) thin films nanostructure are deposited on glass substrates using simple chemical bath deposition technique at 65 °C. Energy band gaps, film thickness and shell size of the honey comb nanostructures are successfully controlled using tin (Sn) doping and number of shells per unit area is found to be maximum for 5% Sn doped (in the reaction mixture) sample. X-ray diffraction and optical absorption analysis showed that cadmium sulfide and cadmium hydroxide coexist in the samples. TEM measurements showed that CdS nanostructures are embedded in cadmium hydroxide just like "plum pudding". Persistent photoconductivity measurements of the samples are also carried out. The decay constants found to be increased with increases in Sn doping.

  13. Low-temperature beam-induced deposition of thin tin films

    NASA Astrophysics Data System (ADS)

    Funsten, H. O.; Boring, J. W.; Johnson, R. E.; Brown, W. L.

    1992-02-01

    Ion and electron beam-induced deposition (BID) of thin (1-4 μm), conductive films is accomplished by dissociating and removing the nonmetallic components of an adsorbed, metal-based, molecular gas [SnCl4 and (CH3)4Sn]. Previous research has focused primarily on room-temperature (monolayer adsorption) BID using electrons and slow, heavy ions. This study investigates low-temperature (120 K) BID in which the condensation rate of the precursor gas is well controlled. The residual metallic films are produced by using as incident beams either 2-keV electrons, 25-keV H2+, or 50-keV H2+, all of which provide predominantly electronic energy deposition, or 30-keV Ar+, which provides predominantly nuclear energy deposition. Residual films are analyzed ex situ by scanning electron microscopy, mechanical thickness measurements, resistivity measurements, Rutherford backscattering spectroscopy, and infrared spectrometry. A model is developed that considers bulk and surface dissociation mechanisms and sputtering to describe the BID process. The derived cross sections for the formation of a residue from condensed (CH3)4Sn are nonlinearly related to the total deposited energy approximately to the 1.4 power. The lowest electrical resistivity values of the residues (650 μΩ cm) are obtained only by significant loss of carbon, which is strongly dependent on the nuclear stopping power.

  14. Experimental and numerical evaluations of adhesion strength and stress in TiN films deposited on ti-implanted aluminum

    SciTech Connect

    Xu Ming; Liu Youming; Li Liuhe; Cai Xun; Chen Qiulong; Chu, Paul K.

    2006-03-15

    Titanium ions were implanted into aluminum substrates at 40 kV prior to magnetron sputtering deposition of the Ti interlayer and TiN film using our custom-designed multifunctional ion implanter without breaking vacuum. An 82-nm-thick modified layer was formed between the TiN film and the substrate. The characteristics of the implanted samples were compared to those of TiN/Al and TiN/Ti/Al samples that were not preimplanted. Based on our scratch tests, the critical loading L{sub c} of the TiN/Ti/Ti-implanted Al sample was significantly improved compared to the unimplanted TiN/Al and TiN/Ti/Al samples. Finite element analysis was conducted to simulate the scratch process to help reveal the stress distributions in the vicinity of the interlayer. The results show that the stress around the interface is largely reduced in the TiN/Ti/Ti-implanted Al sample. Consequently, the mechanical properties such as resistance to loadings are enhanced.

  15. Oxygen-Plasma-Treated Indium-Tin-Oxide Films on Nonalkali Glass Deposited by Super Density Arc Plasma Ion Plating

    NASA Astrophysics Data System (ADS)

    Kim, Soo Young; Hong, Kihyon; Son, Jun Ho; Jung, Gwan Ho; Lee, Jong-Lam; Choi, Kyu Han; Song, Kyu Ho; Ahn, Kyung Chul

    2008-02-01

    The effects of O2 plasma treatment on both the chemical composition and work function of an indium-tin-oxide (ITO) film were investigated. ITO films were deposited on non-alkali glass substrate by super density arc plasma ion plating for application in active-matrix organic light-emitting diodes (OLEDs). The water contact angle decreased from 38 to 11° as the ITO films were treated with O2 plasma for 60 s at a plasma power of 150 W, indicating an increase in the hydrophilicity of the surface. It was found that there were no distinct changes in the microstructure or electrical properties of the ITO films with O2 plasma treatment. Synchrotron radiation photoemission spectroscopy data revealed that O2 plasma treatment decreased the amount of carbon contamination and increased the number of unscreened states of In3+ and (O2)2- peroxo species. This played the role of increasing the work function of the ITO films by 1.7 eV. As a result, the turn-on voltage of the OLED decreased markedly from 24 to 8 V and the maximum luminance value of the OLED increased to 2500 cd/m2.

  16. Synthesis, Deposition, and Microstructure Development of Thin Films Formed by Sulfidation and Selenization of Copper Zinc Tin Sulfide Nanocrystals

    NASA Astrophysics Data System (ADS)

    Chernomordik, Boris David

    Significant reduction in greenhouse gas emission and pollution associated with the global power demand can be accomplished by supplying tens-of-terawatts of power with solar cell technologies. No one solar cell material currently on the market is poised to meet this challenge due to issues such as manufacturing cost, material shortage, or material toxicity. For this reason, there is increasing interest in efficient light-absorbing materials that are comprised of abundant and non-toxic elements for thin film solar cell. Among these materials are copper zinc tin sulfide (Cu2ZnSnS4, or CZTS), copper zinc tin selenide (Cu2ZnSnSe4, or CZTSe), and copper zinc tin sulfoselenide alloys [Cu2ZnSn(SxSe1-x )4, or CZTSSe]. Laboratory power conversion efficiencies of CZTSSe-based solar cells have risen to almost 13% in less than three decades of research. Meeting the terawatt challenge will also require low cost fabrication. CZTSSe thin films from annealed colloidal nanocrystal coatings is an example of solution-based methods that can reduce manufacturing costs through advantages such as high throughput, high material utilization, and low capital expenses. The film microstructure and grain size affects the solar cell performance. To realize low cost commercial production and high efficiencies of CZTSSe-based solar cells, it is necessary to understand the fundamental factors that affect crystal growth and microstructure evolution during CZTSSe annealing. Cu2ZnSnS4 (CZTS) nanocrystals were synthesized via thermolysis of single-source cation and sulfur precursors copper, zinc and tin diethyldithiocarbamates. The average nanocrystal size could be tuned between 2 nm and 40 nm, by varying the synthesis temperature between 150 °C and 340 °C. The synthesis is rapid and is completed in less than 10 minutes. Characterization by X-ray diffraction, Raman spectroscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy confirm that the nanocrystals are nominally

  17. Growth of TiN films at low temperature

    NASA Astrophysics Data System (ADS)

    Wei, L. I.; Jun-Fang, Chen

    2007-06-01

    Thermodynamic analysis on growth of TiN films was given. The driving force for deposition of TiN is dependent on original Ti(g)/N(g) ratio and original partial pressure of N(g). TiN films were deposited by ion beam assisted electron beam evaporation system under suitable nitrogen gas flow rate at 523 K while the density of plasma varied with diverse discharge pressure had been investigated by the Langmuir probe. TiN films were characterized by means of Fourier transform infrared absorption spectrum (FTIR), X-ray diffraction (XRD) and observed by means of atom force microscopy (AFM). The results of these measurements indicated preferential TiN(1 1 1) films were deposited on substrate of Si(1 0 0) and glass by ion beam assisted electron beam evaporation system at low temperature, and it was possible for the deposition of TiN films with a preferential orientation or more orientations if the nitrogen gas flow rate increased enough. Sand Box was used to characterize the fractal dimension of surface of TiN films. The results showed the fractal dimension was a little more than 1.7, which accorded with the model of diffusion limited aggregation (DLA), and the fractal dimension of TiN films increased with increase of the temperature of deposition.

  18. Synthesis, Deposition, and Microstructure Development of Thin Films Formed by Sulfidation and Selenization of Copper Zinc Tin Sulfide Nanocrystals

    NASA Astrophysics Data System (ADS)

    Chernomordik, Boris David

    Significant reduction in greenhouse gas emission and pollution associated with the global power demand can be accomplished by supplying tens-of-terawatts of power with solar cell technologies. No one solar cell material currently on the market is poised to meet this challenge due to issues such as manufacturing cost, material shortage, or material toxicity. For this reason, there is increasing interest in efficient light-absorbing materials that are comprised of abundant and non-toxic elements for thin film solar cell. Among these materials are copper zinc tin sulfide (Cu2ZnSnS4, or CZTS), copper zinc tin selenide (Cu2ZnSnSe4, or CZTSe), and copper zinc tin sulfoselenide alloys [Cu2ZnSn(SxSe1-x )4, or CZTSSe]. Laboratory power conversion efficiencies of CZTSSe-based solar cells have risen to almost 13% in less than three decades of research. Meeting the terawatt challenge will also require low cost fabrication. CZTSSe thin films from annealed colloidal nanocrystal coatings is an example of solution-based methods that can reduce manufacturing costs through advantages such as high throughput, high material utilization, and low capital expenses. The film microstructure and grain size affects the solar cell performance. To realize low cost commercial production and high efficiencies of CZTSSe-based solar cells, it is necessary to understand the fundamental factors that affect crystal growth and microstructure evolution during CZTSSe annealing. Cu2ZnSnS4 (CZTS) nanocrystals were synthesized via thermolysis of single-source cation and sulfur precursors copper, zinc and tin diethyldithiocarbamates. The average nanocrystal size could be tuned between 2 nm and 40 nm, by varying the synthesis temperature between 150 °C and 340 °C. The synthesis is rapid and is completed in less than 10 minutes. Characterization by X-ray diffraction, Raman spectroscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy confirm that the nanocrystals are nominally

  19. Amorphous indium-tin-zinc oxide films deposited by magnetron sputtering with various reactive gases: Spatial distribution of thin film transistor performance

    SciTech Connect

    Jia, Junjun; Torigoshi, Yoshifumi; Shigesato, Yuzo; Kawashima, Emi; Utsuno, Futoshi; Yano, Koki

    2015-01-12

    This work presents the spatial distribution of electrical characteristics of amorphous indium-tin-zinc oxide film (a-ITZO), and how they depend on the magnetron sputtering conditions using O{sub 2}, H{sub 2}O, and N{sub 2}O as the reactive gases. Experimental results show that the electrical properties of the N{sub 2}O incorporated a-ITZO film has a weak dependence on the deposition location, which cannot be explained by the bombardment effect of high energy particles, and may be attributed to the difference in the spatial distribution of both the amount and the activity of the reactive gas reaching the substrate surface. The measurement for the performance of a-ITZO thin film transistor (TFT) also suggests that the electrical performance and device uniformity of a-ITZO TFTs can be improved significantly by the N{sub 2}O introduction into the deposition process, where the field mobility reach to 30.8 cm{sup 2} V{sup –1} s{sup –1}, which is approximately two times higher than that of the amorphous indium-gallium-zinc oxide TFT.

  20. A comparison of ZnO films deposited on indium tin oxide and soda lime glass under identical conditions

    NASA Astrophysics Data System (ADS)

    Deka, Angshuman; Nanda, Karuna Kar

    2013-06-01

    ZnO films have been grown via a vapour phase transport (VPT) on soda lime glass (SLG) and indium-tin oxide (ITO) coated glass. ZnO film on ITO had traces of Zn and C which gives them a dark appearance while that appears yellowish-white on SLG. X-ray photoelectron spectroscopy studies confirm the traces of C in the form of C-O. The photoluminescence studies reveal a prominent green luminescence band for ZnO film on ITO.

  1. A comparison of ZnO films deposited on indium tin oxide and soda lime glass under identical conditions

    SciTech Connect

    Deka, Angshuman; Nanda, Karuna Kar

    2013-06-15

    ZnO films have been grown via a vapour phase transport (VPT) on soda lime glass (SLG) and indium-tin oxide (ITO) coated glass. ZnO film on ITO had traces of Zn and C which gives them a dark appearance while that appears yellowish-white on SLG. X-ray photoelectron spectroscopy studies confirm the traces of C in the form of C-O. The photoluminescence studies reveal a prominent green luminescence band for ZnO film on ITO.

  2. Radiation-induced deposition of transparent conductive tin oxide coatings

    NASA Astrophysics Data System (ADS)

    Umnov, S.; Asainov, O.; Temenkov, V.

    2016-04-01

    The study of tin oxide films is stimulated by the search for an alternative replacement of indium-tin oxide (ITO) films used as transparent conductors, oxidation catalysts, material gas sensors, etc. This work was aimed at studying the influence of argon ions irradiation on optical and electrical characteristics of tin oxide films. Thin films of tin oxide (without dopants) were deposited on glass substrates at room temperature using reactive magnetron sputtering. After deposition, the films were irradiated with an argon ion beam. The current density of the beam was (were) 2.5 mA/cm2, and the particles energy was 300-400 eV. The change of the optical and electrical properties of the films depending on the irradiation time was studied. Films optical properties were investigated by photometry in the range of 300-1100 nm. Films structural properties were studied using X-ray diffraction. The diffractometric research showed that the films, deposited on a substrate, had a crystal structure, and after argon ions irradiation they became quasi-crystalline (amorphous). It has been found that the transmission increases proportionally with the irradiation time, however the sheet resistance increases disproportionally. Tin oxide films (thickness ~30 nm) with ~100% transmittance and sheet resistance of ~100 kOhm/sq. were obtained. The study has proved to be prospective in the use of ion beams to improve the properties of transparent conducting oxides.

  3. Growth of amorphous zinc tin oxide films using plasma-enhanced atomic layer deposition from bis(1-dimethylamino-2-methyl-2propoxy)tin, diethylzinc, and oxygen plasma

    NASA Astrophysics Data System (ADS)

    Han, Jeong Hwan; Lee, Byoung Kook; Jung, Eun Ae; Kim, Hyo-Suk; Kim, Seong Jun; Kim, Chang Gyoun; Chung, Taek-Mo; An, Ki-Seok

    2015-12-01

    Amorphous ZnSnOx (ZTO) films were prepared using plasma-enhanced atomic layer deposition (PEALD) in a temperature range of 100-200 °C. Metal-organic precursors of Sn(dmamp)2 (dmamp = bis(1-dimethylamino-2-methyl-2-propoxide) and diethylzinc were employed as sources of Sn and Zn, respectively, in combination with O2 plasma as a reactant. Sn levels in the ZTO films were controlled by varying the SnO2/ZnO cycle ratio from 0 to 8. According to the growth behaviour of the ZTO film by alternating SnO2 and ZnO PEALD cycles, it was observed that ZnO growth on Sn-rich ZTO film is retarded, whereas SnO2 growth is enhanced on Zn-rich ZTO film. The chemical states of the ZTO films were confirmed by X-ray photoelectron spectroscopy (XPS); the chemical compositions of the ZTO films were characterised by XPS depth profiling. Grazing-angle X-ray diffraction revealed that the PEALD ZTO films possess an amorphous structure, irrespective of Sn levels from 20 to 59 at.%. ZTO films with intermediate Sn at.% exhibited smooth surface morphology compared to binary ZnO and SnO2 films. Additionally, the step coverage of a ZTO film deposited on hole pattern with an aspect ratio of 8 and opening diameter of 110 nm was about 93%, suggesting the realisation of self-limited growth.

  4. An Investigation into Zinc Diffusion and Tin Whisker Growth for Electroplated Tin Deposits on Brass

    NASA Astrophysics Data System (ADS)

    Ashworth, Mark A.; Wilcox, Geoffrey D.; Higginson, Rebecca L.; Heath, Richard J.; Liu, Changqing

    2014-04-01

    It is widely documented that whisker growth is more rapid for tin deposits on brass compared with deposits produced on other substrate materials, such as copper. As a result, studies investigating the effect of process variables on tin whisker formation are often conducted on brass substrates to take advantage of the increased whisker growth rates. Although it has been understood since the 1960s that the increased whisker growth results from zinc diffusion, to date there has not been any detailed analysis of the zinc/zinc oxide distribution at the surface of the tin deposit. Using a commercial bright tin electroplating bath, the formation of zinc oxide at the surface of tin deposits on brass has been investigated. Analyses show that zinc oxide is present on the surface of the deposit within 1 day of electroplating. During storage at room temperature, a network of zinc oxide is formed at the surface grain boundaries, the extent of which increases with time. The critical role that zinc surface diffusion plays in whisker growth for tin deposits on brass has been demonstrated by electrochemical oxidation of the tin shortly after electroplating. This develops a tin oxide film that is thicker than the native air-formed oxide and subsequently serves as a diffusion barrier to zinc surface diffusion, thereby mitigating whisker growth.

  5. Low Temperature Synthesis of Fluorine-Doped Tin Oxide Transparent Conducting Thin Film by Spray Pyrolysis Deposition.

    PubMed

    Ko, Eun-Byul; Choi, Jae-Seok; Jung, Hyunsung; Choi, Sung-Churl; Kim, Chang-Yeoul

    2016-02-01

    Transparent conducting oxide (TCO) is widely used for the application of flat panel display like liquid crystal displays and plasma display panel. It is also applied in the field of touch panel, solar cell electrode, low-emissivity glass, defrost window, and anti-static material. Fluorine-doped tin oxide (FTO) thin films were fabricated by spray pyrolysis of ethanol-added FTO precursor solutions. FTO thin film by spray pyrolysis is very much investigated and normally formed at high temperature, about 500 degrees C. However, these days, flexible electronics draw many attentions in the field of IT industry and the research for flexible transparent conducting thin film is also required. In the industrial field, indium-tin oxide (ITO) film on polymer substrate is widely used for touch panel and displays. In this study, we investigated the possibility of FTO thin film formation at relatively low temperature of 250 degrees C. We found out that the control of volume of input precursor and exhaust gases could make it possible to form FTO thin film with a relatively low electrical resistance, less than 100 Ohm/sq and high optical transmittance about 88%. PMID:27433704

  6. Tin sulfide (SnS) nanostructured films deposited by continuous spray pyrolysis (CoSP) technique for dye-sensitized solar cells applications

    NASA Astrophysics Data System (ADS)

    Alam, Firoz; Dutta, Viresh

    2015-12-01

    Tin sulfide (SnS) nanostructured films have been deposited on transparent conducting glass substrate using continuous spray pyrolysis (CoSP) technique using aqueous spray solution of tin chloride and thiourea. Structural, morphological and optical properties of as-synthesized SnS nanostructured films showed the formation of (1 0 1) oriented orthorhombic SnS with nanoflakes having a direct band gap of 1.40 eV. X-ray photoelectron spectroscopy (XPS) analysis confirms the formation of pure SnS with Sn in +2 oxidation state. The SnS nanostructured film has also been characterized using Brunauer-Emmett-Teller (BET) technique to determine the surface area and pore volume which are found to be 11.4 m2/g and 0.02 cm2/g, respectively. The film has been used as a counter electrode (CE) in a triiodide/iodide (I3-/I-) based dye-sensitized solar cells (DSSCs). The DSSCs of 0.25 cm2 area with SnS nanostructured CE exhibits a lower power conversion efficiency (2.0 ± 0.06%) than that for the cell with standard platinum (Pt) CE (4.5 ± 0.13%). However, the usefulness of the CoSP technique for deposition of nanostructures SnS CE film has been established in the present study.

  7. Effect of solvent volume on the physical properties of undoped and fluorine doped tin oxide films deposited using a low-cost spray technique

    NASA Astrophysics Data System (ADS)

    Muruganantham, G.; Ravichandran, K.; Saravanakumar, K.; Ravichandran, A. T.; Sakthivel, B.

    2011-12-01

    Undoped and fluorine doped tin oxide films were deposited from starting solutions having different values of solvent volume (10-50 ml) by employing a low cost and simplified spray technique using perfume atomizer. X-ray diffraction studies showed that there was a change in the preferential orientation from (2 1 1) plane to (1 1 0) plane as the volume of the solvent was increased. The sheet resistance ( Rsh) of undoped SnO 2 film was found to be minimum (13.58 KΩ/□) when the solvent volume was lesser (10 ml) and there was a sharp increase in Rsh for higher values of solvent volume. Interestingly, it was observed that while the Rsh increases sharply with the increase in solvent volume for undoped SnO 2 films, it decreases gradually in the case of fluorine doped SnO 2 films. The quantitative analysis of EDAX confirmed that the electrical resistivity of the sprayed tin oxide film was mainly governed by the number of oxygen vacancies and the interstitial incorporation of Sn atoms which in turn was governed by the impinging flux on the hot substrate. The films were found to have good optical characteristics suitable for opto-electronic devices.

  8. Formation of TiN Ir particle films using pulsed-laser deposition and their electrolytic properties in producing hypochlorous acid

    NASA Astrophysics Data System (ADS)

    Deno, H.; Kamemoto, T.; Nemoto, S.; Koshio, A.; Kokai, F.

    2008-02-01

    Using sintered TiN and TiN-Ir (Ir contents: 5.9-14.2 at.%) targets, pulsed-laser deposition (PLD) was carried out to produce thin films composed of nanoparticles and particulates in the presence of nitrogen gas. The size (2-100 nm) of the produced crystalline TiN nanoparticles increased as nitrogen pressure was increased in the range from 1.33 to 1.33 × 10 2 Pa. At a pressure of 1.33 × 10 3 Pa, amorphous TiN nanoparticles combined in the form of chains. Large Ir particulates with diameters of up to 2 μm were particularly prominent in TiN-Ir films. Size distributions of the Ir particulates were dependent on ablation laser wavelength; that is, the diameter decreased at laser wavelength shortened. The TiN-Ir films with different Ir contents and morphologies on Ti substrates were evaluated as electrolysis electrodes for water disinfection. The highest current efficiency was 0.45%, which is comparable to that of conventional Ti-Pt electrodes, for a chloride-ion concentration of 9 mg dm -3.

  9. Electrochromic characteristics of niobium-doped titanium oxide film on indium tin oxide/glass by liquid phase deposition

    NASA Astrophysics Data System (ADS)

    Lee, Ming-Kwei; Lee, Chia-Jung

    2015-10-01

    Ammonium hexafluorotitanate and boric acid aqueous solutions were used as precursors for the growth of titanium oxide films on indium tin oxide (ITO)/glass substrate. For as-grown titanium oxide film used in an electrochromic device, Li+ ions from electrolyte will be trapped to hydroxyl groups and degrade the electrochromic durability during the cyclic voltammogram characterization. For niobium doped titanium oxide film, lower growth rate from more HF incorporation from the niobium doped solution and rougher surface morphology from the formation of nanocrystals were obtained. However, niobium doping reduces hydroxyl groups and the electrochromic durability is enhanced from 5 × 103 to 1 × 104 times. The transmittance is enhanced from 37 to 51% at the wavelength of 550 nm.

  10. Mathematical modeling for the composition prediction of compound films grown by ion-assisted deposition technique and its application to TiN x film

    NASA Astrophysics Data System (ADS)

    Kim, Jae-Keun; Colligon, J. S.; Jeong, Sang-Hun

    2004-10-01

    A simple general model has been formulated to explain the composition of compound films during growth simultaneous with ion bombardment. The variables in this model are (a) the sticking probability of the background residual reactive gas in the film, (b) an ion-enhanced sticking probability of these reactive gases arising from ion-enhanced adsorption and mixing and (c) ion implantation of the energetic ions impinging on the growing film. Preferential sputtering of various components in the film is also taken into account. The model is shown to be successful in explaining the experimental variations in the composition of TiN x films produced by ion-assisted growth.

  11. Indium-tin oxide thin films deposited at room temperature on glass and PET substrates: Optical and electrical properties variation with the H2-Ar sputtering gas mixture

    NASA Astrophysics Data System (ADS)

    Álvarez-Fraga, L.; Jiménez-Villacorta, F.; Sánchez-Marcos, J.; de Andrés, A.; Prieto, C.

    2015-07-01

    The optical and electrical properties of indium tin oxide (ITO) films deposited at room temperature on glass and polyethylene terephthalate (PET) substrates were investigated. A clear evolution of optical transparency and sheet resistance with the content of H2 in the gas mixture of H2 and Ar during magnetron sputtering deposition is observed. An optimized performance of the transparent conductive properties ITO films on PET was achieved for samples prepared using H2/(Ar + H2) ratio in the range of 0.3-0.6%. Moreover, flexible ITO-PET samples show a better transparent conductive figure of merit, ΦTC = T10/RS, than their glass counterparts. These results provide valuable insight into the room temperature fabrication and development of transparent conductive ITO-based flexible devices.

  12. Structural, optical and electrical properties studies of ultrasonically deposited tin oxide (SnO2) thin films with different substrate temperatures

    NASA Astrophysics Data System (ADS)

    Rahal, Achour; Benhaoua, Atmane; Jlassi, Mohamed; Benhaoua, Boubaker

    2015-10-01

    Undoped thin films of tin oxide (SnO2) were deposited onto microscopic glass substrates using an ultrasonic spray pyrolysis technique. The thin films were deposited on glass at large scale of temperature ranged in 400-500 °C and stepped by 20 °C. The effect of substrate temperature on structural, electrical and optical properties was studied using X-ray diffraction (XRD), UV-visible spectrophotometer and a conventional four point probe technique. XRD showed that all the films were polycrystalline with major reflex along (1 1 0) plane, manifested with amelioration of grain size from 6.51 to 29.80 nm upon increasing substrate temperature. Lattice constant 'a', 'c', microstrains and dislocation densities were affected by the substrate temperature. Transmittance of about 75% at more than 800 nm for films prepared at 480 °C has been observed. With increasing the substrate temperature the direct band gap energy was averaged in 4.03-4.133 eV. Plasma frequency (ωp) was estimated to be 4 ṡ 1014 Hz and optically estimated free electrons number N leading to predict that, in SnO2 material, the effective density of conduction band states is about 5 ṡ 1019 cm-3. Among all the samples the film that deposited at 480 °C exhibited lowest resistivity of about 9.19 × 10-3 Ω cm.

  13. Hydroxyapatite thin films growth by pulsed laser deposition: effects of the Ti alloys substrate passivation on the film properties by the insertion of a TiN buffer layer

    NASA Astrophysics Data System (ADS)

    Nelea, Valentin D.; Ristoscu, Carmen; Ghica, Cornel; Pelletier, Herve; Mihailescu, Ion N.; Mille, Pierre

    2001-06-01

    Hydroxyapatite (HA), Ca5(PO4)3OH, is now widely used in stomatology and orthopedic surgery. Due to a good biocompatibility combined favorable bioactivity make as HA to be considered as a challenge to successful bone repair. We grow HA thin films on Ti-5Al-2.5Fe alloy substrate by pulsed laser deposition (PLD) technique. The films were deposited in vacuum at room temperature using a KrF excimer laser ((lambda) equals 248 nm, (tau) FWHM >= 20 ns). After deposition the HA films were annealed at 550 degree(s)C in ambient air. The insertion of a bioinert TiN buffer layer at the HA film-metallic substrate interface was studied in terms of HA film microstructure and mechanical properties. SEM, TEM and SAED analysis structurally characterized films. The mechanical properties were evaluated by nanoindentation tests in static and scratch modes. Films with TiN interlayer contain uniquely crystalline HA phase and present better mechanical characteristics as compared with those deposited directly on Ti-alloy substrate.

  14. Patterning of Indium Tin Oxide Films

    NASA Technical Reports Server (NTRS)

    Immer, Christopher

    2008-01-01

    A relatively rapid, economical process has been devised for patterning a thin film of indium tin oxide (ITO) that has been deposited on a polyester film. ITO is a transparent, electrically conductive substance made from a mixture of indium oxide and tin oxide that is commonly used in touch panels, liquid-crystal and plasma display devices, gas sensors, and solar photovoltaic panels. In a typical application, the ITO film must be patterned to form electrodes, current collectors, and the like. Heretofore it has been common practice to pattern an ITO film by means of either a laser ablation process or a photolithography/etching process. The laser ablation process includes the use of expensive equipment to precisely position and focus a laser. The photolithography/etching process is time-consuming. The present process is a variant of the direct toner process an inexpensive but often highly effective process for patterning conductors for printed circuits. Relative to a conventional photolithography/ etching process, this process is simpler, takes less time, and is less expensive. This process involves equipment that costs less than $500 (at 2005 prices) and enables patterning of an ITO film in a process time of less than about a half hour.

  15. Effect of Self-Assembled Monolayer Modification on Indium-Tin Oxide Surface for Surface-Initiated Vapor Deposition Polymerization of Carbazole Thin Films

    NASA Astrophysics Data System (ADS)

    Yuya Umemoto,; Seong-Ho Kim,; Rigoberto C. Advincula,; Kuniaki Tanaka,; Hiroaki Usui,

    2010-04-01

    With the aim of controlling the interface between an inorganic electrode and an organic layer, a surface-initiated vapor deposition polymerization method was employed to prepare carbazole polymer thin films that are chemically bound to an indium-tin oxide (ITO) surface. A self-assembled monolayer (SAM) that has an azo initiator as a terminal group was prepared on an ITO surface, on which carbazole acrylate monomers were evaporated under ultraviolet (UV) irradiation. The surface morphological characteristics of the films prepared with/without UV irradiation and with/without the SAM were compared. It was found that the UV irradiation leads to the polymerization of carbazole monomers irrespective of the type of substrate used. On the other hand, the surface morphological characteristics were largely dependent on the existence of the SAM. Uniform and smooth polymer thin films were obtained only when the monomers were evaporated on the SAM-modified surface under UV irradiation. A comparison of film growth characteristics on a UV-ozone-treated ITO surface suggested that the formation of uniform films was made possible not by the modification of surface energy but by the growth of the polymers chemically bound to the substrate surface.

  16. Characteristics of Fluorine-doped tin oxide thin films grown by Streaming process for Electrodeless Electrochemical Deposition

    NASA Astrophysics Data System (ADS)

    Yusuf, Gbadebo; Khalilzadeh-Rezaie, Farnood; Cleary, Justin W.; Oladeji, Isaiah O.; Suu, Koukou; Schoenfeld, Winston V.; Peale, Robert E.; Awodugba, Ayodeji O.

    2015-04-01

    This work investigated the characteristics of SnO2: F films grown by Streaming Process for Electrodeless Electrochemical Deposition (SPEED). Stannic chloride (SnCl4) and ammonium fluoride (NH4 F) was dissolved in a mixture of deionized water and organic solvents. The preheated substrate temperature was varied between 450 and 530° C. High quality SnO2: F films were grown at all the substrate temperatures studied. The typical film thickness was 250 nm. XRD shows that the grown films are polycrystalline SnO2 with a tetragonal crystal structure. The average optical transmission of the films was around 93% throughout the wavelength of 400 to 1000 nm. The lowest electrical resistivity achieved was 6 x 10-4 Ω cm. The Hall measurements showed that the film is an n-type semiconductor, with the highest carrier mobility of 8.3 cm2/V.s, and concentration of 1 x 1021 cm-3. The direct band gap was determined to be 4 eV from the transmittance spectrum.

  17. Atomic layer deposition of tin oxide and zinc tin oxide using tetraethyltin and ozone

    SciTech Connect

    Warner, Ellis J.; Gladfelter, Wayne L.; Johnson, Forrest; Campbell, Stephen A.

    2015-03-15

    Silicon or glass substrates exposed to sequential pulses of tetraethyltin (TET) and ozone (O{sub 3}) were coated with thin films of SnO{sub 2}. Self-limiting deposition was found using 8 s pulse times, and a uniform thickness per cycle (TPC) of 0.2 nm/cycle was observed in a small, yet reproducible, temperature window from 290 to 320 °C. The as-deposited, stoichiometric SnO{sub 2} films were amorphous and transparent above 400 nm. Interspersing pulses of diethylzinc and O{sub 3} among the TET:O{sub 3} pulses resulted in deposition of zinc tin oxide films, where the fraction of tin, defined as [at. % Sn/(at. % Sn + at. % Zn)], was controlled by the ratio of TET pulses, specifically n{sub TET}:(n{sub TET} + n{sub DEZ}) where n{sub TET} and n{sub DEZ} are the number of precursor/O{sub 3} subcycles within each atomic layer deposition (ALD) supercycle. Based on film thickness and composition measurements, the TET pulse time required to reach saturation in the TPC of SnO{sub 2} on ZnO surfaces was increased to >30 s. Under these conditions, film stoichiometry as a function of the TET pulse ratio was consistent with the model devised by Elliott and Nilsen. The as-deposited zinc tin oxide (ZTO) films were amorphous and remained so even after annealing at 450 °C in air for 1 h. The optical bandgap of the transparent ZTO films increased as the tin concentration increased. Hall measurements established that the n-type ZTO carrier concentration was 3 × 10{sup 17} and 4 × 10{sup 18} cm{sup −3} for fractional tin concentrations of 0.28 and 0.63, respectively. The carrier mobility decreased as the concentration of tin increased. A broken gap pn junction was fabricated using ALD-deposited ZTO and a sputtered layer of cuprous oxide. The junction demonstrated ohmic behavior and low resistance consistent with similar junctions prepared using sputter-deposited ZTO.

  18. Morphology and structure evolution of tin-doped indium oxide thin films deposited by radio-frequency magnetron sputtering: The role of the sputtering atmosphere

    SciTech Connect

    Nie, Man Mete, Tayfun; Ellmer, Klaus

    2014-04-21

    The microstructure and morphology evolution of tin-doped indium oxide (ITO) thin films deposited by radio-frequency magnetron sputtering in different sputtering atmospheres were investigated by X-ray diffraction, X-ray reflectivity, and atomic force microscopy. The surface roughness w increases with increasing film thickness d{sub f}, and exhibits a power law behavior w ∼ d{sub f}{sup β}. The roughness decreases with increasing O{sub 2} flow, while it increases with increasing H{sub 2} flow. The growth exponent β is found to be 0.35, 0.75, and 0.98 for depositions in Ar/10%O{sub 2}, pure Ar, and Ar/10%H{sub 2} atmospheres, respectively. The correlation length ξ increases with film thickness also with a power law according to ξ ∼ d{sub f}{sup z} with exponents z = 0.36, 0.44, and 0.57 for these three different gas atmospheres, respectively. A combination of local and non-local growth modes in 2 + 1 dimensions is discussed for the ITO growth in this work.

  19. Lithium intercalation in sputter deposited antimony-doped tin oxide thin films: Evidence from electrochemical and optical measurements

    SciTech Connect

    Montero, J. Granqvist, C. G.; Niklasson, G. A.; Guillén, C.; Herrero, J.

    2014-04-21

    Transparent conducting oxides are used as transparent electrical contacts in a variety of applications, including in electrochromic smart windows. In the present work, we performed a study of transparent conducting antimony-doped tin oxide (ATO) thin films by chronopotentiometry in a Li{sup +}-containing electrolyte. The open circuit potential vs. Li was used to investigate ATO band lineups, such as those of the Fermi level and the ionization potential, as well as the dependence of these lineups on the preparation conditions for ATO. Evidence was found for Li{sup +} intercalation when a current pulse was set in a way so as to drive ions from the electrolyte into the ATO lattice. Galvanostatic intermittent titration was then applied to determine the lithium diffusion coefficient within the ATO lattice. The electrochemical density of states of the conducting oxide was studied by means of the transient voltage recorded during the chronopotentiometry experiments. These measurements were possible because, as Li{sup +} intercalation took place, charge compensating electrons filled the lowest part of the conduction band in ATO. Furthermore, the charge insertion modified the optical properties of ATO according to the Drude model.

  20. Ovonic type switching in tin selenide thin films

    NASA Technical Reports Server (NTRS)

    Baxter, C. R.; Mclennan, W. D.

    1975-01-01

    Amorphous tin selenide thin films which possess Ovonic type switching properties are fabricated using vacuum deposition techniques. The devices are fabricated in a planar configuration and consist of amorphous tin selenide deposited over silver contacts. Results obtained indicate that Ovonic type memory switching does occur in these films with the energy density required for switching from a high impedance to a low impedance state being dependent on the spacing between the electrodes of the device. There is also a strong implication that the switching is a function of the magnitude of the applied voltage pulse.

  1. Reactive Sputter Deposition of WO3/Ag/WO3 Film for Indium Tin Oxide (ITO)-Free Electrochromic Devices.

    PubMed

    Yin, Yi; Lan, Changyong; Guo, Huayang; Li, Chun

    2016-02-17

    Functioning both as electrochromic (EC) and transparent-conductive (TC) coatings, WO3/Ag/WO3 (WAW) trilayer film shows promising potential application for ITO-free electrochromic devices. Reports on thermal-evaporated WAW films revealed that these bifunctional WAW films have distinct EC characteristics; however, their poor adhesive property leads to rapid degradation of coloring-bleaching cycling. Here, we show that WAW film with improved EC durability can be prepared by reactive sputtering using metal targets. We find that, by introducing an ultrathin tungsten (W) sacrificial layer before the deposition of external WO3, the oxidation of silver, which leads to film insulation and apparent optical haze, can be effectively avoided. We also find that the luminous transmittance and sheet resistance were sensitive to the thicknesses of tungsten and silver layers. The optimized structure for TC coating was obtained to be WO3 (45 nm)/Ag (10 nm)/W (2 nm)/WO3 (45 nm) with a sheet resistance of 16.3 Ω/□ and a luminous transmittance of 73.7%. Such film exhibits compelling EC performance with decent luminous transmittance modulation ΔTlum of 29.5%, fast switching time (6.6 s for coloring and 15.9 s for bleaching time), and long-term cycling stability (2000 cycles) with an applied potential of ±1.2 V. Thicker external WO3 layer (45/10/2/100 nm) leads to larger modulation with maximum ΔTlum of 46.4%, but at the cost of significantly increasing the sheet resistance. The strategy of introducing ultrathin metal sacrificial layer to avoid silver oxidation could be extended to fabricating other oxide-Ag-oxide transparent electrodes via low-cost reactive sputtering. PMID:26726834

  2. X-ray photoelectron spectroscopy study on the chemistry involved in tin oxide film growth during chemical vapor deposition processes

    SciTech Connect

    Mannie, Gilbere J. A.; Gerritsen, Gijsbert; Abbenhuis, Hendrikus C. L.; Deelen, Joop van; Niemantsverdriet, J. W.; Thuene, Peter C.

    2013-01-15

    The chemistry of atmospheric pressure chemical vapor deposition (APCVD) processes is believed to be complex, and detailed reports on reaction mechanisms are scarce. Here, the authors investigated the reaction mechanism of monobutyl tinchloride (MBTC) and water during SnO{sub 2} thin film growth using x-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). XPS results indicate an acid-base hydrolysis reaction mechanism, which is tested with multilayer experiments, demonstrating self-terminating growth. In-house developed TEM wafers are used to visualize nucleation during these multilayer experiments, and results are compared with TEM results of APCVD samples. Results show almost identical nucleation behavior implying that their growth mechanism is identical. Our experiments suggest that in APCVD, when using MBTC and water, SnO{sub 2} film growth occurs via a heterolytic bond splitting of the Sn-Cl bonds without the need to invoke gas-phase radical or coordination chemistry of the MBTC precursor.

  3. Effect of sulfurization time on the properties of copper zinc tin sulfide thin films grown by electrochemical deposition.

    PubMed

    Aldalbahi, Ali; Mkawi, E M; Ibrahim, K; Farrukh, M A

    2016-01-01

    We report growth of quaternary Cu2 ZnSnS4 (CZTS) thin films prepared by the electrochemical deposition from salt precursors containing Cu (II), Zn (II) and Sn (IV) metals. The influence of different sulfurization times t (t = 75, 90, 105, and 120 min) on the structural, compositional, morphological, and optical properties, as well as on the electrical properties is studied. The films sulfurized 2 hours showed a prominent kesterite phase with a nearly stoichiometric composition. Samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and Raman and UV-VIS-NIR spectrometer at different stages of work. X-ray diffraction and Raman spectroscopy analyses confirmed the formation of phase-pure CZTS films. (FESEM) shows that compact and dense morphology and enhanced photo-sensitivity. STEM - EDS elemental map of CZTS cross-section confirms homogeneous distribution. From optical study, energy gap was enlarged with a changed sulfurization times in the range of 1.37-1.47 eV. PMID:27600023

  4. Effect of sulfurization time on the properties of copper zinc tin sulfide thin films grown by electrochemical deposition

    PubMed Central

    Aldalbahi, Ali; Mkawi, E. M.; Ibrahim, K.; Farrukh, M. A.

    2016-01-01

    We report growth of quaternary Cu2 ZnSnS4 (CZTS) thin films prepared by the electrochemical deposition from salt precursors containing Cu (II), Zn (II) and Sn (IV) metals. The influence of different sulfurization times t (t = 75, 90, 105, and 120 min) on the structural, compositional, morphological, and optical properties, as well as on the electrical properties is studied. The films sulfurized 2 hours showed a prominent kesterite phase with a nearly stoichiometric composition. Samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and Raman and UV-VIS-NIR spectrometer at different stages of work. X-ray diffraction and Raman spectroscopy analyses confirmed the formation of phase-pure CZTS films. (FESEM) shows that compact and dense morphology and enhanced photo-sensitivity. STEM - EDS elemental map of CZTS cross-section confirms homogeneous distribution. From optical study, energy gap was enlarged with a changed sulfurization times in the range of 1.37–1.47 eV. PMID:27600023

  5. Synthesis of tin-containing polyimide films

    NASA Technical Reports Server (NTRS)

    Ezzell, S. A.; Taylor, L. T.

    1984-01-01

    A series of tin-containing polyimide films derived from either 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride or pyromellitic dianhydride and 4,4'-oxydianiline have been synthesized and their electrical properties examined. Highest quality materials (i.e., homogeneous, smooth surface, flexible) with the best electrical properties were doped with either SnCl2.2H2O or (n-Bu)2SnCl2. In all cases, extensive reactivity of the tin dopant with water, air or polyamic acid during imidization is observed. Lowered electrical surface resistivities appear to be correlatable with the presence of surface tin oxide on the film surface.

  6. Structural and physical properties of tin oxide thin films for optoelectronic applications

    NASA Astrophysics Data System (ADS)

    Lin, Su-Shia; Tsai, Yung-Shiang; Bai, Kai-Ren

    2016-09-01

    Tin oxide films were deposited on glass substrates by RF magnetron sputtering. At a lower sputtering pressure, the tin oxide film comprised nanocrystalline orthorhombic SnO with a (110) orientation, greater p-type conductivity and better hydrophobicity. Increasing substrate temperature resulted in the coexistence of nanocrystalline orthorhombic SnO and tetragonal SnO2 in the deposited film, favoring hydrophilicity, changing the p-type conductivity to n-type conductivity, and reducing resistivity. As the sputtering pressure or substrate temperature increased, the tin oxide film exhibited a lower surface roughness, a larger optical energy gap, and higher optical transmission.

  7. Brush plating of tin(II) selenide thin films

    NASA Astrophysics Data System (ADS)

    Subramanian, B.; Sanjeeviraja, C.; Jayachandran, M.

    2002-01-01

    Brush plating technique has been adopted for the first time to coat tin selenide thin film on tin oxide coated conducting substrates at room temperature, 50°C and 60°C. Uniform and pinhole free films were deposited at potentials 5.0 V. XRD analyses show the polycrystalline nature of the films with orthorhombic structure. Optical studies show the indirect nature with a bandgap of 1.0 eV. SEM pictures show smooth and uniform surface morphology with a grain size of about 0.3 μm. Film roughness was characterized by atomic force microscopy. Mott-Schottky plot has been drawn to evaluate the semiconductor parameters.

  8. Placer tin deposits in central Alaska

    USGS Publications Warehouse

    Chapman, Robert Mills; Coats, Robert Roy; Payne, Thomas G.

    1963-01-01

    Placer tin, in the form of cassiterite (Sn02) and (or) tinstone (fragments including cassiterite and some vein or rock material), is known or reported in deposits that have been prospected or mined for placer gold in four areas adjacent to the Yukon River in central Alaska, 120 to 240 miles west of Fairbanks. These areas are: the Morelock Creek area, on the north side of the Yukon River about 30 miles upstream from Tanana; the Moran Dome area, about 16 miles north of the Yukon River and 25 miles northwest of Tanana; the Mason Creek area, on the north side of the Yukon River about 36 miles west of Tanana; and the Ruby-Long area, on the south side of the Yukon River near Ruby and about 40 miles east of Galena. The only extensive placer mining in these areas has been in the Ruby-Long area. Other placer deposits including some cassiterite are known in central Alaska but are not discussed in this report. Bedrock in these areas is predominantly schist of various types with some associated greenstone and other metamorphic rocks. Some granite is exposed in the Moran Dome and Ruby-Long areas and in areas close to Morelock and Mason Creeks. Barren, milky quartz veins and veinlets transecting the metamorphic rocks are common. No cassiterite was found in the bedrock, and no bedrock source of the tin has been reported. In the Moran Dome and Mason Creek areas, and in part of the Ruby-Long area, tourmaline is present in the rocks of the tin-bearing drainage basins, and apparently absent elsewhere in these areas. The placer deposits are in both valley floor and bench alluvium, which are predominantly relatively thin, rarely exceeding a thickness of 30 feet. Most of the alluvium deposits are not perennially frozen. In the Morelock Creek area tin-bearing deposits are 5 to 5? miles above the mouth of the creek, and meager evidence indicates that cassiterite and gold are present in Morelock Creek valley and some of the tributaries both upstream and downstream from these deposits. The

  9. Variable temperature semiconductor film deposition

    DOEpatents

    Li, X.; Sheldon, P.

    1998-01-27

    A method of depositing a semiconductor material on a substrate is disclosed. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

  10. Variable temperature semiconductor film deposition

    DOEpatents

    Li, Xiaonan; Sheldon, Peter

    1998-01-01

    A method of depositing a semiconductor material on a substrate. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

  11. Fabrication of TiN nanostructure as a hydrogen peroxide sensor by oblique angle deposition

    PubMed Central

    2014-01-01

    Nanostructured titanium nitride (TiN) films with varying porosity were prepared by the oblique angle deposition technique (OAD). The porosity of films increases as the deposition angle becomes larger. The film obtained at an incident angle of 85° exhibits the best catalytic activity and sensitivity to hydrogen peroxide (H2O2). This could be attributed to its largest contact area with the electrolyte. An effective approach is thus proposed to fabricate TiN nanostructure as H2O2 sensor by OAD. PMID:24589278

  12. Ferroelectric and ferromagnetic properties of epitaxial BiFeO{sub 3}-BiMnO{sub 3} films on ion-beam-assisted deposited TiN buffered flexible Hastelloy

    SciTech Connect

    Xiong, J.; Matias, V.; Jia, Q. X.; Tao, B. W.; Li, Y. R.

    2014-05-07

    Growth of multifunctional thin films on flexible substrates is of great technological significance since such a platform is needed for flexible electronics. In this study, we report the growth of biaxially aligned (BiFeO{sub 3}){sub 0.5}:(BiMnO{sub 3}){sub 0.5} [BFO-BMO] films on polycrystalline Hastelloy by using a biaxially aligned TiN as a seed layer deposited by ion-beam-assisted deposited and a La{sub 0.7}Sr{sub 0.3}MnO{sub 3} (LSMO) as a buffer layer deposited by pulsed laser deposition. The LSMO is used not only as a buffer layer but also as the bottom electrode of the BFO-BMO films. X-ray diffraction showed that the BFO-BMO films are biaxially oriented along both in-plane and out-of-plane directions. The BFO-BMO films on flexible metal substrates showed a polarization of 22.9 μC/cm{sup 2}. The magnetization of the BFO-BMO/LSMO is 62 emu/cc at room temperature.

  13. Deposition of titanium nitride (TiN) on Co-Cr and their potential application as vascular stent

    NASA Astrophysics Data System (ADS)

    Pham, Vuong-Hung; Jun, Shin-Hee; Kim, Hyoun-Ee; Koh, Young-Hag

    2012-01-01

    This study reports the effect of a TiN film on the mechanical properties and endothelial compatibility of a Co-Cr substrate. A dense, columnar TiN film with a preferential orientation of the (1 1 1) plane was deposited successfully on a Co-Cr substrate by reactive DC sputtering, particularly by applying a negative substrate bias during deposition. Good adhesion between the TiN film and Co-Cr substrate was achieved using a thin Ti film as an intermediate layer. The TiN film improved the mechanical properties of the Co-Cr significantly, such as the surface hardness and elastic modulus. In addition, the attachment and proliferation of endothelial cells were enhanced remarkably, which was attributed mainly to the favorable absorption of proteins on a biocompatible TiN surface.

  14. Influence of the Cation Ratio on Optical and Electrical Properties of Amorphous Zinc-Tin-Oxide Thin Films Grown by Pulsed Laser Deposition.

    PubMed

    Bitter, Sofie; Schlupp, Peter; Bonholzer, Michael; von Wenckstern, Holger; Grundmann, Marius

    2016-04-11

    Continuous composition spread (CCS) methods allow fast and economic exploration of composition dependent properties of multielement compounds. Here, a CCS method was applied for room temperature pulsed laser deposition (PLD) of amorphous zinc-tin-oxide to gain detailed insight into the influence of the zinc-to-tin cation ratio on optical and electrical properties of this ternary compound. Our CCS approach for a large-area offset PLD process utilizes a segmented target and thus makes target exchange or movable masks in the PLD chamber obsolete. Cation concentrations of 0.08-0.82 Zn/(Zn + Sn) were achieved across single 50 × 50 mm(2) glass substrates. The electrical conductivity increases for increasing tin content, and the absorption edge shifts to lower energies. The free carrier concentration can be tuned from 10(20) to 10(16) cm(-3) by variation of the cation ratio from 0.1 to 0.5 Zn/(Zn + Sn). PMID:27004935

  15. Evaluation of Fracture Strength of TiN Thin Film on Cemented Carbide

    NASA Astrophysics Data System (ADS)

    Takamatsu, Tohru; Miyoshi, Yoshio; Tanabe, Hirotaka; Itoh, Takayoshi

    To evaluate the fracture strength of TiN thin films deposited on the hard metal substrate WC-Co, and to investigate the influence of the deposition conditions (bias voltage VB) on the fracture strength of TiN thin films, the sphere indentation test was carried out to determine the ring crack initiation strength σf,m in TiN thin films deposited on two kinds of WC-Co substrates differing in hardness using sphere indenters of varying diameter. TiN thin films 2.5 μm thick were deposited by dc magnetron sputtering under various VB. Based on the probabilistic theory assuming a two-parameter Weibull distribution, the averages of the fracture strength σ~f of TiN thin films without residual stress under conditions of uniform tensile stress and the residual stress σ~R of thin films were predicted from the distribution characteristics of σf,m. The main results were as follows: the average σ~f is almost independent of sphere indenter diameter and substrate hardness, and decreases with increasing VB the variation in σ~f is mainly due to the grain size of thin films; the residual stress σ~R increases with increasing VB, and this tendency is qualitatively consistent with the measurements obtained by the X-ray diffraction method.

  16. Spray deposited copper zinc tin sulphide (Cu2ZnSnS4) film as a counter electrode in dye sensitized solar cells.

    PubMed

    Swami, Sanjay Kumar; Chaturvedi, Neha; Kumar, Anuj; Chander, Nikhil; Dutta, Viresh; Kumar, D Kishore; Ivaturi, A; Senthilarasu, S; Upadhyaya, Hari M

    2014-11-21

    Stoichiometric thin films of Cu2ZnSnS4 (CZTS) were deposited by the spray technique on a FTO coated glass substrate, with post-annealing in a H2S environment to improve the film properties. CZTS films were used as a counter electrode (CE) in Dye-Sensitized Solar Cells (DSCs) with N719 dye and an iodine electrolyte. The DSC of 0.25 cm(2) area using a CE of CZTS film annealed in a H2S environment under AM 1.5G illumination (100 mW cm(-2)) exhibited a short circuit current density (JSC) = 18.63 mA cm(-2), an open circuit voltage (VOC) = 0.65 V and a fill factor (FF) = 0.53, resulting in an overall power conversion efficiency (PCE) = 6.4%. While the DSC using as deposited CZTS film as a CE showed the PCE = 3.7% with JSC = 13.38 mA cm(-2), VOC = 0.57 V and FF = 0.48. Thus, the spray deposited CZTS films can play an important role as a CE in the large area DSC fabrication. PMID:25286339

  17. Thermally evaporated mechanically hard tin oxide thin films for opto-electronic apllications

    NASA Astrophysics Data System (ADS)

    Tripathy, Sumanta K.; Rajeswari, V. P.

    2014-01-01

    Tungsten doped tin oxide (WTO) and Molybdenum doped tin oxide (MoTO) thin film were deposited on corn glass by thermal evaporation method. The films were annealed at 350°C for one hour. Structural analysis using Xray diffraction data shows both the films are polycrystalline in nature with monoclinic structure of tin oxide, Sn3O4, corresponding to JCPDS card number 01-078-6064. SEM photograph showed that both the films have spherical grains with size in the range of 20-30 nm. Compositional analysis was carried out using EDS which reveals the presence of Sn, O and the dopant Mo/W only thereby indicating the absence of any secondary phase in the films. The films are found to contain nearly 6 wt% of Mo, 8 wt% of W as dopants respectively. The transmission pattern for both the films in the spectral range 200 - 2000 nm shows that W doping gives a transparency of nearly 80% from 380 nm onwards while Mo doping has less transparency of 39% at 380nm. Film hardness measurement using Triboscope shows a film hardness of about 9-10 GPa for both the films. It indicates that W or M doping in tin oxide provides the films the added advantage of withstanding the mechanical wear and tear due to environmental fluctuations By optimizing the optical and electrical properties, W/Mo doped tin oxide films may be explored as window layers in opto-electronic applications such as solar cells.

  18. A Two-Step Absorber Deposition Approach To Overcome Shunt Losses in Thin-Film Solar Cells: Using Tin Sulfide as a Proof-of-Concept Material System.

    PubMed

    Steinmann, Vera; Chakraborty, Rupak; Rekemeyer, Paul H; Hartman, Katy; Brandt, Riley E; Polizzotti, Alex; Yang, Chuanxi; Moriarty, Tom; Gradečak, Silvija; Gordon, Roy G; Buonassisi, Tonio

    2016-08-31

    As novel absorber materials are developed and screened for their photovoltaic (PV) properties, the challenge remains to reproducibly test promising candidates for high-performing PV devices. Many early-stage devices are prone to device shunting due to pinholes in the absorber layer, producing "false-negative" results. Here, we demonstrate a device engineering solution toward a robust device architecture, using a two-step absorber deposition approach. We use tin sulfide (SnS) as a test absorber material. The SnS bulk is processed at high temperature (400 °C) to stimulate grain growth, followed by a much thinner, low-temperature (200 °C) absorber deposition. At a lower process temperature, the thin absorber overlayer contains significantly smaller, densely packed grains, which are likely to provide a continuous coating and fill pinholes in the underlying absorber bulk. We compare this two-step approach to the more standard approach of using a semi-insulating buffer layer directly on top of the annealed absorber bulk, and we demonstrate a more than 3.5× superior shunt resistance Rsh with smaller standard error σRsh. Electron-beam-induced current (EBIC) measurements indicate a lower density of pinholes in the SnS absorber bulk when using the two-step absorber deposition approach. We correlate those findings to improvements in the device performance and device performance reproducibility. PMID:27494110

  19. Amorphous tin-cadmium oxide films and the production thereof

    DOEpatents

    Li, Xiaonan; Gessert, Timothy A

    2013-10-29

    A tin-cadmium oxide film having an amorphous structure and a ratio of tin atoms to cadmium atoms of between 1:1 and 3:1. The tin-cadmium oxide film may have an optical band gap of between 2.7 eV and 3.35 eV. The film may also have a charge carrier concentration of between 1.times.10.sup.20 cm.sup.-3 and 2.times.10.sup.20 cm.sup.-3. The tin cadmium oxide film may also exhibit a Hall mobility of between 40 cm.sup.2V.sup.-1 s.sup.-1 and 60 cm.sup.2V.sup.-1 s.sup.-1. Also disclosed is a method of producing an amorphous tin-cadmium oxide film as described and devices using same.

  20. Tin induced a-Si crystallization in thin films of Si-Sn alloys

    SciTech Connect

    Neimash, V. E-mail: oleks.goushcha@nuportsoft.com; Poroshin, V.; Goushcha, A. O. E-mail: oleks.goushcha@nuportsoft.com; Shepeliavyi, P.; Yukhymchuk, V.; Melnyk, V.; Kuzmich, A.; Makara, V.

    2013-12-07

    Effects of tin doping on crystallization of amorphous silicon were studied using Raman scattering, Auger spectroscopy, scanning electron microscopy, and X-ray fluorescence techniques. Formation of silicon nanocrystals (2–4 nm in size) in the amorphous matrix of Si{sub 1−x}Sn{sub x}, obtained by physical vapor deposition of the components in vacuum, was observed at temperatures around 300 °C. The aggregate volume of nanocrystals in the deposited film of Si{sub 1−x}Sn{sub x} exceeded 60% of the total film volume and correlated well with the tin content. Formation of structures with ∼80% partial volume of the nanocrystalline phase was also demonstrated. Tin-induced crystallization of amorphous silicon occurred only around the clusters of metallic tin, which suggested the crystallization mechanism involving an interfacial molten Si:Sn layer.

  1. Conduction and electric field effect in ultra-thin TiN films

    NASA Astrophysics Data System (ADS)

    Van Bui, Hao; Kovalgin, Alexey Y.; Schmitz, Jurriaan; Wolters, Rob A. M.

    2013-07-01

    Using low pressure atomic layer deposition, ultra-thin continuous TiN films were prepared. The temperature coefficient of resistance (TCR), resistivity and field effect properties of these films were investigated. With decreasing film thickness, a positive-to-negative transition of TCR and a steep increase of resistivity were observed. This is attributed to the metal-semimetal transition of the TiN films. We demonstrate appreciable field-induced current modulation up to 11% in a 0.65 nm TiN film. The field effect is remarkably independent of temperature. A polarity asymmetry of the current-voltage characteristics is found, attributed to the interplay between different types of the carriers.

  2. Electrical properties of TiN on gallium nitride grown using different deposition conditions and annealing

    SciTech Connect

    Li, Liuan; Kishi, Akinori; Shiraishi, Takayuki; Jiang, Ying; Wang, Qingpeng; Ao, Jin-Ping

    2014-03-15

    This study evaluates the thermal stability of different refractory metal nitrides used as Schottky electrodes on GaN. The results demonstrate that TiN, MoSiN, and MoN possess good rectification and adhesion strength, with barrier heights of 0.56, 0.54, and 0.36 eV, respectively. After thermal treatment at 850 °C for 1 min, the TiN and MoN electrodes still exhibit rectifying characteristics, while the MoSiN degrades to an ohmic-like contact. For further study, several TiN films are deposited using different N{sub 2}/Ar reactive/inert sputtering gas ratios, thereby varying the nitrogen content present in the sputtering gas. Ohmic-like contact is observed with the pure Ti contact film, and Schottky characteristics are observed with the samples possessing nitrogen in the film. The average Schottky barrier height is about 0.5 eV and remains virtually constant with varying nitrogen deposition content. After examining Raman spectra and x-ray photoelectron spectroscopy results, the increase in the film resistivity after thermal treatment is attributed to oxidation and/or nitridation. Films deposited with a medium (40% and 60%) nitrogen content show the best film quality and thermal stability.

  3. Growth behavior and properties of atomic layer deposited tin oxide on silicon from novel tin(II)acetylacetonate precursor and ozone

    SciTech Connect

    Kannan Selvaraj, Sathees; Feinerman, Alan; Takoudis, Christos G.

    2014-01-15

    In this work, a novel liquid tin(II) precursor, tin(II)acetylacetonate [Sn(acac){sub 2}], was used to deposit tin oxide films on Si(100) substrate, using a custom-built hot wall atomic layer deposition (ALD) reactor. Three different oxidizers, water, oxygen, and ozone, were tried. Resulting growth rates were studied as a function of precursor dosage, oxidizer dosage, reactor temperature, and number of ALD cycles. The film growth rate was found to be 0.1 ± 0.01 nm/cycle within the wide ALD temperature window of 175–300 °C using ozone; no film growth was observed with water or oxygen. Characterization methods were used to study the composition, interface quality, crystallinity, microstructure, refractive index, surface morphology, and resistivity of the resulting films. X-ray photoelectron spectra showed the formation of a clean SnO{sub x}–Si interface. The resistivity of the SnO{sub x} films was calculated to be 0.3 Ω cm. Results of this work demonstrate the possibility of introducing Sn(acac){sub 2} as tin precursor to deposit conducting ALD SnO{sub x} thin films on a silicon surface, with clean interface and no formation of undesired SiO{sub 2} or other interfacial reaction products, for transparent conducting oxide applications.

  4. Enhanced photoelectrochemical water oxidation via atomic layer deposition of TiO2 on fluorine-doped tin oxide nanoparticle films

    NASA Astrophysics Data System (ADS)

    Cordova, Isvar A.; Peng, Qing; Ferrall, Isa L.; Rieth, Adam J.; Hoertz, Paul G.; Glass, Jeffrey T.

    2015-04-01

    TiO2 is an exemplary semiconductor anode material for photoelectrochemical (PEC) water-splitting electrodes due to its functionality, long-term stability in corrosive environments, nontoxicity, and low cost. In this study, TiO2 photoanodes with enhanced photocurrent density were synthesized by atomic layer deposition (ALD) of TiO2 onto a porous, transparent, and conductive fluorine-doped tin oxide nanoparticle (nanoFTO) scaffold fabricated by solution processing. The simplicity and disordered nature of the nanoFTO nanostructure combined with the ultrathin conformal ALD TiO2 coatings offers advantages including decoupling charge carrier diffusion length from optical penetration depth, increased photon absorption probability through scattering, complimentary photon absorption, and favorable interfaces for charge separation and transfer across the various junctions. We examine the effects of porosity of the nanoFTO scaffold and thickness of the TiO2 coating on PEC performance and achieve an optimal photocurrent of 0.7 mA cm-2 at 0 V vs. Ag/AgCl under 100 mW cm-2 AM 1.5 G irradiation in a 1 M KOH aqueous electrolyte. Furthermore, the fundamental mechanisms behind the improvements are characterized via cyclic voltammetry, incident photon-to-current efficiency, transient photocurrent spectroscopy, and electrochemical impedance spectroscopy and are contrasted with those of single crystal rutile TiO2 nanowires. The strategies employed in this work highlight the opportunities inherent to these types of heteronanostructures, where the lessons may be applied to improve the PEC conversion efficiencies of other promising semiconductors, such as hematite (α-Fe2O3) and other materials more sensitive to visible light.TiO2 is an exemplary semiconductor anode material for photoelectrochemical (PEC) water-splitting electrodes due to its functionality, long-term stability in corrosive environments, nontoxicity, and low cost. In this study, TiO2 photoanodes with enhanced photocurrent

  5. Enhanced photoelectrochemical water oxidation via atomic layer deposition of TiO2 on fluorine-doped tin oxide nanoparticle films.

    PubMed

    Cordova, Isvar A; Peng, Qing; Ferrall, Isa L; Rieth, Adam J; Hoertz, Paul G; Glass, Jeffrey T

    2015-05-14

    TiO2 is an exemplary semiconductor anode material for photoelectrochemical (PEC) water-splitting electrodes due to its functionality, long-term stability in corrosive environments, nontoxicity, and low cost. In this study, TiO2 photoanodes with enhanced photocurrent density were synthesized by atomic layer deposition (ALD) of TiO2 onto a porous, transparent, and conductive fluorine-doped tin oxide nanoparticle (nanoFTO) scaffold fabricated by solution processing. The simplicity and disordered nature of the nanoFTO nanostructure combined with the ultrathin conformal ALD TiO2 coatings offers advantages including decoupling charge carrier diffusion length from optical penetration depth, increased photon absorption probability through scattering, complimentary photon absorption, and favorable interfaces for charge separation and transfer across the various junctions. We examine the effects of porosity of the nanoFTO scaffold and thickness of the TiO2 coating on PEC performance and achieve an optimal photocurrent of 0.7 mA cm(-2) at 0 V vs. Ag/AgCl under 100 mW cm(-2) AM 1.5 G irradiation in a 1 M KOH aqueous electrolyte. Furthermore, the fundamental mechanisms behind the improvements are characterized via cyclic voltammetry, incident photon-to-current efficiency, transient photocurrent spectroscopy, and electrochemical impedance spectroscopy and are contrasted with those of single crystal rutile TiO2 nanowires. The strategies employed in this work highlight the opportunities inherent to these types of heteronanostructures, where the lessons may be applied to improve the PEC conversion efficiencies of other promising semiconductors, such as hematite (α-Fe2O3) and other materials more sensitive to visible light. PMID:25899449

  6. Film thickness effect on fractality of tin-doped In2O3 thin films

    NASA Astrophysics Data System (ADS)

    Ţălu, Ştefan; Stach, Sebastian; Raoufi, Davood; Hosseinpanahi, Fayegh

    2015-09-01

    In this paper, based on atomic force microscopy (AFM) data the surface morphology of tin-doped In2O3 (ITO) thin films, prepared by electron beam deposition method on float glass substrates, was systematically investigated using the multifractal analysis. Topographical characterization of the ITO film surfaces was realized by a novel multifractal approach which may be applied for AFM data. Detailed surface characterization of the 3D surface topography was obtained using statistical parameters, according to the ISO 25178-2: 2012. Multifractal analysis of the film surfaces revealed that ITO thin films have a multifractal geometry. The generalized dimension D q and the singularity spectrum f( α) provided quantitative values that characterize the local scale properties of film surfaces at nanometer scale. Our results showed that the larger spectrum width Δ α (Δ α = α max - α min) of the multifractal spectra f( α) is related to the larger surface roughness. [Figure not available: see fulltext.

  7. Thermally evaporated mechanically hard tin oxide thin films for opto-electronic apllications

    SciTech Connect

    Tripathy, Sumanta K.; Rajeswari, V. P.

    2014-01-28

    Tungsten doped tin oxide (WTO) and Molybdenum doped tin oxide (MoTO) thin film were deposited on corn glass by thermal evaporation method. The films were annealed at 350°C for one hour. Structural analysis using Xray diffraction data shows both the films are polycrystalline in nature with monoclinic structure of tin oxide, Sn{sub 3}O{sub 4}, corresponding to JCPDS card number 01-078-6064. SEM photograph showed that both the films have spherical grains with size in the range of 20–30 nm. Compositional analysis was carried out using EDS which reveals the presence of Sn, O and the dopant Mo/W only thereby indicating the absence of any secondary phase in the films. The films are found to contain nearly 6 wt% of Mo, 8 wt% of W as dopants respectively. The transmission pattern for both the films in the spectral range 200 – 2000 nm shows that W doping gives a transparency of nearly 80% from 380 nm onwards while Mo doping has less transparency of 39% at 380nm. Film hardness measurement using Triboscope shows a film hardness of about 9–10 GPa for both the films. It indicates that W or M doping in tin oxide provides the films the added advantage of withstanding the mechanical wear and tear due to environmental fluctuations By optimizing the optical and electrical properties, W/Mo doped tin oxide films may be explored as window layers in opto-electronic applications such as solar cells.

  8. Uniformity of TiN Films Fabricated by Hollow Cathode Discharge

    NASA Astrophysics Data System (ADS)

    Jiang, Haifu; Gong, Chunzhi; Tian, Xiubo; Yang, Shiqin; K. Y. Fu, R.; K. Chu, P.

    2010-04-01

    Titanium nitride (TiN) films were deposited on AISI 304 stainless steel substrates using hollow cathode plasma physical vapor deposition (HC-PVD). Titanium was introduced by eroding the Ti cathode nozzle and TiN was formed in the presence of a nitrogen plasma excited by radio frequency (RF). The substrate bias voltage was varied from 0 to -300 V and the uniformity in film thickness, surface roughness, crystal size, microhardness and wear resistance for the film with a diameter of 20 mm was evaluated. Although the central zone of the plasma had the highest ion density, the film thickness did not vary appreciably across the sample. The results from atomic force microscopy (AFM) revealed a low surface roughness dominated by an island-like morphology with a similar crystal size on the entire surface. Higher microhardness was measured at the central zone of the sample. The sample treated at -200 V had excellent tribological properties and uniformity.

  9. Relationship between microstructure and electronic properties of energetically deposited zinc tin oxide

    NASA Astrophysics Data System (ADS)

    Murdoch, Billy James; McCulloch, Dougal G.; Partridge, James G.

    2016-06-01

    Thin films of amorphous n-type zinc tin oxide have been energetically deposited from a filtered cathodic vacuum arc at moderate temperatures. The characteristics of these films span a range suitable for semiconductor devices and transparent conducting oxide interconnects with carrier concentration and mobility dependent on local bonding. X-ray photoelectron spectroscopy (XPS) and electron diffraction have revealed that acceptor-like Sn(II) bonding in the films decreased with increasing growth temperature, resulting in higher n-type carrier concentrations. XPS and in situ Ar plasma treatment showed that downward surface band bending resulted from OH attachment. Persistent photoconductivity was attributed to the photoionization of oxygen vacancies.

  10. Depositing Diamondlike Carbon Films

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J.; Sovey, J. S.; Banks, B. A.

    1986-01-01

    New process demonstrated to make thin films (usually thousands of angstroms to few microns thick) that have properties of diamonds. Various plasma and ion-beam techniques employed to generate films. Films made by radio-frequency plasma decomposition of hydrocarbon gas or other alkanes, by low-energy carbon-ion-beam deposition, or by ion plating and dual ion technique using carbon target. Advantages of new process over others are films produced, though amorphous, are clear, extremely hard, chemically inert, of high resistivity, and have index of refraction of 3.2 properties similar to those of single-crystal diamonds. Films have possible uses in microelectronic applications, high-energy-laser and plastic windows, corrosion protection for metals, and other applications where desired properties of film shaped during the film-formation process.

  11. Structural, optical and electrical properties of tin oxide thin films for application as a wide band gap semiconductor

    NASA Astrophysics Data System (ADS)

    Sethi, Riti; Ahmad, Shabir; Aziz, Anver; Siddiqui, Azher Majid

    2015-08-01

    Tin oxide (SnO) thin films were synthesized using thermal evaporation technique. Ultra pure metallic tin was deposited on glass substrates using thermal evaporator under high vacuum. The thickness of the tin deposited films was kept at 100nm. Subsequently, the as-deposited tin films were annealed under oxygen environment for a period of 3hrs to obtain tin oxide films. To analyse the suitability of the synthesized tin oxide films as a wide band gap semiconductor, various properties were studied. Structural parameters were studied using XRD and SEM-EDX. The optical properties were studied using UV-Vis Spectrophotometry and the electrical parameters were calculated using the Hall-setup. XRD and SEM confirmed the formation of SnO phase. Uniform texture of the film can be seen through the SEM images. Presence of traces of unoxidised Sn has also been confirmed through the XRD spectra. The band gap calculated was around 3.6eV and the optical transparency around 50%. The higher value of band gap and lower value of optical transparency can be attributed to the presence of unoxidised Sn. The values of resistivity and mobility as measured by the Hall setup were 78Ωcm and 2.92cm2/Vs respectively. The reasonable optical and electrical parameters make SnO a suitable candidate for optoelectronic and electronic device applications.

  12. Structural, optical and electrical properties of tin oxide thin films for application as a wide band gap semiconductor

    SciTech Connect

    Sethi, Riti; Ahmad, Shabir; Aziz, Anver; Siddiqui, Azher Majid

    2015-08-28

    Tin oxide (SnO) thin films were synthesized using thermal evaporation technique. Ultra pure metallic tin was deposited on glass substrates using thermal evaporator under high vacuum. The thickness of the tin deposited films was kept at 100nm. Subsequently, the as-deposited tin films were annealed under oxygen environment for a period of 3hrs to obtain tin oxide films. To analyse the suitability of the synthesized tin oxide films as a wide band gap semiconductor, various properties were studied. Structural parameters were studied using XRD and SEM-EDX. The optical properties were studied using UV-Vis Spectrophotometry and the electrical parameters were calculated using the Hall-setup. XRD and SEM confirmed the formation of SnO phase. Uniform texture of the film can be seen through the SEM images. Presence of traces of unoxidised Sn has also been confirmed through the XRD spectra. The band gap calculated was around 3.6eV and the optical transparency around 50%. The higher value of band gap and lower value of optical transparency can be attributed to the presence of unoxidised Sn. The values of resistivity and mobility as measured by the Hall setup were 78Ωcm and 2.92cm{sup 2}/Vs respectively. The reasonable optical and electrical parameters make SnO a suitable candidate for optoelectronic and electronic device applications.

  13. Aspects of nitrogen surface chemistry relevant to TiN chemical vapor deposition

    SciTech Connect

    Schulberg, M.T.; Allendorf, M.D.; Outka, D.A.

    1996-08-01

    NH{sub 3} is an important component of many chemical vapor deposition (CVD) processes for TiN films, which are used for diffusion barriers and other applications in microelectronic circuits. In this study, the interaction of NH{sub 3} with TiN surfaces is examined with temperature programmed desorption (TPD) and Auger electron spectroscopy. NH{sub 3} has two adsorption states on TiN: a chemisorbed state and a multilayer state. A new method for analyzing TPD spectra in systems with slow pumping speeds yields activation energies for desorption for the two states of 24 kcal/mol and 7.3 kcal/mol, respectively. The sticking probability into the chemisorption state is {approximately}0.06. These results are discussed in the context of TiN CVD. In addition, the high temperature stability of TiN is investigated. TiN decomposes to its elements only after heating to 1300 K, showing that decomposition is unlikely to occur under CVD conditions.

  14. Effects of bias on surface properties of TiN films fabricated by hollow cathode discharge

    SciTech Connect

    Jiang, H. F.; Tian, X. B.; Yang, S. Q.; Fu, Ricky K. Y.; Chu, Paul K.

    2007-07-15

    Titanium nitride (TiN) films have been deposited on AISI 304 stainless steel substrates using hollow cathode reactive plasma vapor deposition. Titanium is introduced by sputtering the Ti cathode nozzle and TiN is formed in the presence of a nitrogen plasma excited by radio frequency. The substrate bias voltage is varied from 0 to -300 V to investigate its effect on the mechanical and structural properties of the films. X-ray diffraction results show the formation of TiN (111) and Ti{sub 2}N (220) phases in the films. The sample bias has a critical influence on the thickness of the deposited films. The bias of -200 V leads to the thickest films (about 1680 nm) and the deposition rate is 18.7 nm/min. The microhardness, root-mean-square (rms) roughness values, and tribological properties also exhibit nonlinear relationship with increasing bias voltages. The highest hardness of about 1027 hardness vickers and best wear resistance are achieved at a bias voltage of -100 V. Atomic force microscopy results reveal the lowest rms surface roughness of 3.19 nm when the bias voltage is -200 V.

  15. Biomimetic thin film deposition

    SciTech Connect

    Rieke, P.R.; Graff, G.E.; Campbell, A.A.; Bunker, B.C.; Baskaran, S.; Song, L.; Tarasevich, B.J.; Fryxell, G.E.

    1995-09-01

    Biological mineral deposition for the formation of bone, mollusk shell and other hard tissues provides materials scientists with illustrative materials processing strategies. This presentation will review the key features of biomineralization and how these features can be of technical importance. We have adapted existing knowledge of biomineralization to develop a unique method of depositing inorganic thin films and coating. Our approach to thin film deposition is to modify substrate surfaces to imitate the proteins found in nature that are responsible for controlling mineral deposition. These biomimetic surfaces control the nucleation and growth of the mineral from a supersaturated aqueous solution. This has many processing advantages including simple processing equipment, environmentally benign reagents, uniform coating of highly complex shapes, and enhanced adherence of coating. Many different types of metal oxide, hydroxide, sulfide and phosphate materials with useful mechanical, optical, electronic and biomedical properties can be deposited.

  16. Synthesis and Characterization of Tin(IV) Oxide Obtained by Chemical Vapor Deposition Method.

    PubMed

    Nagirnyak, Svitlana V; Lutz, Victoriya A; Dontsova, Tatiana A; Astrelin, Igor M

    2016-12-01

    The effect of precursors on the characteristics of tin oxide obtained by chemical vapor deposition (CVD) method was investigated. The synthesis of nanosized tin(IV) oxide was carried out with the use of two different precursors: tin(II) oxalate obtained using tin chloride(II) and oxalic acid; tin(II) oxalate obtained using tin chloride(II); and ammonium oxalate. The synthesized tin(IV) oxide samples were studied by electron microscopy, X-ray diffraction and optical spectra. The lattice parameters of tin(IV) oxide samples were defined, the bandgap of samples were calculated. PMID:27456501

  17. Synthesis and Characterization of Tin(IV) Oxide Obtained by Chemical Vapor Deposition Method

    NASA Astrophysics Data System (ADS)

    Nagirnyak, Svitlana V.; Lutz, Victoriya A.; Dontsova, Tatiana A.; Astrelin, Igor M.

    2016-07-01

    The effect of precursors on the characteristics of tin oxide obtained by chemical vapor deposition (CVD) method was investigated. The synthesis of nanosized tin(IV) oxide was carried out with the use of two different precursors: tin(II) oxalate obtained using tin chloride(II) and oxalic acid; tin(II) oxalate obtained using tin chloride(II); and ammonium oxalate. The synthesized tin(IV) oxide samples were studied by electron microscopy, X-ray diffraction and optical spectra. The lattice parameters of tin(IV) oxide samples were defined, the bandgap of samples were calculated.

  18. Optical properties of TiN thin films close to the superconductor-insulator transition.

    SciTech Connect

    Pfuner, F.; Degiorgi, L.; Baturina, T. I.; Vinokur, V. M.; Baklanov, M. R.; Materials Science Division; ETH Zurich; Inst. Semiconductor Physics; IMEC Kapeldreef

    2009-11-10

    We present the intrinsic optical properties over a broad spectral range of TiN thin films deposited on an Si/SiO{sub 2} substrate. We analyze the measured reflectivity spectra of the film-substrate multilayer structure within a well-establish procedure based on the Fresnel equation and extract the real part of the optical conductivity of TiN. We identify the metallic contribution as well as the finite energy excitations and disentangle the spectral weight distribution among them. The absorption spectrum of TiN bears some similarities with the electrodynamic response observed in the normal state of the high-temperature superconductors. Particularly, a mid-infrared feature in the optical conductivity is quite reminiscent of a pseudogap-like excitation.

  19. Nondestructive measurement of the residual stress TiN thin film coated on AISI 304 substrate by x-ray stress analyzer

    NASA Astrophysics Data System (ADS)

    Zhang, Y. K.; Feng, A. X.; Lu, J. Z.; Kong, D. J.; Tang, C. P.

    2006-01-01

    Titanium nitride films are deposited on AISI 304 steel with a hollow-cathode-discharge (HCD) ion-plating technique. The status of residual stresses in TiN thin film coated on AISI304 substrate by HCD is studied by x-ray diffraction stress analyzer. By analyzing morphology of the residual stress of TiN thin film at interface between TiN film and AISI 304 substrate, the adhering mechanism of TiN thin film is understood as follows: the mechanical interlocking had important contribution to the adhesion strength, the thermal stress is the major factor which resulting TiN thin film peeling off spontaneously. The results show that the value of thin film is -210MPa~-650Mpa, and the thermal stress is compressive, the intrinsic stress is tensile, origins of the residual stress are primarily discussed.

  20. The influence of the effective physical properties of tin electrodeposited films on the growth of tin whiskers

    NASA Astrophysics Data System (ADS)

    Pedigo, Aaron E.

    The purpose of the present study was to characterize and calculate the effective film properties of electrodeposited tin films to determine factors influencing the growth of tin (Sn) whiskers. The growth of Sn whiskers represents an increased risk to the reliability of electronic devices, and is a particular concern in the high reliability environments demanded in aerospace and defense applications. Efforts to prevent whisker growth have proven difficult, in part, due to the lack of understanding concerning the fundamental mechanisms responsible for whisker growth. In the present study, Sn, Sn-Cu, and Sn Cu Pb films were electrodeposited from commercial electrolytes with different deposition parameters. The morphology of Sn hillocks and whiskers were characterized leading to a growth model considering the role of grain boundary mobility. Crystallographic texture measurements revealed non-random textures, dependent on electrolyte type, electrolyte additives, deposition current density, and film thickness. The crystallographic texture was also found to evolve with time, indicating recrystallization and grain growth. The corresponding textures were used to calculate the effective physical properties of the films, showing significant differences in the linear modulus of elasticity, biaxial modulus of elasticity, and coefficient of thermal expansion. The influence of these effective properties on the strain energy density of the film was analyzed with respect to the evolution of crystallographic texture and film stress. The results show that the reduction of strain energy and surface energy is not the only driving force dictating the evolution of the crystallographic texture. Recommendations are made for future studies to apply the analysis tools developed in this study for future whisker research, as well as for industrial applications.

  1. Fluorine doped tin oxide film with high haze and transmittance prepared for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Otsuka, Rena; Endo, Takeshi; Takano, Takafumi; Takemura, Shuichiro; Murakami, Ryo; Muramoto, Ryosuke; Madarász, János; Okuya, Masayuki

    2015-08-01

    Fluorine doped tin oxide (FTO) transparent conductive oxide (TCO) film for dye-sensitized solar cell (DSSC) was investigated. Haze of the incident light through TCO film was easily tuned by controlling the surface morphology of FTO deposited on tin doped indium oxide (ITO) nano-particle seed layer pre-coated on a glass substrate, and the light harvest within the cell was effectively enhanced with high haze TCO film. The conversion efficiency of DSSC fabricated with TCO film with the haze of 30.1% reached as high as 7.7%, attributing to the consequence of the effective light harvest with the scattering within the cell.

  2. On-line coating of glass with tin oxide by atmospheric pressure chemical vapor deposition.

    SciTech Connect

    Allendorf, Mark D.; Sopko, J.F. (PPF Industries, Pittsburgh, PA); Houf, William G.; Chae, Yong Kee; McDaniel, Anthony H.; Li, M. (PPF Industries, Pittsburgh, PA); McCamy, J.W.

    2006-11-01

    Atmospheric pressure chemical vapor deposition (APCVD) of tin oxide is a very important manufacturing technique used in the production of low-emissivity glass. It is also the primary method used to provide wear-resistant coatings on glass containers. The complexity of these systems, which involve chemical reactions in both the gas phase and on the deposition surface, as well as complex fluid dynamics, makes process optimization and design of new coating reactors a very difficult task. In 2001 the U.S. Dept. of Energy Industrial Technologies Program Glass Industry of the Future Team funded a project to address the need for more accurate data concerning the tin oxide APCVD process. This report presents a case study of on-line APCVD using organometallic precursors, which are the primary reactants used in industrial coating processes. Research staff at Sandia National Laboratories in Livermore, CA, and the PPG Industries Glass Technology Center in Pittsburgh, PA collaborated to produce this work. In this report, we describe a detailed investigation of the factors controlling the growth of tin oxide films. The report begins with a discussion of the basic elements of the deposition chemistry, including gas-phase thermochemistry of tin species and mechanisms of chemical reactions involved in the decomposition of tin precursors. These results provide the basis for experimental investigations in which tin oxide growth rates were measured as a function of all major process variables. The experiments focused on growth from monobutyltintrichloride (MBTC) since this is one of the two primary precursors used industrially. There are almost no reliable growth-rate data available for this precursor. Robust models describing the growth rate as a function of these variables are derived from modeling of these data. Finally, the results are used to conduct computational fluid dynamic simulations of both pilot- and full-scale coating reactors. As a result, general conclusions are

  3. Electrochromic properties of WO3 thin film onto gold nanoparticles modified indium tin oxide electrodes

    NASA Astrophysics Data System (ADS)

    Deng, Jiajia; Gu, Ming; Di, Junwei

    2011-04-01

    Gold nanoparticles (GNPs) thin films, electrochemically deposited from hydrogen tetrachloroaurate onto transparent indium tin oxide (ITO) thin film coated glass, have different color prepared by variation of the deposition condition. The color of GNP film can vary from pale red to blue due to different particle size and their interaction. The characteristic of GNPs modified ITO electrodes was studied by UV-vis spectroscopy, scanning electron microscope (SEM) images and cyclic voltammetry. WO3 thin films were fabricated by sol-gel method onto the surface of GNPs modified electrode to form the WO3/GNPs composite films. The electrochromic properties of WO3/GNPs composite modified ITO electrode were investigated by UV-vis spectroscopy and cyclic voltammetry. It was found that the electrochromic performance of WO3/GNPs composite films was improved in comparison with a single component system of WO3.

  4. Tailoring of absorption edge by thermal annealing in tin oxide thin films

    SciTech Connect

    Thakur, Anup; Gautam, Sanjeev; Kumar, Virender; Chae, K. H.; Lee, Ik-Jae; Shin, Hyun Joon

    2015-05-15

    Tin oxide (SnO{sub 2}) thin films were deposited by radio-frequency (RF) magnetron sputtering on silicon and glass substrates in different oxygen-to-argon gas-flow ratio (O{sub 2}-to-Ar = 0%, 10%, 50%). All films were deposited at room temperature and fixed working pressures, 10 mTorr. The X-ray diffraction (XRD) measurement suggests that all films were crystalline in nature except film deposited in argon environment. Thin films were annealed in air at 200 °C, 400 °C and 600 °C for two hours. All films were highly transparent except the film deposited only in the argon environment. It was also observed that transparency was improved with annealing due to decrease in oxygen vacancies. Atomic force microscopy (AFM), results showed that the surface of all the films were highly flat and smooth. Blue shift was observed in the absorption edge with annealing temperature. It was also observed that there was not big change in the absorption edge with annealing for films deposited in 10% and 50% oxygen-to-argon gas-flow ratio.

  5. Comparison of characteristics of fluorine doped zinc and gallium tin oxide composite thin films deposited on stainless steel 316 bipolar plate by electron cyclotron resonance-metal organic chemical vapor deposition for proton exchange membrane fuel cells.

    PubMed

    Park, Jihun; Hudaya, Chairul; Lee, Joong Kee

    2011-09-01

    In order to replace the brittle graphite bipolar plates currently used for the PEMFC stack, coated SUS 316 was employed. As a metallic bipolar plate, coated SUS 316 can provide higher mechanical strength, better durability to shocks and vibration, less permeability, improved thermal and bulk electrical conductivity, as well as being thinner and lighter. To enhance the interfacial contact resistance and corrosion resistance of SUS 316, the deposition of GTO:F and ZTO:F composite films was carried out by ECR-MOCVD. The surface morphology of the films consisted of tiny elliptically shaped grains with a thickness of 1 microm. The corrosion current for GTO:F was 0.13 Acm(-2) which was much lower than that of bare SUS 316 (50.16 Acm(-2)). The GTO:F coated film had the smallest corrosion current due to the formation of a tight surface morphology with very few pin-holes. The GTO:F coated film exhibited the highest cell voltage and power density due to its lower ICR values. PMID:22097519

  6. Study of indium tin oxide films exposed to atomic axygen

    NASA Technical Reports Server (NTRS)

    Snyder, Paul G.; De, Bhola N.; Woollam, John A.; Coutts, T. J.; Li, X.

    1989-01-01

    A qualitative simulation of the effects of atomic oxygen has been conducted on indium tin oxide (ITO) films prepared by dc sputtering onto room-temperature substrates, by exposing them to an RF-excited oxygen plasma and characterizing the resulting changes in optical, electrical, and structural properties as functions of exposure time with ellipsometry, spectrophotometry, resistivity, and X-ray measurements. While the films thus exposed exhibit reduced resistivity and optical transmission; both of these effects, as well as partial crystallization of the films, may be due to sample heating by the plasma. Film resistivity is found to stabilize after a period of exposure.

  7. SnS2 Thin Film Deposition by Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Yahia Jaber, Abdallah; Noaiman Alamri, Saleh; Salah Aida, Mohammed

    2012-06-01

    Tin disulfide (SnS2) thin films have been synthesized using a simplified spray pyrolysis technique using a perfume atomizer. The films were deposited using two different solutions prepared by the dilution of SnCl2 and thiourea in distilled water and in methanol. The obtained films have a microcrystalline structure. The film deposited using methanol as the solvent is nearly stochiometric SnS2 with a spinel phase having a (001) preferential orientation. The film prepared with an aqueous solution is Sn-rich. Scanning electronic microscopy (SEM) images reveal that the film deposited with the aqueous solution is rough and is formed with large wires. However, the film deposited with methanol is dense and smooth. Conductivity measurements indicate that the aqueous solution leads to an n-type semiconductor, while methanol leads to a p-type semiconductor.

  8. Antimony-Doped Tin Oxide Thin Films Grown by Home Made Spray Pyrolysis Technique

    NASA Astrophysics Data System (ADS)

    Yusuf, Gbadebo; Babatola, Babatunde Keji; Ishola, Abdulahi Dimeji; Awodugba, Ayodeji O.; Solar cell Collaboration

    2016-03-01

    Transparent conducting antimony-doped tin oxide (ATO) films have been deposited on glass substrates by home made spray pyrolysis technique. The structural, electrical and optical properties of the ATO films have been investigated as a function of Sb-doping level and annealing temperature. The optimum target composition for high conductivity and low resistivity was found to be 20 wt. % SnSb2 + 90 wt. ATO. Under optimized deposition conditions of 450oC annealing temperature, electrical resistivity of 5.2×10-4 Ω -cm, sheet resistance of 16.4 Ω/sq, average optical transmittance of 86% in the visible range, and average optical band-gap of 3.34eV were obtained. The film deposited at lower annealing temperature shows a relatively rough, loosely bound slightly porous surface morphology while the film deposited at higher annealing temperature shows uniformly distributed grains of greater size. Keywords: Annealing, Doping, Homemade spray pyrolysis, Tin oxide, Resistivity

  9. Coating The Inner Walls Of Tubes With TiN Films By Reactive Sputtering

    SciTech Connect

    Kraus, T.; Lindner, J.K.N.; Stritzker, B.; Keckes, J.; Ensinger, W.

    2003-08-26

    It is possible to achieve a homogenous coating of the inner walls of tubes by sputter deposition. For this purpose a conical sputter target is moved through the tube parallel to its axis while an ion beam enters the tube along its axis, impinges onto the target and sputters material onto the tube inner wall. But so far only monatomic coatings were performed with this technique. To improve the mechanical properties of tubes TiN films were deposited by reactive sputtering. Therefore a Ti sputter target is used, the N2 reactive gas is delivered into the tube by a nozzle. The topography of the films is dominated by a ripple structure with the wave vector perpendicular to the tubes length axis. The development of the ripples is discussed in terms of scattered Ar projectiles which impinge onto the substrate as well as the deposited film under grazing incidence angles. Results of RBS, ERD, AFM, and hardness measurements are shown.

  10. Tin diselenide quantum-sized island films

    NASA Astrophysics Data System (ADS)

    Kushkhov, A. R.; Gaev, D. S.; Rabinovich, O. I.; Stolyarov, A. G.

    2012-03-01

    Island films based on the intermediate phases forming in Ge-Se and Sn-Se systems are prepared by the incongruent evaporation of film structures of a Sn1 - x Se x composition. The surface morphology of these structures is studied by atomic force microscopy (AFM). The effect of growth conditions on the size distribution of islands is established.

  11. Ovonic switching in tin selenide thin films. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Baxter, C. R.

    1974-01-01

    Amorphous tin selenide thin films which possess Ovonic switching properties were fabricated using vacuum deposition techniques. Results obtained indicate that memory type Ovonic switching does occur in these films the energy density required for switching from a high impedance to a low impedance state is dependent on the spacing between the electrodes of the device. The switching is also function of the magnitude of the applied voltage pulse. A completely automated computer controlled testing procedure was developed which allows precise control over the shape of the applied voltage switching pulse. A survey of previous experimental and theoretical work in the area of Ovonic switching is also presented.

  12. Nano-crystalline porous tin oxide film for carbon monoxide sensing

    NASA Technical Reports Server (NTRS)

    Liu, Chung-Chiun (Inventor); Savinell, Robert F. (Inventor); Jin, Zhihong (Inventor)

    2000-01-01

    A tin oxide sol is deposited on platinum electrodes (12) of a sensor (10). The sol is calcined at a temperature of 500 to 800.degree. C. to produce a thin film of tin oxide with a thickness of about 150 nm to 2 .mu. and having a nano-crystalline structure with good stability. The sensor rapidly detects reducing gases, such as carbon monoxide, or hydrocarbons and organic vapors. Sensors using films calcined at around 700.degree. C. have high carbon monoxide selectivity with a response time of around 4 minutes and a recovery time of 1 minute, and therefore provide good detection systems for detection of trace amounts of pollutants such as toxic and flammable gases in homes, industrial settings, and hospitals.

  13. Electrically conducting polyimide film containing tin complexes

    NASA Technical Reports Server (NTRS)

    St. Clair, Anne K. (Inventor); Ezzell, Stephen A. (Inventor); Taylor, Larry T. (Inventor); Boston, Harold G. (Inventor)

    1996-01-01

    Disclosed is a thermally-stable SnO.sub.2 -surfaced polyimide film wherein the electrical conductivity of the SnO.sub.2 surface is within the range of about 3.0.times.10.sup.-3 to about 1.times.10.sup.-2 ohms.sup.-1,. Also disclosed is a method of preparing this film from a solution containing a polyamic acid and SnCl.sub.4 (DMSO).sub.2.

  14. Investigation of the Carbon Monoxide Gas Sensing Characteristics of Tin Oxide Mixed Cerium Oxide Thin Films

    PubMed Central

    Durrani, Sardar M. A.; Al-Kuhaili, Mohammad F.; Bakhtiari, Imran A.; Haider, Muhammad B.

    2012-01-01

    Thin films of tin oxide mixed cerium oxide were grown on unheated substrates by physical vapor deposition. The films were annealed in air at 500 °C for two hours, and were characterized using X-ray photoelectron spectroscopy, atomic force microscopy and optical spectrophotometry. X-ray photoelectron spectroscopy and atomic force microscopy results reveal that the films were highly porous and porosity of our films was found to be in the range of 11.6–21.7%. The films were investigated for the detection of carbon monoxide, and were found to be highly sensitive. We found that 430 °C was the optimum operating temperature for sensing CO gas at concentrations as low as 5 ppm. Our sensors exhibited fast response and recovery times of 26 s and 30 s, respectively. PMID:22736967

  15. CO-sensing properties of undoped and doped tin oxide thin films prepared by electron beam evaporation.

    PubMed

    Durrani, S M A; Khawaja, E E; Al-Kuhaili, M F

    2005-03-15

    Undoped thin films of tin oxide and those doped with indium oxide and nickel oxides were deposited by electron beam evaporation. The effects of the film thickness and preparation conditions (films prepared with or without the presence of oxygen environment during deposition) on the optical and carbon monoxide sensing properties of the films were studied. The films were characterized using X-ray diffraction and X-ray photoelectron spectroscopy and optical spectroscopy techniques. All the films were found to be amorphous. It was found that the sensitivity of the films to CO increased with the thickness and the porosity of the films. It was found that their selectivity to CO gas relative to CO(2) and SO(2) gases could be improved upon doping the films with indium (or nickel) oxide. PMID:18969926

  16. Combinatorial study of zinc tin oxide thin-film transistors

    SciTech Connect

    McDowell, M. G.; Sanderson, R. J.; Hill, I. G.

    2008-01-07

    Groups of thin-film transistors using a zinc tin oxide semiconductor layer have been fabricated via a combinatorial rf sputtering technique. The ZnO:SnO{sub 2} ratio of the film varies as a function of position on the sample, from pure ZnO to SnO{sub 2}, allowing for a study of zinc tin oxide transistor performance as a function of channel stoichiometry. The devices were found to have mobilities ranging from 2 to 12 cm{sup 2}/V s, with two peaks in mobility in devices at ZnO fractions of 0.80{+-}0.03 and 0.25{+-}0.05, and on/off ratios as high as 10{sup 7}. Transistors composed predominantly of SnO{sub 2} were found to exhibit light sensitivity which affected both the on/off ratios and threshold voltages of these devices.

  17. Investigation of tungsten doped tin oxide thin film transistors

    NASA Astrophysics Data System (ADS)

    Yang, Jianwen; Meng, Ting; Yang, Zhao; Cui, Can; Zhang, Qun

    2015-11-01

    Tungsten doped tin oxide thin film transistors (TWO-TFTs) were fabricated by radio frequency magnetron sputtering. With TWO thin films as the channel layers, the TFTs show lower off-current and positive shift turn-on voltage than the intrinsic tin oxide TFTs, which can be explained by the reason that W doping is conducive to suppress the carrier concentration of the TWO channel layer. It is important to elect an appropriate channel thickness for improving the TFT performance. The optimum TFT performance in enhancement mode is achieved at W doping content of 2.7 at% and channel thickness of 12 nm, with the saturation mobility, turn-on voltage, subthreshold swing value and on-off current ratio of 5 cm2 V-1 s-1, 0.4 V, 0.4 V/decade and 2.4  ×  106, respectively.

  18. Effects of Substrate Quenching after TiN Coating on Tribological Properties of TiN Film

    NASA Astrophysics Data System (ADS)

    Tanabe, Hirotaka; Miyoshi, Yoshio; Takamatsu, Tohru; Sagara, Syuichi

    To investigate the effects of post-coat substrate quenching on the tribological properties of TiN film, a specimen was prepared in which the steel substrate (carbon tool steel, JIS SK3) was quenched after TiN coating, and the ball-on-disk type wear test was carried out using a ZrO2 ball. The delamination initiation life of TiN film was improved by the high adhesive strength of TiN film obtained by post-coat substrate quenching. The specific wear rate was also improved by post-coat substrate quenching, although TiN hardness was lower than that of the conventional type specimen, which was coated with TiN after substrate quenching. The improvement in the specific wear rate could be explained as follows. In the post-coat substrate quenching process, TiN was partly oxidized and titanium oxide, which acted as a lubricant, was formed on the TiN surface. The formation of titanium oxide resulted in a reduction in the friction coefficient and consequently a lower specific wear rate was obtained.

  19. Experimental and theoretical study of the optical and electrical properties of nanostructured indium tin oxide fabricated by oblique-angle deposition.

    PubMed

    Sood, Adam W; Poxson, David J; Mont, Frank W; Chhajed, Sameer; Cho, Jaehee; Schubert, E Fred; Welser, Roger E; Dhar, Nibir K; Sood, Ashok K

    2012-05-01

    Oblique-angle deposition of indium tin oxide (ITO) is used to fabricate optical thin-film coatings with a porous, columnar nanostructure. Indium tin oxide is a material that is widely used in industrial applications because it is both optically transparent and electrically conductive. The ITO coatings are fabricated, using electron-beam evaporation, with a range of deposition angles between 0 degrees (normal incidence) and 80 degrees. As the deposition angle increases, we find that the porosity of the ITO film increases and the refractive index decreases. We measure the resistivity of the ITO film at each deposition angle, and find that as the porosity increases, the resistivity increases superlinearly. A new theoretical model is presented to describe the relationship between the ITO film's resistivity and its porosity. The model takes into account the columnar structure of the film, and agrees very well with the experimental data. PMID:22852330

  20. Genesis of the Silsilah tin deposit, Kingdom of Saudi Arabia

    USGS Publications Warehouse

    Kamilli, Robert J.; Criss, R.E.

    1996-01-01

    The Silsilah tin deposit (lat 25 degrees 06' N, long 42 degrees 40' E) consists of a group of pervasively greisenized, flat-topped granite cupolas within a 12-km-diam ring complex. The greisens contain varying amounts of disseminated cassiterite and wolframite. Several types of quartz veins are peripheral to the greisens; some of these contain minor wolframite. The deposit is genetically associated with a highly differentiated, peraluminous alkali-feldspar granite (587 + or - 8 Ma) that is part of a mostly peralkaline, igneous ring complex intruded into Late Proterozoic, immature sandstones of the Murdama Group. We recognize four distinct phases of the peraluminous granite. Only the smallest, most highly differentiated cupolas contain significant tin greisen mineralization. Greisens developed beneath aplitic carapaces that overlie the granite and created impermeable barriers to rising volatiles. The geometry of a cupola correlates strongly with the intensity of alteration; cupolas with the smallest cross sectional areas and steepest marginal contacts have the most intensely greisenized apexes. The paragenetic sequence can be divided into five stages: pegmatite formation, locally pervasive albitization, locally pervasive greisenization and deposition of cassiterite, deposition of quartz-wolframite veins, and deposition of quartz veins with minor base metal sulfides. Pressure-corrected fluid inclusion filling temperatures indicate that the hydrothermal system generally cooled as it evolved and that the delta 18O values of the hydrothermal quartz increased from 10.8 to 15.7 per mil. Calculated delta 18O values of the hydrothermal fluid varied concomitantly from the pegmatite stage (delta 18O fluid approximately 8.6ppm; T [asymp] 550 degrees C) to the greisen stage (5.4 and 5.6[ppm; T [asymp] 360 degrees C), the quartz-wolframite vein stage (6.3 and 7.5ppm; T [asymp] 390 degrees C), and the late vein stage (4.0 and 5.1ppm; T [asymp] 270 degrees C). This evolution

  1. Highly conducting and crystalline doubly doped tin oxide films fabricated using a low-cost and simplified spray technique

    NASA Astrophysics Data System (ADS)

    Ravichandran, K.; Muruganantham, G.; Sakthivel, B.

    2009-11-01

    Doubly doped (simultaneous doping of antimony and fluorine) tin oxide films (SnO 2:Sb:F) have been fabricated by employing an inexpensive and simplified spray technique using perfume atomizer from aqueous solution of SnCl 2 precursor. The structural studies revealed that the films are highly crystalline in nature with preferential orientation along the (2 0 0) plane. It is found that the size of the crystallites of the doubly doped tin oxide films is larger (69 nm) than that (27 nm) of their undoped counterparts. The dislocation density of the doubly doped film is lesser (2.08×10 14 lines/m 2) when compared with that of the undoped film (13.2×10 14 lines/m 2), indicating the higher degree of crystallinity of the doubly doped films. The SEM images depict that the films are homogeneous and uniform. The optical transmittance in the visible range and the optical band gap of the doubly doped films are 71% and 3.56 eV respectively. The sheet resistance (4.13 Ω/□) attained for the doubly doped film in this study is lower than the values reported for spray deposited fluorine or antimony doped tin oxide films prepared from aqueous solution of SnCl 2 precursor (without using methanol or ethanol).

  2. Fast Responsive Gas Sensor of Vertically Aligned Fluorine-Doped Tin Oxide Nanorod Thin Film

    NASA Astrophysics Data System (ADS)

    Cho, Chan-Woo; Lee, Jong-Heun; Riu, Doh-Hyung; Kim, Chang-Yeoul

    2012-04-01

    We prepared fluorine-doped tin oxide (FTO) nanorod films and a conventional FTO thin film for the application of a semiconducting gas sensor by spray pyrolysis method. The lengths of FTO nanorods (FTON, 100 and 500 nm) were controlled by changing deposition times, and FTO thin film (FTOT) was also prepared as a reference. The gas sensitivity test shows FTON with long nanorods had higher sensitivity for both hydrogen and ethanol gases but slow response and recovery times, despite an advantage of the higher gas sensitivity. FTO nanorod film with short length about 100 nm showed relatively lower sensitivity, but fast gas response and recovery characteristics. The fast response and recovery for the analyte gases are attributed to the conductance of FTO nanorods, which is closely related to the diameter and length of nanorods.

  3. Characterization of porous indium tin oxide thin films using effective medium theory

    NASA Astrophysics Data System (ADS)

    Ederth, J.; Niklasson, G. A.; Hultâker, A.; Heszler, P.; Granqvist, C. G.; van Doorn, A. R.; Jongerius, M. J.; Burgard, D.

    2003-01-01

    Effective medium theory was used to model optical properties in the 0.3 - 30 μm wavelength range for films comprised of nanoparticles of a transparent conducting oxide that are connected in a percolating network characterized by a filling factor f. The model is based on charge carrier density ne and resistivity ρ of the particles, and it enables analyses of these microscopic parameters upon posttreatment of the film. The theory was used to interpret data on spin coated layers consisting of nanoparticles of indium tin oxide (i.e., In2O3:Sn) with f close to the percolation limit. It showed that the as-deposited film contained nanoparticles with ne as large as ˜5×1020cm-3 and ρ≈5×10-4 Ω cm. The model also provided important data on f, ne, and ρ after heat treatment of the film.

  4. TiN Deposition and Process Diagnostics using Remote Plasma Sputtering

    NASA Astrophysics Data System (ADS)

    Yang, Wonkyun; Kim, Gi-Taek; Lee, Seunghun; Kim, Do-Geun; Kim, Jong-Kuk

    2013-08-01

    The discharge voltage-current characteristics and the optical diagnostics of a remote plasma sputtering system called by high density plasma assisted sputtering source (HiPASS) were investigated. The remote plasma was generated by the hollow cathode discharge (HCD) gun and was transported to the target surface by external electromagnet coils. This showed a wide process window because the sputtering voltage and current could be individually controlled. The ion density and energy distribution could be also controlled unlike the conventional magnetron sputtering. Titanium nitride films were deposited under different sputtering voltage. The high voltage mode induced the high ionization ratio of the sputtered atoms and the high ion energy toward the substrate. That resulted in the enlarged grain size, and the preferred orientation toward (220). Eventually, this optimized condition of HiPASS obtained the best hardness of TiN films to be about 48 GPa at the sputtering voltage of -800 V.

  5. Synthesizing photovoltaic thin films of high quality copper-zinc-tin alloy with at least one chalcogen species

    DOEpatents

    Teeter, Glenn; Du, Hui; Young, Matthew

    2013-08-06

    A method for synthesizing a thin film of copper, zinc, tin, and a chalcogen species ("CZTCh" or "CZTSS") with well-controlled properties. The method includes depositing a thin film of precursor materials, e.g., approximately stoichiometric amounts of copper (Cu), zinc (Zn), tin (Sn), and a chalcogen species (Ch). The method then involves re-crystallizing and grain growth at higher temperatures, e.g., between about 725 and 925 degrees K, and annealing the precursor film at relatively lower temperatures, e.g., between 600 and 650 degrees K. The processing of the precursor film takes place in the presence of a quasi-equilibrium vapor, e.g., Sn and chalcogen species. The quasi-equilibrium vapor is used to maintain the precursor film in a quasi-equilibrium condition to reduce and even prevent decomposition of the CZTCh and is provided at a rate to balance desorption fluxes of Sn and chalcogens.

  6. Pulsed laser deposition of ITO thin films and their characteristics

    SciTech Connect

    Zuev, D. A. Lotin, A. A.; Novodvorsky, O. A.; Lebedev, F. V.; Khramova, O. D.; Petuhov, I. A.; Putilin, Ph. N.; Shatohin, A. N.; Rumyanzeva, M. N.; Gaskov, A. M.

    2012-03-15

    The indium tin oxide (ITO) thin films are grown on quartz glass substrates by the pulsed laser deposition method. The structural, electrical, and optical properties of ITO films are studied as a function of the substrate temperature, the oxygen pressure in the vacuum chamber, and the Sn concentration in the target. The transmittance of grown ITO films in the visible spectral region exceeds 85%. The minimum value of resistivity 1.79 Multiplication-Sign 10{sup -4} {Omega} cm has been achieved in the ITO films with content of Sn 5 at %.

  7. Device performances of organic light-emitting diodes with indium tin oxide, gallium zinc oxide, and indium zinc tin oxide anodes deposited at room temperature.

    PubMed

    Lee, Changhun; Ko, Yoonduk; Kim, Youngsung

    2013-12-01

    Thin films of Indium tin oxide (ITO), Gallium zinc oxide (GZO), and Indium zinc tin oxide (IZTO) were deposited on glass substrates by pulsed direct current magnetron sputtering at room temperature. The structural, optical, and electrical properties of the films were investigated towards evaluating their applications as flexible anodes. IZTO films exhibited the lowest resistivity (6.3 x 10(-4) Omega cm). Organic light-emitting diodes (OLEDs) were fabricated using the ITO, GZO, and IZTO films as anode layers. The turn-on voltages at a current density of 4.5 mA/cm2, 5.5 mA/cm2, 6.5 mA/cm2 were 5.5 V, 13.7 V, and 4.7 V for the devices with ITO, GZO, and IZTO anodes, respectively. The best performance was observed with the IZTO film, indicating its suitability as an alternative material for conventional ITO anodes used in OLEDs and flexible displays. PMID:24266182

  8. Room temperature synthesis of indium tin oxide nanotubes with high precision wall thickness by electroless deposition

    PubMed Central

    Ionescu, Emanuel; Fu, Ganhua; Ensinger, Wolfgang

    2011-01-01

    Summary Conductive nanotubes consisting of indium tin oxide (ITO) were fabricated by electroless deposition using ion track etched polycarbonate templates. To produce nanotubes (NTs) with thin walls and small surface roughness, the tubes were generated by a multi-step procedure under aqueous conditions. The approach reported below yields open end nanotubes with well defined outer diameter and wall thickness. In the past, zinc oxide films were mostly preferred and were synthesized using electroless deposition based on aqueous solutions. All these methods previously developed, are not adaptable in the case of ITO nanotubes, even with modifications. In the present work, therefore, we investigated the necessary conditions for the growth of ITO-NTs to achieve a wall thickness of around 10 nm. In addition, the effects of pH and reductive concentrations for the formation of ITO-NTs are also discussed. PMID:21977422

  9. Effect of solvent ratio on the optoelectronic properties of fluorine doped tin oxide thin films

    SciTech Connect

    Karthick, P.; Divya, V.; Sridharan, M.; Jeyadheepan, K.

    2015-06-24

    Fluorine doped tin oxide (FTO) thin films were deposited on to the well cleaned microscopic glass substrates using nebulized-spray pyrolysis (n-SP) technique by varying the water to ethanol solvent proportion. The deposited thin films were characterized by X-ray diffraction (XRD), UV-Vis-NIR spectroscopy, field emission scanning electron microscopy and Hall measurements to study the structural, optical, surface morphological and electrical properties of the films, respectively. Results of the analyzes show that the films are polycrystalline, having tetragonal structure with the preferred orientation along (110) plane. The grain size varies between 7 to 20 nm. The optimized films exhibit the optical transparency of 85 % at the wavelength of 580 nm. The optical bandgap lies in the range of 3.94 to 4 eV. The optimized films, deposited with 40 % of ethanol proportion are having the mean resistivity 4.72×10{sup −3} Ω-cm, carrier concentration 1.79×10{sup 20} cm{sup 3} and the mobility 7 cm{sup 2}/Vs.

  10. Mechanical testing and microstructural characterization of TiN thin films

    SciTech Connect

    Karimi, A.; Shojaei, O.R.; Martin, J.L.

    1998-12-31

    Mechanical properties of titanium nitride (TiN{sub x}) thin films have been investigated using the bulge test and the depth sensing nanoindentation measurements. The bulge test was performed on the square free standing membranes made by means of standard micromachining of silicon wafers, while the nanoindentation was conducted on the films adhered to their supporting substrate. Thin layers of titanium nitride (t = 300--1000 nm) were deposited in a r.f. magnetron sputtering system on the Si(100) wafers containing a layer of low stress LPCVD silicon nitride (SiN{sub y}). The bulge test was first conducted on the silicon nitride film to determine its proper residual stress and Young`s modulus. Then, the composite membrane made of TiNx together with underlying silicon nitride was bulged and the related load-displacement variation was measured. Finally, using a simple rule of mixture formula the elastic mechanical properties of TiNx coatings were calculated. Both the Young`s modulus and residual stress showed increasing values with negative bias voltage and nitrogen to titanium ratio, but the substrate temperature between 50--570 C was found less significant as compared to the other parameters. Nanoindentation data extracted from dynamically loading-unloading of TiN films converged to the bulge test measurements for compact coatings, but diverged from the bulge test data for porous coatings. Scanning electron microscopy observation of the cross sectioned specimens showed that TiN films first grow by formation of the nanocrystallites of size mostly between 10--15 nm. These nanocrystallites give rise to the columnar morphology beyond a thickness of 50--100 nm. The columns change their aspect with deposition parameters, but remain nearly perpendicular to the film surface. Relationship between microstructural evolution of columns and mechanical properties of coatings are discussed in terms of deposition parameters.

  11. Hydrogen plasma treatment for improved conductivity in amorphous aluminum doped zinc tin oxide thin films

    SciTech Connect

    Morales-Masis, M. Ding, L.; Dauzou, F.; Jeangros, Q.; Hessler-Wyser, A.; Nicolay, S.; Ballif, C.

    2014-09-01

    Improving the conductivity of earth-abundant transparent conductive oxides (TCOs) remains an important challenge that will facilitate the replacement of indium-based TCOs. Here, we show that a hydrogen (H{sub 2})-plasma post-deposition treatment improves the conductivity of amorphous aluminum-doped zinc tin oxide while retaining its low optical absorption. We found that the H{sub 2}-plasma treatment performed at a substrate temperature of 50 °C reduces the resistivity of the films by 57% and increases the absorptance by only 2%. Additionally, the low substrate temperature delays the known formation of tin particles with the plasma and it allows the application of the process to temperature-sensitive substrates.

  12. Hydrogen plasma treatment for improved conductivity in amorphous aluminum doped zinc tin oxide thin films

    NASA Astrophysics Data System (ADS)

    Morales-Masis, M.; Ding, L.; Dauzou, F.; Jeangros, Q.; Hessler-Wyser, A.; Nicolay, S.; Ballif, C.

    2014-09-01

    Improving the conductivity of earth-abundant transparent conductive oxides (TCOs) remains an important challenge that will facilitate the replacement of indium-based TCOs. Here, we show that a hydrogen (H2)-plasma post-deposition treatment improves the conductivity of amorphous aluminum-doped zinc tin oxide while retaining its low optical absorption. We found that the H2-plasma treatment performed at a substrate temperature of 50 °C reduces the resistivity of the films by 57% and increases the absorptance by only 2%. Additionally, the low substrate temperature delays the known formation of tin particles with the plasma and it allows the application of the process to temperature-sensitive substrates.

  13. Reversible superconductivity in electrochromic indium-tin oxide films

    NASA Astrophysics Data System (ADS)

    Aliev, Ali E.; Xiong, Ka; Cho, Kyeongjae; Salamon, M. B.

    2012-12-01

    Transparent conductive indium tin oxide (ITO) thin films, electrochemically intercalated with sodium or other cations, show tunable superconducting transitions with a maximum Tc at 5 K. The transition temperature and the density of states, D(EF) (extracted from the measured Pauli susceptibility χp) exhibit the same dome shaped behavior as a function of electron density. Optimally intercalated samples have an upper critical field ≈ 4 T and Δ/kBTc ≈ 2.0. Accompanying the development of superconductivity, the films show a reversible electrochromic change from transparent to colored and are partially transparent (orange) at the peak of the superconducting dome. This reversible intercalation of alkali and alkali earth ions into thin ITO films opens diverse opportunities for tunable, optically transparent superconductors.

  14. Magnetron deposition of TCO films using ion beam

    NASA Astrophysics Data System (ADS)

    Asainov, O.; Umnov, S.; Chinin, A.

    2015-11-01

    Thin films of tin oxide (TO) were deposited on the glass substrates at room temperature using reactive magnetron sputtering at various oxygen partial pressures. After the deposition the films were irradiated with argon ions beam. The change of the optical and electrical properties of the films depending on the irradiation time was studied. Films optical properties in the range of 300-1100 nm were investigated by photometry as well as their structural properties were studied using X-ray diffraction. Diffractometric research showed that the films, deposited on a substrate, have a crystal structure, and after argon ions irradiation they become quasi-crystalline (amorphous). It was found that the transmission increases proportionally with the irradiation time, but the surface resistance -disproportionally.

  15. Structural and optical studies of 100 MeV Au irradiated thin films of tin oxide

    NASA Astrophysics Data System (ADS)

    Jaiswal, Manoj Kumar; Kanjilal, D.; Kumar, Rajesh

    2013-11-01

    Thin films of tin(IV) oxide (SnO2) of 100 nm thickness were grown on silicon (1 0 0) matrices by electron beam evaporation deposition technique under high vacuum. The thicknesses of these films were monitored by piezo-sensor attached to the deposition chamber. Nanocrystallinity is achieved in these thin films by 100 MeV Au8+ using 1 pnA current at normal incidence with ion fluences varying from 1 × 1011 ions/cm2 to 5 × 1013 ions/cm2. Swift Heavy Ion beam irradiation was carried out by using 15 UD Pelletron Accelerator at IUAC, New Delhi, India. Optical studies of pristine and ion irradiated thin films were characterized by UV-Visible spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy. Prominent peak at 610 cm-1 in FTIR spectrum confirmed the O-Sn-O bonding of tin(IV) oxide. For Surface topographical studies and grain size calculations, these films were characterized by Atomic Force Microscope (AFM) using Nanoscope III-A. Crystallinity and phase transformation due to irradiation of pristine and irradiated films were characterized by Glancing Angle X-ray Diffraction (GAXRD) using Brucker-D8 advance model. GAXRD results show improvement in crystallinity and phase transformation due to swift heavy ion irradiation. Grain size distribution was verified by AFM and GAXRD results. Swift heavy ion induced modifications in thin films of SnO2 were confirmed by the presence of prominent peaks at 2θ values of 30.65°, 32.045°, 43.94°, 44.96° and 52.36° in GAXRD spectrum.

  16. Superconducting T/sub c/ enhancement in weakly disordered Ge-covered tin films

    SciTech Connect

    Parashar, R.S.; Srivastava, V.

    1985-11-01

    We report on the variation of the superconducting transition temperature with the electrical resistance ratio in weakly disordered Ge-covered tin films deposited at room temperature. The normal-state sheet resistance R/sub N//sup D'Alembertian/ varied between 0.2

  17. Characterization of reliability of printed indium tin oxide thin films.

    PubMed

    Hong, Sung-Jei; Kim, Jong-Woong; Jung, Seung-Boo

    2013-11-01

    Recently, decreasing the amount of indium (In) element in the indium tin oxide (ITO) used for transparent conductive oxide (TCO) thin film has become necessary for cost reduction. One possible approach to this problem is using printed ITO thin film instead of sputtered. Previous studies showed potential for printed ITO thin films as the TCO layer. However, nothing has been reported on the reliability of printed ITO thin films. Therefore, in this study, the reliability of printed ITO thin films was characterized. ITO nanoparticle ink was fabricated and printed onto a glass substrate followed by heating at 400 degrees C. After measurement of the initial values of sheet resistance and optical transmittance of the printed ITO thin films, their reliabilities were characterized with an isothermal-isohumidity test for 500 hours at 85 degrees C and 85% RH, a thermal shock test for 1,000 cycles between 125 degrees C and -40 degrees C, and a high temperature storage test for 500 hours at 125 degrees C. The same properties were investigated after the tests. Printed ITO thin films showed stable properties despite extremely thermal and humid conditions. Sheet resistances of the printed ITO thin films changed slightly from 435 omega/square to 735 omega/square 507 omega/square and 442 omega/square after the tests, respectively. Optical transmittances of the printed ITO thin films were slightly changed from 84.74% to 81.86%, 88.03% and 88.26% after the tests, respectively. These test results suggest the stability of printed ITO thin film despite extreme environments. PMID:24245331

  18. Pulsed laser deposited indium tin oxides as alternatives to noble metals in the near-infrared region

    NASA Astrophysics Data System (ADS)

    Fang, Xu; Mak, C. L.; Zhang, Shiyu; Wang, Zhewei; Yuan, Wenjia; Ye, Hui

    2016-06-01

    Transparent conductive indium tin oxide thin films with thickness around 200 nm were deposited on glass substrates by pulsed laser deposition technology. The microstructure and the electrical and optical properties of the ITO films deposited under different oxygen pressures and substrate temperatures were systematically investigated. Distinct different x-ray diffraction patterns revealed that the crystallinity of ITO films was highly influenced by deposition conditions. The highest carrier concentration of the ITO films was obtained as 1.34  ×  1021 cm‑3 with the lowest corresponding resistivity of 2.41  ×  10‑4 Ω cm. Spectroscopic ellipsometry was applied to retrieve the dielectric permittivity of the ITO films to estimate their potential as plasmonic materials in the near-infrared region. The crossover wavelength (the wavelength where the real part of the permittivity changes from positive to negative) of the ITO films exhibited high dependence on the deposition conditions and was optimized to as low as 1270 nm. Compared with noble metals (silver or gold etc), the lower imaginary part of the permittivity (<3) of ITO films suggests the potential application of ITO in the near-infrared range.

  19. Pulsed laser deposited indium tin oxides as alternatives to noble metals in the near-infrared region.

    PubMed

    Fang, Xu; Mak, C L; Zhang, Shiyu; Wang, Zhewei; Yuan, Wenjia; Ye, Hui

    2016-06-01

    Transparent conductive indium tin oxide thin films with thickness around 200 nm were deposited on glass substrates by pulsed laser deposition technology. The microstructure and the electrical and optical properties of the ITO films deposited under different oxygen pressures and substrate temperatures were systematically investigated. Distinct different x-ray diffraction patterns revealed that the crystallinity of ITO films was highly influenced by deposition conditions. The highest carrier concentration of the ITO films was obtained as 1.34  ×  10(21) cm(-3) with the lowest corresponding resistivity of 2.41  ×  10(-4) Ω cm. Spectroscopic ellipsometry was applied to retrieve the dielectric permittivity of the ITO films to estimate their potential as plasmonic materials in the near-infrared region. The crossover wavelength (the wavelength where the real part of the permittivity changes from positive to negative) of the ITO films exhibited high dependence on the deposition conditions and was optimized to as low as 1270 nm. Compared with noble metals (silver or gold etc), the lower imaginary part of the permittivity (<3) of ITO films suggests the potential application of ITO in the near-infrared range. PMID:27054885

  20. Molecular Beam Epitaxial (MBE) Growth and Characterization of Thin Films of Semiconductor Tin

    NASA Astrophysics Data System (ADS)

    Folkes, P.; Taylor, P.; Rong, C.; Nichols, B.; Hier, H.; Burke, R.; Neupane, M.

    Recent theoretical predictions that a two-dimensional monolayer of semiconductor tin is a two-dimensional topological insulator and experimental evidence of three-dimensional topological insulator behavior in strained ultrathin films of semiconductor tin grown by MBE on InSb has generated intense research interest. This research is primarily focused on the MBE growth and topological characteristics of ultrathin films of semiconductor tin. In this talk we present results of a study on the MBE growth and the transport, structural and optical characterization of thin films of semiconductor tin on several different substrates.

  1. Use of amorphous tin-oxide films obtained by spray pyrolysis as electrodes in lithium batteries

    NASA Astrophysics Data System (ADS)

    Ayouchi, R.; Martin, F.; Ramos Barrado, J. R.; Martos, M.; Morales, J.; Sánchez, L.

    Amorphous tin-oxide films were prepared by spray pyrolysis of SnCl 2·2H 2O mixed with CH 3-COOH and deposited onto a stainless steel substrate at mild temperatures (350°C). The films grown were characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX). Also, they were tested as electrodes in lithium rechargeable batteries. The XPS results suggest that the substrate is thoroughly coated and that the films are composed mainly of SnO and SnO 2. These films exhibit good charge-discharge properties over more than 100 cycles. Heating at 600°C causes significant changes in their surface composition, in the virtual disappearance of the tin component and in the presence of oxygen-bound Fe. Under these conditions, the reversible capacity dramatically fades and the cell behaves similarly to that made from uncoated substrate.

  2. Modification of opto-electronic properties of ZnO by incorporating metallic tin for buffer layer in thin film solar cells

    SciTech Connect

    Deepu, D. R.; Jubimol, J.; Kartha, C. Sudha; Louis, Godfrey; Vijayakumar, K. P.; Kumar, K. Rajeev

    2015-06-24

    In this report, the effect of incorporation of metallic tin (Sn) on opto-electronic properties of ZnO thin films is presented. ZnO thin films were deposited through ‘automated chemical spray pyrolysis’ (CSP) technique; later different quantities of ‘Sn’ were evaporated on it and subsequently annealed. Vacuum annealing showed a positive effect on crystallinity of films. Creation of sub band gap levels due to ‘Sn’ diffusion was evident from the absorption and PL spectra. The tin incorporated films showed good photo response in visible region. Tin incorporated ZnO thin films seem to satisfy the desirable criteria for buffer layer in thin film solar cells.

  3. Structural and optical characterisation of tin dioxide thin films by sol-gel dip coating technique

    NASA Astrophysics Data System (ADS)

    Lekshmy, S. Sujatha; Berlin, I. John; Maneeshya, L. V.; Anitha; Joy, K.

    2015-02-01

    Tin oxide (SnO2) thin films were deposited on quartz substrates using sol-gel dip coating technique. X-ray diffraction (XRD) pattern indicated that the film annealed in air at 350°C was amorphous in nature, whereas, the films annealed in oxygen atmosphere at 350°C showed crystalline phase. The films were further annealed in oxygen atmosphere at 450°C and 550°C. All the diffraction peaks can be indexed to the tetragonal phase of SnO2 The surface morphology (SEM) showed that surface of all films were continuous and without micro cracks. The Energy dispersive X-ray spectroscopy (EDXS) spectra indicated an increase in the concentration of oxygen content with increase in annealing temperature. The energy band gap value for the film annealed in air was 3.88 eV. The optical band gap increased to 4.05 eV when annealed in O2 atmosphere. The photoluminescence (PL) spectra showed the presence of emission peaks in UV region and visible region of the electromagnetic spectra. Transparent oxide semiconductor SnO2 film finds potential application as an active channel layer for transparent thin film transistor.

  4. Titanium dioxide-coated fluorine-doped tin oxide thin films for improving overall photoelectric property

    NASA Astrophysics Data System (ADS)

    Li, Bao-jia; Huang, Li-jing; Ren, Nai-fei; Zhou, Ming

    2014-01-01

    Titanium (Ti) layers were deposited by direct current (DC) magnetron sputtering on commercial fluorine-doped tin oxide (FTO) glasses, followed by simultaneous oxidation and annealing treatment in a tubular furnace to prepare titanium dioxide (TiO2)/FTO bilayer films. Large and densely arranged grains were observed on all TiO2/FTO bilayer films. The presence of TiO2 tetragonal rutile phase in the TiO2/FTO bilayer films was confirmed by X-ray diffraction (XRD) analysis. The results of parameter optimization indicated that the TiO2/FTO bilayer film, which was formed by adopting a temperature of 400 °C and an oxygen flow rate of 15 sccm, had the optimal overall photoelectric property with a figure of merit of 2.30 × 10-2 Ω-1, higher than 1.78 × 10-2 Ω-1 for the FTO single-layer film. After coating a 500 nm-thick AZO layer by DC magnetron sputtering on this TiO2/FTO bilayer film, the figure of merit of the trilayer film achieved to a higher figure of merit of 3.12 × 10-2 Ω-1, indicating further improvement of the overall photoelectric property. This work may provide a scientific basis and reference for improving overall photoelectric property of transparent conducting oxide (TCO) films.

  5. High angular sensitivity thin film tin oxide sensor

    NASA Astrophysics Data System (ADS)

    Kaur, Davinder; Madaan, Divya; Sharma, V. K.; Kapoor, A.

    2016-05-01

    We present theoretical anlaysis of a thin film SnO2 (Tin Oxide) sensor for the measurement of variation in the refractive index of the bulk media. It is based on lossy mode resonance between the absorbing thin film lossy modes and the evanescent wave. Also the addition of low index dielectric matching layer between the prism and the lossy waveguiding layer future increase the angular sensitivity and produce an efficient refractive index sensor. The angular interrogation is done and obtained sensitivity is 110 degree/RIU. Theoretical analysis of the proposed sensor based on Fresnel reflection coefficients is presented. This enhanced sensitivity will further improve the monitoring of biomolecular interactions and the higher sensitivity of the proposed configurations makes it to be a much better option to be employed for biosensing applications.

  6. Vapor deposition of thin films

    DOEpatents

    Smith, David C.; Pattillo, Stevan G.; Laia, Jr., Joseph R.; Sattelberger, Alfred P.

    1992-01-01

    A highly pure thin metal film having a nanocrystalline structure and a process of preparing such highly pure thin metal films of, e.g., rhodium, iridium, molybdenum, tungsten, rhenium, platinum, or palladium by plasma assisted chemical vapor deposition of, e.g., rhodium(allyl).sub.3, iridium(allyl).sub.3, molybdenum(allyl).sub.4, tungsten(allyl).sub.4, rhenium(allyl).sub.4, platinum(allyl).sub.2, or palladium(allyl).sub.2 are disclosed. Additionally, a general process of reducing the carbon content of a metallic film prepared from one or more organometallic precursor compounds by plasma assisted chemical vapor deposition is disclosed.

  7. The effect of the annealing temperature on the transition from conductor to semiconductor behavior in zinc tin oxide deposited atomic layer deposition

    SciTech Connect

    Ahn, Byung Du; Choi, Dong-won Choi, Changhwan; Park, Jin-Seong

    2014-09-01

    We investigated the electrical properties of zinc tin oxide (ZTO) films deposited via atomic layer deposition and compared them to ZnO and SnO{sub 2} films as a function of the annealing temperature. The ZTO and ZnO, except for SnO{sub 2}, films exhibited an electrical transition from a metal to semiconductor characteristics when annealed above 300 °C. The X-ray photoelectron spectroscopy analyses indicate that the relative area of the oxygen vacancy-related peak decreased from 58% to 41% when annealing at temperatures above 400 °C. Thin film transistors incorporating ZTO active layers demonstrated a mobility of 13.2 cm{sup 2}/V s and a negative bias instability of −0.2 V.

  8. A novel synthesis of tin oxide thin films by the sol-gel process for optoelectronic applications

    NASA Astrophysics Data System (ADS)

    Marikkannan, M.; Vishnukanthan, V.; Vijayshankar, A.; Mayandi, J.; Pearce, J. M.

    2015-02-01

    A novel and simple chemical method based on sol-gel processing was proposed to deposit metastable orthorhombic tin oxide (SnOx) thin films on glass substrates at room temperature. The resultant samples are labeled according to the solvents used: ethanol (SnO-EtOH), isopropanol (SnO-IPA) and methanol (SnO-MeOH). The variations in the structural, morphological and optical properties of the thin films deposited using different solvents were characterized by X-ray diffraction, atomic force microscopy, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, UV-vis spectroscopy and photoluminescence (PL) analysis. The XRD patterns confirm that all the films, irrespective of the solvents used for preparation, were polycrystalline in nature and contained a mixed phases of tin (II) oxide and tin (IV) oxide in a metastable orthorhombic crystal structure. FTIR spectra confirmed the presence of Sn=O and Sn-O in all of the samples. PL spectra showed a violet emission band centered at 380 nm (3.25 eV) for all of the solvents. The UV-vis spectra indicated a maximum absorption band shown at 332 nm and the highest average transmittance around 97% was observed for the SnO-IPA and SnO-MeOH thin film samples. The AFM results show variations in the grain size with solvent. The structural and optical properties of the SnO thin films indicate that this method of fabricating tin oxide is promising and that future work is warranted to analyze the electrical properties of the films in order to determine the viability of these films for various transparent conducting oxide applications.

  9. A novel synthesis of tin oxide thin films by the sol-gel process for optoelectronic applications

    SciTech Connect

    Marikkannan, M.; Vishnukanthan, V.; Vijayshankar, A.; Mayandi, J.; Pearce, J. M.

    2015-02-15

    A novel and simple chemical method based on sol-gel processing was proposed to deposit metastable orthorhombic tin oxide (SnOx) thin films on glass substrates at room temperature. The resultant samples are labeled according to the solvents used: ethanol (SnO-EtOH), isopropanol (SnO-IPA) and methanol (SnO-MeOH). The variations in the structural, morphological and optical properties of the thin films deposited using different solvents were characterized by X-ray diffraction, atomic force microscopy, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, UV-vis spectroscopy and photoluminescence (PL) analysis. The XRD patterns confirm that all the films, irrespective of the solvents used for preparation, were polycrystalline in nature and contained a mixed phases of tin (II) oxide and tin (IV) oxide in a metastable orthorhombic crystal structure. FTIR spectra confirmed the presence of Sn=O and Sn-O in all of the samples. PL spectra showed a violet emission band centered at 380 nm (3.25 eV) for all of the solvents. The UV-vis spectra indicated a maximum absorption band shown at 332 nm and the highest average transmittance around 97% was observed for the SnO-IPA and SnO-MeOH thin film samples. The AFM results show variations in the grain size with solvent. The structural and optical properties of the SnO thin films indicate that this method of fabricating tin oxide is promising and that future work is warranted to analyze the electrical properties of the films in order to determine the viability of these films for various transparent conducting oxide applications.

  10. Metal Gate (TiN, TiC, TaN) Film Stack Stress

    NASA Astrophysics Data System (ADS)

    Bello, A. F.; Paul, Abhijeet; Kim, Hoon

    2015-10-01

    Successful stress engineering in semiconductor device structures must consider all the contributions to the stress field including those not typically considered for stress, such as work function metal (WFM) gate layers that are used to tune to the desired work function level. These films induce stress especially since they are so close to the channel region. In this study we measure stress from blanket layer films and combinations of TiN, TiC, and TaN deposited on Hf oxide, at thicknesses that are typically used for advanced metal-oxide-semiconductor field-effect transistor (MOSFET) devices. Tungsten (W) deposited on top of the WFM layer stacks is also measured. For combination film stacks, the stress is measured after each deposition step. The induced stress from the WFM is significant, in the range of hundreds of MPa, and varies according to the thickness and processing conditions such as annealing temperature and time, etc. Results from these blanket film measurements were used as a guide for technology computer-aided design (TCAD) modeling of the stress field in FinFET structures with design rules comparable to 10-nm technology. The tensor stress components identify areas of compressive and tensile stress and with a magnitude similar to expected results. The stress field could be used to calculate the FinFET device performance, and in this case an example is provided with the relative improvement in drain current.

  11. Deposition of TiN and HfO{sub 2} in a commercial 200 mm remote plasma atomic layer deposition reactor

    SciTech Connect

    Heil, S. B. S.; Hemmen, J. L. van; Hodson, C. J.; Singh, N.; Klootwijk, J. H.; Roozeboom, F.; Sanden, M. C. M. van de; Kessels, W. M. M.

    2007-09-15

    The authors describe a remote plasma atomic layer deposition reactor (Oxford Instruments FlexAL trade mark sign ) that includes an inductively coupled plasma source and a load lock capable of handling substrates up to 200 mm in diameter. The deposition of titanium nitride (TiN) and hafnium oxide (HfO{sub 2}) is described for the combination of the metal-halide precursor TiCl{sub 4} and H{sub 2}-N{sub 2} plasma and the combination of the metallorganic precursor Hf[N(CH{sub 3})(C{sub 2}H{sub 5})]{sub 4} and O{sub 2} plasma, respectively. The influence of the plasma exposure time and substrate temperature has been studied and compositional, structural, and electrical properties are reported. TiN films with a low Cl impurity content were obtained at 350 deg. C at a growth rate of 0.35 A /cycle with an electrical resistivity as low as 150 {mu}{omega} cm. Carbon-free (detection limit <2 at. %) HfO{sub 2} films were obtained at a growth rate of 1.0 A /cycle at 290 deg. C. The thickness and resisitivity nonuniformity was <5% for the TiN and the thickness uniformality was <2% for the HfO{sub 2} films as determined over 200 mm wafers.

  12. The change in optical and electrical characteristics of tin oxide films under the action of argon ion beam

    NASA Astrophysics Data System (ADS)

    Asainov, O.; Umnov, S.; Temenkov, V.

    2016-01-01

    Thin films of tin oxide (TO) were deposited on the glass substrates at room temperature using reactive magnetron sputtering at various oxygen partial pressures. After the deposition the filmswere irradiated with argon ions beam. The change of the optical and electrical properties of the films depending on the irradiation time was studied. Films optical properties in the range of 300-1100 nm were investigated by photometry as well as their structural properties were studied using X-ray diffraction. Diffractometric research showed that the films, deposited on a substrate, have a crystal structure, and after argon ions irradiation they become quasi-crystalline (amorphous). It was found that the transmission increases proportionally with the irradiation time, but the surface resistance -disproportionally.

  13. Temperature dependence of inductively coupled plasma assisted growth of TiN thin films.

    SciTech Connect

    Meng, W. J.; Curtis, T. J.; Rehn, L. E.; Baldo, P. M.; Materials Science Division; Louisiana State Univ.

    1999-11-01

    The use of low pressure high density plasmas to assist the synthesis of ceramic thin film materials is in its infancy. Using an inductively coupled plasma assisted magnetron sputtering system, we examine the dependence of plasma-assisted growth of TiN thin films on growth temperature at different ratios of ion flux to neutral atom flux. Our results indicate that a temperature independent densification of TiN films occurs above a certain ion to neutral atom flux ratio. As an example of this temperature independent densification, we demonstrate the formation of dense B1 TiN crystalline thin films at growth temperatures down to {approx}100 K.

  14. Effects of Substrate Bias on the Hardness and Resistivity of Reactively Sputtered TaN and TiN Thin Films

    NASA Astrophysics Data System (ADS)

    Lu, Junqing; Arshi, Nishat

    2016-06-01

    TaN and TiN films are being widely used as conductive layers in electronic devices or protective coatings on metal surfaces. Among various deposition methods, reactive magnetron sputtering is preferred partly due to its ability to control the energy of the depositing ions by applying different substrate bias voltages. In this study, TaN and TiN films were deposited on Si/SiO2 substrates by using direct current magnetron sputtering technique with 370 W target power at 1.9 mTorr and under different substrate biases. The effects of the substrate bias on both the resistivity and the hardness of the deposited TaN and TiN films were investigated. The phase and composition of the deposited films were investigated by x-ray diffraction, the resistivity was measured by a four-point probe, and the hardness was obtained by nano-indentation. For TaN films, the use of substrate bias not only increased the hardness but also increased the resistivity. Moreover, the formation of the Ta3N5 phase at the -300 V substrate bias significantly increased the TaN film resistivity. For TiN films, the optimum resistivity (minimum) of 19.5 µΩ-cm and the hardness (maximum) of 31.5 GPa were achieved at the -100 V substrate bias. Since the phase changes occurred in both the TaN and the TiN films at higher substrate biases and these phase changes negatively affected the resistivity or hardness property of the films, the substrate bias should not significantly exceed -100 V.

  15. Deposited films with improved microstructures

    DOEpatents

    Patten, James W.; Moss, Ronald W.; McClanahan, Edwin D.

    1984-01-01

    Methods for improving microstructures of line-of-sight deposited films are described. Columnar growth defects ordinarily produced by geometrical shadowing during deposition of such films are eliminated without resorting to post-deposition thermal or mechanical treatments. The native, as-deposited coating qualities, including homogeneity, fine grain size, and high coating-to-substrate adherence, can thus be retained. The preferred method includes the steps of emitting material from a source toward a substrate to deposit a coating non-uniformly on the substrate surface, removing a portion of the coating uniformly over the surface, again depositing material onto the surface, but from a different direction, and repeating the foregoing steps. The quality of line-of-sight deposited films such as those produced by sputtering, progressively deteriorates as the angle of incidence between the flux and the surface becomes increasingly acute. Depositing non-uniformly, so that the coating becomes progressively thinner as quality deteriorates, followed by uniformly removing some of the coating, such as by resputtering, eliminates the poor quality portions, leaving only high quality portions of the coating. Subsequently sputtering from a different direction applies a high quality coating to other regions of the surface. Such steps can be performed either simultaneously or sequentially to apply coatings of a uniformly high quality, closed microstructure to three-dimensional or large planar surfaces.

  16. Synthesis of tin oxide nanoparticle film by cathodic electrodeposition.

    PubMed

    Kim, Seok; Lee, Hochun; Park, Chang Min; Jung, Yongju

    2012-02-01

    Three-dimensional SnO2 nanoparticle films were deposited onto a copper substrate by cathodic electrodeposition in a nitric acid solution. A new formation mechanism for SnO2 films is proposed based on the oxidation of Sn2+ ion to Sn4+ ion by NO+ ion and the hydrolysis of Sn4+. The particle size of SnO2 was controlled by deposition potential. The SnO2 showed excellent charge capacity (729 mAh/g) at a 0.2 C rate and high rate capability (460 mAh/g) at a 5 C rate. PMID:22630013

  17. The electronic structure of co-sputtered zinc indium tin oxide thin films

    SciTech Connect

    Carreras, Paz; Antony, Aldrin; Bertomeu, Joan; Gutmann, Sebastian; Schlaf, Rudy

    2011-10-01

    Zinc indium tin oxide (ZITO) transparent conductive oxide layers were deposited via radio frequency (RF) magnetron co-sputtering at room temperature. A series of samples with gradually varying zinc content was investigated. The samples were characterized with x-ray and ultraviolet photoemission spectroscopy (XPS, UPS) to determine the electronic structure of the surface. Valence and conduction bands maxima (VBM, CBM), and work function were determined. The experiments indicate that increasing Zn content results in films with a higher defect rate at the surface leading to the formation of a degenerately doped surface layer if the Zn content surpasses {approx}50%. Furthermore, the experiments demonstrate that ZITO is susceptible to ultraviolet light induced work function reduction, similar to what was earlier observed on ITO and TiO{sub 2} films.

  18. Non-aqueous electrodeposition of porous tin-based film as an anode for lithium-ion battery

    NASA Astrophysics Data System (ADS)

    Gu, C. D.; Mai, Y. J.; Zhou, J. P.; You, Y. H.; Tu, J. P.

    2012-09-01

    Porous tin-based films are electrodeposited on copper foils from a choline chloride/ethylene glycol based electrolyte containing SnCl2·2H2O without any complexing agent or additive. Increasing the deposition time and voltage produces thicker films. The initially deposited Sn grains are relatively uniform with an average size of 200-300 nm and a kind of self-assembly distribution constructing an open and bicontinuous porous network. The architecture of these films possesses a double-layer structure, i.e. SnO2 (superficial layer)/Sn-Cu alloy (bottom layer), which is revealed by X-ray diffractometer and X-ray photoelectron spectroscopy. The electrochemical performance of the porous tin-based films as anode for lithium-ion batteries is measured. Although the capacity fades gradually with repeated cycling, a reversible capacity of 300-350 mAh g-1 is maintained for more than 50 cycles, which suggests that the in situ formed Sn--Cu alloy could provide an interlocking interface between active materials and current collector. Therefore, the tin's shedding from the current collector can be restrained. Moreover, the inactive materials, such as the oxide in the superficial layer and the Cu in the bottom layer, could also act as buffers to relieve the induced volume expansion of Sn during the repeated lithiathion/delithiation process, thus giving the good cycle performances.

  19. A study on the high temperature-dependence of the electrical properties in a solution-deposited zinc-tin-oxide thin-film transistor operated in the saturation region

    NASA Astrophysics Data System (ADS)

    Yu, Kyeong Min; Bae, Byung Seong; Jung, Myunghee; Yun, Eui-Jung

    2016-06-01

    We investigate the effects of high temperatures in the range of 292 - 393 K on the electrical properties of solution-processed amorphous zinc-tin-oxide (a-ZTO) thin-film transistors (TFTs) operated in the saturation region. The fabricated a-ZTO TFTs have a non-patterned bottom gate and top contact structure, and they use a heavily-doped Si wafer and SiO2 as a gate electrode and a gate insulator layer, respectively. In a-ZTO TFTs, the trap release energy ( E TR ) was deduced by using Maxwell-Boltzmann statistics. The decreasing E TR toward zero with increasing gate voltage (the density of trap states ( n s )) in the a-ZTO active layer can be attributed to a shift of the Fermi level toward the mobility edge with increasing gate voltage. The TFTs with low gate voltage (low n s ) exhibit multiple trap and release characteristics and show thermally-activated behavior. In TFTs with a high gate voltage (high n s ), however, we observe decreasing mobility and conductivity with increasing temperature at temperatures ranging from 303 to 363 K. This confirms that the E TR can drop to zero, indicating a shift of the Fermi level beyond the mobility edge. Hence, the mobility edge is detected at the cusp between thermally-activated transport and band transport.

  20. Defects evolution and their impacts on conductivity of indium tin oxide thin films upon thermal treatment

    SciTech Connect

    Li, Qichao; Mao, Wenfeng; Zhou, Yawei; Yang, Chunhong; Liu, Yong; He, Chunqing

    2015-07-14

    Indium tin oxide (ITO) thin films were deposited on silicon substrates by radio-frequency magnetron sputtering. The influence of annealing temperature on the crystallite, surface morphology, defects evolution, and electrical property of the thin films was studied. The conductivity of the ITO films was significantly enhanced by two orders of magnitude by increasing the annealing temperature up to 600 °C, which was interpreted in point view of defects evolution in ITO films as revealed by positron annihilation. It was interesting to find that positron diffusion length was amazingly comparable to crystallite size in ITO films annealed below 300 °C, indicating positrons were preferentially localized and annihilated in defects around crystallite boundaries. By further increasing the temperature, positron diffusion length was far beyond the grain size with little increment. This demonstrated that defects were effectively removed around grain boundaries. The results indicated defect structure around crystallite/grain boundaries played an important role on carrier transportation in nanocrystal ITO films.

  1. Effect of thickness on electrical properties of SILAR deposited SnS thin films

    NASA Astrophysics Data System (ADS)

    Akaltun, Yunus; Astam, Aykut; Cerhan, Asena; ćayir, Tuba

    2016-03-01

    Tin sulfide (SnS) thin films of different thickness were prepared on glass substrates by successive ionic layer adsorption and reaction (SILAR) method at room temperature using tin (II) chloride and sodium sulfide aqueous solutions. The thicknesses of the films were determined using spectroscopic ellipsometry measurements and found to be 47.2, 65.8, 111.0, and 128.7nm for 20, 25, 30 and 35 deposition cycles respectively. The electrical properties of the films were investigated using d.c. two-point probe method at room temperature and the results showed that the resistivity was found to decrease with increasing film thickness.

  2. Improved conductivity of indium-tin-oxide film through the introduction of intermediate layer

    NASA Astrophysics Data System (ADS)

    Ng, S. W.; Yam, F. K.; Beh, K. P.; Tneh, S. S.; Hassan, Z.

    2016-09-01

    A thin intermediate layer (Ag, AuSn, In, Ni, Sn, SiO2) was individually deposited on glass substrates prior to the deposition of indium-tin-oxide (ITO) thin film by radio-frequency (RF) magnetron sputtering employing ITO target (composition ratio of In2O3:SnO2 = 9:1). The structural, optical and electrical properties were investigated to compare the ITO thin film with and without an intermediate layer. The preferential orientation of all ITO films was along (222) plane. Although all thin films were polycrystalline, the presence of intermediate layer promoted the overall crystallinity. The sheet resistance and resistivity of the ITO film were reduced from ∼68 Ω/□ to ∼29-45 Ω/□, and 16.2 × 10-4 Ω cm up to 7.58 × 10-4 Ω cm, respectively, by inserting a thin metal layer underneath the ITO film, and it is dependent on the degree of crystallization. The optical transmittance in the visible region varies from 40 to 88% for different samples. Based on the evaluation from Tauc plot, the optical band gap falls in the range of 4.02-4.12 eV. Physical film thickness was compared with that evaluated by optical measurement in the visible range and the physical thickness was found to be smaller. Similarly, the carrier concentration/scattering time from Hall effect measurement were also compared with that from optical measurement in the infrared region. Haacke's figure of merit (FOM) was employed to assess the quality of the ITO films, and the highest FOM is credited to ITO/In up to ∼8 × 10-3 Ω-1 in the visible light region.

  3. Deposition of diamondlike carbon films

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J.; Sovey, J. S.; Banks, B. A. (Inventor)

    1984-01-01

    A diamondlike carbon film is deposited in the surface of a substrate by exposing the surface to an argon ion beam containing a hydrocarbon. The current density in the ion beam is low during initial deposition of the film. Subsequent to this initial low current condition, the ion beam is increased to full power. At the same time, a second argon ion beam is directed toward the surface of the substrate. The second ion beam has an energy level much greater than that of the ion beam containing the hydrocarbon. This addition of energy to the system increases mobility of the condensing atoms and serves to remove lesser bound atoms.

  4. Influence of high power impulse magnetron sputtering plasma ionization on the microstructure of TiN thin films

    NASA Astrophysics Data System (ADS)

    Ehiasarian, A. P.; Vetushka, A.; Gonzalvo, Y. Aranda; Sáfrán, G.; Székely, L.; Barna, P. B.

    2011-05-01

    HIPIMS (High Power Impulse Magnetron Sputtering) discharge is a new PVD technology for the deposition of high-quality thin films. The deposition flux contains a high degree of metal ionization and nitrogen dissociation. The microstructure of HIPIMS-deposited nitride films is denser compared to conventional sputter technologies. However, the mechanisms acting on the microstructure, texture and properties have not been discussed in detail so far. In this study, the growth of TiN by HIPIMS of Ti in mixed Ar and N2 atmosphere has been investigated. Varying degrees of metal ionization and nitrogen dissociation were produced by increasing the peak discharge current (Id) from 5 to 30 A. The average power was maintained constant by adjusting the frequency. Mass spectrometry measurements of the deposition flux revealed a high content of ionized film-forming species, such as Ti1+, Ti2+ and atomic nitrogen N1+. Ti1+ ions with energies up to 50 eV were detected during the pulse with reducing energy in the pulse-off times. Langmuir probe measurements showed that the peak plasma density during the pulse was 3 × 1016 m-3. Plasma density, and ion flux ratios of N1+: N21+ and Ti1+: Ti0 increased linearly with peak current. The ratios exceeded 1 at 30 A. TiN films deposited by HIPIMS were analyzed by X-ray diffraction, and transmission electron microscopy. At high Id, N1+: N21+> 1 and Ti1+: Ti0> 1 were produced; a strong 002 texture was present and column boundaries in the films were atomically tight. As Id reduced and N1+: N21+ and Ti1+: Ti0 dropped below 1, the film texture switched to strong 111 with a dense structure. At very low Id, porosity between columns developed. The effects of the significant activation of the deposition flux observed in the HIPIMS discharge on the film texture, microstructure, morphology and properties are discussed.

  5. Mineralogy of the Santa Fe Tin deposit, Bolivia

    NASA Astrophysics Data System (ADS)

    Jiménez-Franco, Abigail; Alfonso, Pura; Canet, Carles; Garcia-Valles, Maite; Elvys Trujillo, Juan

    2014-05-01

    Santa Fe is a Sn-Zn-Pb-Ag ore deposit located in the Oruro district, Central Andean Tin Belt, Bolivia. Mineralization occurs in veins and disseminations. It is hosted in Silurian shales and greywackes. The sedimentary sequence is folded and unconformably covered by a volcanic complex of the Morococala Formation, mainly constituted by tuffs of Miocene age. A wide Nº40 shear zone and two systems of fracture are developed. A Nº40 fracture system, dipping 60ºW, which hosts Sn and Zn minerals, and other in the same direction but dipping 75ºE, which is related to Zn-Pb-Ag veins. The mineralization is associated to intrusive felsic magmatism. Although there are not intrusive rocks in Santa Fe, a dyke and the felsic San Pablo stock occur at a distance of about 10 km. In the present work we describe the geology and mineralogy of the Santa Fe deposit. X-ray diffraction, scanning electron microscopy and electron microprobe analyses were used to characterize the minerals. Veins are filled with quartz and an ore mineral assemblage of cassiterite, sulfides and sulfosalts. Cassiterite constitutes the earliest formed mineralization. Preliminar microprobe analyses indicate that it is nearly pure, with negligible contents in Nb and Ta. Rutile occurs as a late phase associated with a late generation of cassiterite. It forms thin neddle-like crystals. In addition, Sn is also present in sulfides as stannite, stannoidite and kësterite. Other sulfides are pyrrhotite, pyrite, arsenopyrite, galena, sphalerite, marchasite and argentite. Bismuthinite and berndite are found nin trace amounts. Sulfosalts include tetrahedrite, myarhyrite, boulangerite, jamesonite, franckeite, zinckenite, cilindrite and andorite. Associated with the mineralization, several phosphate minerals are found filling cavities and small fractures. The most abundant are monacite (Ce,La,Nd,Th)PO4 and plumbogummite (PbAl3(PO4)2(OH)5•(H2O)). Crandallite CaAl3(PO4)2(OH)5•(H2O) and vivianite (Fe3+(PO4)2•8(H2O)) also

  6. Properties of TiN and TiN deposited by CVD on graphite for pyrochemical applications.

    SciTech Connect

    Maiya, P. S.; Moon, B. M.

    1997-12-17

    High-density TiN (>98% of theoretical) has been prepared by hot pressing TiN powder with 2-4 wt.% Li{sub 2}C0{sub 3} at temperatures between 1150-1550 C and pressures of {approx}40-50 MPa. The Li{sub 2}C0{sub 3} served as a fugitive sintering aid, enabling attainment of high density at low temperatures without adversely affecting the inherently good properties. Variation in processing variables and TiN powder characteristics resulted in material with various porosities. Measurement of mechanical properties such as flexural strength and fracture toughness showed that the high-density material has mechanical properties that are superior to those of several oxide ceramics. We have also quantified the effects of porosity on mechanical properties. In addition, adhesion and chemical stability tests were used to investigate graphite coated with TiN by chemical vapor deposition (CVD). Pin-pull tests were used to determine coating adhesion and failure stresses were analyzed by Weibull statistics. All pin-pull tests resulted in fracture of the graphite substrate, rather than separation at the TiN/graphite interface. The data showed a good fit to the two-parameter Weibull expression, with a failure strength of 16.4 MPa and Weibull modulus of 9.3. Both the high-density TiN and the TiN coating on the graphite were exposed to a corrosive molten salt CaCl{sub 2}-7 wt.% CaO and a liquid metal alloy (Zn-10 wt.% Mg) at 800 C for 168 h to determine chemical interactions. No reaction was detected by scanning electron microscopy (SEM) or energy-dispersive X-ray (EDX) analysis. Thus, graphite coated with TiN by CVD combines the thermodynamic stability of TiN when exposed to reactive molten metals and salts, with the excellent machinability of graphite, and hence is promising for use in container vessels for pyrochemical processing of certain rare-earth and nuclear metals, where chemical inertness and good matching of thermal expansion coefficients are required.

  7. Influence of Preferred Orientation on the Electrical Conductivity of Fluorine-Doped Tin Oxide Films

    PubMed Central

    Wang, Jian Tao; Shi, Xiang Lei; Liu, Wei Wei; Zhong, Xin Hua; Wang, Jian Nong; Pyrah, Leo; Sanderson, Kevin D.; Ramsey, Philip M.; Hirata, Masahiro; Tsuri, Keiko

    2014-01-01

    Current development of high-performance transparent conductive oxide (TCO) films is limited with tradeoff between carrier mobility and concentration since none of them can be improved without sacrificing the other. In this study, we prepare fluorine doped tin oxide (FTO) films by chemical vapor deposition with inclusions of different additives and report that the mobility can be varied from 0.65 to 28.5 cm2 V−1 s−1 without reducing the achieved high carrier concentration of 4 × 1020 cm−3. Such an increase in mobility is shown to be clearly associated with the development of (200) preferred orientation (PO) but concurrent degradation of (110) PO in films. Thus, at a constant high carrier concentration, the electrical conductivity can be improved via carrier mobility simply by PO control. Such a one-step approach avoiding conventional post-deposition treatment is suggested for developing next-generation FTO as well as other TCO films with better than ever conductivities. PMID:24419455

  8. Influence of preferred orientation on the electrical conductivity of fluorine-doped tin oxide films.

    PubMed

    Wang, Jian Tao; Shi, Xiang Lei; Liu, Wei Wei; Zhong, Xin Hua; Wang, Jian Nong; Pyrah, Leo; Sanderson, Kevin D; Ramsey, Philip M; Hirata, Masahiro; Tsuri, Keiko

    2014-01-01

    Current development of high-performance transparent conductive oxide (TCO) films is limited with tradeoff between carrier mobility and concentration since none of them can be improved without sacrificing the other. In this study, we prepare fluorine doped tin oxide (FTO) films by chemical vapor deposition with inclusions of different additives and report that the mobility can be varied from 0.65 to 28.5 cm(2) V(-1) s(-1) without reducing the achieved high carrier concentration of 4 × 10(20) cm(-3). Such an increase in mobility is shown to be clearly associated with the development of (200) preferred orientation (PO) but concurrent degradation of (110) PO in films. Thus, at a constant high carrier concentration, the electrical conductivity can be improved via carrier mobility simply by PO control. Such a one-step approach avoiding conventional post-deposition treatment is suggested for developing next-generation FTO as well as other TCO films with better than ever conductivities. PMID:24419455

  9. Preparation and Characterization of SnO2 thin films deposited by Chemical Bath Deposition method

    NASA Astrophysics Data System (ADS)

    Yusuf, Gbadebo; Raimi, Adepoju; Familusi, Timothy; Awodugba, Ayodeji; Efunwole, Hezekiah

    2013-04-01

    SnO2 thin films have been deposited onto the soda lime glass substrates by the chemical bath deposition method. The structural and optical properties of the SnO2 thin films were investigated. Tin chloride solution (SnCl2) and methanol were used as starting materials at substrate temperature 300°C. The crystal structure and orientation of the SnO2 thin films were investigated by X-ray diffraction (XRD) patterns. The average grain size of the films was calculated using the Scherer formula and was found to be 29.6 nm which increased to 30.04nm after annealing in air at 400°C. The optical absorbance and transmittance measurements were recorded by using spectrophotometer. The average transmittance of the film was around 80 % at wavelength 550 nm. The optical band gap of the thin films was determined and found to be 3.71eV. The gas sensing properties of tin oxide thin films obtained in this work could be performed for different gases like CO, CH4, H2S, H2 etc. The Authors would like to acknowledge the encouragement and financial support from the Management of Osun state Polytechnic, Iree.

  10. Preparation and Characterization of SnO2 thin films deposited by Chemical Bath Deposition method

    NASA Astrophysics Data System (ADS)

    Yusuf, Gbadebo T.; Raimi, Adepoju M.; Familusi, Timothy O.; Awodugba, Ayodeji O.; Efunwole, Hezekiah O.

    2013-04-01

    SnO2 thin films have been deposited onto the soda lime glass substrates by the chemical bath deposition method. The structural and optical properties of the SnO2 thin films were investigated. Tin chloride solution (SnCl2) and methanol were used as starting materials at substrate temperature 300^oC. The crystal structure and orientation of the SnO2 thin films were investigated by X-ray diffraction (XRD) patterns. The average grain size of the films was calculated using the Scherer formula and was found to be 29.6 nm which increased to 30.04nm after annealing in air at 400^oC. The optical absorbance and transmittance measurements were recorded by using spectrophotometer. The average transmittance of the film was around 80 % at wavelength 550 nm. The optical band gap of the thin films was determined and found to be 3.71eV. The gas sensing properties of tin oxide thin films obtained in this work could be performed for different gases like CO, CH4, H2S, H2 etc.

  11. Low-temperature and solution-processed indium tin oxide films and their applications in flexible transparent capacitive pressure sensors

    NASA Astrophysics Data System (ADS)

    Yu, Jian; Chen, Sujie; Wang, Nana; Ye, Zhizhen; Qi, Hang; Guo, Xiaojun; Jin, Yizheng

    2016-04-01

    It is of great interest to fabricate indium tin oxide (ITO) films by solution-based techniques at low temperatures. Here, we combined the use of colloidal ITO nanoflowers synthesized by the strategy of limited ligand protection and oxygen plasma treatment which effectively remove the surface ligands of ITO nanocrystals to meet this goal. These efforts led to high-quality ITO films with resistivity as low as 2.33 × 10-2 Ω cm, which is the best result for solution-processed ITO nanocrystal films deposited at temperatures lower than 200 °C. The annealing-free processing allowed us to deposit ITO nanoflower films onto plastic substrates and apply them in flexible capacitive pressure sensors. The single-pixel device showed decent sensitivity and reproducibility, and the arrayed sensors exhibited good spatial resolution.

  12. Optimal deposition conditions of TiN barrier layers for the growth of vertically aligned carbon nanotubes onto metallic substrates

    NASA Astrophysics Data System (ADS)

    García-Céspedes, J.; Álvarez-García, J.; Zhang, X.; Hampshire, J.; Bertran, E.

    2009-05-01

    Plasma enhanced chemical deposition (PECVD) has proven over the years to be the preferred method for the growth of vertically aligned carbon nanotubes and nanofibres (VACNTs and VACNFs, respectively). In particular, carbon nanotubes (CNTs) grown on metallic surfaces present a great potential for high power applications, including low resistance electrical contacts, high power switches, electron guns or supercapacitors. Nevertheless, the deposition of CNTs onto metallic substrates is challenging, due to the intrinsic incompatibility between such substrates and the metallic precursor layers required to promote the growth of CNTs. In particular, the formation of CNT films is assisted by the presence of a nanometric (10-100 nm) monolayer of catalyst clusters, which act as nucleation sites for CNTs. The nanometric character of the precursor layer, together with the high growth temperature involved during the PECVD process (~700 °C), strongly favours the in-diffusion of the catalyst nanoclusters into the bulk of the metallic substrate, which results in a dramatic reduction in the nucleation of CNTs. In order to overcome this problem, it is necessary to coat the metallic substrate with a diffusion barrier layer, prior to the growth of the catalyst precursor. Unlike other conventional ceramic barrier layers, TiN provides high electrical conductivity, thus being a promising candidate for use as barrier material in applications involving low resistance contacts. In this work we investigate the anti-diffusion properties of TiN sputtered coatings and its potential applicability to the growth of CNTs onto copper substrates, using Fe as catalyst material. The barrier and catalyst layers were deposited by magnetron sputtering. Auger electron spectroscopy was used to determine the diffusivity of Fe into TiN. Morphological characterization of the CNTs coatings was performed on scanning and transmission electron microscopes. Raman spectroscopy and x-ray diffraction were employed to

  13. Indium tin oxide with titanium doping for transparent conductive film application on CIGS solar cells

    NASA Astrophysics Data System (ADS)

    Liu, Wei-Sheng; Cheng, Huai-Ming; Hu, Hung-Chun; Li, Ying-Tse; Huang, Shi-Da; Yu, Hau-Wei; Pu, Nen-Wen; Liang, Shih-Chang

    2015-11-01

    In this study, Ti-doped indium tin oxide (ITO:Ti) thin films were fabricated using a DC-magnetron sputtering deposition method. The thin films were grown without introducing oxygen or heating the substrate, and no post-growth annealing was performed after fabrication. The thickness of the ITO:Ti thin films (350 nm) was controlled while increasing the sputtering power from 50 to 150 W. According to the results, the optimal optoelectronic properties were observed in ITO:Ti thin films grown at a sputtering power of 100 W, yielding a reduced resistivity of 3.2 × 10-4 Ω-cm and a mean high transmittance of 83% at wavelengths ranging from 400 to 800 nm. The optimal ITO:Ti thin films were used to fabricate a Cu(In,Ga)Se2 solar cell that exhibited a photoelectric conversion efficiency of 11.3%, a short-circuit current density of 33.1 mA/cm2, an open-circuit voltage of 0.54 V, and a fill factor of 0.64.

  14. Effect of structural defects on corrosion initiation of TiN nanocrystalline films

    NASA Astrophysics Data System (ADS)

    He, Chunlin; Zhang, Jinlin; Wang, Jianming; Ma, Guofeng; Zhao, Dongliang; Cai, Qingkui

    2013-07-01

    TiN thin films were deposited on AISI304 stainless steel using a DC reactive magnetron sputtering process. An in situ observation is carried out in order to investigate the relationship between the corrosion initiation and the structural defects such as pores and pinholes by using atomic force microscopy (AFM). It is found that the corrosion initiates at some larger structural pores in the form of the detachment of the particles which will plug the transport path for the corrosion products, whereas the small enough pinholes are easily filled in by corrosion products at the beginning of corrosion. Also, the surface roughness of the corroded film is improved with increasing the corrosion time. The corrosion morphology after polarization test shows that fewer and large pits appear on the TiN-coated substrates probably associated with large structural defects such as high density area of through film pores or pinholes present in the films, which is in accord with those results obtained by in situ AFM observation. Additionally, the effect of bias voltages on corrosion resistance of the films is also involved because the structural defects are strongly associated with the bias voltages.

  15. Microstructure and electrical properties of Na{sub 0.5}Bi{sub 0.5}(Ti{sub 0.98}Zr{sub 0.02})O{sub 3} thin film deposited on indium tin oxide/glass substrate

    SciTech Connect

    Yang, C.H.; Sui, H.T.; Geng, F.J.; Feng, C.; Qian, J.

    2015-05-15

    Highlights: • NBTZr deposited on ITO/glass under O{sub 2} exhibits a phase-pure perovskite structure. • NBTZr shows a well-defined P–E with a remanent polarization of 11.5 μC/cm{sup 2}. • At 100 kHz and 14 V, the dielectric tunability is 44.97% and FOM is 3.58. • At 100 kHz, the ϵ{sub r} and tanδ are 205 and 0.092, respectively. - Abstract: Na{sub 0.5}Bi{sub 0.5}(Ti{sub 0.98}Zr{sub 0.02})O{sub 3} (NBTZr) thin film has been prepared by chemical solution deposition onto indium tin oxide (ITO)/glass under O{sub 2} atmosphere. The microstructure and related electrical performance are investigated. The film exhibits a phase-pure polycrystalline perovskite structure, with evenly distributed grain size and full compactness. A well-defined polarization-electric field (P–E) loop can be observed with a remanent polarization (P{sub r}) of 11.5 μC/cm{sup 2} and small gap. At 14 V and 100 kHz, the dielectric tunability as high as 44.97% can be achieved and the dielectric constant of 205, dissipation factor of 0.092 as well as figure of merit of 3.58 are obtained.

  16. Ion beam sputter deposited diamond like films

    NASA Technical Reports Server (NTRS)

    Banks, B. A.; Rutledge, S. K.

    1982-01-01

    A single argon ion beam source was used to sputter deposit carbon films on fused silica, copper, and tantalum substrates under conditions of sputter deposition alone and sputter deposition combined with simultaneous argon ion bombardment. Simultaneously deposited and ion bombarded carbon films were prepared under conditions of carbon atom removal to arrival ratios of 0, 0.036, and 0.71. Deposition and etch rates were measured for films on fused silica substrates. Resulting characteristics of the deposited films are: electrical resistivity of densities of 2.1 gm/cu cm for sputter deposited films and 2.2 gm/cu cm for simultaneously sputter deposited and Ar ion bombarded films. For films approximately 1700 A thick deposited by either process and at 5550 A wavelength light the reflectance was 0.2, the absorptance was 0.7, the absorption coefficient was 67,000 cm to the -1 and the transmittance was 0.1.

  17. Electrophoretic deposition of tannic acid-polypyrrolidone films and composites.

    PubMed

    Luo, Dan; Zhang, Tianshi; Zhitomirsky, Igor

    2016-05-01

    Thin films of polyvinylpyrrolidone (PVP)-tannic acid (TA) complexes were prepared by a conceptually new strategy, based on electrophoretic deposition (EPD). Proof of concept investigations involved the analysis of the deposition yield, FTIR and UV-vis spectroscopy of the deposited material, and electron microscopy studies. The analysis of the deposition mechanism indicated that the limitations of the EPD in the deposition of small phenolic molecules, such as TA, and electrically neutral polymers, similar to PVP, containing hydrogen-accepting carbonyl groups, can be avoided. The remarkable adsorption properties of TA and film forming properties of the PVP-TA complexes allowed for the EPD of materials of different types, such as huntite mineral platelets and hydrotalcite clay particles, TiO2 and MnO2 oxide nanoparticles, multiwalled carbon nanotubes, TiN and Pd nanoparticles. Moreover, PVP-TA complexes were used for the co-deposition of different materials and formation of composite films. In another approach, TA was used as a capping agent for the hydrothermal synthesis of ZnO nanorods, which were then deposited by EPD using PVP-TA complexes. The fundamental adsorption and interaction mechanisms of TA involved chelation of metal atoms on particle surfaces with galloyl groups, π-π interactions and hydrogen bonding. The films prepared by EPD can be used for various applications, utilizing functional properties of TA, PVP, inorganic and organic materials of different types and their composites. PMID:26878711

  18. Indium tin oxide films prepared by atmospheric plasma annealing and their semiconductor-metal conductivity transition around room temperature

    NASA Astrophysics Data System (ADS)

    Li, Yali; Li, Chunyang; He, Deyan; Li, Junshuai

    2009-05-01

    We report the synthesis of indium tin oxide (ITO) films using the atmospheric plasma annealing (APA) technique combined with the spin-coating method. The ITO film with a low resistivity of ~4.6 × 10-4 Ω cm and a high visible light transmittance, above 85%, was achieved. Hall measurement indicates that compared with the optimized ITO films deposited by magnetron sputtering, the above-mentioned ITO film has a higher carrier concentration of ~1.21 × 1021 cm-3 and a lower mobility of ~11.4 cm2 V-1 s-1. More interestingly, these electrical characteristics result in the semiconductor-metal conductivity transition around room temperature for the ITO films prepared by APA.

  19. Ion beam deposited protective films

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J.

    1981-01-01

    Sputter deposition of adherent thin films on complex geometric surfaces by ion beam sources is examined in order to evaluate three different types of protective coatings for die materials. In the first experiment, a 30 cm diameter argon ion source was used to sputter deposit adherent metallic films up to eight microns thick on H-13 steel, and a thermal fatigue test specimen sputter deposited with metallic coatings one micron thick was immersed in liquid aluminum and cooled by water for 15,000 cycles to simulate operational environments. Results show that these materials do protect the steel by reducing thermal fatigue and thereby increasing die lifetime. The second experiment generated diamond-like carbon films using a dual beam ion source system that directed an eight cm argon ion source beam at the substrates. These films are still in the process of being evaluated for crystallinity, hardness and infrared absorption. The third experiment coated a fiber glass beam shield incorporated in the eight-cm diameter mercury ion thruster with molybdenum to ensure proper electrical and thermal properties. The coating maintained its integrity even under acceleration tests.

  20. The effect of annealing temperature on the stability of gallium tin zinc oxide thin film transistors

    NASA Astrophysics Data System (ADS)

    Nguyen, Ngoc; McCall, Briana; Alston, Robert; Collis, Ward; Iyer, Shanthi

    2015-10-01

    With the growing need for large area display technology and the push for a faster and cheaper alternative to the current amorphous indium gallium zinc oxide (a-IGZO) as the active channel layer for pixel-driven thin film transistors (TFTs) display applications, gallium tin zinc oxide (GSZO) has shown to be a promising candidate due to the similar electronic configuration of Sn4+ and In3+. In this work TFTs of GSZO sputtered films with only a few atomic % of Ga and Sn have been fabricated. A systematic and detailed comparison has been made of the properties of the GSZO films annealed at two temperatures: 140 °C and 450 °C. The electrical and optical stabilities of the respective devices have been studied to gain more insight into the degradation mechanism and are correlated with the initial TFT performance prior to the application of stress. Post deposition annealing at 450 °C of the films in air was found to lead to a higher atomic concentration of Sn4+ in these films and a superior quality of the film, as attested by the higher film density and less surface and interface roughness in comparison to the lower annealed temperature device. These result in significantly reduced shallow and deep interface traps with improved performance of the device exhibiting VON of -3.5 V, ION/IOFF of 108, field-effect mobility (μFE) of 4.46 cm2 V-1s-1, and sub-threshold swing of 0.38 V dec-1. The device is stable under both electrical and optical bias for wavelengths of 550 nm and above. Thus, this work demonstrates GSZO-based TFTs as a promising viable option to the IGZO TFTs by further tailoring the film composition and relevant processing temperatures.

  1. Thin porous indium tin oxide nanoparticle films: effects of annealing in vacuum and air

    NASA Astrophysics Data System (ADS)

    Ederth, J.; Hultåker, A.; Niklasson, G. A.; Heszler, P.; van Doorn, A. R.; Jongerius, M. J.; Burgard, D.; Granqvist, C. G.

    2005-11-01

    Electrical and optical properties were investigated in porous thin films consisting of In2O3:Sn (indium tin oxide; ITO) nanoparticles. The temperature-dependent resistivity was successfully described by a fluctuation-induced tunneling model, indicating a sample morphology dominated by clusters of ITO nanoparticles separated by insulating barriers. An effective-medium model, including the effect of ionized impurity scattering, was successfully fitted to measured reflectance and transmittance. Post-deposition treatments were carried out at 773 K for 2 h in both air and vacuum. It is shown that vacuum annealing increases either the barrier width or the area between two conducting clusters in the samples and, furthermore, an extra optical absorption occurs close to the band gap. A subsequent air annealing then reduces the effect of the barriers on the electrical properties and diminishes the absorption close to the band gap.

  2. Thickness effect on laser-induced-damage threshold of indium-tin oxide films at 1064 nm

    SciTech Connect

    Wang Haifeng; Huang Zhimeng; Zhang Dayong; Luo Fei; Huang Lixian; Li Yanglong; Luo Yongquan; Wang Weiping; Zhao Xiangjie

    2011-12-01

    Laser-induced-damage characteristics of commercial indium-tin oxide (ITO) films deposited by DC magnetron sputtering deposition on K9 glass substrates as a function of the film thickness have been studied at 1064 nm with a 10 ns laser pulse in the 1-on-1 mode, and the various mechanisms for thickness effect on laser-induced-damage threshold (LIDT) of the film have been discussed in detail. It is observed that laser-damage-resistance of ITO film shows dramatic thickness effect with the LIDT of the 50-nm ITO film 7.6 times as large as the value of 300 nm film, and the effect of depressed carrier density by decreasing the film thickness is demonstrated to be the primary reason. Our experiment findings indicate that searching transparent conductive oxide (TCO) film with low carrier density and high carrier mobility is an efficient technique to improve the laser-damage-resistance of TCO films based on maintaining their well electric conductivity.

  3. Thermal conductivity of nitride films of Ti, Cr, and W deposited by reactive magnetron sputtering

    SciTech Connect

    Jagannadham, Kasichainula

    2015-05-15

    Nitride films of Ti, Cr, and W were deposited using reactive magnetron sputtering from metal targets in argon and nitrogen plasma. TiN films with (200) orientation were achieved on silicon (100) at the substrate temperature of 500 and 600 °C. The films were polycrystalline at lower temperature. An amorphous interface layer was observed between the TiN film and Si wafer deposited at 600 °C. TiN film deposited at 600 °C showed the nitrogen to Ti ratio to be near unity, but films deposited at lower temperature were nitrogen deficient. CrN film with (200) orientation and good stoichiometry was achieved at 600 °C on Si(111) wafer but the film deposited at 500 °C showed cubic CrN and hexagonal Cr{sub 2}N phases with smaller grain size and amorphous back ground in the x-ray diffraction pattern. An amorphous interface layer was not observed in the cubic CrN film on Si(111) deposited at 600 °C. Nitride film of tungsten deposited at 600 °C on Si(100) wafer was nitrogen deficient, contained both cubic W{sub 2}N and hexagonal WN phases with smaller grain size. Nitride films of tungsten deposited at 500 °C were nonstoichiometric and contained cubic W{sub 2}N and unreacted W phases. There was no amorphous phase formed along the interface for the tungsten nitride film deposited at 600 °C on the Si wafer. Thermal conductivity and interface thermal conductance of all the nitride films of Ti, Cr, and W were determined by transient thermoreflectance technique. The thermal conductivity of the films as function of deposition temperature, microstructure, nitrogen stoichiometry and amorphous interaction layer at the interface was determined. Tungsten nitride film containing both cubic and hexagonal phases was found to exhibit much higher thermal conductivity and interface thermal conductance. The amorphous interface layer was found to reduce effective thermal conductivity of TiN and CrN films.

  4. Chemical vapor deposition and atomic layer deposition of metal oxide and nitride thin films

    NASA Astrophysics Data System (ADS)

    Barton, Jeffrey Thomas

    Processes for depositing thin films with various electronic, optical, mechanical, and chemical properties are indispensable in many industries today. Of the many deposition methods available, chemical vapor deposition (CVD) has proved over time to be one of the most flexible, efficient, and cost-effective. Atomic layer deposition (ALD) is a newer process that is gaining favor as a method for depositing films with excellent properties and unparalleled precision. This work describes the development of novel CVD and ALD processes to deposit a variety of materials. Hafnium oxide and zirconium oxide show promise as replacements for SiO 2 as gate dielectrics in future-generation transistors. These high-k materials would provide sufficient capacitance with layers thick enough to avoid leakage from tunneling. An ALD method is presented here for depositing conformal hafnium oxide from tetrakis-(diethylamido)hafnium and oxygen gas. A CVD method for depositing zirconium oxide from tetrakis-(dialkylamido)zirconium and either oxygen gas or water vapor is also described. The use of copper for interconnects in integrated circuits requires improved diffusion barrier materials, given its high diffusivity compared to the previously-used aluminum and tungsten. Tungsten nitride has a low resistivity among barrier materials, and can be deposited in amorphous films that are effective diffusion barriers in layers as thin as a few nanometers. Here we demonstrate CVD and plasma-enhanced CVD methods to deposit tungsten nitride films from bis-(dialkylamido)bis-( tert-butylimido)tungsten precursors and ammonia gas. Recent findings had shown uniform copper growth on tantalum silicate films, without the dewetting that usually occurs on oxide surfaces. Tantalum and tungsten silicates were deposited by a CVD reaction from the reaction of either tris-(diethylamido)ethylimido tantalum or bis-(ethylmethylamido)-bis-( tert-butylimido)tungsten with tris-(tert-butoxy)silanol. The ability of evaporated

  5. Preparation of RF reactively sputtered indium-tin oxide thin films with optical properties suitable for heat mirrors

    NASA Astrophysics Data System (ADS)

    Boyadzhiev, S.; Dobrikov, G.; Rassovska, M.

    2008-05-01

    Technologies are discussed for preparing and characterizing indium-tin oxide (ITO) thin films with properties appropriate for usage as heat mirrors in solar thermal collectors. The samples were prepared by means of radio frequency (RF) reactive sputtering of indium-tin targets in oxygen. The technological parameters were optimized to obtain films with optimal properties for heat mirrors. The optical properties of the films were studied by visible and infra-red (IR) spectrophotometry and laser ellipsometry. The reflectance of the films in the thermal IR range was investigated by a Fourier transform infra-red (FTIR) spectrophotometer. Heating of the substrates during the sputtering and their post deposition annealing in different environments were also studied. The ultimate purpose of the present research being the development of a technological process leading to low-cost ITO thin films with high transparency in the visible and near IR (0.3-2.4 μm) and high reflection in the thermal IR range (2.5-25 μm), we investigated the correlation of the ITO thin films structural and optical properties with the technological process parameters - target composition and heat treatment.

  6. Gas barrier properties of titanium oxynitride films deposited on polyethylene terephthalate substrates by reactive magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Lin, M.-C.; Chang, L.-S.; Lin, H. C.

    2008-03-01

    Titanium oxynitride (TiN xO y) films were deposited on polyethylene terephthalate (PET) substrates by means of a reactive radio frequency (RF) magnetron sputtering system in which the power density and substrate bias were the varied parameters. Experimental results show that the deposited TiN xO y films exhibited an amorphous or a columnar structure with fine crystalline dependent on power density. The deposition rate increases significantly in conjunction as the power density increases from 2 W/cm 2 to 7 W/cm 2. The maximum deposition rate occurs, as the substrate bias is -40 V at a certain power densities chosen in this study. The film's roughness slightly decreases with increasing substrate bias. The TiN xO y films deposited at power densities above 4 W/cm 2 show a steady Ti:N:O ratio of about 1:1:0.8. The water vapor and oxygen transmission rates of the TiN xO y films reach values as low as 0.98 g/m 2-day-atm and 0.60 cm 3/m 2-day-atm which are about 6 and 47 times lower than those of the uncoated PET substrate, respectively. These transmission rates are comparable to those of DLC, carbon-based and Al 2O 3 barrier films. Therefore, TiN xO y films are potential candidates to be used as a gas permeation barrier for PET substrate.

  7. Surface and optical properties of indium tin oxide layer deposition by RF magnetron sputtering in argon atmosphere

    NASA Astrophysics Data System (ADS)

    Yudar, H. Hakan; Korkmaz, Şadan; Özen, Soner; Şenay, Volkan; Pat, Suat

    2016-08-01

    This study focused on the characterization and properties of transparent and conductive indium tin oxide (ITO) thin films deposited in argon atmosphere. ITO thin films were coated onto glass substrates by radio frequency (RF) magnetron sputtering technique at 75 and 100 W RF powers. Structural characteristics of producing films were investigated through X-ray diffraction analysis. UV-Vis spectrophotometer and interferometer were used to determine transmittance, absorbance and reflectance values of samples. The surface morphology of the films was characterized by atomic force microscope. The calculated band gaps were 3.8 and 4.1 eV for the films at 75 and 100 W, respectively. The effect of RF power on crystallinity of prepared films was explored using mentioned analysis methods. The high RF power caused higher poly crystallinity in the produced samples. The thickness and refractive index values for all samples increased respect to an increment of RF power and were calculated as 20, 50 nm and 1.71, 1.86 for samples at 75 and 100 W, respectively. Finally, the estimated grain sizes for all prepared films decreased with increasing of 2 θ degrees, and the number of crystallite per unit volume was calculated. It was found that nearly all properties including sheet resistance and resistivity depend on the RF power.

  8. Rectifying properties of ZnO thin films deposited on FTO by electrodeposition technique

    NASA Astrophysics Data System (ADS)

    Lv, Jianguo; Sun, Yue; Zhao, Min; Cao, Li; Xu, Jiayuan; He, Gang; Zhang, Miao; Sun, Zhaoqi

    2016-03-01

    ZnO thin films were successfully grown on fluorine-doped tin oxide glass by electrodeposition technique. The crystal structure, surface morphology and optical properties of the thin films were investigated. The average crystallite size and intensity of A1(LO) mode increase with improving the absolute value of deposition potential. The best preferential orientation along c-axis and the richest oxygen interstitial defects have been observed in the sample deposited at -0.8 V. A heterojunction device consisting of ZnO thin film and n-type fluorine-doped tin oxide was fabricated. The current-voltage (I-V) characteristic of the p-n heterojunction device deposited at -0.8 V shows the best rectifying diode behavior. The p-type conductivity of the ZnO thin film could be attributed to complex defect of unintentional impurity and interstitial oxygen.

  9. Perpendicular coercivity enhancement of CoPt/TiN films by nitrogen incorporation during deposition

    SciTech Connect

    An, Hongyu; Harumoto, Takashi; Sannomiya, Takumi; Muraishi, Shinji; Nakamura, Yoshio; Shi, Ji; Wang, Jian; Szivos, Janos; Safran, Gyorgy

    2015-11-28

    The effect of N incorporation on the structure and magnetic properties of CoPt thin films deposited on glass substrates with TiN seed layers has been investigated. During the deposition of CoPt, introducing 20% N{sub 2} into Ar atmosphere promotes the (001) texture and enhances the perpendicular coercivity of CoPt film compared with the film deposited in pure Ar and post-annealed under the same conditions. From the in situ x-ray diffraction results, it is confirmed that N incorporation expands the lattice parameter of CoPt, which favors the epitaxial growth of CoPt on TiN. During the post-annealing process, N releases from CoPt film and promotes the L1{sub 0} ordering transformation of CoPt.

  10. Perpendicular coercivity enhancement of CoPt/TiN films by nitrogen incorporation during deposition

    NASA Astrophysics Data System (ADS)

    An, Hongyu; Wang, Jian; Szivos, Janos; Harumoto, Takashi; Sannomiya, Takumi; Muraishi, Shinji; Safran, Gyorgy; Nakamura, Yoshio; Shi, Ji

    2015-11-01

    The effect of N incorporation on the structure and magnetic properties of CoPt thin films deposited on glass substrates with TiN seed layers has been investigated. During the deposition of CoPt, introducing 20% N2 into Ar atmosphere promotes the (001) texture and enhances the perpendicular coercivity of CoPt film compared with the film deposited in pure Ar and post-annealed under the same conditions. From the in situ x-ray diffraction results, it is confirmed that N incorporation expands the lattice parameter of CoPt, which favors the epitaxial growth of CoPt on TiN. During the post-annealing process, N releases from CoPt film and promotes the L10 ordering transformation of CoPt.

  11. Physical Characterization and Effect of Effective Surface Area on the Sensing Properties of Tin Dioxide Thin Solid Films in a Propane Atmosphere

    PubMed Central

    Gómez-Pozos, Heberto; González-Vidal, José Luis; Torres, Gonzalo Alberto; de la Luz Olvera, María; Castañeda, Luis

    2014-01-01

    The physical properties and the effect of effective surface area (ESA) on the sensing properties of tin dioxide [SnO2] thin films in air and propane [C3H8] atmosphere as a function of operating temperature and gas concentration have been studied in this paper. SnO2 thin films with different estimated thicknesses (50, 100 and 200 nm) were deposited on glass substrates by the chemical spray technique. Besides, they were prepared at two different deposition temperatures (400 and 475 °C). Tin chloride [SnCl4 · 5H2O] with 0.2 M concentration value and ethanol [C2H6O] were used as tin precursor and solvent, respectively. The morphological, and structural properties of the as-prepared films were analyzed by AFM and XRD, respectively. Gas sensing characteristics of SnO2 thin solid films were measured at operating temperatures of 22, 100, 200, and 300 °C, and at propane concentration levels (0, 5, 50, 100, 200, 300, 400, and 500 ppm). ESA values were calculated for each sample. It was found that the ESA increased with the increasing thickness of the films. The results demonstrated the importance of the achieving of a large effective surface area for improving gas sensing performance. SnO2 thin films deposited by spray chemical were chosen to study the ESA effect on gas sensing properties because their very rough surfaces were appropriate for this application. PMID:24379046

  12. Electrical and optical characterization of multilayered thin film based on pulsed laser deposition of metal oxides

    NASA Astrophysics Data System (ADS)

    Marotta, V.; Orlando, S.; Parisi, G. P.; Giardini, A.; Perna, G.; Santoro, A. M.; Capozzi, V.

    2000-12-01

    Thin films of semiconducting oxides such as In2O3, SnO2, and multilayers of these two compounds have been deposited by reactive pulsed laser ablation, with the aim to produce toxic gas sensors. Deposition of these thin films has been carried out by a frequency doubled Nd-YAG laser (λ=532 nm) on silicon (1 0 0) substrates. A comparison, among indium oxide, tin oxide, and multilayers of indium and tin oxides, has been performed. The influence of physical parameters such as substrate temperature, laser fluence and oxygen pressure in the deposition chamber has been investigated. The deposited films have been characterized by X-ray diffraction (XRD), optical and electric resistance measurements.

  13. Experiments on In2S3:Sn Thin Films with up to 1% Tin Content

    NASA Astrophysics Data System (ADS)

    Kraini, M.; Bouguila, N.; Koaib, J.; Vázquez-Vázquez, C.; López-Quintela, M. A.; Alaya, S.

    2016-08-01

    Tin-doped indium sulfide (In2S3:Sn) thin films with different Sn:In molar ratios (0% to 1% by mol in solution) have been deposited on glass substrates by a chemical spray pyrolysis method. The films were investigated by x-ray diffraction analysis, optical absorption, Raman, and photoluminescence spectroscopies, field-emission scanning electron microscopy, energy-dispersive x-ray spectroscopy, and atomic force microscopy. The structural properties revealed that the In2S3:Sn thin films had polycrystalline cubic structure with average crystallite size increasing from 16.3 nm to 25.5 nm. The surface morphology of the films was continuous and crack free. The average and root-mean-square roughness increased from 13.12 nm to 31.65 nm and from 16.14 nm to 39.39 nm, respectively, with increasing Sn:In molar ratio. Raman studies revealed the presence of vibration modes related to In2S3 phase, with no signature of secondary phases. The transmission coefficient was about 65% to 70% in the visible region and 70% to 90% in the near-infrared region. The optical bandgap values for allowed direct transitions in In2S3:Sn were found to lie in the range from 2.68 eV to 2.80 eV. The refractive index of the In2S3:Sn thin films decreased from 2.45 to 2.37 while the k values lay in the range from 0.02 to 0.25 for all wavelengths. Defect-related photoluminescence properties are also discussed. These In2S3:Sn films are promising candidates for use in optoelectronic and photovoltaic devices.

  14. Electrodeposition and characterisation of lead tin superconducting films for application in heavy ion booster

    NASA Astrophysics Data System (ADS)

    Lobanov, Nikolai R.

    2015-12-01

    The ANU has developed experimental systems and procedures for lead-tin (PbSn) film deposition and characterisation. The 12 split loop resonators have been electroplated with 96%Pb4%Sn film to the final thickness of 1.5 micron using methanesulfonic acid (MSA) chemistry. As a result, an average acceleration field of 3.6 MV/m off-line at 6 W rf power was achieved at extremely low technological cost. Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Heavy Ion Elastic Detection Analyses (HIERDA), Rutherford Backscattering Spectroscopy (RBS), Secondary Ion Mass Spectroscopy (SIMS) and Electron Backscattering Diffraction (EBSD) revealed correlation between the substrate and film structure, morphology and the rf performance of the cavity. The PbSn plating, exercised on the existing split loop resonators (SLR), has been extended to the two stub quarter wave resonator (QWR) as a straightforward step to quickly explore the superconducting performance of the new geometry. The oxygen free copper (OHFC) substrate for two stub QWR was prepared by reverse pulse electropolishing. The ultimate superconducting properties and long-term stability of the coatings have been assessed by operation of the ANU superconducting linac over the last few years.

  15. Microstructural characteristics of tin oxide-based thin films on (0001) Al2O3 substrates: effects of substrate temperature and RF power during co-sputtering.

    PubMed

    Hwang, Sooyeon; Lee, Ju Ho; Kim, Young Yi; Yun, Myeong Goo; Lee, Kwan-Hun; Lee, Jeong Yong; Cho, Hyung Koun

    2014-12-01

    While tin oxides such as SnO and SnO2 are widely used in various applications, surprisingly, only a limited number of reports have been presented on the microstructural characteristics of tin oxide thin films grown under various growth conditions. In this paper, the effects of the substrate temperature and content of foreign Zn ion on the microstructural characteristics of tin oxide thin films grown by radio-frequency magnetron sputtering were investigated. The increase in substrate temperature induced change in the stoichiometry of the thin films from SnO(1+x) to SnO(2-x). Additionally, the phase contrast in the transmission electron microscopy image revealed that SnO(1+x) and SnO(2-x) phases were alternating in thin films and the width of each phase became narrower at high substrate temperature. The ternary zinc tin oxide thin films were deposited using the co-sputtering method. As the ZnO target power increased, the crystallinity of the thin films became poly-crystalline, and then showed improved crystallinity again with two types of phases. PMID:25970980

  16. Deposition of polyaniline film onto porous silicon layer

    SciTech Connect

    Parkhutik, V.P.; Martinez-Duart, J.M.; Callegja, R.D.; Matveeva, E.M.

    1993-12-31

    Presently porous silicon (PS) layers are being considered a promising visible light emitting sources. Current research concentrates on the understanding of the nature of the light emission and the development of practical luminescent devices. The last goal is to find an appropriate solid contact to the rough surface of PS layers to ensure high electric conductivity and transparency. The aim of this work is to study the deposition of polyaniline (PANI) films onto porous silicon layers as an alternative to indium tin oxide (ITO) as the electrode.

  17. Composition dependence of the photochemical reduction of Ag+ by as-grown Pb(ZrxTi1-x)O3 films on indium tin oxide electrode

    NASA Astrophysics Data System (ADS)

    Zhang, Man; Jiang, Chunxiang; Dong, Wen; Zheng, Fengang; Fang, Liang; Su, Xiaodong; Shen, Mingrong

    2013-09-01

    Photochemical growth of metal particles on ferroelectric films has usually been found to depend on polarization effect solely. This research exploits the interplay of the film/electrode interface barrier and depolarization field on the photoreduction of Ag+ to Ag onto Pb(Zr,Ti)O3 (PZT) films deposited on indium tin oxide (ITO) electrodes. Ag nanoparticles are observed on the as-grown polycrystalline PZT films without poling, while the particle size and density are closely related to the concentration of Zr in PZT and the poling direction. The enhancement on the photoelectrochemical properties of the ITO/PZT photocathode by the decoration of Ag nanoparticles is finally demonstrated.

  18. Reversible wettability of electron-beam deposited indium-tin-oxide driven by ns-UV irradiation

    SciTech Connect

    Persano, Luana; Del Carro, Pompilio; Pisignano, Dario

    2012-04-09

    Indium tin oxide (ITO) is one of the most widely used semiconductor oxides in the field of organic optoelectronics, especially for the realization of anode contacts. Here the authors report on the control of the wettability properties of ITO films deposited by reactive electron beam deposition and irradiated by means of nanosecond-pulsed UV irradiation. The enhancement of the surface water wettability, with a reduction of the water contact angle larger than 50 deg., is achieved by few tens of seconds of irradiation. The analyzed photo-induced wettability change is fully reversible in agreement with a surface-defect model, and it can be exploited to realize optically transparent, conductive surfaces with controllable wetting properties for sensors and microfluidic circuits.

  19. Hydroxyapatite thin films grown by pulsed laser deposition and radio-frequency magnetron sputtering: comparative study

    NASA Astrophysics Data System (ADS)

    Nelea, V.; Morosanu, C.; Iliescu, M.; Mihailescu, I. N.

    2004-04-01

    Hydroxyapatite (HA) thin films for applications in the biomedical field were grown by pulsed laser deposition (PLD) and radio-frequency magnetron sputtering (RF-MS) techniques. The depositions were performed from pure hydroxyapatite targets on Ti-5Al-2.5Fe (TiAlFe) alloys substrates. In order to prevent the HA film penetration by Ti atoms or ions diffused from the Ti-based alloy during and after deposition, the substrates were pre-coated with a thin buffer layer of TiN. In both cases, TiN was introduced by reactive PLD from TiN targets in low-pressure N 2. The PLD films were grown in vacuum onto room temperature substrates. The RF-MS films were deposited in low-pressure argon on substrates heated at 550 °C. The initially amorphous PLD thin films were annealed at 550 °C for 1 h in ambient air in order to restore the initial crystalline structure of HA target. The thickness of the PLD and RF-MS films were ˜1 μm and ˜350 nm, respectively. All films were structurally studied by scanning electron microscopy (SEM), grazing incidence X-ray diffraction (GIXRD), energy dispersive X-ray spectrometry (EDS) and white light confocal microscopy (WLCM). The mechanical properties of the films were tested by Berkovich nano-indentation. Both PLD and RF-MS films mostly contain HA phase and exhibit good mechanical characteristics. Peaks of CaO were noticed as secondary phase in the GIXRD patterns only for RF-MS films. By its turn, the sputtered films were smoother as compared to the ones deposited by PLD (50 nm versus 250 nm average roughness). The RF-MS films were harder, more mechanically resistant and have a higher Young modulus.

  20. Coherent growth of superconducting TiN thin films by plasma enhanced molecular beam epitaxy

    SciTech Connect

    Krockenberger, Yoshiharu; Karimoto, Shin-ichi; Yamamoto, Hideki; Semba, Kouich

    2012-10-15

    We have investigated the formation of titanium nitride (TiN) thin films on (001) MgO substrates by molecular beam epitaxy and radio frequency acitvated nitrogen plasma. Although cubic TiN is stabile over a wide temperature range, superconducting TiN films are exclusively obtained when the substrate temperature exceeds 710 Degree-Sign C. TiN films grown at 720 Degree-Sign C show a high residual resistivity ratio of approximately 11 and the superconducting transition temperature (T{sub c}) is well above 5 K. Superconductivity has been confirmed also by magnetiztion measurements. In addition, we determined the upper critical magnetic field ({mu}{sub 0}H{sub c2}) as well as the corresponding coherence length ({xi}{sub GL}) by transport measurements under high magnetic fields. High-resolution transmission electron microscopy data revealed full in plane coherency to the substrate as well as a low defect density in the film, in agreement with a mean-free path length Script-Small-L Almost-Equal-To 106 nm, which is estimated from the residual resistivity value. The observations of reflection high energy electron diffraction intensity oscillations during the growth, distinct Laue fringes around the main Bragg peaks, and higher order diffraction spots in the reciprocal space map suggest the full controlability of the thickness of high quality superconducting TiN thin films.

  1. Depositing Adherent Ag Films On Ti Films On Alumina

    NASA Technical Reports Server (NTRS)

    Honecy, Frank S.

    1995-01-01

    Report discusses cleaning of ceramic (principally, alumina) substrates in preparation for sputter deposition of titanium intermediate films on substrates followed by sputter deposition of outer silver films. Principal intended application, substrates sliding parts in advanced high-temperature heat engines, and outer silver films serve as solid lubricants: lubricating properties described in "Solid Lubricant for Alumina" (LEW-15495).

  2. Electrochemical deposition of conductive and adhesive polypyrrole-dopamine films

    NASA Astrophysics Data System (ADS)

    Kim, Semin; Jang, Lindy K.; Park, Hyun S.; Lee, Jae Young

    2016-07-01

    Electrode surfaces have been widely modified with electrically conductive polymers, including polypyrrole (PPY), to improve the performance of electrodes. To utilize conductive polymers for electrode modification, strong adhesion between the polymer films and electrode substrates should be ensured with high electrical/electrochemical activities. In this study, PPY films were electrochemically polymerized on electrodes (e.g., indium tin oxide (ITO)) with dopamine as a bio-inspired adhesive molecule. Efficient and fast PPY electrodeposition with dopamine (PDA/PPY) was found; the resultant PDA/PPY films exhibited greatly increased adhesion strengths of up to 3.7 ± 0.8 MPa and the modified electrodes had electrochemical impedances two to three orders of magnitude lower than that of an unmodified electrode. This electrochemical deposition of adhesive and conductive PDA/PPY offers a facile and versatile electrode modification for various applications, such as biosensors and batteries.

  3. Electrochemical deposition of conductive and adhesive polypyrrole-dopamine films.

    PubMed

    Kim, Semin; Jang, Lindy K; Park, Hyun S; Lee, Jae Young

    2016-01-01

    Electrode surfaces have been widely modified with electrically conductive polymers, including polypyrrole (PPY), to improve the performance of electrodes. To utilize conductive polymers for electrode modification, strong adhesion between the polymer films and electrode substrates should be ensured with high electrical/electrochemical activities. In this study, PPY films were electrochemically polymerized on electrodes (e.g., indium tin oxide (ITO)) with dopamine as a bio-inspired adhesive molecule. Efficient and fast PPY electrodeposition with dopamine (PDA/PPY) was found; the resultant PDA/PPY films exhibited greatly increased adhesion strengths of up to 3.7 ± 0.8 MPa and the modified electrodes had electrochemical impedances two to three orders of magnitude lower than that of an unmodified electrode. This electrochemical deposition of adhesive and conductive PDA/PPY offers a facile and versatile electrode modification for various applications, such as biosensors and batteries. PMID:27459901

  4. Electrochemical deposition of conductive and adhesive polypyrrole-dopamine films

    PubMed Central

    Kim, Semin; Jang, Lindy K.; Park, Hyun S.; Lee, Jae Young

    2016-01-01

    Electrode surfaces have been widely modified with electrically conductive polymers, including polypyrrole (PPY), to improve the performance of electrodes. To utilize conductive polymers for electrode modification, strong adhesion between the polymer films and electrode substrates should be ensured with high electrical/electrochemical activities. In this study, PPY films were electrochemically polymerized on electrodes (e.g., indium tin oxide (ITO)) with dopamine as a bio-inspired adhesive molecule. Efficient and fast PPY electrodeposition with dopamine (PDA/PPY) was found; the resultant PDA/PPY films exhibited greatly increased adhesion strengths of up to 3.7 ± 0.8 MPa and the modified electrodes had electrochemical impedances two to three orders of magnitude lower than that of an unmodified electrode. This electrochemical deposition of adhesive and conductive PDA/PPY offers a facile and versatile electrode modification for various applications, such as biosensors and batteries. PMID:27459901

  5. Analysis of carrier transport and band tail states in p-type tin monoxide thin-film transistors by temperature dependent characteristics

    NASA Astrophysics Data System (ADS)

    Zhang, Jiawei; Kong, Xi; Yang, Jia; Li, Yunpeng; Wilson, Joshua; Liu, Jie; Xin, Qian; Wang, Qingpu; Song, Aimin

    2016-06-01

    Tin monoxide (SnO) has drawn much attention in recent years due to its high hole mobility, transparency, and potential for mass production. However, due to its metastable nature, the deposited film often contains multi-phases such as metallic tin and tin dioxide, which may degrade its electrical properties. Here, we presented the temperature dependent characteristics of p-type SnO thin-film transistors. The hole transport mechanism is dominated by band conduction at high temperatures and variable-range hopping at low temperatures. The maximum activation energy was found to be 308 meV, which denotes a bandgap of around 0.6 eV. The density of states was found to be 1.12 × 1021 cm-3 eV-1 at VG = -80 V, and 6.75 × 1020 cm-3 eV-1 at VG = 0 V, respectively.

  6. Secondary Electron Yield Measurements of TiN coating and TiZrV getter film(LCC-128)

    SciTech Connect

    Le Pimpec, F

    2003-10-09

    In the beam pipe of the positron Main Damping Ring (MDR) of the Next Linear Collider (NLC), ionization of residual gases and secondary electron emission give rise to an electron cloud which can cause the loss of the circulating beam. One path to avoid the electron cloud is to ensure that the vacuum wall has low secondary emission yield and, therefore, we need to know the secondary emission yield (SEY) for candidate wall coatings. We report on SEY measurements at SLAC on titanium nitride (TiN) and titanium-zirconium-vanadium (TiZrV) thin sputter deposited films, as well as describe our experimental setup.

  7. Low temperature atmospheric pressure chemical vapor deposition of group 14 oxide films

    SciTech Connect

    Hoffman, D.M.; Atagi, L.M. |; Chu, Wei-Kan; Liu, Jia-Rui; Zheng, Zongshuang; Rubiano, R.R.; Springer, R.W.; Smith, D.C.

    1994-06-01

    Depositions of high quality SiO{sub 2} and SnO{sub 2} films from the reaction of homoleptic amido precursors M(NMe{sub 2})4 (M = Si,Sn) and oxygen were carried out in an atmospheric pressure chemical vapor deposition r. The films were deposited on silicon, glass and quartz substrates at temperatures of 250 to 450C. The silicon dioxide films are stoichiometric (O/Si = 2.0) with less than 0.2 atom % C and 0.3 atom % N and have hydrogen contents of 9 {plus_minus} 5 atom %. They are deposited with growth rates from 380 to 900 {angstrom}/min. The refractive indexes of the SiO{sub 2} films are 1.46, and infrared spectra show a possible Si-OH peak at 950 cm{sup {minus}1}. X-Ray diffraction studies reveal that the SiO{sub 2} film deposited at 350C is amorphous. The tin oxide films are stoichiometric (O/Sn = 2.0) and contain less than 0.8 atom % carbon, and 0.3 atom % N. No hydrogen was detected by elastic recoil spectroscopy. The band gap for the SnO{sub 2} films, as estimated from transmission spectra, is 3.9 eV. The resistivities of the tin oxide films are in the range 10{sup {minus}2} to 10{sup {minus}3} {Omega}cm and do not vary significantly with deposition temperature. The tin oxide film deposited at 350C is cassitterite with some (101) orientation.

  8. Chemical-Vapor-Deposited Diamond Film

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    1999-01-01

    This chapter describes the nature of clean and contaminated diamond surfaces, Chemical-vapor-deposited (CVD) diamond film deposition technology, analytical techniques and the results of research on CVD diamond films, and the general properties of CVD diamond films. Further, it describes the friction and wear properties of CVD diamond films in the atmosphere, in a controlled nitrogen environment, and in an ultra-high-vacuum environment.

  9. Thermochromic properties of Sn, W co-doped VO2 nanostructured thin film deposited by pulsed laser deposition.

    PubMed

    Hur, M G; Masaki, T; Yoon, D H

    2014-12-01

    Tin (Sn) and tungsten (W) co-doped vanadium dioxide (VO2) nanostructured thin films with 50-nm thickness were deposited by pulsed laser deposition (PLD) to reduce the transition temperature and improve the IR transmittance. The crystal structure of the nanostructured thin films and the presence of elements were evaluated by XRD and XPS analysis. The transition temperature (T(c)) of 1 at% Sn-1 at% W co-doped VO2 nanostructured thin film was decreased to about 22 degrees C (from 70.3 to 48.5 degrees C) compared with the undoped VO2 nanostructured thin film. The transmittance width in the IR range of the co-doped nanostructured thin film decreased from 37.5% to 27% compared with the undoped VO2 nanostructured thin film. Also, the width of hysteresis was narrowed by Sn doping. PMID:25970986

  10. Chemical vapor deposition and characterization of zirconium tin titanate as a high dielectric constant material for potential electronic applications

    NASA Astrophysics Data System (ADS)

    Mays, Ebony Lynn

    Integrated circuit (IC) manufacturers increasingly need new high dielectric constant (epsilon) materials for gate stacks to maintain the pace of developing faster, higher capacity CMOS and DRAM devices. Identification of new high-epsilon materials that can be integrated into current manufacturing processes is critical to the continued development of IC devices. Using magnetron sputtering and a compositional spread approach, a key composition of amorphous zirconium tin titanate (a-ZTT) films was found to exhibit a dielectric constant from 50 to 70 and leakage currents from 10-9 to 10 -7 A/cm2 at 1 MV/cm. Chemical Vapor Deposition (CVD) is an attractive technique for deposition of ZTT films because it offers several advantages over sputter deposition. Many processing parameters can be controlled and varied in the optimization of the film microstructure and composition. In addition, high-epsilon phases of the compounds might be achieved at low temperatures by using plasma enhancement of the CVD process. Alternatively, use of ozone or other oxidants may allow complete oxidation of metal precursors at lower processing temperatures. The following discussion details the construction and modification of a CVD reactor for the deposition of ZTT thin films. In addition, characterization of a precursor "cocktail"---a solution containing all the metal components of the film---for the deposition of ZTT thin films is discussed. Discussion includes experiments characterizing the dielectric and device properties (dielectric constant, dielectric loss, capacitance, and leakage current) of CVD-grown, a-ZTT thin films using the precursor "cocktail". The importance of the relationship of the cation ratio in the precursor that is translated to the film and its relationship to the dielectric properties are shown. The device properties of ZTT films were measured using Capacitance-Voltage (CV) and Current-Voltage (IV) analysis, while dielectric properties were explored using Impedance

  11. High Temperature - Thin Film Strain Gages Based on Alloys of Indium Tin Oxide

    NASA Technical Reports Server (NTRS)

    Gregory, Otto J.; Cooke, James D.; Bienkiewicz, Joseph M.

    1998-01-01

    A stable, high temperature strain gage based on reactively sputtered indium tin oxide (ITO) was demonstrated at temperatures up to 1050 C. These strain sensors exhibited relatively large, negative gage factors at room temperature and their piezoresistive response was both linear and reproducible when strained up to 700 micro-in/in. When cycled between compression and tension, these sensors also showed very little hysteresis, indicating excellent mechanical stability. Thin film strain gages based on selected ITO alloys withstood more than 50,000 strain cycles of +/- 500 micro-in/in during 180 hours of testing in air at 1000 C, with minimal drift at temperature. Drift rates as low as 0.0009%/hr at 1000 C were observed for ITO films that were annealed in nitrogen at 700 C prior to strain testing. These results compare favorably with state of the art 10 micro-m thick PdCr films deposited by NASA, where drift rates of 0.047%/hr at 1050 C were observed. Nitrogen annealing not only produced the lowest drift rates to date, but also produce the largest dynamic gage factors (G = 23.5). These wide bandgap, semiconductor strain sensors also exhibited moderately low temperature coefficients of resistance (TCR) at temperatures up to 1100 C, when tested in a nitrogen ambient. A TCR of +230 ppm/C over the temperature range 200 C < T < 500 C and a TCR of -469 ppm/C over the temperature range 600 C < T < 1100 C was observed for the films tested in nitrogen. However, the resistivity behavior changed considerably when the same films were tested in oxygen ambients. A TCR of -1560 ppm/C was obtained over the temperature range of 200 C < T < 1100 C. When similar films were protected with an overcoat or when ITO films were prepared with higher oxygen contents in the plasma, two distinct TCR's were observed. At T < 800 C, a linear TCR of -210 ppm/C was observed and at T > 800 C, a linear TCR of -2170 DDm/C was observed. The combination of a moderately low TCR and a relatively large gage

  12. Fabrication and characterization of highly disordered TiN thin films by reactive evaporation for circuit-QED

    NASA Astrophysics Data System (ADS)

    Lin, Yen-Hsiang; Mencia, Raymond; Nguyen, Baolong; Manucharyan, Vladimir

    Titanium nitride (TiN) has been identified as one of the potentially new materials for circuit-QED. In particular, disordered TiN films close to superconductor-insulator transition can be beneficial to greatly enhance kinetic inductance due to low superfluid density. Here we report TiN thin films prepared by e-beam evaporation within a nitrogen rich environment. By controlling nitrogen gas flow rate, the normal sheet resistance of TiN film can be tuned higher than 1kOhms while superconductivity still remains above 2K. Here, we present our characterization results and microwave measurement of quality factor Q and kinetic inductance L.

  13. Pulsed laser deposition: Prospects for commercial deposition of epitaxial films

    SciTech Connect

    Muenchausen, R.E.

    1999-03-01

    Pulsed laser deposition (PLD) is a physical vapor deposition (PVD) technique for the deposition of thin films. The vapor source is induced by the flash evaporation that occurs when a laser pulse of sufficient intensity (about 100 MW/cm{sup 2}) is absorbed by a target. In this paper the author briefly defines pulsed laser deposition, current applications, research directed at gaining a better understanding of the pulsed laser deposition process, and suggests some future directions to enable commercial applications.

  14. 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.

  15. Effect of gas ratio on tribological properties of sputter deposited TiN coatings

    NASA Astrophysics Data System (ADS)

    Chavda, Mahesh R.; Chauhan, Kamlesh V.; Rawal, Sushant K.

    2016-05-01

    Titanium nitride (TiN) coatings were deposited on Si, corning glass, pins of mild steel (MS, ϕ3mm), aluminium (Al, ϕ4mm) and brass (ϕ6mm) substratesby DC magnetron sputtering. The argon and nitrogen (Ar:N2)gas ratio was precisely controlled by Mass Flow Controller (MFC) and was varied systematically at diffract values of 10:10,12:08, 16:04 and 18:02sccm. The structural properties of TiN coatings were characterized by X-ray diffraction (XRD) and its surface topography was studied using field emission scanning electron microscopy (FE-SEM). The tribological properties of TiN coatings were investigated using pin-on-disc tribometer.

  16. Influence of high power impulse magnetron sputtering plasma ionization on the microstructure of TiN thin films

    SciTech Connect

    Ehiasarian, A. P.; Vetushka, A.; Gonzalvo, Y. Aranda; Safran, G.; Szekely, L.; Barna, P. B.

    2011-05-15

    HIPIMS (High Power Impulse Magnetron Sputtering) discharge is a new PVD technology for the deposition of high-quality thin films. The deposition flux contains a high degree of metal ionization and nitrogen dissociation. The microstructure of HIPIMS-deposited nitride films is denser compared to conventional sputter technologies. However, the mechanisms acting on the microstructure, texture and properties have not been discussed in detail so far. In this study, the growth of TiN by HIPIMS of Ti in mixed Ar and N{sub 2} atmosphere has been investigated. Varying degrees of metal ionization and nitrogen dissociation were produced by increasing the peak discharge current (I{sub d}) from 5 to 30 A. The average power was maintained constant by adjusting the frequency. Mass spectrometry measurements of the deposition flux revealed a high content of ionized film-forming species, such as Ti{sup 1+}, Ti{sup 2+} and atomic nitrogen N{sup 1+}. Ti{sup 1+} ions with energies up to 50 eV were detected during the pulse with reducing energy in the pulse-off times. Langmuir probe measurements showed that the peak plasma density during the pulse was 3 x 10{sup 16} m{sup -3}. Plasma density, and ion flux ratios of N{sup 1+}: N{sub 2}{sup 1+} and Ti{sup 1+}: Ti{sup 0} increased linearly with peak current. The ratios exceeded 1 at 30 A. TiN films deposited by HIPIMS were analyzed by X-ray diffraction, and transmission electron microscopy. At high I{sub d}, N{sup 1+}: N{sub 2}{sup 1+} > 1 and Ti{sup 1+}: Ti{sup 0} > 1 were produced; a strong 002 texture was present and column boundaries in the films were atomically tight. As I{sub d} reduced and N{sup 1+}: N{sub 2}{sup 1+} and Ti{sup 1+}: Ti{sup 0} dropped below 1, the film texture switched to strong 111 with a dense structure. At very low I{sub d}, porosity between columns developed. The effects of the significant activation of the deposition flux observed in the HIPIMS discharge on the film texture, microstructure, morphology and

  17. Work function of sol gel indium tin oxide (ITO) films on glass

    NASA Astrophysics Data System (ADS)

    Biswas, P. K.; De, A.; Dua, L. K.; Chkoda, L.

    2006-12-01

    Indium tin oxide (ITO) films (physical thickness, 250-560 ± 25 nm) were deposited on soda lime silica (SLS) glass and silica layer coated (˜200 nm physical thickness) SLS glass substrates by sol-gel technique using alcohol based precursors containing different In:Sn atomic percentages, namely, 90:10, 70:30, 50:50, 30:70. Cubic phase of In 2O 3 was observed up to 50 at.% Sn while cassiterite SnO 2 phase was observed for 70 at.% Sn. Work function of the films was evaluated from inelastic secondary electron cutoff of ultraviolet photoelectron spectroscopy (UPS) energy distribution curve (EDC) obtained under two experimental conditions (i) as-introduced (ii) after the cleaning of the surface by sputtering. Elemental distribution and the presence of oxygen containing contaminant and carbon contaminant of the samples were done by XPS analysis under same conditions. The work function changed little due to the presence of surface contaminants. It was in the range, 3.9-4.2 eV (±0.1 eV).

  18. Mirrorlike pulsed laser deposited tungsten thin film

    SciTech Connect

    Mostako, A. T. T.; Khare, Alika; Rao, C. V. S.

    2011-01-15

    Mirrorlike tungsten thin films on stainless steel substrate deposited via pulsed laser deposition technique in vacuum (10{sup -5} Torr) is reported, which may find direct application as first mirror in fusion devices. The crystal structure of tungsten film is analyzed using x-ray diffraction pattern, surface morphology of the tungsten films is studied with scanning electron microscope and atomic force microscope. The film composition is identified using energy dispersive x-ray. The specular and diffuse reflectivities with respect to stainless steel substrate of the tungsten films are recorded with FTIR spectra. The thickness and the optical quality of pulsed laser deposition deposited films are tested via interferometric technique. The reflectivity is approaching about that of the bulk for the tungsten film of thickness {approx}782 nm.

  19. Mirrorlike pulsed laser deposited tungsten thin film.

    PubMed

    Mostako, A T T; Rao, C V S; Khare, Alika

    2011-01-01

    Mirrorlike tungsten thin films on stainless steel substrate deposited via pulsed laser deposition technique in vacuum (10(-5) Torr) is reported, which may find direct application as first mirror in fusion devices. The crystal structure of tungsten film is analyzed using x-ray diffraction pattern, surface morphology of the tungsten films is studied with scanning electron microscope and atomic force microscope. The film composition is identified using energy dispersive x-ray. The specular and diffuse reflectivities with respect to stainless steel substrate of the tungsten films are recorded with FTIR spectra. The thickness and the optical quality of pulsed laser deposition deposited films are tested via interferometric technique. The reflectivity is approaching about that of the bulk for the tungsten film of thickness ∼782 nm. PMID:21280810

  20. Morphology of Imidazolium-Based Ionic Liquids as Deposited by Vapor Deposition: Micro-/Nanodroplets and Thin Films.

    PubMed

    Costa, José C S; Mendes, Adélio; Santos, Luís M N B F

    2016-07-18

    The morphology of micro- and nanodroplets and thin films of ionic liquids (ILs) prepared through physical vapor deposition is presented. The morphology of droplets deposited on indium-tin-oxide-coated glass is presented for the extended 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Cn C1 im][Ntf2 ]; n=1-8) series, and the results show the nanostructuration of ILs. The use of in-vacuum energetic particles enhances/increases the nanodroplets mobility/coalescence mechanisms and can be a pathway to the fabrication of thin IL films. PMID:27028765

  1. Structural characterization and electronic structure of laser treated TiN thin film

    SciTech Connect

    Soni, Sheetal; Nair, K. G. M.; Phase, D. M.; Gupta, Ratnesh

    2012-06-05

    TiN thin films prepared by laser treatment using Kr-F excimer laser in the controlled atmosphere. The depth distribution and composition of nitrogen and contaminated oxygen have been determined by non-Rutherford proton backscattering using 1.7 MeV Tendetron accelerator. The electronic structure of TiN thin film have been characterized by resonant photoelectron spectroscopy using indus-I synchrotron radiation. Specifically, complex resonance profile that shows the enhancement at 45 eV which is consistent with the resonant photoemission of Ti 3d states involved in the Titanium nitride and oxide.

  2. Tin nanoparticle thin film electrodes fabricated by the vacuum filtration method for enhanced battery performance.

    PubMed

    Lee, Jae Hyun; Kong, Byung-Seon; Baek, Youn-Kyoung; Yang, Seung Bo; Jung, Hee-Tae

    2009-06-10

    A novel method for fabricating tin nanoparticle thin film electrodes that show good performance in lithium ion batteries during cycling is reported. The vacuum filtration method has the advantage of affording a high degree of dispersion of the electrode components, thereby providing good electrical contacts between the tin nanoparticles and the conductive carbon or current collector. The reversible capacity and initial Coulombic efficiency are 726 mA h g(-1) and 85.3%, respectively, with this thin film electrode. Cycle life performance tests under real battery conditions show that the battery capacity and reaction peaks remained stable for up to 50 cycles. SEM shows that the uniform morphology of the vacuum filtered film was maintained throughout the cycle life test. This novel vacuum filtration method for providing nanoparticle-based film electrodes has further potential applications for use in various devices such as high power, thin film batteries, supercapacitors and organic-inorganic hybrid photovoltaic cells. PMID:19448286

  3. Tin-tungsten mineralizing processes in tungsten vein deposits: Panasqueira, Portugal

    NASA Astrophysics Data System (ADS)

    Lecumberri-Sanchez, P.; Pinto, F.; Vieira, R.; Wälle, M.; Heinrich, C. A.

    2015-12-01

    Tungsten has a high heat resistance, density and hardness, which makes it widely applied in industry (e.g. steel, tungsten carbides). Tungsten deposits are typically magmatic-hydrothermal systems. Despite the economic significance of tungsten, there are no modern quantitative analytical studies of the fluids responsible for the formation of its highest-grade deposit type (tungsten vein deposits). Panasqueira (Portugal) is a tungsten vein deposit, one of the leading tungsten producers in Europe and one of the best geologically characterized tungsten vein deposits. In this study, compositions of the mineralizing fluids at Panasqueira have been determined through combination of detailed petrography, microthermometric measurements and LA-ICPMS analyses, and geochemical modeling has been used to determine the processes that lead to tungsten mineralization. We characterized the fluids related to the various mineralizing stages in the system: the oxide stage (tin and tungsten mineralization), the sulfide stage (chalcopyrite and sphalerite mineralization) and the carbonate stage. Thus, our results provide information on the properties of fluids related with specific paragenetic stages. Furthermore we used those fluid compositions in combination with host rock mineralogy and chemistry to evaluate which are the controlling factors in the mineralizing process. This study provides the first quantitative analytical data on fluid composition for tungsten vein deposits and evaluates the controlling mineralization processes helping to determine the mechanisms of formation of the Panasqueira tin-tungsten deposit and providing additional geochemical constraints on the local distribution of mineralization.

  4. Electrical and optical properties of thin films prepared by spin coating a dispersion of nano-sized tin-doped indium-oxide particles

    NASA Astrophysics Data System (ADS)

    Ederth, Jesper; Hultaker, Annette; Heszler, Peter; Niklasson, Gunnar A.; Granqvist, Claes-Goeran; van Doorn, Arie K. J.; van Haag, Chris; Jongerius, Michel J.; Burgard, Detlef

    2001-11-01

    Thin films were made by spinning a dispersion of tin-doped indium-oxide particles, having an average diameter of 14 nm, onto glass substrates. As-deposited thin films displayed a resistivity (rho) of 0.3 (Omega) m and some optical absorption. Annealing in vacuum at 200 to 400 degree(s)C for 2 h, and subsequently in air at 500 degree(s)C for 2 h, produced films with (rho) equals10--3 (Omega) m and a visible transmittance exceeding 90 %. Leaving out the vacuum treatment yielded higher resistivity.

  5. Polymer-assisted deposition of films

    DOEpatents

    McCleskey, Thomas M.; Burrell; Anthony K.; Jia; Quanxi; Lin; Yuan

    2009-10-20

    A polymer assisted deposition process for deposition of metal oxide films and the like is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures to yield metal oxide films and the like. Such films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

  6. Polymer-assisted deposition of films

    DOEpatents

    McCleskey, Thomas M.; Burrell, Anthony K.; Jia, Quanxi; Lin, Yuan

    2008-04-29

    A polymer assisted deposition process for deposition of metal oxide films is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures to yield metal oxide films. Such films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

  7. Microstructures and properties of titanium nitride films prepared by pulsed laser deposition at different substrate temperatures

    NASA Astrophysics Data System (ADS)

    Guo, Hongjian; Chen, Wenyuan; Shan, Yu; Wang, Wenzhen; Zhang, Zhenyu; Jia, Junhong

    2015-12-01

    The nanostructured titanium nitride (TiN) films were fabricated by pulsed laser deposition (PLD) technique at different substrate temperatures under residual vacuum, and the influence of substrate temperatures on the microstructure, mechanical and tribological properties of TiN films was investigated and discussed. The results shown that the consistent stoichiometric TiN films were obtained and the grain size increased from 10.5 to 38.7 nm with the increasing of substrate temperature. The hardness of films decreased with the substrate temperatures increasing, the highest hardness reached to 30.6 GPa at the substrate temperature of 25 °C, and the critical load increased first and decreased at 500 °C, the highest critical load was 23.8 N at the substrate temperature of 300 °C. The film deposited at the substrate temperature of 25 °C registered the lowest friction coefficient of 0.088 and wear rate of 7.8 × 10-7 mm3/(N m). The excellent tribological performance of the films was attributed to the small grain size, high hardness and smooth surface of the film.

  8. (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.

  9. Porous copper zinc tin sulfide thin film as photocathode for double junction photoelectrochemical solar cells.

    PubMed

    Dai, Pengcheng; Zhang, Guan; Chen, Yuncheng; Jiang, Hechun; Feng, Zhenyu; Lin, Zhaojun; Zhan, Jinhua

    2012-03-21

    Porous copper zinc tin sulfide (CZTS) thin film was prepared via a solvothermal approach. Compared with conventional dye-sensitized solar cells (DSSCs), double junction photoelectrochemical cells using dye-sensitized n-type TiO(2) (DS-TiO(2)) as the photoanode and porous p-type CZTS film as the photocathode shows an increased short circuit current, external quantum efficiency and power conversion efficiency. PMID:22322239

  10. Defect engineered d{sup 0} ferromagnetism in tin-doped indium oxide nanostructures and nanocrystalline thin-films

    SciTech Connect

    Khan, Gobinda Gopal E-mail: sghoshphysics@gmail.com; Sarkar, Ayan; Ghosh, Shyamsundar E-mail: sghoshphysics@gmail.com; Mandal, Guruprasad; Mukherjee, Goutam Dev; Manju, Unnikrishnan; Banu, Nasrin; Dev, Bhupendra Nath

    2015-08-21

    Origin of unexpected defect engineered room-temperature ferromagnetism observed in tin-doped indium oxide (ITO) nanostructures (Nanowires, Nano-combs) and nanocrystalline thin films fabricated by pulsed laser deposition has been investigated. It is found that the ITO nanostructures prepared under argon environment exhibit strongest ferromagnetic signature as compared to that nanocrystalline thin films grown at oxygen. The evidence of singly ionized oxygen vacancy (V{sub 0}{sup +}) defects, obtained from various spectroscopic measurements, suggests that such V{sub 0}{sup +} defects are mainly responsible for the intrinsic ferromagnetic ordering. The exchange interaction of the defects provides extensive opportunity to tune the room-temperature d{sup 0} ferromagnetism and optical properties of ITOs.

  11. Observation of deviation of electronic behaviour of indium tin oxide film at grain boundary using Scanning Tunneling Microscope

    NASA Astrophysics Data System (ADS)

    Kasiviswanathan, S.; Srinivas, V.; Kar, A. K.; Mathur, B. K.; Chopra, K. L.

    1997-03-01

    Scanning Tunneling Microscopy and Spectroscopy investigations have been carried out on electron beam deposited indium tin oxide films. The STM images reveal a rather smooth surface, which appears to have been formed due to the coalescence of islands with different shapes. The spectroscopic data, in general, exhibit characteristics typical of metal-insulator-semiconductor structures, with a heavily doped semiconductor. From the I- V curves, a band gap of ≈3.5 eV is obtained, which is very close to the bulk value. The I- V studies at some grain boundary interfaces suggest the presence of regions showing electronic characteristics, that differ significantly from what is observed on the rest of the film surface.

  12. The Tribological Behaviors of Three Films Coated on Biomedical Titanium Alloy by Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Wang, Song; Liao, Zhenhua; Liu, Yuhong; Liu, Weiqiang

    2015-11-01

    Three thin films (DLC, a-C, and TiN) were performed on Ti6Al4V by chemical vapor deposition. Carbon ion implantation was pretreated for DLC and a-C films while Ti transition layer was pretreated for TiN film to strengthen the bonding strength. X-ray diffraction, Raman measurement, nano-hardness and nano-scratch tester, and cross-section etching by FIB method were used to analyze film characteristics. Tribological behaviors of these coatings were studied by articulation with both ZrO2 and UHMWPE balls using ball-on-disk sliding. The thickness values reached ~0.46, ~0.33, and ~1.67 μm for DLC, a-C, and TiN film, respectively. Nano-hardness of the coatings compared with that of untreated and bonding strength (critical load in nano-scratch test) values of composite coatings compared with that of monolayer film all increased significantly, respectively. Under destructive test (ZrO2 ball conterface) in bovine serum lubrication, TiN coating revealed the best wear resistance while DLC showed the worst. Film failure was mainly attributed to the plowing by hard ZrO2 ball characterized by abrasive and adhesive wear. Under normal test (UHMWPE ball conterface), all coatings showed significant improvement in wear resistance both in dry sliding and bovine serum lubrication. Both DLC and a-C films showed less surface damage than TiN film due to the self-lubricating phenomenon in dry sliding. TiN film showed the largest friction coefficient both in destructive and normal tests, devoting to the big TiN grains thus leading to much rougher surface and then a higher value. The self-lubricating film formed on DLC and a-C coating could also decrease their friction coefficients. The results indicated that three coatings revealed different wear mechanisms, and thick DLC or a-C film was more promising in application in lower stress conditions such as artificial cervical disk.

  13. Deposition of thin films of multicomponent materials

    NASA Technical Reports Server (NTRS)

    Thakoor, Sarita (Inventor)

    1993-01-01

    Composite films of multicomponent materials, such as oxides and nitrides, e.g., lead zirconate titanate, are deposited by dc magnetron sputtering, employing a rotating substrate holder, which rotates relative to a plurality of targets, one target for each metal element of the multicomponent material. The sputtering is carried out in a reactive atmosphere. The substrates on which the layers are deposited are at ambient temperature. Following deposition of the composite film, the film is heated to a temperature sufficient to initiate a solid state reaction and form the final product, which is substantially single phase and substantially homogeneous.

  14. Polymer-assisted deposition of films

    DOEpatents

    McCleskey,Thomas M.; Burrell,Anthony K.; Jia,Quanxi; Lin,Yuan

    2012-02-28

    A polymer assisted deposition process for deposition of metal nitride films and the like is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures under a suitable atmosphere to yield metal nitride films and the like. Such films can be conformal on a variety of substrates including non-planar substrates. In some instances, the films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

  15. Properties of TiAlN coating deposited by MPIIID on TiN substrates

    NASA Astrophysics Data System (ADS)

    El-Hossary, F. M.; Abd El-Rahman, A. M.; Raaif, M.; Ghareeb, D. A.

    2016-03-01

    Metal plasma immersion ion implantation and deposition (MPIIID) is employed to produce TiAlN hard coatings on Ti substrate. To improve the load-bearing capacity of Ti substrate, nitrogen PIII is used to prepare a bearing TiN layer on Ti-base substrate. The MPIIID process is performed using Ti50:Al50 target for different nitrogen/argon gas fractions. The effect of N2/Ar gas ratio on the microstructure, mechanical and tribological properties of TiAlN coatings has been studied. The plastic microhardness of TiAlN increases with increasing the nitrogen gas fraction to reach a maximum value of 30 GPa at 100 % N2. The plasticity index and the resistance to plastic deformation increase with increasing the nitrogen gas fraction. The wear volume loss of TiAlN coating deposited on TiN substrate decreases by a factor of 103 in comparison with pure Ti. Moreover, the friction coefficient decreases from nearly 0.8 for Ti to 0.25 for TiAlN coatings. The enhanced mechanical and tribological properties of the coating are correlated with the formation of TiAlN hard phase. This phase has random-oriented microstructure, finer grain size, high oxidation resistance and residual internal stress. Moreover, the TiN interface acts as a barrier for the motion of dislocations.

  16. Continuous Microreactor-Assisted Solution Deposition for Scalable Production of CdS Films

    SciTech Connect

    Ramprasad, Sudhir; Su, Yu-Wei; Chang, Chih-Hung; Paul, Brian; Palo, Daniel R.

    2013-06-13

    Solution deposition offers an attractive, low temperature option in the cost effective production of thin film solar cells. Continuous microreactor-assisted solution deposition (MASD) was used to produce nanocrystalline cadmium sulfide (CdS) films on fluorine doped tin oxide (FTO) coated glass substrates with excellent uniformity. We report a novel liquid coating technique using a ceramic rod to efficiently and uniformly apply reactive solution to large substrates (152 mm × 152 mm). This technique represents an inexpensive approach to utilize the MASD on the substrate for uniform growth of CdS films. Nano-crystalline CdS films have been produced from liquid phase at ~90°C, with average thicknesses of 70 nm to 230 nm and with a 5 to 12% thickness variation. The CdS films produced were characterized by UV-Vis spectroscopy, transmission electron microscopy, and X-Ray diffraction to demonstrate their suitability to thin-film solar technology.

  17. Ferroelectric thin films deposited by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Dinu, Raluca; Vrejoiu, I.; Verardi, P.; Craciun, F.; Dinescu, Maria

    2001-06-01

    Influence of substrate and electrode on the properties of PbZr0.53Ti0.47O3 (PZT) thin films grown by pulsed laser deposition technique (1060 nm wavelength Nd:YAG laser light, 10 ns pulse duration, 10 Hz repetition rate, 0.35 J/pulse, 25 J/cm2 laser fluence, deposition rate about 1 angstrom/pulse) was studied. The substrate temperatures were in the range 380 degree(s)C-400 degree(s)C. Oriented crystalline PZT layers with 1-3 micrometers thickness were deposited on glass substrates plated with Au/Pt/NiCr electrodes, from a PZT commercial target in oxygen reactive atmosphere. The deposited PZT films with perovskite structure were preferentially oriented along the (111) direction as revealed from XRD spectra. Piezoelectric d33 coefficients up to 30 pC/N were obtained on as deposited films. Ferroelectric hysteresis loops at 100 Hz revealed a remanent polarization of 15 (mu) C/cm2 and a coercive field of 100 kV/cm. A comparison with properties of PZT films deposited using a KrF laser and with SrBi2Ta2O9 (SBT) films is reported.

  18. Molybdenum as a contact material in zinc tin oxide thin film transistors

    SciTech Connect

    Hu, W.; Peterson, R. L.

    2014-05-12

    Amorphous oxide semiconductors are of increasing interest for a variety of thin film electronics applications. Here, the contact properties of different source/drain electrode materials to solution-processed amorphous zinc tin oxide (ZTO) thin-film transistors are studied using the transmission line method. The width-normalized contact resistance between ZTO and sputtered molybdenum is measured to be 8.7 Ω-cm, which is 10, 20, and 600 times smaller than that of gold/titanium, indium tin oxide, and evaporated molybdenum electrodes, respectively. The superior contact formed using sputtered molybdenum is due to a favorable work function lineup, an insulator-free interface, bombardment of ZTO during molybdenum sputtering, and trap-assisted tunneling. The transfer length of the sputtered molybdenum/ZTO contact is 0.34 μm, opening the door to future radio-frequency sub-micron molybdenum/ZTO thin film transistors.

  19. Physicochemical characterization of point defects in fluorine doped tin oxide films

    SciTech Connect

    El Akkad, Fikry; Joseph, Sudeep

    2012-07-15

    The physical and chemical properties of spray deposited FTO films are studied using FESEM, x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), electrical and optical measurements. The results of XRD measurements showed that the films are polycrystalline (grain size 20-50 nm) with Rutile structure and mixed preferred orientation along the (200) and (110) planes. An angular shift of the XRD peaks after F-doping is observed and interpreted as being due to the formation of substitutional fluorine defects (F{sub O}) in presence of high concentration of oxygen vacancies (V{sub O}) that are electrically neutral. The electrical neutrality of oxygen vacancies is supported by the observation that the electron concentration n is two orders of magnitude lower than the V{sub O} concentration calculated from chemical analyses using XPS measurements. It is shown that an agreement between XPS, XRD, and Hall effect results is possible provided that the degree of deviation from stoichiometry is calculated with the assumption that the major part of the bulk carbon content is involved in O-C bonds. High temperature thermal annealing is found to cause an increase in the F{sub O} concentration and a decrease in both n and V{sub O} concentrations with the increase of the annealing temperature. These results could be interpreted in terms of a high temperature chemical exchange reaction between the SnO{sub 2} matrix and a precipitated fluoride phase. In this reaction, fluorine is released to the matrix and Sn is trapped by the fluoride phase, thus creating substitutional fluorine F{sub O} and tin vacancy V{sub Sn} defects. The enthalpy of this reaction is determined to be approximately 2.4 eV while the energy of formation of a V{sub Sn} through the migration of Sn{sub Sn} host atom to the fluoride phase is approximately 0.45 eV.

  20. Surface Analysis of Stressed and Control Tin Oxide Thin Films on Soda Lime Glass

    SciTech Connect

    Pankow, J. W.

    2003-05-01

    Surface analysis techniques have been used to investigate tin oxide-coated soda lime glass specimens prior and subsequent to their exposure to DC bias, heat, and humidity. All specimens reported here comprise the following layered structure: tin oxide/silicon oxycarbide/glass. Depth profiling using X-ray photoelectron spectroscopy (XPS) clearly shows the interfacial regions in both control samples and samples exposed to the above-mentioned conditions (stressed). Control samples show distinct and relatively compact interfacial regions as well as an intact silicon oxycarbide diffusion barrier. Stressed films, however, show more diffuse interfacial regions and a physically and chemically altered silicon oxycarbide diffusion barrier. This deterioration of the diffusion barrier is proposed to be a pre-requisite event to enable tin oxide delamination.

  1. Liquid phase deposition of electrochromic thin films

    SciTech Connect

    Richardson, Thomas J.; Rubin, Michael D.

    2000-08-18

    Thin films of titanium, zirconium and nickel oxides were deposited on conductive SnO2:F glass substrates by immersion in aqueous solutions. The films are transparent, conformal, of uniform thickness and appearance, and adhere strongly to the substrates. On electrochemical cycling, TiO2, mixed TiO2-ZrO2, and NiOx films exhibited stable electrochromism with high coloration efficiencies. These nickel oxide films were particularly stable compared with films prepared by other non-vacuum techniques. The method is simple, inexpensive, energy efficient, and readily scalable to larger substrates.

  2. Impact of thermal oxygen annealing on the properties of tin oxide films and characteristics of p-type thin-film transistors

    NASA Astrophysics Data System (ADS)

    Zhong, Chia-Wen; Lin, Horng-Chih; Liu, Kou-Chen; Huang, Tiao-Yuan

    2016-01-01

    In this work, we study the properties of tin oxide films, which were annealed in oxygen ambient for various periods. The as-deposited tin oxides are tin-dominant and, from the Hall measurements, they are of the n-type with high electron concentrations (>1019 cm-3) and would change to the p-type when the oxygen annealing is sufficiently long. We have also found that changes in the structure and crystallinity of the channel layer can be clearly observed by X-ray diffraction analysis and optical microscopy. On the basis of the observations, a physical scheme is proposed to describe the evolution of the electrical performance of oxygen-annealed devices. A hole mobility of 3.24 cm2 V-1 s-1, a subthreshold swing of 0.43 V/dec, a threshold voltage of 1.4 V, and an on/off current ratio larger than 103 are obtained as the channel is transformed into SnO.

  3. Characteristics of Indium-Tin Oxide Thin Film Etched by Reactive Ion Etching

    NASA Astrophysics Data System (ADS)

    Yokoyama, Meiso; Li, Jiin; Su, Shui; Su, Yan

    1994-12-01

    Indium-tin oxide (ITO) films coated on glass have been etched by reactive ion etching (RIE) with a gas mixture of Ar and Cl2. The etching rates of ITO films depend strongly on power density, gas pressure, the composition of reactive gases, and the total flow rate of etchants. According to the results from the study, we can postulate that the ITO films' etching follows the ion-assisted chemical etching. A high etching rate above 100 Å/min can be achieved, and an etching mechanism will be proposed. The selectivity of ITO films to glass reaches 35 with a 30 line/mm pattern. After exposure of ITO films to an Ar/Cl2 mixed gas plasma discharge, their sheet resistance does not markedly change. The residue of Cl atoms exists only in the region near the surface. By means of parameter control, we can obtain good pattern images of ITO films measured by scanning electron microscopy (SEM).

  4. Effect of cationic/anionic organic surfactants on evaporation induced self assembled tin oxide nanostructured films

    NASA Astrophysics Data System (ADS)

    Khun Khun, Kamalpreet; Mahajan, Aman; Bedi, R. K.

    2011-01-01

    Tin oxide nanostructures with well defined morphologies have been obtained through an evaporation induced self assembly process. The technique has been employed using an ultrasonic nebulizer for production of aersol and its subsequent deposition onto a heated glass substrate. The precursor used for aersol production was modified by introducing cationic and anionic surfactants namely cetyl trimethyl ammonium bromide and sodium dodecyl sulphate respectively. The effect of surfactants on the structural, electrical and optical properties of self assembled tin oxide nanostructures were investigated by using X-ray diffraction, field emission scanning electroscope microscopy, two probe technique and photoluminiscence studies. The results reveal that high concentration of surfactants in the precursor solution leads to reduction in crystallite size with significant changes in the morphology of tin oxide nanostructures. Photoluminiscence studies of the nanostructures show emissions in the visible region which exhibit marked changes in the intensities upon variation of surfactants in the precursor solutions.

  5. Effect of substrate temperature on electrochromic properties of spray-deposited Ir-oxide thin films

    NASA Astrophysics Data System (ADS)

    Patil, P. S.; Kawar, R. K.; Sadale, S. B.

    2005-08-01

    Electrochromic iridium oxide thin films were prepared by using a simple and inexpensive spray pyrolysis technique onto fluorine doped tin oxide (FTO)-coated glass substrates, from iridium chloride solution. The substrate temperature was varied between 250 and 400 °C. The as-deposited samples were amorphous. The electrochromic properties of thin films were studied in aqueous electrolyte (0.5N H 2SO 4) using cyclic voltammetry (CV), chronoamperometry (CA) and spectroelectrochemical techniques. The films exhibit anodic electrochromism upon intercalation and deintercalation of H + ions. The colouration efficiency at 630 nm was calculated and found maximum for I 250 sample, owing its hydration.

  6. Microwave-enhanced thin-film deposition

    NASA Technical Reports Server (NTRS)

    Chitre, S.

    1984-01-01

    The deposition of semiconducting and insulating thin films at low temperatures using microwave technology was explored. The method of plasma formations, selection of a power source, the design of the microwave plasma cavity, the microwave circuitry, impedance matching, plasma diagnostics, the deposition chamber and the vacuum system were studied.

  7. Ion plating technique improves thin film deposition

    NASA Technical Reports Server (NTRS)

    Mattox, D. M.

    1968-01-01

    Ion plating technique keeps the substrate surface clean until the film is deposited, allows extensive diffusion and chemical reaction, and joins insoluble or incompatible materials. The technique involves the deposition of ions on the substrate surface while it is being bombarded with inert gas ions.

  8. Electrochemical deposition of patterning and highly luminescent organic films for light emitting diodes

    NASA Astrophysics Data System (ADS)

    Li, Mao; Tang, Shi; Lu, Dan; Shen, Fangzhong; Liu, Meirong; Wang, Huan; Lu, Ping; Hanif, Muddasir; Ma, Yuguang

    2007-08-01

    This paper describes a simple electrochemical deposition (ED) technique to prepare luminescent and patterned films for light-emitting devices (LEDs). The luminescent films are deposited directly on the patterned ITO (indium tin oxide) electrodes through an oxidation coupling reaction of an electroactive and luminescent precursor. The ED films deposited on the ITO strips (width of 200 µm) exhibit smooth surface morphology (roughness of morphology surface of 3.1 nm), small roughness in electrode edge of 1-2 µm and high fluorescence quantum efficiency (>60%). The LEDs with structure ITO/ED film/Ba/Al show pure blue emission (CIE coordinates of (0.16, 0.07)), high brightness of 3080 cd m-2 and the maximum external quantum efficiency of 0.60%.

  9. Characteristics Of Vacuum Deposited Sucrose Thin Films

    NASA Astrophysics Data System (ADS)

    Ungureanu, F.; Predoi, D.; Ghita, R. V.; Vatasescu-Balcan, R. A.; Costache, M.

    Thin films of sucrose (C12H22O11) were deposited on thin cut glass substrates by thermal evaporation technique (p ~ 10-5 torr). The surface morphology was putted into evidence by FT-IR and SEM analysis. The experimental results confirm a uniform deposition of an adherent sucrose layer. The biological tests (e.g., cell morphology and cell viability evaluated by measuring mitochondrial dehydrogenise activity with MTT assay) confirm the properties of sucrose thin films as bioactive material. The human fetal osteoblast system grown on thin sucrose film was used for the determination of cell proliferation, cell viability and cell morphology studies.

  10. 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.