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Sample records for deposited thin films

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  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. 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.

  8. Pulsed laser deposition of pepsin thin films

    NASA Astrophysics Data System (ADS)

    Kecskeméti, G.; Kresz, N.; Smausz, T.; Hopp, B.; Nógrádi, A.

    2005-07-01

    Pulsed laser deposition (PLD) of organic and biological thin films has been extensively studied due to its importance in medical applications among others. Our investigations and results on PLD of a digestion catalyzing enzyme, pepsin, are presented. Targets pressed from pepsin powder were ablated with pulses of an ArF excimer laser ( λ = 193 nm, FWHM = 30 ns), the applied fluence was varied between 0.24 and 5.1 J/cm 2. The pressure in the PLD chamber was 2.7 × 10 -3 Pa. The thin layers were deposited onto glass and KBr substrates. Our IR spectroscopic measurements proved that the chemical composition of deposited thin films is similar to that of the target material deposited at 0.5 and 1.3 J/cm 2. The protein digesting capacity of the transferred pepsin was tested by adapting a modified "protein cube" method. Dissolution of the ovalbumin sections proved that the deposited layers consisted of catalytically active pepsin.

  9. Substrate heater for thin film deposition

    DOEpatents

    Foltyn, Steve R.

    1996-01-01

    A substrate heater for thin film deposition of metallic oxides upon a target substrate configured as a disk including means for supporting in a predetermined location a target substrate configured as a disk, means for rotating the target substrate within the support means, means for heating the target substrate within the support means, the heating means about the support means and including a pair of heating elements with one heater element situated on each side of the predetermined location for the target substrate, with one heater element defining an opening through which desired coating material can enter for thin film deposition and with the heating means including an opening slot through which the target substrate can be entered into the support means, and, optionally a means for thermal shielding of the heating means from surrounding environment is disclosed.

  10. Apparatus for laser assisted thin film deposition

    DOEpatents

    Warner, Bruce E.; McLean, II, William

    1996-01-01

    A pulsed laser deposition apparatus uses fiber optics to deliver visible output beams. One or more optical fibers are coupled to one or more laser sources, and delivers visible output beams to a single chamber, to multiple targets in the chamber or to multiple chambers. The laser can run uninterrupted if one of the deposition chambers ceases to operate because other chambers can continue their laser deposition processes. The laser source can be positioned at a remote location relative to the deposition chamber. The use of fiber optics permits multi-plexing. A pulsed visible laser beam is directed at a generally non-perpendicular angle upon the target in the chamber, generating a plume of ions and energetic neutral species. A portion of the plume is deposited on a substrate as a thin film. A pulsed visible output beam with a high pulse repetition frequency is used. The high pulse repetition frequency is greater than 500 Hz, and more preferably, greater than about 1000 Hz. Diamond-like-carbon (DLC) is one of the thin films produced using the apparatus.

  11. Apparatus for laser assisted thin film deposition

    DOEpatents

    Warner, B.E.; McLean, W. II

    1996-02-13

    A pulsed laser deposition apparatus uses fiber optics to deliver visible output beams. One or more optical fibers are coupled to one or more laser sources, and delivers visible output beams to a single chamber, to multiple targets in the chamber or to multiple chambers. The laser can run uninterrupted if one of the deposition chambers ceases to operate because other chambers can continue their laser deposition processes. The laser source can be positioned at a remote location relative to the deposition chamber. The use of fiber optics permits multi-plexing. A pulsed visible laser beam is directed at a generally non-perpendicular angle upon the target in the chamber, generating a plume of ions and energetic neutral species. A portion of the plume is deposited on a substrate as a thin film. A pulsed visible output beam with a high pulse repetition frequency is used. The high pulse repetition frequency is greater than 500 Hz, and more preferably, greater than about 1000 Hz. Diamond-like-carbon (DLC) is one of the thin films produced using the apparatus. 9 figs.

  12. Studies of Niobium Thin Film Produced by Energetic Vacuum Deposition

    SciTech Connect

    Genfa Wu; Anne-Marie Valente; H. Phillips; Haipeng Wang; Andy Wu; T. J. Renk; P Provencio

    2004-05-01

    An energetic vacuum deposition system has been used to study deposition energy effects on the properties of niobium thin films on copper and sapphire substrates. The absence of working gas avoids the gaseous inclusions commonly seen with sputtering deposition. A biased substrate holder controls the deposition energy. Transition temperature and residual resistivity ratio of the niobium thin films at several deposition energies are obtained together with surface morphology and crystal orientation measurements by AFM inspection, XRD and TEM analysis. The results show that niobium thin films on sapphire substrate exhibit the best cryogenic properties at deposition energy around 123 eV. The TEM analysis revealed that epitaxial growth of film was evident when deposition energy reaches 163 eV for sapphire substrate. Similarly, niobium thin film on copper substrate shows that film grows more oriented with higher deposition energy and grain size reaches the scale of the film thickness at the deposition energy around 153 eV.

  13. Glow discharge plasma deposition of thin films

    DOEpatents

    Weakliem, Herbert A.; Vossen, Jr., John L.

    1984-05-29

    A glow discharge plasma reactor for deposition of thin films from a reactive RF glow discharge is provided with a screen positioned between the walls of the chamber and the cathode to confine the glow discharge region to within the region defined by the screen and the cathode. A substrate for receiving deposition material from a reactive gas is positioned outside the screened region. The screen is electrically connected to the system ground to thereby serve as the anode of the system. The energy of the reactive gas species is reduced as they diffuse through the screen to the substrate. Reactive gas is conducted directly into the glow discharge region through a centrally positioned distribution head to reduce contamination effects otherwise caused by secondary reaction products and impurities deposited on the reactor walls.

  14. 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.

  15. Pulsed Laser Deposition of Oxide Thin Films

    NASA Astrophysics Data System (ADS)

    Brodoceanu, D.; Scarisoreanu, N. D.; Filipescu, M. (Morar); Epurescu, G. N.; Matei, D. G.; Verardi, P.; Craciun, F.; Dinescu, M.

    2004-10-01

    Pulsed Laser Deposition (PLD) emerged as an attractive technique for growth of thin films with different properties as metals, semiconductors, ferroelectrics, biocompatibles, polymers, etc., due to its important advantages: (i) the stoichiometric transfer of a complex composition from target to film and film crystallization at lower substrate temperature respect to other techniques (due to the high energy of species in the laser plasma); (ii) single step process, synthesis and deposition; (iii) creation in plasma of species impossible to be obtained by other processes; (iv) possibility of "in situ" heterostructure deposition using a multi-target system, etc. Simple or complex oxides are between the materials widely studied for their applications. PMN is the most known relaxor ferroelectric material: it exhibits a high dielectric constant value around the (diffuse) maximum phase transition temperature, of more than 35 000 in bulk form. Other oxides as lead zirconate titanate, Pb(ZrxTi1-x)O3 simple or La doped exhibit exceptional properties as large remanent polarization, high dielectric permittivity, high piezoelectric coefficient. SrBi2Ta2O9 (SBT) is characterized by a high "fatigue resistance" (constant remanent polarization until 1012 switching cycles), low imprint, and low leakage current. The physical properties of zirconium oxide (or zirconia) -- high strength, stability at high temperatures -- make it useful for applications involving gas sensors, corrosion or heat resistant mechanical parts, high refractive index optical coatings. Of particular interest is its use as an alternative gate dielectric in metal-oxide-semiconductor (MOS) devices or capacitor in dynamic random access memory (DRAM) chips. All these oxides have been deposited by laser ablation in oxygen reactive atmosphere and some of their properties will be presented in this paper.

  16. 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.

  17. 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.

  18. Morphology dependent electrochemical performance of sputter deposited Sn thin films

    SciTech Connect

    Nimisha, C.S.; Venkatesh, G.; Rao, K. Yellareswara; Rao, G. Mohan; Munichandraiah, N.

    2012-08-15

    Graphical abstract: Smooth homogenous anode surface results in better electrochemical performance in terms of capacity and cycle life. Highlights: ► Controlling rate of deposition of Sn thin films for different surface morphology. ► Higher deposition rate results in poor capacity retention. ► Lower deposition rate of 0.25 nm s{sup −1} helps in higher capacity retention. ► Electrochemical performance correlated homogeneity and interparticle contact area. -- Abstract: This study deals with tailoring of the surface morphology, microstructure, and electrochemical properties of Sn thin films deposited by magnetron sputtering with different deposition rates. Scanning electron microscopy and atomic force microscopy are used to characterize the film surface morphology. Electrochemical properties of Sn thin film are measured and compared by cyclic voltammetry and charge–discharge cycle data at a constant current density. Sn thin film fabricated with a higher deposition rate exhibited an initial discharge capacity of 798 mAh g{sup −1} but reduced to 94 mAh g{sup −1} at 30th cycle. Film deposited with lower deposition rate delivered 770 mAh g{sup −1} during 1st cycle with improved capacity retention of 521 mAh g{sup −1} on 30th cycle. Comparison of electrochemical performances of these films has revealed important distinctions, which are associated with the surface morphology and hence on rate of deposition.

  19. Ultrashort pulse laser deposition of thin films

    DOEpatents

    Perry, Michael D.; Banks, Paul S.; Stuart, Brent C.

    2002-01-01

    Short pulse PLD is a viable technique of producing high quality films with properties very close to that of crystalline diamond. The plasma generated using femtosecond lasers is composed of single atom ions with no clusters producing films with high Sp.sup.3 /Sp.sup.2 ratios. Using a high average power femtosecond laser system, the present invention dramatically increases deposition rates to up to 25 .mu.m/hr (which exceeds many CVD processes) while growing particulate-free films. In the present invention, deposition rates is a function of laser wavelength, laser fluence, laser spot size, and target/substrate separation. The relevant laser parameters are shown to ensure particulate-free growth, and characterizations of the films grown are made using several diagnostic techniques including electron energy loss spectroscopy (EELS) and Raman spectroscopy.

  20. Sputter deposition of metallic thin film and directpatterning

    SciTech Connect

    Ji, L.; Chen, Y.; Jiang, X.; Ji, Q.; Leung, K.-N.

    2005-09-09

    A compact apparatus is developed for deposition of metal thin film. The system employs an RF discharge plasma source with a straight RF antenna, which is made of or covered with deposition material, serving as sputtering target at the same time. The average deposition rate of copper thin film is as high as 450nm/min. By properly allocating the metal materials on the sputtering antenna, mixture deposition of multiple metal species is achieved. Using an ion beam imprinting scheme also taking advantage of ion beam focusing technique, two different schemes of direct patterning deposition process are developed: direct depositing patterned metallic thin film and resistless ion beam sputter patterning. Preliminary experiments have demonstrated direct pattern transfer from a template with feature size of micro scale; patterns with more than 10x reduction are achieved by sputtering patterning method.

  1. Off-axis sputter deposition of thin films

    SciTech Connect

    Capuano, L.A.; Newman, N. )

    1990-01-01

    Currently there are several techniques for making high Tc thin films, e.g., sputter deposition, laser ablation, coevaporation (including MBE), chemical vapor deposition and solution coating/pyrolysis. Of these techniques, the authors have demonstrated that high-pressure in-situ off-axis rf-magnetron sputter deposition is a simple, relatively inexpensive process capable of reproducibly yielding YBCO superconducting thin films with excellent surface resistance properties. This article describes the off-axis technique, the basic equipment requirements and the performance characteristics of high Tc superconductor films produced using this technique.

  2. Crystalline Indium Sulphide thin film by photo accelerated deposition technique

    NASA Astrophysics Data System (ADS)

    Dhanya, A. C.; Preetha, K. C.; Deepa, K.; Remadevi, T. L.

    2015-02-01

    Indium sulfide thin films deserve special attention because of its potential application as buffer layers in CIGS based solar cells. Highly transparent indium sulfide (InS) thin films were prepared using a novel method called photo accelerated chemical deposition (PCD). Ultraviolet source of 150 W was used to irradiate the solution. Compared to all other chemical methods, PCD scores its advantage for its low cost, flexible substrate and capable of large area of deposition. Reports on deposition of high quality InS thin films at room temperature are very rare in literature. The precursor solution was initially heated to 90°C for ten minutes and then deposition was carried out at room temperature for two hours. The appearance of the film changed from lemon yellow to bright yellow as the deposition time increased. The sample was characterized for its structural and optical properties. XRD profile showed the polycrystalline behavior of the film with mixed phases having crystallite size of 17 nm. The surface morphology of the films exhibited uniformly distributed honey comb like structures. The film appeared to be smooth and the value of extinction coefficient was negligible. Optical measurements showed that the film has more than 80% transmission in the visible region. The direct band gap energy was 2.47eV. This method is highly suitable for the synthesis of crystalline and transparent indium sulfide thin films and can be used for various photo voltaic applications.

  3. Preparation of Epoxy Resin Thin Film by Electroless Deposition Method

    NASA Astrophysics Data System (ADS)

    Fukui, Hitoshi; Hirai, Makoto; Shinagawa, Tsutomu; Kobayashi, Yasuyuki; Chigane, Masaya; Fujiwara, Yutaka; Fujita, Naoyuki

    The electrodeposition coating process, which is a polymer film deposition method using water electrolysis, is widely used for automobile body primers. Recently this process is being used in the insulating polymer films deposition for the microelectromechanical system (MEMS) or micro electric components. However, this process has difficulty in depositing polymer film on complex shapes and non-conductive surfaces. In this paper, we demonstrate that epoxy resin thin films used extensively as insulating polymer films were successfully deposited using the electroless chemical reaction in aqueous solution on a non-conductive surface and high aspect glass tube. The substrates catalyzed using a commercialized three-step Sn/Ag/Pd activation process were immersed in the reaction solution containing water-soluble resin and NO3- ion, reducing agent (DMAB). The pH near the substrate rose when NO3- was reduced by released electrons from DMAB. Water-soluble resin combined with OH- hence, polymer thin film was deposited by the electroless deposition reaction. By FE-SEM and FT-IR measurement, it was clear that the conformal and dense epoxy resin films were deposited. Using the present method, epoxy films could be deposited on the surface of a high aspect ratio glass tube 50 mm in length and φ3 in inner diameter. These films had high insulation resistivity of 108∼1011Ωm with applied voltage of 250 V.

  4. 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.

  5. Surface tension gradient enhanced thin film flow for particle deposition

    NASA Astrophysics Data System (ADS)

    Gilchrist, James; Joshi, Kedar; Muangnapoh, Tanyakorn; Stever, Michael

    2015-11-01

    We investigate the effect of varying concentration in binary mixtures of water and ethanol as the suspending medium for micron-scale silica particles on convective deposition. By pulling a suspension along a substrate, a thin film is created that results in enhanced evaporation of the solvent and capillary forces that order particles trapped in the thin film. In pure water or pure ethanol, assembly and deposition is easily understood by a simply flux balance first developed by Dimitrov and Nagayama in 1996. In solvent mixtures having only a few percent of ethanol, Marangoni stresses from the concentration gradient set by unbalanced solvent evaporation dominates the thin film flow. The thin film profile is similar to that found in ``tears of wine'' where the particles are deposited in the thin film between the tears and the reservoir. A simple model describes the 10x increase of deposition speed found in forming well-ordered monolayers of particles. At higher ethanol concentrations, lateral instabilities also generated by Marangoni stresses cause nonuniform deposition in the form of complex streaks that mirror sediment deposits in larger scale flows. We acknowledge funding from the NSF Scalable Nanomanufacturing Program under grant No. 1120399.

  6. Deposition, Characterization, And Simulation Of Thin Films With Form Birefringence

    NASA Astrophysics Data System (ADS)

    Jacobson, M. R.; Horowitz, F.; Liao, Bangjun

    1984-12-01

    Birefringence in optical thin films due to structure on a scale large compared to atoms but small compared to optical wavelengths, known as form birefringence (FB), was observed almost a century ago. More recently, studies of obliquely deposited metal films stimulated new interest in birefringent films. The link between structure, which is predominantly columnar in evaporated thin films, and birefringence has been conclusively demonstrated through ellipsometric measurement and modeling. Direct measurements of form birefringence are especially tedious in tilted films, since essentially four quantities must be derived: three indices of refraction and the film thickness. Clearly, four measurements are required; Horowitz' used an ellipsometric method to perform such measurements on a zirconium oxide (Zr02) film. Later, a 4.6-μm-thick film of Zr02 was obliquely deposited; spectrophotometric measurements revealed its utility as a half-wave plate. A parallel effort directed at understanding FB films through computer simulations has been undertaken by Sikkens and Liao. These simulations can be specialized to include defects, epitaxy, and anisotropic surface mobility. Applications of obliquely deposited FB films of familiar thin film materials can be anticipated if their structure and performance can be more thoroughly understood.

  7. Formation of diamond nanoparticle thin films by electrophoretic deposition

    NASA Astrophysics Data System (ADS)

    Goto, Yosuke; Ohishi, Fujio; Tanaka, Kuniaki; Usui, Hiroaki

    2016-03-01

    Thin films of diamond nanoparticles were prepared by electrophoretic deposition (EPD) using 0.5 wt % dispersions in water, ethanol, and 2-propanol. The film growth rate increased with increasing voltage applied to the electrodes. However, an excessive increase in voltage caused the degradation of film morphology. The optimum voltage was 4 V with an electrode separation of 5 mm. The film growth rate was higher in organic solvents than in water. The deposited film had a smooth surface with an average surface roughness comparable to the size of primary particles of the source material. It is notable that the EPD films had a considerably higher physical stability than spin-coated and cast films. The stability was further improved by thermally annealing the films. IR analysis revealed that the diamond nanoparticles have carboxy and amino groups on their surfaces. It is considered that the stability of the EPD films originate from a chemical reaction between these functional groups.

  8. SnS thin films deposited by chemical bath deposition, dip coating and SILAR techniques

    NASA Astrophysics Data System (ADS)

    Chaki, Sunil H.; Chaudhary, Mahesh D.; Deshpande, M. P.

    2016-05-01

    The SnS thin films were synthesized by chemical bath deposition (CBD), dip coating and successive ionic layer adsorption and reaction (SILAR) techniques. In them, the CBD thin films were deposited at two temperatures: ambient and 70 °C. The energy dispersive analysis of X-rays (EDAX), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and optical spectroscopy techniques were used to characterize the thin films. The electrical transport properties studies on the as-deposited thin films were done by measuring the I–V characteristics, DC electrical resistivity variation with temperature and the room temperature Hall effect. The obtained results are deliberated in this paper.

  9. Helical structured thin films deposited at a glancing angle

    NASA Astrophysics Data System (ADS)

    Jen, Yi-Jun; Jheng, Ci-Yao; Chan, San; Tseng, Chien-Hoa

    2015-08-01

    Gold nanohelical structured thin films (NHFs) were tried to be deposited on a glass substrate using glancing angle deposition technique. At a deposition angle of 89°, gold NHFs were fabricated by introducing liquid nitrogen to flow under the backside of BK7 glass substrate holder. The temperature of substrate was reduced to be less than -140°C before deposition. The spin rate was controlled with respect to the deposition rate to grow three different sized nanohelices. The morphology and optical properties of Au NHFs were measured and compared between the three samples. The strong g-factor implies high sensitivity of deposited helixes in biosensing in the future.

  10. Deposition and investigation of lanthanum cerium hexaboride thin films

    NASA Astrophysics Data System (ADS)

    Kuzanyan, A. S.; Harutyunyan, S. R.; Vardanyan, V. O.; Badalyan, G. R.; Petrosyan, V. A.; Kuzanyan, V. S.; Petrosyan, S. I.; Karapetyan, V. E.; Wood, K. S.; Wu, H.-D.; Gulian, A. M.

    2006-09-01

    Thin films of lanthanum-cerium hexaboride, the promising thermoelectric material for low-temperature applications, are deposited on various substrates by the electron-beam evaporation, pulsed laser deposition and magnetron sputtering. The influence of the deposition conditions on the films X-ray characteristics, composition, microstructure and physical properties, such as the resistivity and Seebeck coefficient, is studied. The preferred (100) orientation of all films is obtained from XRD traces. In the range of 780-800 °C deposition temperature the highest intensity of diffractions peaks and the highest degree of the preferred orientation are observed. The temperature dependence of the resistivity and the Seebeck coefficient of films are investigated in the temperature range of 4-300 K. The features appropriate to Kondo effect in the dependences ρ( T) and S( T) are detected at temperatures below 20 K. Interplay between the value of the Seebeck coefficient, metallic parameters and Kondo scattering of investigated films is discussed.

  11. Measuring Thicknesses Of Vacuum-Deposited Organic Thin Films

    NASA Technical Reports Server (NTRS)

    David, Carey E.

    1996-01-01

    Method of measuring thickness of thin organic liquid film deposited in vacuum involves use of quartz-crystal monitor (QCM) calibrated by use of witness plate that has, in turn, calibrated by measurement of absorption of infrared light in deposited material. Present procedure somewhat tedious, but once calibration accomplished, thicknesses of organic liquid deposits monitored in real time and in situ by use of QCM.

  12. Niobium Thin Film Properties Affected by Deposition Energy during Vacuum Deposition

    SciTech Connect

    Genfa Wu; H. Phillips; Ronald Sundelin; Anne-Marie Valente

    2003-05-01

    In order to understand and improve the super-conducting performance of niobium thin films at cryogenic temperatures, an energetic vacuum deposition system has been developed to study deposition energy effects on the properties of niobium thin films on various substrates. Ultra high vacuum avoids the gaseous inclusions in thin films commonly seen in sputtering deposition. A retarding field energy analyzer is used to measure the kinetic energy of niobium ions at the substrate location. A biased substrate holder controls the deposition energy. Transition temperature and residual resistivity ratio (RRR) of the niobium thin films at several deposition energies are obtained together with crystal orientation measurements and atomic force microscope (AFM) inspection, and the results show that there exists a preferred deposition energy around 115eV (the average deposition energy 64 eV plus the 51 V bias voltage).

  13. Sputter deposition for multi-component thin films

    DOEpatents

    Krauss, Alan R.; Auciello, Orlando

    1990-01-01

    Ion beam sputter-induced deposition using a single ion beam and a multicomponent target is capable of reproducibly producing thin films of arbitrary composition, including those which are close to stoichiometry. Using a quartz crystal deposition monitor and a computer controlled, well-focused ion beam, this sputter-deposition approach is capable of producing metal oxide superconductors and semiconductors of the superlattice type such as GaAs-AlGaAs as well as layered metal/oxide/semiconductor/superconductor structures. By programming the dwell time for each target according to the known sputtering yield and desired layer thickness for each material, it is possible to deposit composite films from a well-controlled sub-monolayer up to thicknesses determined only by the available deposition time. In one embodiment, an ion beam is sequentially directed via a set of X-Y electrostatic deflection plates onto three or more different element or compound targets which are constituents of the desired film. In another embodiment, the ion beam is directed through an aperture in the deposition plate and is displaced under computer control to provide a high degree of control over the deposited layer. In yet another embodiment, a single fixed ion beam is directed onto a plurality of sputter targets in a sequential manner where the targets are each moved in alignment with the beam under computer control in forming a multilayer thin film. This controlled sputter-deposition approach may also be used with laser and electron beams.

  14. Sputter deposition for multi-component thin films

    DOEpatents

    Krauss, A.R.; Auciello, O.

    1990-05-08

    Ion beam sputter-induced deposition using a single ion beam and a multicomponent target is capable of reproducibly producing thin films of arbitrary composition, including those which are close to stoichiometry. Using a quartz crystal deposition monitor and a computer controlled, well-focused ion beam, this sputter-deposition approach is capable of producing metal oxide superconductors and semiconductors of the superlattice type such as GaAs-AlGaAs as well as layered metal/oxide/semiconductor/superconductor structures. By programming the dwell time for each target according to the known sputtering yield and desired layer thickness for each material, it is possible to deposit composite films from a well-controlled sub-monolayer up to thicknesses determined only by the available deposition time. In one embodiment, an ion beam is sequentially directed via a set of X-Y electrostatic deflection plates onto three or more different element or compound targets which are constituents of the desired film. In another embodiment, the ion beam is directed through an aperture in the deposition plate and is displaced under computer control to provide a high degree of control over the deposited layer. In yet another embodiment, a single fixed ion beam is directed onto a plurality of sputter targets in a sequential manner where the targets are each moved in alignment with the beam under computer control in forming a multilayer thin film. This controlled sputter-deposition approach may also be used with laser and electron beams. 10 figs.

  15. 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 %.

  16. Sputtering deposition of aluminium molybdenum alloy thin film anodes for thin film microbatteries

    NASA Astrophysics Data System (ADS)

    Thirumoolam, Mani Chandran; Sivaramakrishnan, Balaji; Devarajan, Mutharasu

    2015-05-01

    Al5Mo thin film anodes for Li-ion batteries were prepared using DC sputtering under different conditions, the latter being specified as deposition at room temperature (S0), deposition at 300°C (S1), and deposition at room temperature followed by thermal annealing at 300°C (S2). The thin films were deposited using an aluminum target tiled with molybdenum discs at a ratio calculated based on the theoretical sputtering yields. The structural and compositional analyses performed with x-ray diffraction (XRD) and energy-dispersive x-ray spectroscopy (EDX) confirmed the Al5Mo compound formation and the Al/Mo elemental ratio, respectively. The compound formation was observed to be evident only for the thin films subjected to heat treatment during or after deposition. Scanning electron micrographs reveal a higher porosity of approximately 23% for sample S0 and a lower porosity of around 18% for sample S1. The chronopotentiometry results show a higher volumetric specific capacity of approximately 197 mAh/cm3 for sample S1. Capacity increments have been observed for all samples upon charge-discharge cycles, whose values after 25 cycles for samples S0, S1, and S2 were 41.2%, 20.4%, and 21.1%, respectively. [Figure not available: see fulltext.

  17. Chemical Vapor Deposition of Aluminum Oxide Thin Films

    ERIC Educational Resources Information Center

    Vohs, Jason K.; Bentz, Amy; Eleamos, Krystal; Poole, John; Fahlman, Bradley D.

    2010-01-01

    Chemical vapor deposition (CVD) is a process routinely used to produce thin films of materials via decomposition of volatile precursor molecules. Unfortunately, the equipment required for a conventional CVD experiment is not practical or affordable for many undergraduate chemistry laboratories, especially at smaller institutions. In an effort to…

  18. Smoothing of mirror substrates by thin-film deposition

    SciTech Connect

    Baker, S; Parra, E; Spiller, E; Tarrio, C

    1999-08-03

    Superpolished optical flats with high spatial frequency roughness below 0.1 nm have been commercially available for years. However, it is much more difficult to obtain figured optics of similar quality. We have obtained and tested the finish of figured optics from different vendors by atomic force microscopy and optical profilometry and have investigated how the substrate quality can be improved by the deposition of thin films. We have determined the growth parameters of several thin-film structures. From these parameters we can determine how the surface topography of a coated mirror differs from that of the substrate, select the best thin-film structure, and predict the possible improvement. Keywords: Smoothing films, multilayer coatings, finish of mirror substrates

  19. Substrates suitable for deposition of superconducting thin films

    DOEpatents

    Feenstra, Roeland; Boatner, Lynn A.

    1993-01-01

    A superconducting system for the lossless transmission of electrical current comprising a thin film of superconducting material Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x epitaxially deposited upon a KTaO.sub.3 substrate. The KTaO.sub.3 is an improved substrate over those of the prior art since the it exhibits small lattice constant mismatch and does not chemically react with the superconducting film.

  20. Pulsed laser deposition of anatase thin films on textile substrates

    NASA Astrophysics Data System (ADS)

    Krämer, André; Kunz, Clemens; Gräf, Stephan; Müller, Frank A.

    2015-10-01

    Pulsed laser deposition (PLD) is a highly versatile tool to prepare functional thin film coatings. In our study we utilised a Q-switched CO2 laser with a pulse duration τ ≈ 300 ns, a laser wavelength λ = 10.59 μm, a repetition frequency frep = 800 Hz and a peak power Ppeak = 15 kW to deposit crystalline anatase thin films on carbon fibre fabrics. For this purpose, preparatory experiments were performed on silicon substrates to optimise the anatase deposition conditions including the influence of different substrate temperatures and oxygen partial pressures. Processing parameters were then transferred to deposit anatase on carbon fibres. Scanning electron microscopy, X-ray diffraction analyses, Raman spectroscopy and tactile profilometry were used to characterise the samples and to reveal the formation of phase pure anatase without the occurrence of a secondary rutile phase. Methanol conversion test were used to prove the photocatalytic activity of the coated carbon fibres.

  1. Sputter deposited Terfenol-D thin films for multiferroic applications

    NASA Astrophysics Data System (ADS)

    Mohanchandra, K. P.; Prikhodko, S. V.; Wetzlar, K. P.; Sun, W. Y.; Nordeen, P.; Carman, G. P.

    2015-09-01

    In this paper, we study the sputter deposition and crystallization process to produce high quality Terfenol-D thin film (100 nm) with surface roughness below 1.5 nm. The Terfenol-D thin film was produced using DC magnetron sputtering technique with various sputtering parameters and two different crystallization methods, i.e. substrate heating and post-annealing. Several characterization techniques including WDS, XRD, TEM, AFM, SQUID and MOKE were used to determine the physical and magnetic properties of the Terfenol-D films. TEM studies reveal that the film deposited on the heated substrate has large grains grown along the film thickness producing undesirable surface roughness while the film crystallized by post-annealing method shows uniformly distributed small grains producing a smooth surface. The Terfenol-D film was also deposited onto (011) cut PMN-PT single crystal substrate. With the application of an electric field the film exhibited a 1553 Oe change in coercivity with an estimated saturation magnetostriction of λs = 910 x 10-6.

  2. Deposition of pure gold thin films from organometallic precursors

    NASA Astrophysics Data System (ADS)

    Parkhomenko, Roman G.; Trubin, Sergey V.; Turgambaeva, Asiya E.; Igumenov, Igor К.

    2015-03-01

    Using metallorganic chemical vapor deposition, pure gold thin films have been obtained from a number of volatile dimethylgold(III) complexes with different types of chelating organic ligands. Deposition was performed in argon (10 Torr) with and without hydrogen and oxygen as reactant gases and with additional VUV (vacuum ultraviolet) stimulation. According to the XRD phase analysis, gold films grow mainly in [111] direction. The influence of precursor structure on the morphology of the deposited layers was demonstrated. It was established that presence of H2 raises the growth rate and porosity of the films significantly with decreased amount of any impurities. With the VUV stimulation, the gold content in the films amounts to >99 at%.

  3. Modified chemical route for deposition of molybdenum disulphide thin films

    SciTech Connect

    Vyas, Akshay N. Sartale, S. D.

    2014-04-24

    Molybdenum disulphide (MoS{sub 2}) thin films were deposited on quartz substrates using a modified chemical route. Sodium molybdate and sodium sulphide were used as precursors for molybdenum and sulphur respectively. The route involves formation of tetrathiomolybdate ions (MoS{sub 4}{sup 2−}) and further reduction by sodium borohydride to form MoS{sub 2}. The deposition was performed at room temperature. The deposited films were annealed in argon atmosphere at 1073 K for 1 hour to improve its crystallinity. The deposited films were characterized using scanning electron microscopy (SEM) for morphology, UV-Vis absorption spectroscopy for optical studies and X-ray diffraction (XRD) for structure determination.

  4. Thin film deposition by means of atmospheric pressure microplasma jet

    NASA Astrophysics Data System (ADS)

    Benedikt, J.; Raballand, V.; Yanguas-Gil, A.; Focke, K.; von Keudell, A.

    2007-12-01

    An RF microplasma jet working at atmospheric pressure has been developed for thin film deposition application. It consists of a capillary coaxially inserted in the ceramic tube. The capillary is excited by an RF frequency of 13.56 MHz at rms voltages of around 200-250 V. The plasma is generated in a plasma forming gas (helium or argon) in the annular space between the capillary and the ceramic tube. By adjusting the flows, the flow pattern prevents the deposition inside the source and mixing of the reactive species with the ambient air in the discharge and deposition region, so that no traces of air are found even when the microplasma is operated in an air atmosphere. All these properties make our microplasma design of great interest for applications such as thin film growth or surface treatment. The discharge operates probably in a γ-mode as indicated by high electron densities of around 8 × 1020 m-3 measured using optical emission spectroscopy. The gas temperature stays below 400 K and is close to room temperature in the deposition region in the case of argon plasma. Deposition of hydrogenated amorphous carbon films and silicon oxide films has been tested using Ar/C2H2 and Ar/hexamethyldisiloxane/O2 mixtures, respectively. In the latter case, good control of the film properties by adjusting the source parameters has been achieved with the possibility of depositing carbon free SiOx films even without the addition of oxygen. Preliminary results regarding permeation barrier properties of deposited films are also given.

  5. Chemical vapor deposition and characterization of titanium dioxide thin films

    NASA Astrophysics Data System (ADS)

    Gilmer, David Christopher

    1998-12-01

    The continued drive to decrease the size and increase the speed of micro-electronic Metal-Oxide-Semiconductor (MOS) devices is hampered by some of the properties of the SiOsb2 gate dielectric. This research has focused on the CVD of TiOsb2 thin films to replace SiOsb2 as the gate dielectric in MOS capacitors and transistors. The relationship of CVD parameters and post-deposition anneal treatments to the physical and electrical properties of thin films of TiOsb2 has been studied. Structural and electrical characterization of TiOsb2 films grown from the CVD precursors tetraisopropoxotitanium (IV) (TTIP) and TTIP plus Hsb2O is described in Chapter 3. Both types of deposition produced stoichiometric TiOsb2 films comprised of polycrystalline anatase, but the interface properties were dramatically degraded when water vapor was added. Films grown with TTIP in the presence of Hsb2O contained greater than 50% more hydrogen than films grown using only TTIP and the hydrogen content of films deposited in both wet and dry TTIP environments decreased sharply with a post deposition Osb2 anneal. A significant thickness variation of the dielectric constant was observed which could be explained by an interfacial oxide and the finite accumulation thickness. Fabricated TiOsb2 capacitors exhibited electrically equivalent SiOsb2 gate dielectric thicknesses and leakage current densities as low as 38, and 1×10sp{-8} Amp/cmsp2 respectively. Chapter 4 discusses the low temperature CVD of crystalline TiOsb2 thin films deposited using the precursor tetranitratotitanium (IV), TNT, which produces crystalline TiOsb2 films of the anatase phase in UHV-CVD at temperatures as low as 184sp°C. Fabricated TiOsb2 capacitors exhibited electrically equivalent SiOsb2 gate dielectric thicknesses and leakage current densities as low as 17, and 1×10sp{-8} Amp/cmsp2 respectively. Chapter 5 describes the results of a comparison of physical and electrical properties between TiOsb2 films grown via LPCVD using

  6. X-ray reflectivity measurements of vacuum deposited thin films

    SciTech Connect

    Chason, M.; Chason, E.

    1992-12-31

    X-ray reflectivity using energy dispersive X-ray detection, a nondestructive probe of surface roughness over the region of {approximately} 1--50 {Angstrom}, has been used to investigate the characteristicsof vacuum deposited thin films. With a surface roughness sensitivity better than 1 {Angstrom} X-ray reflectivity is sensitive to interfaces between different materials for sample thicknesses up to approximately2000 {Angstrom} (depending on material density). We have investigated discrete Cr/Al deposits on quartz substrates and determined the surface roughness at the interfaces. We have also monitored the evolution ofthe Cr/Al interface following annealing. The experimental data is presented and discussed. The use of the technique for studying thin film deposits is addressed.

  7. X-ray reflectivity measurements of vacuum deposited thin films

    SciTech Connect

    Chason, M. ); Chason, E. )

    1992-01-01

    X-ray reflectivity using energy dispersive X-ray detection, a nondestructive probe of surface roughness over the region of [approximately] 1--50 [Angstrom], has been used to investigate the characteristicsof vacuum deposited thin films. With a surface roughness sensitivity better than 1 [Angstrom] X-ray reflectivity is sensitive to interfaces between different materials for sample thicknesses up to approximately2000 [Angstrom] (depending on material density). We have investigated discrete Cr/Al deposits on quartz substrates and determined the surface roughness at the interfaces. We have also monitored the evolution ofthe Cr/Al interface following annealing. The experimental data is presented and discussed. The use of the technique for studying thin film deposits is addressed.

  8. Properties of zirconia thin films deposited by laser ablation

    NASA Astrophysics Data System (ADS)

    Cancea, V. N.; Filipescu, M.; Colceag, D.; Mustaciosu, C.; Dinescu, M.

    2013-11-01

    Zirconia thin films have been deposited by laser ablation of a ceramic ZrO2 target in vacuum or in oxygen background at 0.01 mbar. The laser beam generated by an ArF laser (λ=193 nm, ν=40 Hz) has been focalized on the target through a spherical lens at an incident angle of 45°. The laser fluence has been established to a value from 2.0 to 3.4 Jcm-2. A silicon (100) substrate has been placed parallel to the target, at a distance of 4 cm, and subsequently has been heated to temperatures ranging between 300 °C and 600 °C. Thin films morphology has been characterized by atomic force microscopy and secondary ion mass spectrometry. Biocompatibility of these thin films has been assessed by studying the cell attachment of L929 mouse fibroblasts.

  9. Properties of zirconia thin films deposited by laser ablation

    SciTech Connect

    Cancea, V. N.; Filipescu, M.; Colceag, D.; Dinescu, M.; Mustaciosu, C.

    2013-11-13

    Zirconia thin films have been deposited by laser ablation of a ceramic ZrO{sub 2} target in vacuum or in oxygen background at 0.01 mbar. The laser beam generated by an ArF laser (λ=193 nm, ν=40 Hz) has been focalized on the target through a spherical lens at an incident angle of 45°. The laser fluence has been established to a value from 2.0 to 3.4 Jcm{sup −2}. A silicon (100) substrate has been placed parallel to the target, at a distance of 4 cm, and subsequently has been heated to temperatures ranging between 300 °C and 600 °C. Thin films morphology has been characterized by atomic force microscopy and secondary ion mass spectrometry. Biocompatibility of these thin films has been assessed by studying the cell attachment of L929 mouse fibroblasts.

  10. Low Temperature Chemical Vapor Deposition Of Thin Film Magnets

    DOEpatents

    Miller, Joel S.; Pokhodnya, Kostyantyn I.

    2003-12-09

    A thin-film magnet formed from a gas-phase reaction of tetracyanoetheylene (TCNE) OR (TCNQ), 7,7,8,8-tetracyano-P-quinodimethane, and a vanadium-containing compound such as vanadium hexcarbonyl (V(CO).sub.6) and bis(benzene)vanalium (V(C.sub.6 H.sub.6).sub.2) and a process of forming a magnetic thin film upon at least one substrate by chemical vapor deposition (CVD) at a process temperature not exceeding approximately 90.degree. C. and in the absence of a solvent. The magnetic thin film is particularly suitable for being disposed upon rigid or flexible substrates at temperatures in the range of 40.degree. C. and 70.degree. C. The present invention exhibits air-stable characteristics and qualities and is particularly suitable for providing being disposed upon a wide variety of substrates.

  11. Microwave plasma assisted supersonic gas jet deposition of thin film materials

    DOEpatents

    Schmitt, III, Jerome J.; Halpern, Bret L.

    1993-01-01

    An apparatus for fabricating thin film materials utilizing high speed gas dynamics relies on supersonic free jets of carrier gas to transport depositing vapor species generated in a microwave discharge to the surface of a prepared substrate where the vapor deposits to form a thin film. The present invention generates high rates of deposition and thin films of unforeseen high quality at low temperatures.

  12. Mechanical reinforcement of nanoparticle thin films using atomic layer deposition.

    PubMed

    Dafinone, Majemite I; Feng, Gang; Brugarolas, Teresa; Tettey, Kwadwo E; Lee, Daeyeon

    2011-06-28

    Thin films composed of nanoparticles exhibit synergistic properties, making them useful for numerous advanced applications. Nanoparticle thin films (NTFs), however, have a very low resistance to mechanical loading and abrasion, presenting a major bottleneck to their widespread use and commercialization. High-temperature sintering has been shown to improve the mechanical durability of NTFs on inorganic substrates; however, these high-temperature processes are not amenable to organic substrates. In this study, we demonstrate that the mechanical durability of TiO(2)/SiO(2) nanoparticle layer-by-layer (LbL) films on glass and polycarbonate substrates can be drastically improved using atomic layer deposition (ALD) at a relatively low temperature. The structure and physical properties of ALD-treated TiO(2)/SiO(2) nanoparticle LbL films are studied using spectroscopic ellipsometry, UV-vis spectroscopy, contact angle measurements, and nanoindentation. The composition of TiO(2)/SiO(2) LbL films as a function of ALD-cycle number is determined through solution ellipsometry, enabling the determination of the characteristic pore size of nanoparticle thin films. Mechanical durability is also investigated by abrasion tests, showing that the robustness of ALD-treated nanoparticle films is comparable to that of thermally calcined films. More importantly, ALD-treated nanoparticle films retain the original functionality of the TiO(2)/SiO(2) LbL films, such as superhydrophilicity and antireflection properties, demonstrating the utility of ALD as a reinforcement method for nanoparticle thin films. PMID:21557541

  13. Growth Simulation and Structure Analysis of Obliquely Deposited Thin Films

    NASA Astrophysics Data System (ADS)

    Belyaev, B. A.; Izotov, A. V.; Solovev, P. N.

    2016-06-01

    Based on the Monte Carlo method, a model of growth of thin films prepared by oblique angle deposition of particles is constructed. The morphology of structures synthesized by simulation is analyzed. To study the character of distribution of microstructural elements (columns) in the film plane, the autocorrelation function of the microstructure and the fast Fourier transform are used. It is shown that with increasing angle of particle incidence, the film density monotonically decreases; in this case, anisotropy arises and monotonically increases in the cross sections of columns, and the anisotropy of distribution of columns in the substrate plane also increases.

  14. Liquid phase deposition synthesis of hexagonal molybdenum trioxide thin films

    SciTech Connect

    Deki, Shigehito; Beleke, Alexis Bienvenu; Kotani, Yuki; Mizuhata, Minoru

    2009-09-15

    Hexagonal molybdenum trioxide thin films with good crystallinity and high purity have been fabricated by the liquid phase deposition (LPD) technique using molybdic acid (H{sub 2}MoO{sub 4}) dissolved in 2.82% hydrofluoric acid (HF) and H{sub 3}BO{sub 3} as precursors. The crystal was found to belong to a hexagonal hydrate system MoO{sub 3}.nH{sub 2}O (napprox0.56). The unit cell lattice parameters are a=10.651 A, c=3.725 A and V=365.997 A{sup 3}. Scanning electron microscope (SEM) images of the as-deposited samples showed well-shaped hexagonal rods nuclei that grew and where the amount increased with increase in reaction time. X-ray photon electron spectroscopy (XPS) spectra showed a Gaussian shape of the doublet of Mo 3d core level, indicating the presence of Mo{sup 6+} oxidation state in the deposited films. The deposited films exhibited an electrochromic behavior by lithium intercalation and deintercalation, which resulted in coloration and bleaching of the film. Upon dehydration at about 450 deg. C, the hexagonal MoO{sub 3}.nH{sub 2}O was transformed into the thermodynamically stable orthorhombic phase. - Abstract: SEM photograph of typical h-MoO{sub 3}.nH{sub 2}O thin film nuclei obtained after 36 h at 40 deg. C by the LPD method. Display Omitted

  15. Magnetic thin film deposition with pulsed magnetron sputtering: deposition rate and film thickness distribution

    NASA Astrophysics Data System (ADS)

    Ozimek, M.; Wilczyński, W.; Szubzda, B.

    2016-02-01

    The goal of conducted study was an experimental determining the relations between technological parameters of magnetron sputtering process on deposition rate (R) and thickness uniformity of magnetic thin films. Planar Ni79Fei6Mo5 target with a diameter of 100 mm was sputtered in argon (Ar) atmosphere. Deposition rate was measured in a function of gas pressure, target power and target-substrate distance. The highest value of R≈280 nmmin-1. The obtained results in deposition rate of magnetic film were compared to deposition rate of cooper (Cu), aluminum (Al), titanium (Ti) and titanium oxide (TiOx) and the deposition rate of Ni-Fe alloy were higher that Al and Ti. The film thickness distribution was measured for radial distance from the target centre ranging up to 60 mm and target-substrate distance ranging form 70 to 115 mm. Among others it was stated that for the larger value of target-substrate distance the larger uniform of film thickness are obtained.

  16. Atomic layer deposition of superparamagnetic and ferrimagnetic magnetite thin films

    SciTech Connect

    Zhang, Yijun; Liu, Ming E-mail: wren@mail.xjtu.edu.cn Ren, Wei E-mail: wren@mail.xjtu.edu.cn; Zhang, Yuepeng; Chen, Xing; Ye, Zuo-Guang E-mail: wren@mail.xjtu.edu.cn

    2015-05-07

    One of the key challenges in realizing superparamagnetism in magnetic thin films lies in finding a low-energy growth way to create sufficiently small grains and magnetic domains which allow the magnetization to randomly and rapidly reverse. In this work, well-defined superparamagnetic and ferrimagnetic Fe{sub 3}O{sub 4} thin films are successfully prepared using atomic layer deposition technique by finely controlling the growth condition and post-annealing process. As-grown Fe{sub 3}O{sub 4} thin films exhibit a conformal surface and poly-crystalline nature with an average grain size of 7 nm, resulting in a superparamagnetic behavior with a blocking temperature of 210 K. After post-annealing in H{sub 2}/Ar at 400 °C, the as-grown α−Fe{sub 2}O{sub 3} sample is reduced to Fe{sub 3}O{sub 4} phase, exhibiting a ferrimagnetic ordering and distinct magnetic shape anisotropy. Atomic layer deposition of magnetite thin films with well-controlled morphology and magnetic properties provides great opportunities for integrating with other order parameters to realize magnetic nano-devices with potential applications in spintronics, electronics, and bio-applications.

  17. Development of a Co-deposition method for Deposition of Low-Contamination Pyrite Thin Films

    NASA Astrophysics Data System (ADS)

    Walimbe, Aditya

    Pyrite is a 0.95 eV bandgap semiconductor which is purported to have great potential in widespread, low--cost photovoltaic cells. A thorough material selection process was used in the design of a pyrite sequential vapor deposition chamber aimed at reducing and possibly eliminating contamination during thin film growth. The design process focused on identifying materials that do not produce volatile components when exposed to high temperatures and high sulfur pressures. Once the materials were identified and design was completed, the ultra--high vacuum growth system was constructed and tested. Pyrite thin films were deposited using the upgraded sequential vapor deposition chamber by varying the substrate temperature from 250°C to 420°C during deposition, keeping sulfur pressure constant at 1 Torr. Secondary Ion Mass Spectrometry (SIMS) results showed that all contaminants in the films were reduced in concentration by orders of magnitude from those grown with the previous system. Characterization techniques of Rutherford Back--scattering Spectrometry (RBS), X--Ray Diffraction (XRD), Raman Spectroscopy, Optical Profilometry and UV/Vis/Near--IR Spectroscopy were performed on the deposited thin films. The results indicate that stoichiometric ratio of S:Fe, structural--quality (epitaxy), optical roughness and percentage of pyrite in the deposited thin films improve with increase in deposition temperature. A Tauc plot of the optical measurements indicates that the pyrite thin films have a bandgap of 0.94 eV.

  18. Formation of ultrasmooth thin silver films by pulsed laser deposition

    SciTech Connect

    Kuznetsov, I. A.; Garaeva, M. Ya.; Mamichev, D. A. Grishchenko, Yu. V.; Zanaveskin, M. L.

    2013-09-15

    Ultrasmooth thin silver films have been formed on a quartz substrate with a buffer yttrium oxide layer by pulsed laser deposition. The dependence of the surface morphology of the film on the gas (N{sub 2}) pressure in the working chamber and laser pulse energy is investigated. It is found that the conditions of film growth are optimal at a gas pressure of 10{sup -2} Torr and lowest pulse energy. The silver films formed under these conditions on a quartz substrate with an initial surface roughness of 0.3 nm had a surface roughness of 0.36 nm. These films can be used as a basis for various optoelectronics and nanoplasmonics elements.

  19. Chemically Deposited Thin-Film Solar Cell Materials

    NASA Technical Reports Server (NTRS)

    Raffaelle, R.; Junek, W.; Gorse, J.; Thompson, T.; Harris, J.; Hehemann, D.; Hepp, A.; Rybicki, G.

    2005-01-01

    We have been working on the development of thin film photovoltaic solar cell materials that can be produced entirely by wet chemical methods on low-cost flexible substrates. P-type copper indium diselenide (CIS) absorber layers have been deposited via electrochemical deposition. Similar techniques have also allowed us to incorporate both Ga and S into the CIS structure, in order to increase its optical bandgap. The ability to deposit similar absorber layers with a variety of bandgaps is essential to our efforts to develop a multi-junction thin-film solar cell. Chemical bath deposition methods were used to deposit a cadmium sulfide (CdS) buffer layers on our CIS-based absorber layers. Window contacts were made to these CdS/CIS junctions by the electrodeposition of zinc oxide (ZnO). Structural and elemental determinations of the individual ZnO, CdS and CIS-based films via transmission spectroscopy, x-ray diffraction, x-ray photoelectron spectroscopy and energy dispersive spectroscopy will be presented. The electrical characterization of the resulting devices will be discussed.

  20. Pulsed laser deposition and characterization of cellulase thin films

    NASA Astrophysics Data System (ADS)

    Cicco, N.; Morone, A.; Verrastro, M.; Viggiano, V.

    2013-08-01

    Thin films of cellulase were obtained by pulsed laser deposition (PLD) on an appropriate substrate. Glycoside hydrolase cellulase has received our attention because it emerges among the antifouling enzymes (enzymes being able to remove and prevent the formation of micro-organism biofilms) used in industry and medicine field. Pressed cellulase pellets, used as target material, were ablated with pulses of a Nd-YAG laser working at wavelength of 532 nm. In this work, we evaluated the impact of PLD technique both on molecular structure and hydrolytic activity of cellulase. Characteristic chemical bonds and morphology of deposited layers were investigated by FTIR spectroscopy and SEM respectively. The hydrolytic activity of cellulase thin films was detected by a colorimetric assay.

  1. Nanostructured zinc oxide thin film by simple vapor transport deposition

    NASA Astrophysics Data System (ADS)

    Athma, P. V.; Martinez, Arturo I.; Johns, N.; Safeera, T. A.; Reshmi, R.; Anila, E. I.

    2015-09-01

    Zinc oxide (ZnO) nanostructures find applications in optoelectronic devices, photo voltaic displays and sensors. In this work zinc oxide nanostructures in different forms like nanorods, tripods and tetrapods have been synthesized by thermal evaporation of zinc metal and subsequent deposition on a glass substrate by vapor transport in the presence of oxygen. It is a comparatively simpler and environment friendly technique for the preparation of thin films. The structure, morphology and optical properties of the synthesized nanostructured thin film were characterized in detail by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and photoluminescence (PL). The film exhibited bluish white emission with Commission International d'Eclairage (CIE) coordinates x = 0.22, y = 0.31.

  2. Composition and structure of sputter deposited erbium hydride thin films

    SciTech Connect

    ADAMS,DAVID P.; ROMERO,JUAN A.; RODRIGUEZ,MARK A.; FLORO,JERROLD A.; BANKS,JAMES C.

    2000-05-10

    Erbium hydride thin films are grown onto polished, a-axis {alpha} Al{sub 2}O{sub 3} (sapphire) substrates by reactive ion beam sputtering and analyzed to determine composition, phase and microstructure. Erbium is sputtered while maintaining a H{sub 2} partial pressure of 1.4 x 10{sup {minus}4} Torr. Growth is conducted at several substrate temperatures between 30 and 500 C. Rutherford backscattering spectrometry (RBS) and elastic recoil detection analyses after deposition show that the H/Er areal density ratio is approximately 3:1 for growth temperatures of 30, 150 and 275 C, while for growth above {approximately}430 C, the ratio of hydrogen to metal is closer to 2:1. However, x-ray diffraction shows that all films have a cubic metal sublattice structure corresponding to that of ErH{sub 2}. RBS and Auger electron that sputtered erbium hydride thin films are relatively free of impurities.

  3. Combinatorial thin film composition mapping using three dimensional deposition profiles

    NASA Astrophysics Data System (ADS)

    Suram, Santosh K.; Zhou, Lan; Becerra-Stasiewicz, Natalie; Kan, Kevin; Jones, Ryan J. R.; Kendrick, Brian M.; Gregoire, John M.

    2015-03-01

    Many next-generation technologies are limited by material performance, leading to increased interest in the discovery of advanced materials using combinatorial synthesis, characterization, and screening. Several combinatorial synthesis techniques, such as solution based methods, advanced manufacturing, and physical vapor deposition, are currently being employed for various applications. In particular, combinatorial magnetron sputtering is a versatile technique that provides synthesis of high-quality thin film composition libraries. Spatially addressing the composition of these thin films generally requires elemental quantification measurements using techniques such as energy-dispersive X-ray spectroscopy or X-ray fluorescence spectroscopy. Since these measurements are performed ex-situ and post-deposition, they are unable to provide real-time design of experiments, a capability that is required for rapid synthesis of a specific composition library. By using three quartz crystal monitors attached to a stage with translational and rotational degrees of freedom, we measure three-dimensional deposition profiles of deposition sources whose tilt with respect to the substrate is robotically controlled. We exhibit the utility of deposition profiles and tilt control to optimize the deposition geometry for specific combinatorial synthesis experiments.

  4. Combinatorial thin film composition mapping using three dimensional deposition profiles.

    PubMed

    Suram, Santosh K; Zhou, Lan; Becerra-Stasiewicz, Natalie; Kan, Kevin; Jones, Ryan J R; Kendrick, Brian M; Gregoire, John M

    2015-03-01

    Many next-generation technologies are limited by material performance, leading to increased interest in the discovery of advanced materials using combinatorial synthesis, characterization, and screening. Several combinatorial synthesis techniques, such as solution based methods, advanced manufacturing, and physical vapor deposition, are currently being employed for various applications. In particular, combinatorial magnetron sputtering is a versatile technique that provides synthesis of high-quality thin film composition libraries. Spatially addressing the composition of these thin films generally requires elemental quantification measurements using techniques such as energy-dispersive X-ray spectroscopy or X-ray fluorescence spectroscopy. Since these measurements are performed ex-situ and post-deposition, they are unable to provide real-time design of experiments, a capability that is required for rapid synthesis of a specific composition library. By using three quartz crystal monitors attached to a stage with translational and rotational degrees of freedom, we measure three-dimensional deposition profiles of deposition sources whose tilt with respect to the substrate is robotically controlled. We exhibit the utility of deposition profiles and tilt control to optimize the deposition geometry for specific combinatorial synthesis experiments. PMID:25832242

  5. Novel solutions for thin film layer deposition for organic materials

    NASA Astrophysics Data System (ADS)

    Keiper, Dietmar; Long, Michael; Schwambera, Markus; Gersdorff, Markus; Kreis, Juergen; Heuken, Michael

    2011-03-01

    Innovative systems for carrier-gas enhanced vapor phase deposition of organic layers offer advanced methods for the precise deposition of complex thin-film layer stacks. The approach inherently avoids potential short-comings from solvent-based polymer deposition and offers new opportunities. The process operates at low pressure (thus avoiding complex vacuum setups), and, by employing AIXTRON's extensive experience in freely scalable solutions, can be adapted to virtually any production process and allows for R&D and production systems alike. Deposition of organic layers and stacks recommends the approach for a wide range of organic small molecule and polymer materials (including layers with gradual change of the composition), for conductive layers, for dielectric layers, for barrier systems, for OLED materials, and surface treatments such as oleophobic / hydrophobic coatings. With the combination of other vapor phase deposition solutions, hybrid systems combining organic and inorganic materials and other advanced stacks can be realized.

  6. Light-assisted deposition of CdS thin films

    NASA Astrophysics Data System (ADS)

    Bacaksiz, E.; Novruzov, V.; Karal, H.; Yanmaz, E.; Altunbas, M.; Kopya, A. I.

    2001-11-01

    The effects of white light illumination during the deposition of CdS thin films in a quasi-closed volume on the structural, photoelectrical and optical properties are investigated. The films were highly c-axis oriented with an increasing intensity of (002) reflection as the illumination increases. The room temperature resistivity values of the CdS films decreased in the range of 107-104 Ω cm. The photosensitivity in the fundamental absorption region and the transparency in the transmission region considerably increased as the illumination increased. Under 100 mW cm-2 insolation, the efficiencies of the CdS/CdTe solar cells based on CdS window materials which were deposited: (1) in the dark; and (2) under an illumination of 150 mW cm-2 were found to be 1.8% and 7.3%, respectively.

  7. Studies on atomic layer deposition of IRMOF-8 thin films

    SciTech Connect

    Salmi, Leo D. Heikkilä, Mikko J.; Vehkamäki, Marko; Puukilainen, Esa; Ritala, Mikko; Sajavaara, Timo

    2015-01-15

    Deposition of IRMOF-8 thin films by atomic layer deposition was studied at 260–320 °C. Zinc acetate and 2,6-naphthalenedicarboxylic acid were used as the precursors. The as-deposited amorphous films were crystallized in 70% relative humidity at room temperature resulting in an unknown phase with a large unit cell. An autoclave with dimethylformamide as the solvent was used to recrystallize the films into IRMOF-8 as confirmed by grazing incidence x-ray diffraction. The films were further characterized by high temperature x-ray diffraction (HTXRD), field emission scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), time-of-flight elastic recoil detection analysis (TOF-ERDA), nanoindentation, and energy-dispersive x-ray spectroscopy. HTXRD measurements revealed similar behavior to bulk IRMOF-8. According to TOF-ERDA and FTIR, composition of the films was similar to IRMOF-8. Through-porosity was confirmed by loading the films with palladium using Pd(thd){sub 2} (thd = 2,2,6,6-tetramethyl-3,5-heptanedionato) as the precursor.

  8. Nanostructuring and texturing of pulsed laser deposited hydroxyapatite thin films

    NASA Astrophysics Data System (ADS)

    Kim, Hyunbin; Catledge, Shane; Vohra, Yogesh; Camata, Renato; Lacefield, William

    2003-03-01

    Hydroxyapatite (HA) [Ca_10(PO_4)_6(OH)_2] is commonly deposited onto orthopedic and dental metallic implants to speed up bone formation around devices, allowing earlier stabilization in a patient. Pulsed laser deposition (PLD) is a suitable means of placing thin HA films on these implants because of its control over stoichiometry, crystallinity, and nanostructure. These characteristics determine the mechanical properties of the films that must be optimized to improve the performance of load-bearing implants and other devices that undergo bone insertion. We have used PLD to produce nanostructured and preferentially oriented HA films and evaluated their mechanical properties. Pure, highly crystalline HA films on Ti-6Al-4V substrates were obtained using a KrF excimer laser (248nm) with energy density of 4-8 J/cm^2 and deposition temperature of 500-700^rcC. Scanning electron and atomic force microscopies reveal that our careful manipulation of energy density and substrate temperature has led to films made up of HA grains in the nanometer scale. Broadening of x-ray diffraction peaks as a function of deposition temperature suggests it may be possible to control the film nanostructure to a great extent. X-ray diffraction also shows that as the laser energy density is increased in the 4-8 J/cm^2 range, the hexagonal HA films become preferentially oriented along the c-axis perpendicular to the substrate. Texture, nanostructure, and phase make-up all significantly influence the mechanical properties. We will discuss how each of these factors affects hardness and Young's modulus of the HA films as measured by nanoindentation.

  9. Spray Deposition of Multilayer Gas Barrier Thin Films

    NASA Astrophysics Data System (ADS)

    Givens, Tara; Xiang, Fangming; Grunlan, Jaime

    2015-03-01

    Dip-assisted assembly is the norm for making multilayer thin films (also known as layer-by-layer [LbL] assembly). Spray-based deposition possesses several advantages over dipping, but has not been studied in great detail, especially for gas barrier layers. In this study, polyethylenimine [PEI]/poly(acylic acid) [PAA] bilayers were deposited with varying spray parameters. Spraying time was found to be the most influential parameter to control the roughness, thickness, and gas barrier of the PEI/PAA assembly. A spray-coated sample was prepared using optimized parameters and compared to a dip-coated sample using the same deposition time (5s). The sprayed sample was better in terms of thickness, roughness, and gas barrier. This study is the first report showing that a sprayed multilayer assembly has better properties than its dipped counterpart. These findings could revolutionize the multilayer deposition process, making it more commercially-friendly.

  10. Water-Assisted Vapor Deposition of PEDOT Thin Film.

    PubMed

    Goktas, Hilal; Wang, Xiaoxue; Ugur, Asli; Gleason, Karen K

    2015-07-01

    The synthesis and characterization of poly(3,4-ethylenedioxythiophene) (PEDOT) using water-assisted vapor phase polymerization (VPP) and oxidative chemical vapor deposition (oCVD) are reported. For the VPP PEDOT, the oxidant, FeCl3 , is sublimated onto the substrate from a heated crucible in the reactor chamber and subsequently exposed to 3,4-ethylenedioxythiophene (EDOT) monomer and water vapor in the same reactor. The oCVD PEDOT was produced by introducing the oxidant, EDOT monomer, and water vapor simultaneously to the reactor. The enhancement of doping and crystallinity is observed in the water-assisted oCVD thin films. The high doping level observed at UV-vis-NIR spectra for the oCVD PEDOT, suggests that water acts as a solubilizing agent for oxidant and its byproducts. Although the VPP produced PEDOT thin films are fully amorphous, their conductivities are comparable with that of the oCVD produced ones. PMID:25882241

  11. Zinc Oxide Thin Films Fabricated with Direct Current Magnetron Sputtering Deposition Technique

    SciTech Connect

    Hoon, Jian-Wei; Chan, Kah-Yoong; Krishnasamy, Jegenathan; Tou, Teck-Yong

    2011-03-30

    Zinc oxide (ZnO) is a very promising material for emerging large area electronic applications including thin-film sensors, transistors and solar cells. We fabricated ZnO thin films by employing direct current (DC) magnetron sputtering deposition technique. ZnO films with different thicknesses ranging from 100 nm to 1020 nm were deposited on silicon (Si) substrate. The deposition pressure was varied from 12 mTorr to 25 mTorr. The influences of the film thickness and the deposition pressure on structural properties of the ZnO films were investigated using Mahr surface profilometer and atomic force microscopy (AFM). The experimental results reveal that the film thickness and the deposition pressure play significant role in the structural formation of the deposited ZnO thin films. ZnO films deposited on Si substrates are promising for variety of thin-film sensor applications.

  12. Thin-Film Deposition of Metal Oxides by Aerosol-Assisted Chemical Vapour Deposition: Evaluation of Film Crystallinity

    NASA Astrophysics Data System (ADS)

    Takeuchi, Masahiro; Maki, Kunisuke

    2007-12-01

    Sn-doped In2O3 (ITO) thin films are deposited on glass substrates using 0.2 M aqueous and methanol solutions of InCl3(4H2O) with 5 mol % SnCl2(2H2O) by aerosol-assisted chemical vapour deposition under positive and negative temperature gradient conditions. The film crystallinity is evaluated by determining the film thickness dependence of X-ray diffraction peak height. When using aqueous solution, the ITO films grow with the same crystallinity during the deposition, but when using methanol solution, the preferred orientation of ITO changes during the deposition.

  13. thin films by an hybrid deposition configuration: pulsed laser deposition and thermal evaporation

    NASA Astrophysics Data System (ADS)

    Escobar-Alarcón, L.; Solís-Casados, D. A.; Perez-Alvarez, J.; Romero, S.; Morales-Mendez, J. G.; Haro-Poniatowski, E.

    2014-10-01

    The aim of this work was to report the application of an hybrid deposition configuration to deposit Titanium dioxide (TiO2) thin films modified with different amounts of bismuth (Bi:TiO2). The samples were synthesized combining a TiO2 laser ablation plasma with a flux of vapor of bismuth produced by thermal evaporation. By varying the deposition rate of Bi it was possible to control the amount of Bi incorporated in the film and consequently the film properties. A detailed compositional, structural, and optical characterization by XPS, RBS, Raman spectroscopy, and UV-Vis spectrometry techniques is discussed. Photocatalytic response of the deposited thin films was studied through the degradation of a malachite green solution.

  14. Novel doped hydroxyapatite thin films obtained by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Duta, L.; Oktar, F. N.; Stan, G. E.; Popescu-Pelin, G.; Serban, N.; Luculescu, C.; Mihailescu, I. N.

    2013-01-01

    We report on the synthesis of novel ovine and bovine derived hydroxyapatite thin films on titanium substrates by pulsed laser deposition for a new generation of implants. The calcination treatment applied to produce the hydroxyapatite powders from ovine/bovine bones was intended to induce crystallization and to prohibit the transmission of diseases. The deposited films were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy. Pull-off adherence and profilometry measurements were also carried out. X-ray diffraction ascertained the polycrystalline hydroxyapatite nature of the powders and films. Fourier transform infrared spectroscopy evidenced the vibrational bands characteristic to a hydroxyapatite material slightly carbonated. The micrographs of the films showed a uniform distribution of spheroidal particulates with a mean diameter of ∼2 μm. Pull-off measurements demonstrated excellent bonding strength values between the hydroxyapatite films and the titanium substrates. Because of their physical-chemical properties and low cost fabrication from renewable resources, we think that these new coating materials could be considered as a prospective competitor to synthetic hydroxyapatite used for implantology applications.

  15. Chemical bath deposition of II-VI compound thin films

    NASA Astrophysics Data System (ADS)

    Oladeji, Isaiah Olatunde

    II-VI compounds are direct bandgap semiconductors with great potentials in optoelectronic applications. Solar cells, where these materials are in greater demand, require a low cost production technology that will make the final product more affordable. Chemical bath deposition (CBD) a low cost growth technique capable of producing good quality thin film semiconductors over large area and at low temperature then becomes a suitable technology of choice. Heterogeneous reaction in a basic aqueous solution that is responsible for the II-VI compound film growth in CBD requires a metal complex. We have identified the stability constant (k) of the metal complex compatible with CBD growth mechanism to be about 106.9. This value is low enough to ensure that the substrate adsorbed complex relax for subsequent reaction with the chalcogen precursor to take place. It is also high enough to minimize the metal ion concentration in the bath participating in the precipitation of the bulk compounds. Homogeneous reaction that leads to precipitation in the reaction bath takes place because the solubility products of bulk II-VI compounds are very low. This reaction quickly depletes the bath of reactants, limit the film thickness, and degrade the film quality. While ZnS thin films are still hard to grow by CBD because of lack of suitable complexing agent, the homogeneous reaction still limits quality and thickness of both US and ZnS thin films. In this study, the zinc tetraammine complex ([Zn(NH3) 4]2+) with k = 108.9 has been forced to acquire its unsaturated form [Zn(NH3)3]2+ with a moderate k = 106.6 using hydrazine and nitrilotriacetate ion as complementary complexing agents and we have successfully grown ZnS thin films. We have also, minimized or eliminated the homogeneous reaction by using ammonium salt as a buffer and chemical bath with low reactant concentrations. These have allowed us to increase the saturation thickness of ZnS thin film by about 400% and raise that of US film

  16. Optimization and testing of solid thin film lubrication deposition processes

    NASA Astrophysics Data System (ADS)

    Danyluk, Michael J.

    A novel method for testing solid thin films in rolling contact fatigue (RCF) under ultra-high vacuum (UHV) and high rotational speeds (130 Hz) is presented in this thesis. The UHV-RCF platform is used to quantify the adhesion and lubrication aspects of two thin film coatings deposited on ball-bearings using a physical vapor deposition ion plating process. Plasma properties during ion plating were measured using a Langmuir probe and there is a connection between ion flux, film stress, film adhesion, process voltage, pressure, and RCF life. The UHV-RCF platform and vacuum chamber were constructed using off-the-shelf components and 88 RCF tests in high vacuum have been completed. Maximum RCF life was achieved by maintaining an ion flux between 10 13 to 1015 (cm-2 s-1) with a process voltage and pressure near 1.5 kV and 15 mTorr. Two controller schemes were investigated to maintain optimal plasma conditions for maximum RCF life: PID and LQR. Pressure disturbances to the plasma have a detrimental effect on RCF life. Control algorithms that mitigate pressure and voltage disturbances already exist. However, feedback from the plasma to detect disturbances has not been explored related to deposition processes in the thin-film science literature. Manometer based pressure monitoring systems have a 1 to 2 second delay time and are too slow to detect common pressure bursts during the deposition process. Plasma diagnostic feedback is much faster, of the order of 0.1 second. Plasma total-current feedback was used successfully to detect a typical pressure disturbance associated with the ion plating process. Plasma current is related to ion density and process pressure. A real-time control application was used to detect the pressure disturbance by monitoring plasma-total current and converting it to feedback-input to a pressure control system. Pressure overshoot was eliminated using a nominal PID controller with feedback from a plasma-current diagnostic measurement tool.

  17. The Effect of Deposition Temperature to Photoconductivity Properties of Amorphous Carbon Thin Films Deposited By Thermal CVD

    NASA Astrophysics Data System (ADS)

    Mohamad, F.; Suriani, A. B.; Noor, U. M.; Rusop, M.

    2010-07-01

    Amorphous carbon (a-C) thin films were deposited by thermal chemical vapor deposition (CVD) using camphor oil on quartz substrates. The photoconductivity and optical properties of the thin films were studied with varying the deposition temperatures ranging from 650 to 900 °C. The film deposited at 750 °C shows large photoconductivity compare to other films. The optical characterization shows that the optical band gap of the thin films decreased from 0.65 to ˜0.0eV with increasing the deposition temperature due to the increase of sp2 bonded carbon configuration. The electrical conductivity of the thin films grown at higher temperature is much higher compared with the thin films deposited at low temperature.

  18. Deposition, characterization, and laser ablation patterning of YBCO thin films

    NASA Astrophysics Data System (ADS)

    Vase, Per; Yueqiang, Shen; Freltoft, Torsten

    1990-12-01

    High quality epitaxial thin films of YBa 2Cu 3O 7 have been deposited on single-crystal MgO(001) substrates by 355 nm Nd:YAG laser ablation. Through a systematic optimization of the deposition parameters, it was found that for a target-substrate distance of 30 mm, the optimal laser intensity, substrate temperature, and deposition oxygen pressure were 300 MW/cm 2, 750 ° C, and 0.5-1.0 mbar, respectively. Microstrips with dimensions down to 10 μm across were fabricated using both a photoresist technique and laser ablation through a metal mask. The superconducting transition takes place over 1 K, and the critical temperature is reproducible within ±1.5 K, the best result being Tc,0 = 90 K. The highest critical current density measured on a 10 X 0.15 μm 2 strips was 4 X 10 6 A/cm 2 at 77 K . Film patterning using laser ablation through a metal mask was studied in detail to investigate the applicability of this method. Etch rates as a function of laser intensity were measured, and the process was followed in situ by on-line monitoring of the film resistivity.

  19. Beam-Induced Deposition of Thin Metallic Films.

    NASA Astrophysics Data System (ADS)

    Funsten, Herbert Oliver, III

    1990-01-01

    Ion and electron beam induced deposition (BID) of thin (1 μm), conductive films is accomplished by dissociating and removing the nonmetallic components of an adsorbed, metal-based, molecular gas. Current research has focused primarily on room temperature (monolayer adsorption) BID using electrons and slow, heavy ions. This study investigates low temperature (50 to 200 K) BID in which the condensation of the precursor gases (SnCl _4 and (CH_3) _4Sn) maximizes the efficiency of the incident radiation which can create and remove nonmetallic fragments located several monolayers below the film surface. The desired properties of the residual metallic films are produced by using as incident radiation either nuclear (35 keV Ar ^+) or electronic (2 keV electrons, 25 keV H^+, or 50 keV H ^+) energy loss mechanisms. Residual films are analyzed ex situ by Scanning Electron Microscopy (SEM), thickness measurements, resistivity measurements, Rutherford Backscattering Spectroscopy (RBS), and infrared spectroscopy. Low temperature BID film growth models, which are derived from both a computer simulation and a mathematical analysis, closely agree. Both the fragmentation and sputtering cross sections for a particular ion and energy are derived for films created from (CH_3) _4Sn. The fragmentation cross section, which corresponds to film growth, is roughly related to the electronic stopping power by the 1.9 power. The loss of carbon in films which were created from (CH_3) _4Sn is strongly dependent on the nuclear stopping power. Film growth rates for low temperature BID have been found to be 10 times those of room temperature BID.

  20. 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.

  1. 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.

  2. Microwave plasma assisted supersonic gas jet deposition of thin film materials

    DOEpatents

    Schmitt, J.J. III; Halpern, B.L.

    1993-10-26

    An apparatus for fabricating thin film materials utilizing high speed gas dynamics relies on supersonic free jets of carrier gas to transport depositing vapor species generated in a microwave discharge to the surface of a prepared substrate where the vapor deposits to form a thin film. The present invention generates high rates of deposition and thin films of unforeseen high quality at low temperatures. 5 figures.

  3. Thin nanocrystalline zirconia films prepared by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Dikovska, A. Og; Atanasova, G. B.; Avdeev, G. V.; Strijkova, V. Y.

    2016-03-01

    In the present work, thin zirconia films were prepared by pulsed laser deposition at different substrate temperatures and oxygen partial pressures. The substrate temperature was varied from 400 °C to 600 °C, and the oxygen pressure, from 0.01 to 0.05 mbar. The effect was investigated of the substrate temperature and oxygen pressure on the formation of m-zirconia and t-zirconia phases.The formation of a cubic phase of ZrO2 by using targets doped with 3 and 8 mol % content Y2O3 was also investigated. The variation in the optical properties was studied and discussed in relation with the zirconia films' microstructure.

  4. Prussian Blue thin films: electrochemical deposition and characterization

    NASA Astrophysics Data System (ADS)

    Pasa, Andre A.; Alamini, Marilia F.; da Silva, Rene C.; Zoldan, Vinícius C.; Isoppo, Eduardo A.; Rodrigues Filho, Ubirajara P.; Klein, Aloísio N.

    2010-03-01

    Prussian Blue thin films Fe4[Fe(CN)6]3 are relevant for many applications such as molecular magnets, electrochromism and electrochemical sensors. In this work, Prussian Blue layers were grown through electrochemical deposition on 50 nm Au coated n-type Si (100) substrates, at room temperature, from electrolyte containing HCl, KCl, FeCl3 and K3[Fe(CN)6]. The layer formation was promoted by scanning sequentially the applied voltage, varying the scan rate and the number of cycles. Emphasis was given to the characterization of the samples with scanning and transmission electron microscopy, X-ray diffraction and atomic force microscopy. Pyramidal grains were typically observed with size increasing with the deposition time. The analysis of the topographic images allowed the determination of important practical parameters as the saturation roughness and correlation length, and scaling regime and exponents.

  5. Residual stress in zinc oxide thin films deposited by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Elam, David; Kotha, Ramakrishna; Ayon, Arturo; Chabanov, Andrey

    2010-10-01

    The residual stress in a thin film can have an impact on the electrical and optical properties of the film. In addition, stress is an important consideration when incorporating the material into a microelectromechanical (MEMS) device as large unexpected stresses can cause such a device to fail. The residual stress in ZnO thin films prepared by atomic layer deposition was measured using a radius of curvature technique. The results show relatively low residual stresses on the order of ˜0.1 GPa. The stress is observed to change from tensile to compressive as a function of increasing deposition temperature. The polycrystalline structures of the films are also investigated using XRD techniques.

  6. Crystallization of amorphous silicon thin films deposited by PECVD on nickel-metalized porous silicon

    PubMed Central

    2012-01-01

    Porous silicon layers were elaborated by electrochemical etching of heavily doped p-type silicon substrates. Metallization of porous silicon was carried out by immersion of substrates in diluted aqueous solution of nickel. Amorphous silicon thin films were deposited by plasma-enhanced chemical vapor deposition on metalized porous layers. Deposited amorphous thin films were crystallized under vacuum at 750°C. Obtained results from structural, optical, and electrical characterizations show that thermal annealing of amorphous silicon deposited on Ni-metalized porous silicon leads to an enhancement in the crystalline quality and physical properties of the silicon thin films. The improvement in the quality of the film is due to the crystallization of the amorphous film during annealing. This simple and easy method can be used to produce silicon thin films with high quality suitable for thin film solar cell applications. PMID:22901341

  7. Crystallization of amorphous silicon thin films deposited by PECVD on nickel-metalized porous silicon.

    PubMed

    Ben Slama, Sonia; Hajji, Messaoud; Ezzaouia, Hatem

    2012-01-01

    Porous silicon layers were elaborated by electrochemical etching of heavily doped p-type silicon substrates. Metallization of porous silicon was carried out by immersion of substrates in diluted aqueous solution of nickel. Amorphous silicon thin films were deposited by plasma-enhanced chemical vapor deposition on metalized porous layers. Deposited amorphous thin films were crystallized under vacuum at 750°C. Obtained results from structural, optical, and electrical characterizations show that thermal annealing of amorphous silicon deposited on Ni-metalized porous silicon leads to an enhancement in the crystalline quality and physical properties of the silicon thin films. The improvement in the quality of the film is due to the crystallization of the amorphous film during annealing. This simple and easy method can be used to produce silicon thin films with high quality suitable for thin film solar cell applications. PMID:22901341

  8. Deposition of Nanostructured Thin Film from Size-Classified Nanoparticles

    NASA Technical Reports Server (NTRS)

    Camata, Renato P.; Cunningham, Nicholas C.; Seol, Kwang Soo; Okada, Yoshiki; Takeuchi, Kazuo

    2003-01-01

    Materials comprising nanometer-sized grains (approximately 1_50 nm) exhibit properties dramatically different from those of their homogeneous and uniform counterparts. These properties vary with size, shape, and composition of nanoscale grains. Thus, nanoparticles may be used as building blocks to engineer tailor-made artificial materials with desired properties, such as non-linear optical absorption, tunable light emission, charge-storage behavior, selective catalytic activity, and countless other characteristics. This bottom-up engineering approach requires exquisite control over nanoparticle size, shape, and composition. We describe the design and characterization of an aerosol system conceived for the deposition of size classified nanoparticles whose performance is consistent with these strict demands. A nanoparticle aerosol is generated by laser ablation and sorted according to size using a differential mobility analyzer. Nanoparticles within a chosen window of sizes (e.g., (8.0 plus or minus 0.6) nm) are deposited electrostatically on a surface forming a film of the desired material. The system allows the assembly and engineering of thin films using size-classified nanoparticles as building blocks.

  9. Optical characterization of deposited ITO thin films on glass and PET substrates

    NASA Astrophysics Data System (ADS)

    Elmas, Saliha; Korkmaz, Şadan; Pat, Suat

    2013-07-01

    This work focuses on fabrication, characterization and understanding some physical properties of transparent and conductive ITO thin films. ITO thin films were deposited onto glass and polyethylene terephthalate (PET) substrates by thermionic vacuum arc (TVA) technique. TVA is a different technology for thin film deposition. Thicknesses and refractive indices of the ITO thin films have been determined by spectroscopic ellipsometry (SE) technique using Cauchy model for fitting. SE is a novel, nondestructive and powerful technique to investigate the optical characteristics of materials. Especially thickness and optical constants are measuring this device. Transmittances, reflectance of ITO coated samples were measured by UV-vis spectrophotometer and interferometer, respectively. The optical method was used to determine the band gaps of ITO thin films. Surface morphologies of produced films were characterized by atomic force microscope (AFM) for surface topography and roughness of ITO thin films. Resistivity measurements show that produced films show semiconductor properties.

  10. Atomic layer deposition of sodium and potassium oxides: evaluation of precursors and deposition of thin films.

    PubMed

    Østreng, E; Sønsteby, H H; Øien, S; Nilsen, O; Fjellvåg, H

    2014-11-28

    Thin films of sodium and potassium oxides have for the first time been deposited using atomic layer deposition. Sodium and potassium complexes of tert-butanol, trimethylsilanol and hexamethyldisilazide have been evaluated as precursors by characterising their thermal properties as well as tested in applications for thin film depositions. Out of these, sodium and potassium tert-butoxide and sodium trimethylsilanolate and hexamethyldisilazide were further tested as precursors together with the Al(CH3)3 + H2O/O3 process to form aluminates and together with ozone to form silicates. Sodium and potassium tert-butoxide and sodium trimethylsilanolate showed self-limiting growth and proved useable at deposition temperatures from 225 to 375 or 300 °C, respectively. The crystal structures of NaO(t)Bu and KO(t)Bu were determined by single crystal diffraction revealing hexamer- and tetramer structures, respectively. The current work demonstrates the suitability of the ALD technique to deposit thin films containing alkaline elements even at 8'' wafer scale. PMID:25265332

  11. (abstract) Optical Scattering and Surface Microroughness of Ion Beam Deposited Au and Pt Thin Films

    NASA Technical Reports Server (NTRS)

    Al-Jumaily, Ghanim A.; Raouf, Nasrat A.; Edlou, Samad M.; Simons, John C.

    1994-01-01

    Thin films of gold and platinum have been deposited onto superpolished fused silica substrates using thermal evaporation, ion assisted deposition (IAD), and ion assisted sputtering. The influence of ion beam flux, thin film material, and deposition rate on the films microroughness have been investigated. Short range surface microroughness of the films has been examined using scanning tunneling microscopy (STM) and atomic force microscopy (AFM). Long range surface microroughness has been characterized using an angle resolved optical scatterometer. Results indicate that ion beam deposited coatings have improved microstructure over thermally evaporated films.

  12. Macroscopic exploration and visual quality inspection of thin film deposit

    NASA Astrophysics Data System (ADS)

    Désage, Simon-Frédéric; Pitard, Gilles; Favrelière, Hugues; Pillet, Maurice; Dellea, Olivier; Fugier, Pascal; Coronel, Philippe; Ollier, Emmanuel

    2014-04-01

    Micro/nanotechnologies evolve causing an evolution of surface characterization systems of thin films. Today, these systems are not adapted to the future needs (or current) to characterize and qualify a large effective area within industrial production. This concerns the thin film active layers or simple mask for structuring the surface. This paper proposes a quality control method for thin films of self-assembled particles and high quality. This method is founded on the intersection of several skills available in our laboratories: Industrial process of visual inspection, optical methods for quality control (large area relative to the state of the art) and advances in micro/nanotechnology (CEA/Liten).

  13. Influence of Deposition Time on ZnS Thin Films Performance with Chemical Bath Deposition

    NASA Astrophysics Data System (ADS)

    Zhou, Limei; Tang, Nan; Wu, Sumei; Hu, Xiaofei; Xue, Yuzhi

    ZnS thin films had been deposited by chemical bath deposition method onto glass substrates in alkaline liquor. The reaction solution is made of ZnSO4, NH4OH and SC(NH2)2. Different deposition times (1 h, 1.5 h, 2 h, 2.5 h and 3 h) were selected to study the performance of ZnS thin films. As the results, the ZnS films' thickness were about 50-207 nm. XRD results showed an amorphous structure. Through comparing the surface morphology before and after annealing, it could be seen that annealing made some particles grow up and the surface smooth and even. The transmittance decreased with the increase of deposition time in the range of 300-800 nm. The transmittance of annealed ZnS film was lower than that of deposited one in the range of 300-800 nm. The ZnS band gap values were calculated in the range of 3.72-3.9 eV.

  14. Deposition of thermal and hot-wire chemical vapor deposition copper thin films on patterned substrates.

    PubMed

    Papadimitropoulos, G; Davazoglou, D

    2011-09-01

    In this work we study the hot-wire chemical vapor deposition (HWCVD) of copper films on blanket and patterned substrates at high filament temperatures. A vertical chemical vapor deposition reactor was used in which the chemical reactions were assisted by a tungsten filament heated at 650 degrees C. Hexafluoroacetylacetonate Cu(I) trimethylvinylsilane (CupraSelect) vapors were used, directly injected into the reactor with the aid of a liquid injection system using N2 as carrier gas. Copper thin films grown also by thermal and hot-wire CVD. The substrates used were oxidized silicon wafers on which trenches with dimensions of the order of 500 nm were formed and subsequently covered with LPCVD W. HWCVD copper thin films grown at filament temperature of 650 degrees C showed higher growth rates compared to the thermally ones. They also exhibited higher resistivities than thermal and HWCVD films grown at lower filament temperatures. Thermally grown Cu films have very uniform deposition leading to full coverage of the patterned substrates while the HWCVD films exhibited a tendency to vertical growth, thereby creating gaps and incomplete step coverage. PMID:22097561

  15. AlN thin films prepared by DC arc deposition

    NASA Astrophysics Data System (ADS)

    Liang, Hai-feng; Yan, Yi-xin; Miao, Shu-fan

    2006-02-01

    Many researchers are interested in AlN films because of their novel thermal, chemical, mechanical, acoustic, and optical properties. Many methodsincluding such as DC/RF sputtering, chemical vapor deposition (CVD), laser chemical vapor deposition(LCVD), molecular beam epitaxy (MBE), thermal vapor deposition, can be used to prepare AlN films. In this paper, a new method, DC arc deposition, is used to deposite AlN films. It is an anti-reflective, protective film on optical elements. FTIR are used to determine the ALN structure and measure the transmittance spectrum. Ellipsometry is used to determine the films' refractive index, extinction index and thickness. The films' anti-wear properties are tested by pin-on-disc way and the anti-corrosion(anti-acid, anti-alkali, anti-salt) properties are also tested. The results show that the films is AlN films by the 670cm -1 typical peak, the films' extinction index is near to zero in the range of visible and infrared waveband, the films' refractive index is varied from 1.7 to 2.1 at range of visible and infrared waveband. The films have better anti-wear, anti-acid and anti-alkali properties, but their anti-salt properties are not good.

  16. Nano-oxide thin films deposited via atomic layer deposition on microchannel plates

    NASA Astrophysics Data System (ADS)

    Yan, Baojun; Liu, Shulin; Heng, Yuekun

    2015-04-01

    Microchannel plate (MCP) as a key part is a kind of electron multiplied device applied in many scientific fields. Oxide thin films such as zinc oxide doped with aluminum oxide (ZnO:Al2O3) as conductive layer and pure aluminum oxide (Al2O3) as secondary electron emission (SEE) layer were prepared in the pores of MCP via atomic layer deposition (ALD) which is a method that can precisely control thin film thickness on a substrate with a high aspect ratio structure. In this paper, nano-oxide thin films ZnO:Al2O3 and Al2O3 were prepared onto varied kinds of substrates by ALD technique, and the morphology, element distribution, structure, and surface chemical states of samples were systematically investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoemission spectroscopy (XPS), respectively. Finally, electrical properties of an MCP device as a function of nano-oxide thin film thickness were firstly studied, and the electrical measurement results showed that the average gain of MCP was greater than 2,000 at DC 800 V with nano-oxide thin film thickness approximately 122 nm. During electrical measurement, current jitter was observed, and possible reasons were preliminarily proposed to explain the observed experimental phenomenon.

  17. Thin Film?

    NASA Astrophysics Data System (ADS)

    Kariper, İ. Afşin

    2014-09-01

    This study focuses on the critical surface tension of lead sulfite (PbSO3) crystalline thin film produced with chemical bath deposition on substrates (commercial glass).The PbSO3 thin films were deposited at room temperature at different deposition times. The structural properties of the films were defined and examined according to X-ray diffraction (XRD) and the XRD results such as dislocation density, average grain size, and no. of crystallites per unit area. Atomic force microscopy was used to measure the film thickness and the surface properties. The critical surface tension of the PbSO3 thin films was measured with an optical tensiometer instrument and calculated using the Zisman method. The results indicated that the critical surface tension of films changed in accordance with the average grain size and film thickness. The film thickness increased with deposition time and was inversely correlated with surface tension. The average grain size increased according to deposition time and was inversely correlated with surface tension.

  18. Development of vapor deposited thin films for bio-microsystems

    NASA Astrophysics Data System (ADS)

    Popat, Ketul Chandrakant

    Increasing demands for more biocompatible and sophisticated bio-microsystems in recent years has led to the development of a new technology called BioMEMS (biological micro-electro-mechanical systems). The foundation of this technology is the same as that of the traditional field of IC (integrated circuits), but an emphasis on developing new diagnostic and therapeutic modalities. Micro- and nano-fabrication techniques are currently being used to develop implants that can record, sense, stimulate and deliver to biological systems. Micromachined substrates can provide unique advantages over traditional implantable devices in terms of their ability to control surface micro-architecture, topography and feature size in micron and nano sizes. However, as BioMEMS technology is rapidly being developed, the practical use of these bio-microsystems is limited due to the inability to effectively interface with the biological system in non-immunogenic and stable manner. This is one of the most important considerations, and hence it is useful to focus on the fundamental scientific issues relating to material science, surface chemistry and immunology of silicon based bio-microsystems. This results in development of biomolecular interfaces that are compatible with both microfabrication processing and biological systems. The overall thrust of this research is to develop, characterize and integrate vapor deposited thin films with bio-microsystems in a manner that it is both reproducible and fully integrated with existing technologies. The main strategy is to use silane coatings precursor coatings on which poly (ethylene glycol) (PEG) will be coated in vapor phase. Silane has been coated user vapor phase, but its chemical and biological characterization and stability of the films under physiological conditions has not been investigated for biological applications. PEG has been coated in solution phase on silicon surface. However, it has not been coated under vapor phase. Here we are

  19. Femtosecond Laser Ablation of Frozen Alcohols for Deposition of Diamond-Like Carbon Thin Films

    NASA Astrophysics Data System (ADS)

    Okoshi, Masayuki; Inoue, Wataru; Inoue, Narumi

    2008-06-01

    A 790 nm, 130 fs Ti:sapphire laser pulse ablated various frozen alcohols (CnH2n + 1OH, n = 1-6) to deposit diamond-like carbon (DLC) thin films. The larger the carbon number (n) of the alcohols, the higher the hydrogen content of the DLC films; the sp3 carbon content ranged from 35 to 45%. The hydrogen content caused a change in the optical band gap of the films. Moreover, the deposition rate of the films increased linearly as the carbon number increased. The deposition rate did not simply relate to the amount of carbon species ejected from the frozen alcohols. Even though carbon species were largely generated, the ejected oxygen radicals etched the carbon to lower the deposition rate. When we used frozen benzene as a laser target, DLC thin films were not deposited. By dissolving boric acid in an alcohol, we could deposit boron-doped DLC thin films.

  20. 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

  1. Effect of Deposition Temperature on the Properties of TIO2 Thin Films Deposited by Mocvd

    NASA Astrophysics Data System (ADS)

    Khalifa, Zaki S.

    2016-02-01

    Crystal structure, microstructure, and optical properties of TiO2 thin films deposited on quartz substrates by metal-organic chemical vapor deposition (MOCVD) in the temperature range from 250∘C to 450∘C have been studied. The crystal structure, thickness, microstructure, and optical properties have been carried out using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), atomic force microscope (AFM), and UV-visible transmittance spectroscopy, respectively. XRD patterns show that the obtained films are pure anatase. Simultaneously, the crystal size calculated using XRD peaks, and the grain size measured by AFM decrease with the increase in deposition temperature. Moreover, the texture of the films change and roughness decrease with the increase in deposition temperature. The spectrophotometric transmittance spectra have been used to calculate the refractive index, extinction coefficient, dielectric constant, optical energy gap, and porosity of the deposited films. While the refractive index and dielectric constant decrease with the increase of deposition temperature, the porosity shows the opposite.

  2. 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

  3. The effect of deposition rate on the intrinsic stress in copper and silver thin films

    NASA Astrophysics Data System (ADS)

    Del Vecchio, A. L.; Spaepen, F.

    2007-03-01

    The effect of changing the deposition rate on the development of stress in evaporated copper and silver thin films deposited on oxidized silicon was examined. In situ stress measurements were made during deposition in ultrahigh vacuum using a scanning laser curvature system. In some experiments, the deposition rate was alternated without interruption of deposition. For copper thin films, a change in deposition rate has no effect on the development of the tensile stress, while the magnitude of the postcoalescence compressive stress decreases with increasing deposition rate. In silver films, the film thickness at the tensile maximum increases slightly with increasing deposition rate, while the magnitude of the postcoalescence compressive stress again decreases with increasing deposition rate. Analysis of the heat flow during deposition shows that the radiative heating and condensation contribute roughly equally to the temperature rise of the sample.

  4. Self-supported aluminum thin films produced by vacuum deposition process

    NASA Technical Reports Server (NTRS)

    Neff, J. E.; Timme, R. W.

    1966-01-01

    Self-supported aluminum thin film is produced by vacuum depositing the film on a polyvinyl formal resin film and then removing the resin by radiant heating in the vacuum. The aluminum film can be used as soon as the resin is eliminated.

  5. Plasma sputtering system for deposition of thin film combinatorial libraries

    NASA Astrophysics Data System (ADS)

    Cooper, James S.; Zhang, Guanghai; McGinn, Paul J.

    2005-06-01

    The design of a plasma sputtering system for the deposition of combinatorial libraries is described. A rotating carousel is used to position shadow masks between the targets and the substrate. Multilayer films are built up by depositing sequentially through various masks. Postdeposition annealing is used to promote interdiffusion of the layered structures. Either discrete or compositional gradient libraries can be deposited in this system. Samples appropriate for characterization with a scanning electrochemical microscope or a multichannel microelectrode array system can be produced. The properties of some deposited Pt-Ru films for fuel cell applications are described.

  6. rf plasma oxidation of Ni thin films sputter deposited to generate thin nickel oxide layers

    NASA Astrophysics Data System (ADS)

    Hoey, Megan L.; Carlson, J. B.; Osgood, R. M.; Kimball, B.; Buchwald, W.

    2010-10-01

    Nickel oxide (NiO) layers were formed on silicon (Si) substrates by plasma oxidation of nickel (Ni) film lines. This ultrathin NiO layer acted as a barrier layer to conduction, and was an integral part of a metal-insulator-metal (MIM) diode, completed by depositing gold (Au) on top of the oxide. The electrical and structural properties of the NiO thin film were examined using resistivity calculations, current-voltage (I-V) measurements and cross-sectional transmission electron microscopy (XTEM) imaging. The flow rate of the oxygen gas, chamber pressure, power, and exposure time and their influence on the characteristics of the NiO thin film were studied.

  7. On the deposition mechanisms and the formation of glassy Cu-Zr thin films

    NASA Astrophysics Data System (ADS)

    Almyras, G. A.; Matenoglou, G. M.; Komninou, Ph.; Kosmidis, C.; Patsalas, P.; Evangelakis, G. A.

    2010-04-01

    We report on molecular dynamics (MD) simulations and physical vapor deposition experimental results concerning the development of glassy and nanocrystalline Cu-Zr thin films. MD has revealed that when Cu and Zr are deposited sequentially, a thin film overlayer is formed that consists of nanocrystalline a-Zr and t-Zr2Cu, while if Cu and Zr are simultaneously deposited, amorphous CuZr thin film emerges, due to the formation of icosahedral-like clusters that impede nucleation. Thin films grown by pulsed laser deposition and magnetron sputtering techniques were analyzed by x-ray diffraction and high-resolution transmission electron microscopy and yielded unequivocal evidence that validates our MD predictions. These findings may indicate an alternative pathway for the growth of metallic nanocomposites or glassy films.

  8. Induced Recrystallization of CdTe Thin Films Deposited by Close-Spaced Sublimation

    SciTech Connect

    Moutinho, H. R.; Dhere, R. G.; Al-Jassim, M. M.; Levi, D. H.; Kazmerski, L. L.; Mayo, B.

    1998-10-29

    We have deposited CdTe thin films by close-spaced sublimation at two different temperature ranges. The films deposited at the lower temperature partially recrystallized after CdCl{sub 2} treatment at 350 C and completely recrystallized after the same treatment at 400 C. The films deposited at higher temperature did not recrystallize at these two temperatures. These results confirmed that the mechanisms responsible for changes in physical properties of CdTe films treated with CdCl{sub 2} are recrystallization and grain growth, and provided an alternative method to deposit CSS films using lower temperatures.

  9. Induced Recrystallization of CdTe Thin Films Deposited by Close-Spaced Sublimation

    SciTech Connect

    Moutinho, H. R.; Dhere, R. G.; Al-Jassim, M. M.; Levi, D. H.; Kazmerski, L. L.; Mayo, B.

    1998-10-26

    We have deposited CdTe thin films by close-spaced sublimation at two different temperature ranges. The films deposited at the lower temperature partially recrystallized after CdCl2 treatment at 350 C and completely recrystallized after the same treatment at 400 C. The films deposited at higher temperature did not recrystallize at these two temperatures. These results confirmed that the mechanisms responsible for changes in physical properties of CdTe films treated with CdCl2 are recrystallization and grain growth, and provided an alternative method to deposit CSS films using lower temperatures.

  10. Biocompatibility of atomic layer-deposited alumina thin films.

    PubMed

    Finch, Dudley S; Oreskovic, Tammy; Ramadurai, Krishna; Herrmann, Cari F; George, Steven M; Mahajan, Roop L

    2008-10-01

    Presented in this paper is a study of the biocompatibility of an atomic layer-deposited (ALD) alumina (Al2O3) thin film and an ALD hydrophobic coating on standard glass cover slips. The pure ALD alumina coating exhibited a water contact angle of 55 degrees +/- 5 degrees attributed, in part, to a high concentration of -OH groups on the surface. In contrast, the hydrophobic coating (tridecafluoro-1,1,2,2-tetrahydro-octyl-methyl-bis(dimethylamino)silane) had a water contact angle of 108 degrees +/- 2 degrees. Observations using differential interference contrast microscopy on human coronary artery smooth muscle cells showed normal cell proliferation on both the ALD alumina and hydrophobic coatings when compared to cells grown on control substrates. These observations suggested good biocompatibility over a period of 7 days in vitro. Using a colorimetric assay technique to assess cell viability, the cellular response between the three substrates can be differentiated to show that the ALD alumina coating is more biocompatible and that the hydrophobic coating is less biocompatible when compared to the control. These results suggest that patterning a substrate with hydrophilic and hydrophobic groups can control cell growth. This patterning can further enhance the known advantages of ALD alumina, such as conformality and excellent dielectric properties for bio-micro electro mechanical systems (Bio-MEMS) in sensors, actuators, and microfluidics devices. PMID:18085647

  11. Wettability of oxide thin films prepared by pulsed laser deposition: New insights

    NASA Astrophysics Data System (ADS)

    Prakash, Saurav

    The objective of the thesis is to investigate the wettability of good quality oxide thin films prepared by pulsed laser deposition (PLD). In this work, many shortfalls in the water contact angle measurement of thin films of oxides, responsible for the wide scatter in the values reported in literature, have been addressed. (Abstract shortened by UMI.).

  12. Chemical vapour deposition of zeolitic imidazolate framework thin films

    NASA Astrophysics Data System (ADS)

    Stassen, Ivo; Styles, Mark; Grenci, Gianluca; Gorp, Hans Van; Vanderlinden, Willem; Feyter, Steven De; Falcaro, Paolo; Vos, Dirk De; Vereecken, Philippe; Ameloot, Rob

    2016-03-01

    Integrating metal-organic frameworks (MOFs) in microelectronics has disruptive potential because of the unique properties of these microporous crystalline materials. Suitable film deposition methods are crucial to leverage MOFs in this field. Conventional solvent-based procedures, typically adapted from powder preparation routes, are incompatible with nanofabrication because of corrosion and contamination risks. We demonstrate a chemical vapour deposition process (MOF-CVD) that enables high-quality films of ZIF-8, a prototypical MOF material, with a uniform and controlled thickness, even on high-aspect-ratio features. Furthermore, we demonstrate how MOF-CVD enables previously inaccessible routes such as lift-off patterning and depositing MOF films on fragile features. The compatibility of MOF-CVD with existing infrastructure, both in research and production facilities, will greatly facilitate MOF integration in microelectronics. MOF-CVD is the first vapour-phase deposition method for any type of microporous crystalline network solid and marks a milestone in processing such materials.

  13. Deposition of thermoelectric strontium hexaboride thin films by a low pressure CVD method

    NASA Astrophysics Data System (ADS)

    Tynell, Tommi; Aizawa, Takashi; Ohkubo, Isao; Nakamura, Katsumitsu; Mori, Takao

    2016-09-01

    Thin films of SrB6 were deposited on sapphire substrates using a chemical vapor deposition method, with elemental strontium and decaborane, B10H14, used as the strontium and boron sources, respectively. The formation of highly crystalline, phase-pure SrB6 films was confirmed with X-ray diffraction and reflection high energy diffraction (RHEED) analysis, and the films' thermoelectric transport properties were measured. A relatively high deposition temperature of 850-950 °C was found to be optimal for obtaining well-crystallized films at an extremely high deposition rate. The thermoelectric transport properties of the SrB6 thin films were observed to be comparable to those reported for bulk materials, but an unexpectedly high electrical resistivity led to a reduced power factor value for the thin films.

  14. Computer modeling of Y-Ba-Cu-O thin film deposition and growth

    SciTech Connect

    Burmester, C.; Gronsky, R. ); Wille, L. . Dept. of Physics)

    1991-07-01

    The deposition and growth of epitaxial thin films of YBa{sub 2}Cu{sub 3}O{sub 7} are modeled by means of Monte Carlo simulations of the deposition and diffusion of Y, Ba, and Cu oxide particles. This complements existing experimental characterization techniques to allow the study of kinetic phenomena expected to play a dominant role in the inherently non-equilibrium thin film deposition process. Surface morphologies and defect structures obtained in the simulated films are found to closely resemble those observed experimentally. A systematic study of the effects of deposition rate and substrate temperature during in-situ film fabrication reveals that the kinetics of film growth can readily dominate the structural formation of the thin film. 16 refs., 4 figs.

  15. Investigation of the optical property and structure of WO3 thin films with different sputtering depositions

    NASA Astrophysics Data System (ADS)

    Chen, Hsi-Chao; Jan, Der-Jun; Chen, Chien-Han; Huang, Kuo-Ting; Lo, Yen-Ming; Chen, Sheng-Hui

    2011-09-01

    The purpose of this research was to compare the optical properties and structure of tungsten oxide (WO3) thin films that was deposited by different sputtering depositions. WO3 thin films deposited by two different depositions of direct current (DC) magnetron sputtering and pulsed DC sputtering. A 99.95% WO3 target was used as the starting material for these depositions. These WO3 thin films were deposited on the ITO glass, PET and silicon substrate by different ratios of oxygen and argon. A shadow moiré interferometer would be introduced to measure the residual stress for PET substrate. RF magnetron sputtering had the large residual stress than the other's depositions. A Raman spectrum could exhibit the phase of oxidation of WO3 thin film by different depositions. At the ratio of oxygen and argon was about 1:1, and the WO3 thin films had the best oxidation. However, it was important at the change of the transmittance (ΔT = Tbleached - Tcolored) between the coloring and bleaching for the smart window. Therefore, we also found the WO3 thin films had the large variation of transmittance between the coloring and bleaching at the gas ratios of oxygen and argon of 1:1.

  16. Spectroscopic ellipsometry investigations of optical anisotropy in obliquely deposited hafnia thin films

    NASA Astrophysics Data System (ADS)

    Tokas, R. B.; Jena, Shuvendu; Haque, S. Maidul; Rao, K. Divakar; Thakur, S.; Sahoo, N. K.

    2016-05-01

    In present work, HfO2 thin films have been deposited at various oblique incidences on Si substrates by electron beam evaporation. These refractory oxide films exhibited anisotropy in refractive index predictably due to special columnar microstructure. Spectroscopic ellipsometry being a powerful tool for optical characterization has been employed to investigate optical anisotropy. It was observed that the film deposited at glancing angle (80°) exhibits the highest optical anisotropy. Further, anisotropy was noticed to decrease with lower values of deposition angles while effective refractive index depicts opposite trend. Variation in refractive index and anisotropy has been explained in light of atomic shadowing during growth of thin films at oblique angles.

  17. Characterisation of CdO thin films deposited by activated reactive evaporation

    NASA Astrophysics Data System (ADS)

    Ramakrishna Reddy, K. T.; Sravani, C.; Miles, R. W.

    1998-02-01

    The paper describes the preparation of cadmium oxide thin films produced by "activated reactive evaporation" onto heated glass substrates. The structural, electrical and optical properties of the deposited films were investigated and the effect of substrate temperature on the different physical properties of the films investigated. Highly conducting, polycrystalline CdO films with good transmittances were prepared by controlling the deposition temperature. These layers can be used to produce CdO/CdTe solar cells with efficiencies > 7%.

  18. Ion beams as a means of deposition and in-situ characterization of thin films and thin film layered structures

    SciTech Connect

    Krauss, A.R.; Rangaswamy, M.; Gruen, D.M. ); Lin, Y.P. Northwestern Univ., Evanston, IL . Dept. of Materials Science); Schultz, J.A. ); Schmidt, H. ); Liu, Y.L. (Argonne National Lab., IL (United States

    1992-01-01

    Ion beam-surface interactions produce many effects in thin film deposition which are similar to those encountered in plasma deposition processes. However, because of the lower pressures and higher directionality associated with the ion beam process, it is easier to avoid some sources of film contamination and to provide better control of ion energies and fluxes. Additional effects occur in the ion beam process because of the relatively small degree of thermalization resulting from gas phase collisions with both the ion beam and atoms sputtered from the target. These effects may be either beneficial or detrimental to the film properties, depending on the material and deposition conditions. Ion beam deposition is particularly suited to the deposition of multi-component films and layered structures, and can in principle be extended to a complete device fabrication process. However, complex phenomena occur in the deposition of many materials of high technical interest which make it desirable to monitor the film growth at the monolayer level. It is possible to make use of ion-surface interactions to provide a full suite of surface analytical capabilities in one instrument, and this data may be obtained at ambient pressures which are far too high for conventional surface analysis techniques. Such an instrument is under development and its current performance characteristics and anticipated capabilities are described.

  19. Ion beams as a means of deposition and in-situ characterization of thin films and thin film layered structures

    SciTech Connect

    Krauss, A.R.; Rangaswamy, M.; Gruen, D.M.; Lin, Y.P.; Schultz, J.A.; Schmidt, H.; Liu, Y.L.; Auciello, O.; Barr, T.; Chang, R.P.H.

    1992-08-01

    Ion beam-surface interactions produce many effects in thin film deposition which are similar to those encountered in plasma deposition processes. However, because of the lower pressures and higher directionality associated with the ion beam process, it is easier to avoid some sources of film contamination and to provide better control of ion energies and fluxes. Additional effects occur in the ion beam process because of the relatively small degree of thermalization resulting from gas phase collisions with both the ion beam and atoms sputtered from the target. These effects may be either beneficial or detrimental to the film properties, depending on the material and deposition conditions. Ion beam deposition is particularly suited to the deposition of multi-component films and layered structures, and can in principle be extended to a complete device fabrication process. However, complex phenomena occur in the deposition of many materials of high technical interest which make it desirable to monitor the film growth at the monolayer level. It is possible to make use of ion-surface interactions to provide a full suite of surface analytical capabilities in one instrument, and this data may be obtained at ambient pressures which are far too high for conventional surface analysis techniques. Such an instrument is under development and its current performance characteristics and anticipated capabilities are described.

  20. Research on titanium nitride thin films deposited by reactive magnetron sputtering for MEMS applications

    NASA Astrophysics Data System (ADS)

    Merie, Violeta; Pustan, Marius; Negrea, Gavril; Bîrleanu, Corina

    2015-12-01

    Titanium nitride can be used among other materials as diffusion barrier for MEMS (microelectromechanical systems) applications. The aim of this study is to elaborate and to characterize at nanoscale titanium nitride thin films. The thin films were deposited by reactive magnetron sputtering on silicon substrates using a 99.99% purity titanium target. Different deposition parameters were employed. The deposition temperature, deposition time, substrate bias voltage and the presence/absence of a titanium buffer layer are the parameters that were modified. The so-obtained films were then investigated by atomic force microscopy. A significant impact of the deposition parameters on the determined mechanical and tribological characteristics was highlighted. The results showed that the titanium nitride thin films deposited for 20 min at room temperature without the presence of a titanium buffer layer when a negative bias of -90 V was applied to the substrate is characterized by the best tribological and mechanical behavior.

  1. Deposition and characterization of molybdenum thin films using dc-plasma magnetron sputtering

    SciTech Connect

    Khan, Majid; Islam, Mohammad

    2013-12-15

    Molebdenum (Mo) thin films were deposited on well-cleaned soda-lime glass substrates using DC-plasma magnetron sputtering. In the design of experiment deposition was optimized for maximum beneficial characteristics by monitoring effect of process variables such as deposition power (100–200 W). Their electrical, structural and morphological properties were analyzed to study the effect of these variables. The electrical resistivity of Mo thin films could be reduced by increasing deposition power. Within the range of analyzed deposition power, Mo thin films showed a mono crystalline nature and the crystallites were found to have an orientation along [110] direction. The surface morphology of thin films showed that a highly dense micro structure has been obtained. The surface roughness of films increased with deposition power. The adhesion of Mo thin films could be improved by increasing the deposition power. Atomic force microscopy was used for the topographical study of the films and to determine the roughness of the films. X-ray diffractrometer and scanning electron microscopy analysis were used to investigate the crystallinity and surface morphology of the films. Hall effect measurement system was used to find resistivity, carrier mobility and carrier density of deposited films. The adhesion test was performed using scotch hatch tape adhesion test. Mo thin films prepared at deposition power of 200 W, substrate temperature of 23°C and Ar pressure of 0.0123 mbar exhibited a mono crystalline structure with an orientation along (110) direction, thickness of ∼550 nm and electrical resistivity value of 0.57 × 10{sup −4} Ω cm.

  2. Pulsed laser deposition of niobium nitride thin films

    SciTech Connect

    Farha, Ashraf Hassan Elsayed-Ali, Hani E.; Ufuktepe, Yüksel; Myneni, Ganapati

    2015-12-04

    Niobium nitride (NbN{sub x}) films were grown on Nb and Si(100) substrates using pulsed laser deposition. NbN{sub x} films were deposited on Nb substrates using PLD with a Q-switched Nd:YAG laser (λ = 1064 nm, ∼40 ns pulse width, and 10 Hz repetition rate) at different laser fluences, nitrogen background pressures and deposition substrate temperatures. When all the fabrication parameters are fixed, except for the laser fluence, the surface roughness, nitrogen content, and grain size increase with increasing laser fluence. Increasing nitrogen background pressure leads to a change in the phase structure of the NbN{sub x} films from mixed β-Nb{sub 2}N and cubic δ-NbN phases to single hexagonal β-Nb{sub 2}N. The substrate temperature affects the preferred orientation of the crystal structure. The structural and electronic, properties of NbN{sub x} deposited on Si(100) were also investigated. The NbN{sub x} films exhibited a cubic δ-NbN with a strong (111) orientation. A correlation between surface morphology, electronic, and superconducting properties was found. The observations establish guidelines for adjusting the deposition parameters to achieve the desired NbN{sub x} film morphology and phase.

  3. Annealing effect on Cu2S thin films prepared by chemical bath deposition

    NASA Astrophysics Data System (ADS)

    More, Pawan; Dhanayat, Swapnali; Gattu, Ketan; Mahajan, Sandeep; Upadhye, Deepak; Sharma, Ramphal

    2016-05-01

    In present work Cu2S thin film fabricated on glass substrate by simple, cost effective chemical bath deposition method subsequently it annealed at 150°c.These films were studied for their structural, optical and electrical properties using X-ray diffraction, UV-vis spectrophotometer and I-V system. The results show successful synthesis of Cu2S thin films and improvement in crystalline nature of the thin film which resulted in reduced bad gap and resistance of the film. Thus these thinfilms prove to be a promising candidate for solar cell application.

  4. Third order nonlinearity in pulsed laser deposited LiNbO3 thin films

    NASA Astrophysics Data System (ADS)

    Tumuluri, Anil; Rapolu, Mounika; Rao, S. Venugopal; Raju, K. C. James

    2016-05-01

    Lithium niobate (LiNbO3) thin films were prepared using pulsed laser deposition technique. Structural properties of the same were examined from XRD and optical band gap of the thin films were measured from transmittance spectra recorded using UV-Visible spectrophotometer. Nonlinear optical properties of the thin films were recorded using Z-Scan technique. The films were exhibiting third order nonlinearity and their corresponding two photon absorption, nonlinear refractive index, real and imaginary part of nonlinear susceptibility were calculated from open aperture and closed aperture transmission curves. From these studies, it suggests that these films have potential applications in nonlinear optical devices.

  5. Optical Response in Amorphous GaAs Thin Films Prepared by Pulsed Laser Deposition

    NASA Astrophysics Data System (ADS)

    Kiwa, Toshihiko; Kawashima, Ichiro; Nashima, Shigeki; Hangyo, Masanori; Tonouchi, Masayoshi

    2000-11-01

    Femtosecond optical response in GaAs thin films has been studied. We prepared GaAs thin films on MgO substrates and on YBa2Cu3O7-δ (YBCO) thin films using pulsed laser deposition (PLD) at temperatures below 250^\\circC@. A photocarrier lifetime of less than 1 ps is measured for the prepared GaAs thin films using femtosecond time-domain reflectivity change measurements. Pulsed electromagnetic wave [terahertz (THz) radiaiton] containing a frequency component of up to 1 THz is emitted from fabricated photoconductive switches using the prepared thin films. We also evaluated the THz radiation properties emitted from the photoswitches on the YBCO thin films.

  6. Titanium dioxide thin film deposited on flexible substrate by multi-jet electrospraying

    NASA Astrophysics Data System (ADS)

    Ni, Daihong; Yi, Wuming; Cao, Zhoubin; Gu, Wenhua

    2015-10-01

    Titanium dioxide thin film plays an important role in thin film solar cells, and has promising future in everyday applications including air cleaning and self-cleaning glass. With the concepts of flexible solar cells and wearable devices being more and more popular, there is increasing interest to coat titanium dioxide thin films on flexible substrates, such as aluminum foils. Many methods have been used to fabricate titanium dioxide thin films, such as dip-coating, spin coating, aerosol spray, plasma-assisted coating, electrospraying, and so on. Among them, electrospraying is especially suitable for thin film deposition on flexible substrates. This work reports fabrication of dense and uniform titanium dioxide thin films on glass as well as flexible aluminum foil using multi-jet electrospraying technique.

  7. Ultraviolet laser deposition of graphene thin films without catalytic layers

    NASA Astrophysics Data System (ADS)

    Sarath Kumar, S. R.; Alshareef, H. N.

    2013-01-01

    In this letter, the formation of nanostructured graphene by ultraviolet laser ablation of a highly ordered pyrolytic graphite target under optimized conditions is demonstrated, without a catalytic layer, and a model for the growth process is proposed. Previously, graphene film deposition by low-energy laser (2.3 eV) was explained by photo-thermal models, which implied that graphene films cannot be deposited by laser energies higher than the C-C bond energy in highly ordered pyrolytic graphite (3.7 eV). Here, we show that nanostructured graphene films can in fact be deposited using ultraviolet laser (5 eV) directly over different substrates, without a catalytic layer. The formation of graphene is explained by bond-breaking assisted by photoelectronic excitation leading to formation of carbon clusters at the target and annealing out of defects at the substrate.

  8. ZnO Thin Films Deposited on Textile Material Substrates for Biomedical Applications

    NASA Astrophysics Data System (ADS)

    Duta, L.; Popescu, A. C.; Dorcioman, G.; Mihailescu, I. N.; Stan, G. E.; Zgura, I.; Enculescu, I.; Dumitrescu, I.

    We report on the coating with ZnO adherent thin films of cotton woven fabrics by Pulsed laser deposition technique in order to obtain innovative textile materials, presenting protective effects against UV radiations and antifungal action.

  9. Complex surfaces plated by thin-film deposition in one operation

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.; Przybyszewski, J. S.; Spalvins, T.

    1967-01-01

    Ion plating deposits thin film on complex surface in one operation. The ionized materials follow electric lines of force to all points on the objects, uniformly plating the surface from all sides simultaneously.

  10. Role of deposition time on the properties of ZnO:Tb(3+) thin films prepared by pulsed laser deposition.

    PubMed

    Kumar, Vinod; Ntwaeaborwa, O M; Coetsee, E; Swart, H C

    2016-07-15

    Terbium (Tb(3+)) doped zinc oxide (ZnO:Tb(3+)) thin films were grown on silicon (100) substrates by the pulsed laser deposition technique at different deposition times that varied from 15 to 55min. The effects of deposition time on the structural and optical properties of the ZnO:Tb(3+) films were investigated by X-ray diffraction, scanning electron microscopy and photoluminescence spectroscopy. As expected, the thickness of the ZnO:Tb(3+) film has increased with an increase in the deposition time. The photoluminescence intensity of the band to band emission has also increased with deposition time, while the deep level defect emission has decreased. The blue emission was observed from all the ZnO:Tb(3+) thin films deposited at the different deposition times excited by 325nm He-Cd laser, while a green emission was observed when excited by 228nm. PMID:27124806

  11. Chromium Carbide Thin Films Synthesized by Pulsed Nd:YAG Laser Deposition

    NASA Astrophysics Data System (ADS)

    Suda, Yoshiaki; Kawasaki, Hiroharu; Terajima, Ryou; Emura, Masanari

    1999-06-01

    Chromium carbide thin films are synthesized on Si(100)substrates by a pulsed Nd:YAG laser deposition method at differentsubstrate temperatures. Glancing-angle X-ray diffraction shows that acrystalline chromium carbide film can be prepared at the substratetemperature of 700°C. Grain size of the films, examined witha field-emission secondary electron microscope, increases withincreasing substrate temperature.

  12. Structural Properties of Gold Thin Films Deposited on Technologically Important Substrates by Magnetron Sputtering

    NASA Astrophysics Data System (ADS)

    Glaser, Caleb; Schell, Michael; Tzolov, Marian; Senevirathne, Indrajith; Syed, Moniruzzaman

    2013-03-01

    Gold (Au) thin films offer a wide range of applications and may be used for memory storage, energy harvesting, nanosensors, optics, and biosensing devices. Au thin films are currently being studied more closely since they are highly conductive and yet not easily oxidized. Therefore, it is necessary to understand the growth mechanisms of film on various substrates. The structural properties of gold thin films also play an important role on the film quality, which may affect its' optical properties and the sensing capability of the device. In this study, Gold (Au) thin films were deposited on glass (SiO2), silicon (100) and other substrates at room temperature (RT) in an argon (Ar) gas environment as a function of deposition time. The structural properties and surface morphology of the Au thin film has been studied using an Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectrometry (EDX), and X-Ray Diffraction (XRD) measurements. The deposition rate was found to be decreased monotonically as deposition time increased for the films on glass substrates. The effect of the annealing temperature on the structural properties of the Au film deposited on the aforementioned substrates will also be discussed in this study. Lock Haven University of Pennsylvania

  13. Deposition and characterizations of ultrasmooth silver thin films assisted with a germanium wetting layer

    NASA Astrophysics Data System (ADS)

    Zhang, Junce; Fryauf, David M.; Diaz Leon, Juan J.; Garrett, Matthew; VJ, Logeeswaran; Islam, Saif M.; Kobayashi, Nobuhiko P.

    2015-08-01

    In this paper, silver thin films deposited on SiO2 substrates with a germanium wetting layer fabricated by electron-beam evaporation were studied. The characterization methods of XTEM, FTIR, XRD and XRR were used to study the structural properties of silver thin films with various thicknesses of germanium layers. Silver films deposited with very thin (1-5nm) germanium wetting layers show about one half of improvement in the crystallite sizes comparing silver films without germanium layer. The surface roughness of silver thin films significantly decrease with a thin germanium wetting layer, reaching a roughness minimum around 1-5nm of germanium, but as the germanium layer thickness increases, the silver thin film surface roughness increases. The relatively higher surface energy of germanium and bond dissociation energy of silver-germanium were introduced to explain the effects the germanium layer made to the silver film deposition. However, due to the Stranski-Krastanov growth mode of germanium layer, germanium island formation started with increased thickness (5-15nm), which leads to a rougher surface of silver films. The demonstrated silver thin films are very promising for large-scale applications as molecular anchors, optical metamaterials, plasmonic devices, and several areas of nanophotonics.

  14. Zinc oxide epitaxial thin film deposited over carbon on various substrate by pulsed laser deposition technique.

    PubMed

    Manikandan, E; Moodley, M K; Sinha Ray, S; Panigrahi, B K; Krishnan, R; Padhy, N; Nair, K G M; Tyagi, A K

    2010-09-01

    Zinc Oxide (ZnO) is a promising candidate material for optical and electronic devices due to its direct wide band gap (3.37 eV) and high exciton binding energy (60 meV). For applications in various fields such as light emitting diode (LED) and laser diodes, growth of p-type ZnO is a prerequisite. ZnO is an intrinsically n-type semiconductor. In this paper we report on the synthesis of Zinc Oxide-Carbon (ZnO:C) thin films using pulsed laser deposition technique (PLD). The deposition parameters were optimized to obtain high quality epitaxial ZnO films over a carbon layer. The structural and optical properties were studied by glazing index X-ray diffraction (GIXRD), photoluminescence (PL), optical absorption (OA), and Raman spectroscopy. Rutherford backscattering spectroscopy (RBS), scanning electron microscopy with energy dispersive spectroscopy (SEMEDS) and atomic force microscopy (AFM) were employed to determine the composition and surface morphology of these thin films. The GIXRD pattern of the synthesized films exhibited hexagonal wurtzite crystal structure with a preferred (002) orientation. PL spectroscopy results showed that the emission intensity was maximum at -380 nm at a deposition temperature of 573 K. In the Raman spectra, the E2 phonon frequency around at 438 cm(-1) is a characteristic peak of the wurtzite lattice and could be seen in all samples. Furthermore, the optical direct band gap of ZnO films was found to be in the visible region. The growth of the epitaxial layer is discussed in the light of carbon atoms from the buffer layer. Our work demonstrates that the carbon is a novel dopant in the group of doped ZnO semiconductor materials. The introduction of carbon impurities enhanced the visible emission of red-green luminescence. It is concluded that the carbon impurities promote the zinc related native defect in ZnO. PMID:21133080

  15. Optical switching of vanadium dioxide thin films deposited by reactive pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Soltani, M.; Chaker, M.; Haddad, E.; Kruzelecky, R. V.; Nikanpour, D.

    2004-05-01

    The parameters of reactive pulsed laser deposition were successfully optimized for fabrication of vanadium dioxide thin films. It is observed that the O2 concentration in Ar gas and the total deposition pressure are critical in stabilizing the single VO2 phase. Thermochromic VO2 and V1-xWxO2 (x=0.014) thin films were synthesized on various substrates (silicon, quartz, and sapphire) at 5% of O2/Ar ratio gas and total pressure of 90 mTorr. The structural properties of the deposited films were analyzed by x-ray diffraction, while their semiconductor-to-metal phase transitions were studied by electrical resistivity using the four-point technique and infrared transmittance from room temperature up to 100 °C. The observed transition temperature was about 36 °C for W-doped VO2 compared to 68 °C for VO2 films. This transition temperature was then lowered by about 22.85 °C per 1 at. % of W added. The temperature coefficient of resistance was about 1.78%/°C for VO2 and about 1.90%/°C for W-doped VO2. Using the pump-probe experiment, the application of these thermochromic films as optical switches was demonstrated at the wavelength of 1.55 μm. The transmission switching was about 25 dB for VO2 and 28 dB for W-doped VO2. In addition, application of VO2 on optical fiber components was demonstrated by direct VO2 coating on the end faces of cleaved single mode optical fibers and optical fiber connectors. .

  16. Structural, morphological, optical and electrical properties of spray deposited lithium doped CdO thin films

    NASA Astrophysics Data System (ADS)

    Velusamy, P.; Babu, R. Ramesh; Ramamurthi, K.

    2016-05-01

    In the present work, CdO and Li doped CdO thin films were deposited on microscopic glass substrates at 300˚C by a spray pyrolysis experimental setup. The deposited CdO and Li doped CdO thin films were subjected to XRD, SEM, UV-VIS spectroscopy and Hall measurement analyses. XRD studies revealed the polycrystalline nature of the deposited films and confirmed that the deposited CdO and Li doped CdO thin films belong to cubic crystal system. The Scanning electron microscopy analysis revealed the information on shape of CdO and Li doped CdO films. Electrical study reveals the n-type semiconducting nature of CdO and the optical band gap is varied between 2.38 and 2.44 eV, depending on the Li doping concentrations.

  17. Process for thin film deposition of cadmium sulfide

    DOEpatents

    Muruska, H. Paul; Sansregret, Joseph L.; Young, Archie R.

    1982-01-01

    The present invention teaches a process for depositing layers of cadmium sulfide. The process includes depositing a layer of cadmium oxide by spray pyrolysis of a cadmium salt in an aqueous or organic solvent. The oxide film is then converted into cadmium sulfide by thermal ion exchange of the O.sup.-2 for S.sup.-2 by annealing the oxide layer in gaseous sulfur at elevated temperatures.

  18. Second harmonic generation in ZnO thin films fabricated by metalorganic chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Liu, C. Y.; Zhang, B. P.; Binh, N. T.; Segawa, Y.

    2004-07-01

    Second harmonic generation (SHG) from ZnO thin films fabricated by metalorganic chemical vapor deposition (MOCVD) technique was carried out. By comparing the second harmonic signal generated in a series of ZnO films with different deposition temperatures, we conclude that a significant part of second harmonic signal is generated at the film deposited with appropriate temperature. The second-order susceptibility tensor χ(2)zzz=9.2 pm/V was deduced for a film deposited at 250 °C.

  19. Deposition And Characterization Of Ultra Thin Diamond Like Carbon Films

    NASA Astrophysics Data System (ADS)

    Tomcik, B.

    2010-07-01

    Amorphous hydrogenated and/or nitrogenated carbon films, a-C:H/a-C:N, in overall thickness up to 2 nm are materials of choice as a mechanical and corrosion protection layer of the magnetic media in modern hard disk drive disks. In order to obtain high density and void-free films the sputtering technology has been replaced by different plasma and ion beam deposition techniques. Hydrocarbon gas precursors, like C2H2 or CH4 with H2 and N2 as reactive gases are commonly used in Kaufman DC ion and RF plasma beam sources. Optimum incident energy of carbon ions, C+, is up to 100 eV while the typical ion current densities during the film formation are in the mA/cm2 range. Other carbon deposition techniques, like filtered cathodic arc, still suffer from co-deposition of fine nanosized carbon clusters (nano dust) and their improvements are moving toward arc excitation in the kHz and MHz frequency range. Non-destructive film analysis like μ-Raman optical spectroscopy, spectroscopic ellipsometry, FTIR and optical surface analysis are mainly used in the carbon film characterization. Due to extreme low film thicknesses the surface enhanced Raman spectroscopy (SERS) with pre-deposited layer of Au can reduce the signal collection time and minimize photon-induced damage during the spectra acquisition. Standard approach in the μ-Raman film evaluation is the measurement of the position (shift) and area of D and G-peaks under the deconvoluted overall carbon spectrum. Also, a slope of the carbon spectrum in the 1000-2000 cm-1 wavenumber range is used as a measure of the hydrogen intake within a film. Diamond like carbon (DLC) film should possess elasticity and self-healing properties during the occasional crash of the read-write head flying only couple of nanometers above the spinning film. Film corrosion protection capabilities are mostly evaluated by electrochemical tests, potentio-dynamic and linear polarization method and by business environmental method. Corrosion mechanism

  20. Electrochromic properties of molybdenum trioxide thin films prepared by chemical vapor deposition

    SciTech Connect

    Maruyama, Toshiro; Kanagawa, Tetsuya

    1995-05-01

    Electrochromic molybdenum trioxide thin films were prepared by chemical vapor deposition. The source material was molybdenum carbonyl. Amorphous molybdenum trioxide thin films were produced at a substrate temperature 300 C. Reduction and oxidation of the films in a 0.3M LiClO{sub 4} propylene carbonate solution caused desirable changes in optical absorption. Coulometry indicated that the coloration efficiency was 25.8 cm{sup 2}/C.

  1. Annealing dependence of residual stress and optical properties of TiO2 thin film deposited by different deposition methods.

    PubMed

    Chen, Hsi-Chao; Lee, Kuan-Shiang; Lee, Cheng-Chung

    2008-05-01

    Titanium oxide (TiO(2)) thin films were prepared by different deposition methods. The methods were E-gun evaporation with ion-assisted deposition (IAD), radio-frequency (RF) ion-beam sputtering, and direct current (DC) magnetron sputtering. Residual stress was released after annealing the films deposited by RF ion-beam or DC magnetron sputtering but not evaporation, and the extinction coefficient varied significantly. The surface roughness of the evaporated films exceeded that of both sputtered films. At the annealing temperature of 300 degrees C, anatase crystallization occurred in evaporated film but not in the RF ion-beam or DC magnetron-sputtered films. TiO(2) films deposited by sputtering were generally more stable during annealing than those deposited by evaporation. PMID:18449260

  2. Surface Acoustic Wave Monitor for Deposition and Analysis of Ultra-Thin Films

    NASA Technical Reports Server (NTRS)

    Hines, Jacqueline H. (Inventor)

    2015-01-01

    A surface acoustic wave (SAW) based thin film deposition monitor device and system for monitoring the deposition of ultra-thin films and nanomaterials and the analysis thereof is characterized by acoustic wave device embodiments that include differential delay line device designs, and which can optionally have integral reference devices fabricated on the same substrate as the sensing device, or on a separate device in thermal contact with the film monitoring/analysis device, in order to provide inherently temperature compensated measurements. These deposition monitor and analysis devices can include inherent temperature compensation, higher sensitivity to surface interactions than quartz crystal microbalance (QCM) devices, and the ability to operate at extreme temperatures.

  3. Effect of deposition pressure on the structural and magnetic properties of cobalt ferrite thin films

    SciTech Connect

    Nongjai, R.; Khan, S.; Ahmad, H.; Khan, I.; Asokan, K.

    2013-06-03

    We present the influence of deposition pressure on the structural and magnetic properties of cobalt ferrite thin films. Thin films of Co ferrite were deposited by rf sputtering on Si (100) substrate and characterized by X - Ray Diffraction (XRD), Atomic Force Microscopy (AFM) and Vibrating Sample Magnetometer (VSM). The XRD patterns showed the formation of crystalline single phase of the films. The particle size and surface roughness of the films were strongly influence by gas pressure. Hysteresis loops measured at room temperature showed the enhancement of magnetic properties with the increase of gas pressure which is attributed to the decrease of particle size.

  4. Nanostructured silicon thin films deposited by PECVD in the presence of silicon nanoparticles

    SciTech Connect

    Viera, G.; Cabarrocas, P.R.; Hamma, S.; Sharma, S.N.; Costa, J.; Bertran, E.

    1997-07-01

    Nanostructured silicon thin films have been deposited by plasma enhanced chemical vapor deposition at low substrate temperature (100 C) in the presence of silicon nanoparticles. The nanostructure of the films was revealed by transmission electron microscopy, Raman spectroscopy and X-ray diffraction, which showed ordered silicon domains (1--2 nm) embedded in an amorphous silicon matrix. These ordered domains are due to the particles created in the discharge that contribute to the film growth. One consequence of the incorporation of nanoparticles is the accelerated crystallization of the nanostructured silicon thin films when compared to standard a-Si:H, as shown by the electrical characterization during the annealing.

  5. Measurements of stress evolution during thin film deposition

    SciTech Connect

    Chason, E.; Floro, J.A.

    1996-05-01

    We have developed a technique for measuring thin film stress during growth by monitoring the wafer curvature. By measuring the deflection of multiple parallel laser beams with a CCD detector, the sensivity to vibration is reduced and a radius of curvature limit of 4 km has been obtained in situ. This technique also enables us to obtain a 2-dimensional profile of the surface curvature from the simultaneous reflection of a rectangular array of beams. Results from the growth of SiG alloy films are presented to demonstrate the unique information that can be obtained during growth.

  6. Chemical solution deposition of the highly c-axis oriented apatite type lanthanum silicate thin films.

    PubMed

    Hori, Shigeo; Takatani, Yasuhiro; Kadoura, Hiroaki; Uyama, Takeshi; Fujita, Satoru; Tani, Toshihiko

    2015-10-28

    Highly c-axis oriented apatite-type lanthanum silicate (LSO) thin films were fabricated by a simple solution coating method. In the solution coating method, LSO thin films are obtained by crystallization of initially deposited amorphous LSO precursor thin films. The degree of orientation was influenced by the precursor morphologies and a dense LSO precursor led to a high c-axis orientation perpendicular to the substrate. The oriented LSO thin films were composed of columnar grains with a single crystal orientation over the entire film thickness. In-plane orientation was not detected, which indicates that the c-axis orientation of the LSO thin films can be attributed to self-orientation. PMID:26391101

  7. Formation of polymer thin films and interface control by physical vapor deposition

    NASA Astrophysics Data System (ADS)

    Usui, Hiroaki

    2009-08-01

    Some strategies of physical vapor deposition (PVD) of polymer thin films have been proposed. Direct vapor deposition can be applied for simple polymers like polyethylene and Teflon. Coevaporation of bifunctional monomers can be achieved to deposit polyimide, polyurea etc., while chain polymerization assisted by ultraviolet or electron irradiation can be used to form vinyl or acryl polymers from single evaporation source. Surface-initiated deposition polymerization, which combines the self-assembled monolayer and vapor deposition, is another unique method to grow polymer thin films that are chemically bound to the substrate surface. The last method is also effective in controlling the interface between polymer films and inorganic substrates. The solvent-free nature of PVD is convenient for the formation of nanometer-thick films and especially multilayers that are required for device fabrication. Application of vapor deposition polymerization for fabrication of organic light-emitting diode is also described.

  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. Effect of deposition temperature on the properties of ZnO-doped indium oxide thin films

    NASA Astrophysics Data System (ADS)

    Lee, Seung Jin; Cho, Shinho

    2014-05-01

    ZnO-doped In2O3 (ZIO) thin films were deposited on quartz substrates at various deposition temperatures by radio-frequency magnetron sputtering. All the ZIO thin films showed a significant dependence on the deposition temperature. A strong preferential growth orientation was observed for all samples except the one deposited at 25 °C. As the deposition temperature was increased, the crystalline orientation of the main (222) plane did not change, but the full width at half maximum got smaller and the intensity increased rapidly. The ZIO thin film deposited at 100 °C showed the highest figure of merit with an average particle size of 60 nm, a bandgap energy of 3.51 eV, an electrical resistivity of 2.63 × 10-3 Ωcm, and an electron concentration of 4.99 × 1020 cm-3. A blue-shift of optical bandgap enegy was observed with increasing deposition temperature. These results suggest that the optimum deposition temperature for growing high-quality ZIO films is 100 °C and that the structural, optical, and electrical properties of ZIO thin films can be modulated by controlling the deposition temperature.

  10. Evaporation system and method for gas jet deposition of thin film materials

    DOEpatents

    Schmitt, Jerome J.; Halpern, Bret L.

    1994-01-01

    A method and apparatus for depositing thin films of materials such as metals, oxides and nitrides at low temperature relies on a supersonic free jet of inert carrier gas to transport vapor species generated from an evaporation source to the surface of a substrate. Film deposition vapors are generated from solid film precursor materials, including those in the form of wires or powders. The vapor from these sources is carried downstream in a low pressure supersonic jet of inert gas to the surface of a substrate where the vapors deposit to form a thin film. A reactant gas can be introduced into the gas jet to form a reaction product with the evaporated material. The substrate can be moved from the gas jet past a gas jet containing a reactant gas in which a discharge has been generated, the speed of movement being sufficient to form a thin film which is chemically composed of the evaporated material and reactant gases.

  11. Microstructure and optoelectronic properties of galliumtitanium-zinc oxide thin films deposited by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Chen, Shou-bu; Lu, Zhou; Zhong, Zhi-you; Long, Hao; Gu, Jin-hua; Long, Lu

    2016-07-01

    Gallium-titanium-zinc oxide (GTZO) transparent conducting oxide (TCO) thin films were deposited on glass substrates by radio frequency magnetron sputtering. The dependences of the microstructure and optoelectronic properties of GTZO thin films on Ar gas pressure were observed. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) results show that all the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. With the increment of Ar gas pressure, the microstructure and optoelectronic properties of GTZO thin films will be changed. When Ar gas pressure is 0.4 Pa, the deposited films possess the best crystal quality and optoelectronic properties.

  12. Detection of copper ions from aqueous solutions using layered double hydroxides thin films deposited by PLD

    NASA Astrophysics Data System (ADS)

    Vlad, A.; Birjega, R.; Matei, A.; Luculescu, C.; Nedelcea, A.; Dinescu, M.; Zavoianu, R.; Pavel, O. D.

    2015-10-01

    Layered double hydroxides (LDHs) thin films with Mg-Al were deposited using pulsed laser deposition (PLD) technique. We studied the ability of our films to detect copper ions in aqueous solutions. Copper is known to be a common pollutant in water, originating from urban and industrial waste. Clay minerals, including layered double hydroxides (LDHs), can reduce the toxicity of such wastes by adsorbing copper. We report on the uptake of copper ions from aqueous solution on LDH thin films obtained via PLD. The obtained thin films were characterized using X-ray Diffraction, Atomic Force Microscopy, and Scanning Electron Microscopy with Energy Dispersive X-ray analysis. The results in this study indicate that LDHs thin films obtained by PLD have potential as an efficient adsorbent for removing copper from aqueous solution.

  13. Aerosol assisted chemical vapor deposition using nanoparticle precursors: a route to nanocomposite thin films.

    PubMed

    Palgrave, Robert G; Parkin, Ivan P

    2006-02-01

    Gold nanoparticle and gold/semiconductor nanocomposite thin films have been deposited using aerosol assisted chemical vapor deposition (CVD). A preformed gold colloid in toluene was used as a precursor to deposit gold films onto silica glass. These nanoparticle films showed the characteristic plasmon absorption of Au nanoparticles at 537 nm, and scanning electron microscopic (SEM) imaging confirmed the presence of individual gold particles. Nanocomposite films were deposited from the colloid concurrently with conventional CVD precursors. A film of gold particles in a host tungsten oxide matrix resulted from co-deposition with [W(OPh)(6)], while gold particles in a host titania matrix resulted from co-deposition with [Ti(O(i)Pr)(4)]. The density of Au nanoparticles within the film could be varied by changing the Au colloid concentration in the original precursor solution. Titania/gold composite films were intensely colored and showed dichromism: blue in transmitted light and red in reflected light. They showed metal-like reflection spectra and plasmon absorption. X-ray photoelectron spectroscopy and energy-dispersive X-ray analysis confirmed the presence of metallic gold, and SEM imaging showed individual Au nanoparticles embedded in the films. X-ray diffraction detected crystalline gold in the composite films. This CVD technique can be readily extended to produce other nanocomposite films by varying the colloids and precursors used, and it offers a rapid, convenient route to nanoparticle and nanocomposite thin films. PMID:16448130

  14. NH3 sensing characteristics of nano-WO3 thin films deposited on porous silicon.

    PubMed

    Sun, Fengyun; Hu, Ming; Sun, Peng; Zhang, Jie; Liu, Bo

    2010-11-01

    The NH3 sensing characteristics of nano-tungsten trioxide (WO3) thin films deposited on porous silicon (PS) were investigated in the present study. Porous silicon layer was first prepared by electrochemical etching in an HF-based solution on a p(+)-type silicon substrate. Then, WO3 nano-films were deposited on the porous silicon layer by DC magnetron sputtering. Pt electrodes were deposited on the top surface of the WO3 films to obtain the WO3/PS gas sensor. The WO3 films deposited on PS were characterized by SEM, XRD and XPS. The NH3 sensing characteristics for WO3/PS gas sensor were tested at room temperature and 50 degrees C. The results showed that the NH3 sensing characteristics of WO3/PS were superior to WO3/Al2O3 at room temperature. The sensing mechanism of the nano-WO3 thin films based on PS was also discussed. PMID:21138022

  15. Deposition of hydroxyapatite thin films by Nd:YAG laser ablation: a microstructural study

    SciTech Connect

    Nistor, L.C.; Ghica, C.; Teodorescu, V.S.; Nistor, S.V. . E-mail: snistor@alpha1.infim.ro; Dinescu, M.; Matei, D.; Frangis, N.; Vouroutzis, N.; Liutas, C.

    2004-11-02

    Hydroxyapatite (HA) thin films has been successfully deposited by Nd:YAG laser ablation at {lambda} = 532 nm. The morphology and microstructure of the deposited layers was studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). Polycrystalline HA films were directly obtained with the substrate at 300 deg. C and without introducing water vapors in the deposition chamber. Electron paramagnetic resonance (EPR) measurements show that the oxygen stoichiometry in the HA films is also maintained. Depositions performed at {lambda} = 335 nm laser wavelength and 300 deg. C substrate temperature resulted in polycrystalline layers of mixed composition of HA and tricalciumphosphate (TCP)

  16. Annealing effect on structural and optical properties of chemical bath deposited MnS thin film

    NASA Astrophysics Data System (ADS)

    Ulutas, Cemal; Gumus, Cebrail

    2016-03-01

    MnS thin film was prepared by the chemical bath deposition (CBD) method on commercial microscope glass substrate deposited at 30 °C. The as-deposited film was given thermal annealing treatment in air atmosphere at various temperatures (150, 300 and 450 °C) for 1 h. The MnS thin film was characterized by using X-ray diffraction (XRD), UV-vis spectrophotometer and Hall effect measurement system. The effect of annealing temperature on the structural, electrical and optical properties such as optical constants of refractive index (n) and energy band gap (Eg) of the film was determined. XRD measurements reveal that the film is crystallized in the wurtzite phase and changed to tetragonal Mn3O4 phase after being annealed at 300 °C. The energy band gap of film decreased from 3.69 eV to 3.21 eV based on the annealing temperature.

  17. SrCoO3-δ thin films by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Ahvenniemi, Esko; Matvejeff, Mikko; Karppinen, Maarit

    2014-11-01

    Novel atomic layer deposition (ALD) process to deposit high-quality SrCoO3-δ thin films is introduced. Linear film growth is demonstrated within the film-thickness range of 15-300 nm. Post-annealing at 600 °C (in O2 or N2 atmosphere) is required to crystallize the as-deposited amorphous films. The new ALD process produces SrCoO3-δ films with a precisely controlled cation stoichiometry (±2.5%) and an appreciably high growth rate (1.67 Å per supercycle), hence providing us with a prominent method of fabricating high-quality SrCoO3-δ thin films in a readily scalable manner e.g. for intermediate-temperature solid oxide fuel cell cathodes.

  18. Perpendicularly oriented barium ferrite thin films with low microwave loss, prepared by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Da-Ming, Chen; Yuan-Xun, Li; Li-Kun, Han; Chao, Long; Huai-Wu, Zhang

    2016-06-01

    Barium ferrite (BaM) thin films are deposited on platinum coated silicon wafers by pulsed laser deposition (PLD). The effects of deposition substrate temperature on the microstructure, magnetic and microwave properties of BaM thin films are investigated in detail. It is found that microstructure, magnetic and microwave properties of BaM thin film are very sensitive to deposition substrate temperature, and excellent BaM thin film is obtained when deposition temperature is 910 °C and oxygen pressure is 300 mTorr (1 Torr = 1.3332 × 102 Pa). X-ray diffraction patterns and atomic force microscopy images show that the best thin film has perpendicular orientation and hexagonal morphology, and the crystallographic alignment degree can be calculated to be 0.94. Hysteresis loops reveal that the squareness ratio (M r/M s) is as high as 0.93, the saturated magnetization is 4004 Gs (1 Gs = 104 T), and the anisotropy field is 16.5 kOe (1 Oe = 79.5775 A·m‑1). Ferromagnetic resonance measurements reveal that the gyromagnetic ratio is 2.8 GHz/kOe, and the ferromagnetic resonance linewith is 108 Oe at 50 GHz, which means that this thin film has low microwave loss. These properties make the BaM thin films have potential applications in microwave devices. Project supported by the Open Foundation of State Key Laboratory of Electronic Thin Films and Integrated Devices (Grant No. KFJJ201506), the Scientific Research Starting Foundation of Hainan University (Grant No. kyqd1539), and the Natural Science Foundation of Hainan Province (Grant No. 20165187).

  19. A simple chemical method for deposition of electrochromic Prussian blue thin films

    SciTech Connect

    Demiri, Sani; Najdoski, Metodija; Velevska, Julijana

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Prussian blue thin films were prepared by a simple chemical deposition method. Black-Right-Pointing-Pointer The films can be easily prepared from aqueous solution of Fe{sub 2}(SO{sub 4}){sub 3} and K{sub 4}[Fe(CN){sub 6}]. Black-Right-Pointing-Pointer The films show good electrochromic properties. Black-Right-Pointing-Pointer They change from deep blue color into green, and then back to blue and colorless. Black-Right-Pointing-Pointer The PB thin films exhibit stability and excellent reversibility. -- Abstract: This paper is about a recently developed new chemical method for deposition of Prussian blue thin films. The films are easily prepared by successive immersion of the substrates into an acidic aqueous solution of Fe{sub 2}(SO{sub 4}){sub 3} and K{sub 4}[Fe(CN){sub 6}]. It is calculated of the results from AFM analysis that the growth in the film thickness by one immersion cycle corresponds to an average increase of 6 nm. The characterization of the films with X-ray diffraction, SEM-EDS analysis and FTIR spectroscopy shows that the deposited material is amorphous hydrated Fe{sub 4}[Fe(CN){sub 6}]{sub 3}. The electrochromic properties are characterized by cyclic voltammetry and VIS spectrophotometry. The PB thin films exhibit stability and excellent reversibility, which make these films favorable for electrochromic devices.

  20. Ag Nanodots Emitters Embedded in a Nanocrystalline Thin Film Deposited on Crystalline Si Solar Cells.

    PubMed

    Park, Seungil; Ryu, Sel Gi; Ji, HyungYong; Kim, Myeong Jun; Peck, Jong Hyeon; Kim, Keunjoo

    2016-06-01

    We fabricated crystalline Si solar cells with the inclusion of various Ag nanodots into the additional emitters of nanocrystallite Si thin films. The fabricated process was carried out on the emitter surface of p-n junction for the textured p-type wafer. The Ag thin films were deposited on emitter surfaces and annealed at various temperatures. The amorphous Si layers were also deposited on the Ag annealed surfaces by hot-wire chemical vapor deposition and then the deposited layers were doped by the second n-type doping process to form an additional emitter. From the characterization, both the Ag nanodots and the deposited amorphous Si thin films strongly reduce photo-reflectances in a spectral region between 200-400 nm. After embedding Ag nanodots in nanocrystallite Si thin films, a conversion efficiency of the sample with added emitter was achieved to 15.1%, which is higher than the 14.1% of the reference sample and the 14.7% of the de-posited sample with a-Si:H thin film after the Ag annealing process. The additional nanocrystallite emitter on crystalline Si with Ag nanodots enhances cell properties. PMID:27427665

  1. Interface control by homoepitaxial growth in pulsed laser deposited iron chalcogenide thin films

    PubMed Central

    Molatta, Sebastian; Haindl, Silvia; Trommler, Sascha; Schulze, Michael; Wurmehl, Sabine; Hühne, Ruben

    2015-01-01

    Thin film growth of iron chalcogenides by pulsed laser deposition (PLD) is still a delicate issue in terms of simultaneous control of stoichiometry, texture, substrate/film interface properties, and superconducting properties. The high volatility of the constituents sharply limits optimal deposition temperatures to a narrow window and mainly challenges reproducibility for vacuum based methods. In this work we demonstrate the beneficial introduction of a semiconducting FeSe1−xTex seed layer for subsequent homoepitaxial growth of superconducting FeSe1−xTex thin film on MgO substrates. MgO is one of the most favorable substrates used in superconducting thin film applications, but the controlled growth of iron chalcogenide thin films on MgO has not yet been optimized and is the least understood. The large mismatch between the lattice constants of MgO and FeSe1−xTex of about 11% results in thin films with a mixed texture, that prevents further accurate investigations of a correlation between structural and electrical properties of FeSe1−xTex. Here we present an effective way to significantly improve epitaxial growth of superconducting FeSe1−xTex thin films with reproducible high critical temperatures (≥17 K) at reduced deposition temperatures (200 °C–320 °C) on MgO using PLD. This offers a broad scope of various applications. PMID:26548645

  2. Using different chemical methods for deposition of copper selenide thin films and comparison of their characterization.

    PubMed

    Güzeldir, Betül; Sağlam, Mustafa

    2015-11-01

    Different chemical methods such as Successive Ionic Layer Adsorption and Reaction (SILAR), spin coating and spray pyrolysis methods were used to deposite of copper selenide thin films on the glass substrates. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray analysis (EDX) spectroscopy and UV-vis spectrophotometry. The XRD and SEM studies showed that all the films exhibit polycrystalline nature and crystallinity of copper selenide thin films prepared with spray pyrolysis greater than spin coating and SILAR methods. From SEM and AFM images, it was observed copper selenide films were uniform on the glass substrates without any visible cracks or pores. The EDX spectra showed that the expected elements exist in the thin films. Optical absorption studies showed that the band gaps of copper selenide thin films were in the range 2.84-2.93 eV depending on different chemical methods. The refractive index (n), optical static and high frequency dielectric constants (ε0, ε∞) values were calculated by using the energy bandgap values for each deposition method. The obtained results from different chemical methods revealed that the spray pyrolysis technique is the best chemical deposition method to fabricate copper selenide thin films. This absolute advantage was lead to play key roles on performance and efficiency electrochromic and photovoltaic devices. PMID:26037495

  3. Chemical Vapor Deposition for Ultra-lightweight Thin-film Solar Arrays for Space

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Raffaelle, Ryne P.; Banger, Kulbinder K.; Jin, Michael H.; Lau, Janice E.; Harris, Jerry D.; Cowen, Jonathan E.; Duraj, Stan A.

    2002-01-01

    The development of thin-film solar cells on flexible, lightweight, space-qualified substrates provides an attractive cost solution to fabricating solar arrays with high specific power, (W/kg). The use of a polycrystalline chalcopyrite absorber layer for thin film solar cells is considered as the next generation photovoltaic devices. A key technical issues outlined in the 2001 U.S. Photovoltaic Roadmap, is the need to develop low cost, high throughput manufacturing for high-efficiency thin film solar cells. At NASA GRC we have focused on the development of new single-source-precursors (SSPs) and their utility to deposit the chalcopyrite semi-conducting layer (CIS) onto flexible substrates for solar cell fabrication. The syntheses and thermal modulation of SSPs via molecular engineering is described. Thin-film fabrication studies demonstrate the SSPs can be used in a spray CVD process, for depositing CIS at reduced temperatures, which display good electrical properties, suitable for PV devices.

  4. Properties of RF sputtered cadmium telluride (CdTe) thin films: Influence of deposition pressure

    NASA Astrophysics Data System (ADS)

    Kulkarni, R. R.; Pawbake, A. S.; Waykar, R. G.; Rondiya, S. R.; Jadhavar, A. A.; Pandharkar, S. M.; Karpe, S. D.; Diwate, K. D.; Jadkar, S. R.

    2016-04-01

    Influence of deposition pressure on structural, morphology, electrical and optical properties of CdTe thin films deposited at low substrate temperature (100°C) by RF magnetron sputtering was investigated. The formation of CdTe was confirmed by low angle XRD and Raman spectroscopy. The low angle XRD analysis revealed that the CdTe films have zinc blende (cubic) structure with crystallites having preferred orientation in (111) direction. Raman spectra show the longitudinal optical (LO) phonon mode peak ˜ 165.4 cm-1 suggesting high quality CdTe film were obtained over the entire range of deposition pressure studied. Scanning electron microscopy analysis showed that films are smooth, homogenous, and crack-free with no evidence of voids. The EDAX data revealed that CdTe films deposited at low deposition pressure are high-quality stoichiometric. However, for all deposition pressures, films are rich in Cd relative to Te. The UV-Visible spectroscopy analysis show the blue shift in absorption edge with increasing the deposition pressure while the band gap show decreasing trend. The highest electrical conductivity was obtained for the film deposited at deposition pressure 1 Pa which indicates that the optimized deposition pressure for our sputtering unit is 1 Pa. Based on the experimental results, these CdTe films can be useful for the application in the flexible solar cells and other opto-electronic devices.

  5. Transparent Thin Films Deposited onto Polyester Film Substrate by Radio Frequency Sputtering with a Poly(tetrafluoroethylene) Target

    NASA Astrophysics Data System (ADS)

    Seino, Shou; Nagai, Yuki; Kobayashi, Masashi; Iwamori, Satoru; Noda, Kazuhiro

    2013-05-01

    Improvement technologies for antireflection property of transparent plastic substrates are required in computer displays. Inorganic coatings have been used to reduce the surface reflection. We have already reported that fluorocarbon thin films sputtered with a poly(tetrafluoroethylene) (PTFE) target are transparent and can be used for an antireflection film, although the pristine PTFE plate used for the sputtering target is white. The fluorocarbon thin films were deposited onto a polyester (PET) film substrate by an rf sputtering, and characterized their optical properties. Elemental ratio, fluorine for carbon, of the thin films increased and degree of cross-linking of the thin films decreased with an increase of the rf power. Arithmetical surface roughness of the fluorocarbon thin films slightly increased with an increase of the rf power. Surface roughness of the fluorocarbon thin film affects the transmittance as well as the chemical structure of the thin film. To enhance the transparency, the diffuse transmittance should be suppressed, and flat surface thin films should be prepared by the sputtering at lower rf power and pressure.

  6. Pulsed laser deposition of AlMgB14 thin films

    SciTech Connect

    Britson, Jason Curtis

    2008-11-18

    Hard, wear-resistant coatings of thin film borides based on AlMgB14 have the potential to be applied industrially to improve the tool life of cutting tools and pump vanes and may account for several million dollars in savings as a result of reduced wear on these parts. Past work with this material has shown that it can have a hardness of up to 45GPa and be fabricated into thin films with a similar hardness using pulsed laser deposition. These films have already been shown to be promising for industrial applications. Cutting tools coated with AlMgB14 used to mill titanium alloys have been shown to substantially reduce the wear on the cutting tool and extend its cutting life. However, little research into the thin film fabrication process using pulsed laser deposition to make AlMgB14 has been conducted. In this work, research was conducted into methods to optimize the deposition parameters for the AlMgB14 films. Processing methods to eliminate large particles on the surface of the AlMgB14 films, produce films that were at least 1m thick, reduce the surface roughness of the films, and improve the adhesion of the thin films were investigated. Use of a femtosecond laser source rather than a nanosecond laser source was found to be effective in eliminating large particles considered detrimental to wear reduction properties from the films. Films produced with the femtosecond laser were also found to be deposited at a rate 100 times faster than those produced with the nanosecond laser. However, films produced with the femtosecond laser developed a relatively high RMS surface roughness around 55nm. Attempts to decrease the surface roughness were largely unsuccessful. Neither increasing the surface temperature of the substrate during deposition nor using a double pulse to ablate the material was found to be extremely successful to reduce the surface roughness. Finally, the adhesion of the thin films to M2 tool steel

  7. Proton Transport and Microstructure Properties in Superlattice Thin Films Fabricated by Pulsed Laser Deposition

    NASA Astrophysics Data System (ADS)

    Kuwata, Naoaki; Sata, Noriko; Tsurui, Takao; Yugami, Hiroo

    2005-12-01

    Superlattice thin films of the perovskite-type oxide proton conductor SrZr0.95Y0.05O3/SrTiO3 was fabricated by pulsed laser deposition. Their structural and proton transport properties were reported. X-ray diffraction analysis and selected area electron diffraction revealed that the thin films were epitaxially grown on MgO(001) substrate. High-density edge dislocations and a columnar structure were observed in the films by high-resolution electron microscopy. The in-plane electrical conductivity of the thin films was determined by impedance spectroscopy. The contribution of proton transport to the total conductivity of the films was confirmed by H2O/D2O exchange measurement. The conductivity of superlattice films was increased by introducing heterointerfaces. The high activation energy (Ea=1.0 eV) was explained by the grain-boundary effect of the columnar structure in the films.

  8. Pyrolyzed thin film carbon

    NASA Technical Reports Server (NTRS)

    Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor)

    2010-01-01

    A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.

  9. Slit-based supersonic microplasma jets: Scalable sources for nanostructured thin film deposition

    NASA Astrophysics Data System (ADS)

    Koh, T.; Chiles, I.; Gordon, M.

    2013-10-01

    Slit-based, hollow cathode microplasma jets operating in under-expanded supersonic flow were investigated as spray deposition sources to realize nanostructured metal oxide thin films. Design of the slit cathode, its operation (e.g., IV characteristics, fluorescence imaging of supersonic flow shock structures, etc.), and companion CuO nanowire deposition experiments are discussed. Overall, this work demonstrates that slit-based, flow-through microplasmas are a promising way to scale up hollow cathode discharges for large area deposition of thin films at high pressures (>10 Torr).

  10. Stabilizing laser energy density on a target during pulsed laser deposition of thin films

    DOEpatents

    Dowden, Paul C.; Jia, Quanxi

    2016-05-31

    A process for stabilizing laser energy density on a target surface during pulsed laser deposition of thin films controls the focused laser spot on the target. The process involves imaging an image-aperture positioned in the beamline. This eliminates changes in the beam dimensions of the laser. A continuously variable attenuator located in between the output of the laser and the imaged image-aperture adjusts the energy to a desired level by running the laser in a "constant voltage" mode. The process provides reproducibility and controllability for deposition of electronic thin films by pulsed laser deposition.

  11. Nanomechanical properties of platinum thin films synthesized by atomic layer deposition

    SciTech Connect

    Mamun, M.A.; Gu, D.; Baumgart, H.; Elmustafa, A.A.

    2015-03-01

    The nanomechanical properties of Pt thin films grown on Si (100) using atomic layer deposition (ALD) were investigated using nanoindentation. Recently, atomic layer deposition (ALD) has successfully demonstrated the capability to deposit ultra-thin films of platinum (Pt). Using (methylcyclopentadienyl) trimethylplatinum (MeCpPtMe3) as chemical platinum precursor and oxygen (O2) as the oxidizing agent, the ALD synthesis of Pt can be achieved with high conformity and excellent film uniformity. The ALD process window for Pt films was experimentally established in the temperature range between 270 °C and 320 °C, where the sheet conductance was constant over that temperature range, indicating stable ALD Pt film growth rate. ALD growth of Pt films exhibits very poor nucleation and adhesion characteristics on bare Si surfaces when the native oxide was removed by 2% HF etch. Pt adhesion improves for thermally oxidized Si wafers and for Si wafers covered with native oxide. Three ALD Pt films deposited at 800, 900, and 1000 ALD deposition cycles were tested for the structural and mechanical properties. Additionally, the sample with 900 ALD deposition cycles was further annealed in forming gas (95% N2 and 5% H2) at 450 °C for 30 min in order to passivate dangling bonds in the grain boundaries of the polycrystalline Pt film. Cross-sectional transmission electron microscopy (TEM), X-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electron microscope (SEM) were employed to characterize the films' surface structure and morphology. Nanoindentation technique was used to evaluate the hardness and modulus of the ALD Pt films of various film thicknesses. The results indicate that the films depict comparable hardness and modulus results; however, the 800 and 1000 ALD deposition cycles films without forming gas annealing experienced significant amount of pileup, whereas the 900 ALD deposition cycles sample annealed in forming gas resulted in a smaller pileup.

  12. Structural and morphological properties of metallic thin films grown by pulsed laser deposition for photocathode application

    NASA Astrophysics Data System (ADS)

    Lorusso, A.; Gontad, F.; Caricato, A. P.; Chiadroni, E.; Broitman, E.; Perrone, A.

    2016-03-01

    In this work yttrium and lead thin films have been deposited by pulsed laser deposition technique and characterized by ex situ different diagnostic methods. All the films were adherent to the substrates and revealed a polycrystalline structure. Y films were uniform with a very low roughness and droplet density, while Pb thin films were characterized by a grain morphology with a relatively high roughness and droplet density. Such metallic materials are studied because they are proposed as a good alternative to copper and niobium photocathodes which are generally used in radiofrequency and superconducting radiofrequency guns, respectively. The photoemission performances of the photocathodes based on Y and Pb thin films have been also studied and discussed.

  13. Characterization of nanostructured ZnO thin films deposited through vacuum evaporation

    PubMed Central

    Maldonado, Arturo; Juarez, Héctor; Pacio, Mauricio; Perez, Rene

    2015-01-01

    Summary This work presents a novel technique to deposit ZnO thin films through a metal vacuum evaporation technique using colloidal nanoparticles (average size of 30 nm), which were synthesized by our research group, as source. These thin films had a thickness between 45 and 123 nm as measured by profilometry. XRD patterns of the deposited thin films were obtained. According to the HRSEM micrographs worm-shaped nanostructures are observed in samples annealed at 600 °C and this characteristic disappears as the annealing temperature increases. The films obtained were annealed from 25 to 1000 °C, showing a gradual increase in transmittance spectra up to 85%. The optical band gaps obtained for these films are about 3.22 eV. The PL measurement shows an emission in the red and in the violet region and there is a correlation with the annealing process. PMID:25977868

  14. Engineering the Crystalline Morphology of Polymer Thin Films via Physical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Jeong, Hyuncheol; Arnold, Craig; Priestley, Rodney

    Thin-film growth via physical vapor deposition (PVD) has been successfully exploited for the delicate control of film structure for molecular and atomic systems. The application of such a high-energetic process to polymeric film growth has been challenged by chemical degradation. However, recent development of Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique opened up a way to deposit a variety of macromolecules in a PVD manner. Here, employing MAPLE technique to the growth of semicrystalline polymer thin films, we show the engineering of crystalline film morphology can be achieved via manipulation of substrate temperature. This is accomplished by exploiting temperature effect on crystallization kinetics of polymers. During the slow film growth crystallization can either be permitted or suppressed, and crystal thickness can be tuned via temperature modulation. In addition, we report that the crystallinity of polymer thin films may be significantly altered with deposition temperature in MAPLE processing. We expect that this ability to manipulate crystallization kinetics during polymeric film growth will open the possibility to engineer structure in thin film polymeric-based devices in ways that are difficult by other means.

  15. Room Temperature Oxide Deposition Approach to Fully Transparent, All-Oxide Thin-Film Transistors.

    PubMed

    Rembert, Thomas; Battaglia, Corsin; Anders, André; Javey, Ali

    2015-10-28

    A room temperature cathodic arc deposition technique is used to produce high-mobility ZnO thin films for low voltage thin-film transistors (TFTs) and digital logic inverters. All-oxide, fully transparent devices are fabricated on alkali-free glass and flexible polyimide foil, exhibiting high performance. This provides a practical materials platform for the low-temperature fabrication of all-oxide TFTs on virtually any substrate. PMID:26455916

  16. Enhanced localized superconductivity in Sr2RuO4 thin film by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Cao, J.; Massarotti, D.; Vickers, M. E.; Kursumovic, A.; Di Bernardo, A.; Robinson, J. W. A.; Tafuri, F.; MacManus-Driscoll, J. L.; Blamire, M. G.

    2016-09-01

    Superconducting c-axis-oriented Sr2RuO4 thin film has been fabricated using pulsed laser deposition. Although the superconductivity is localized, the onset critical temperature is enhanced over the bulk value. X-ray microstructural analysis of Sr2RuO4 superconducting and non-superconducting thin films suggests the existence of the localized stacking faults and an overall c-axis lattice expansion which may account for the locally enhanced superconductivity.

  17. Conductivity of Thin Films Based on Single-Walled Carbon Nanotubes Grown by Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Rybakov, M. S.; Kosobutsky, A. V.; Sevostyanov, O. G.; Russakov, D. M.; Lomakin, M. V.; Chirkova, I. M.; Shandakov, S. D.

    2015-03-01

    Electrical and optical properties of thin films of single-walled carbon nanotubes (SWCNT) obtained by aerosol chemical vapor deposition using ethanol, ferrocene, and sulfur are studied. Structural and geometrical characteristics of the synthesis products are determined by the methods of Raman spectroscopy and transmission electron microscopy. The effect of sulfur on the properties of the SWCNTs and thin films based on them is found.

  18. Development of a fluorescence based flux sensor for thin film growth and nanoparticle deposition.

    PubMed

    De Roo, Bert; Vervaele, Mattias; Rajala, Markku; Miller, Toni; Guillon, Herve; Seo, Jin Won; Locquet, Jean-Pierre

    2016-07-01

    An optical flux sensor, based on the fluorescence properties of materials and nanoparticles, has been developed to control the deposition rate in thin film deposition systems. Using a simple diode laser and a photomultiplier tube with a light filter, we report the detection of gallium atoms and CdSe-ZnS quantum dots. This setup has a high sensitivity and reproducibility. PMID:27475600

  19. Development of a fluorescence based flux sensor for thin film growth and nanoparticle deposition

    NASA Astrophysics Data System (ADS)

    De Roo, Bert; Vervaele, Mattias; Rajala, Markku; Miller, Toni; Guillon, Herve; Seo, Jin Won; Locquet, Jean-Pierre

    2016-07-01

    An optical flux sensor, based on the fluorescence properties of materials and nanoparticles, has been developed to control the deposition rate in thin film deposition systems. Using a simple diode laser and a photomultiplier tube with a light filter, we report the detection of gallium atoms and CdSe-ZnS quantum dots. This setup has a high sensitivity and reproducibility.

  20. Pulsed laser deposited iron fluoride thin films for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Makimura, Yoshinari; Rougier, Aline; Tarascon, Jean-Marie

    2006-04-01

    Iron fluoride thin films were successfully grown by Pulsed Laser Deposition (PLD), and their physico-chemical properties and electrochemical behaviours were examined by adjusting the deposition conditions, such as the target nature (FeF 2 or FeF 3), the substrate temperature ( Ts ≤ 600 °C), the gas pressure (under vacuum or in oxygen atmosphere) and the repetition rates (2 and 10 Hz). Irrespective of the FeF 2 or FeF 3 target nature, iron fluoride thin films, deposited at 600 °C under vacuum, showed X-ray diffraction (XRD) patterns corresponding to the FeF 2 phase. On the other hand, iron fluoride thin films deposited at room temperature (RT) from FeF 2 target were amorphous, whereas the thin films deposited from FeF 3 target consisted of a two-phase mixture of FeF 3 and FeF 2 showing sharp and broad diffraction peaks by XRD, respectively. Their electrochemical behaviour in rechargeable lithium cells was investigated in the 0.05-3.60 V voltage window. Despite a large irreversible capacity on the first discharge, good cycling life was observed up to 30 cycles. Finally, their electrochemical properties were compared to the ones of iron oxide thin films.

  1. Nanoindentation of plasma-deposited nitrogen-rich silicon nitride thin films

    NASA Astrophysics Data System (ADS)

    Soh, Martin T. K.; Fischer-Cripps, A. C.; Savvides, N.; Musca, C. A.; Faraone, L.

    2006-07-01

    Nanoindentation was performed on plasma-deposited nitrogen-rich silicon nitride thin films deposited on various substrates between 150 and 300°C. A very simple and effective depth-profiling method is introduced, which involves indentation of thin films deposited on substrates with different mechanical properties. The primary advantage of this method is that it avoids the complications associated with many of the complex mathematical models available to deconvolve thin film mechanical properties, while nevertheless allowing the user to visually identify thin film properties. This method is demonstrated on our thin films, which have a hardness between 14 and 21GPa, and reduced modulus between 120 and 160GPa. The initial rise in hardness at low contact depths, commonly attributed to an indentation-size effect, is shown to be due to elastic contact between the indenter and thin film surface. This demonstrates the perils of blindly following the 10% rule for hardness calculation. The contribution of elastic and plastic deformations from nanoindentation is used to clarify the physical meaning of hardness and reduced modulus.

  2. Optical and mechanical properties of nanocrystalline ZrC thin films grown by pulsed laser deposition.

    SciTech Connect

    Craciun, D.; Socol, G.; Lambers, E.; McCumiskey, E. J.; Taylor, C. R.; Martin, C.; Argibay, Nicolas; Craciun, V.; Tanner, D. B.

    2015-01-17

    Thin ZrC films (<500 nm) were grown on (100) Si substrates at a substrate temperature of 500 °C by the pulsed laser deposition (PLD) technique using a KrF excimer laser under different CH4 pressures. Glancing incidence X-ray diffraction showed that films were nanocrystalline, while X-ray reflectivity studies found out films were very dense and exhibited a smooth surface morphology. Optical spectroscopy data shows that the films have high reflectivity (>90%) in the infrared region, characteristic of metallic behavior. Nanoindentation results indicated that films deposited under lower CH4 pressures exhibited slightly higher nanohardness and Young modulus values than films deposited under higher pressures. As a result, tribological characterization revealed that these films exhibited relatively high wear resistance and steady-state friction coefficients on the order of μ = 0.4.

  3. Optical and mechanical properties of nanocrystalline ZrC thin films grown by pulsed laser deposition.

    DOE PAGESBeta

    Craciun, D.; Socol, G.; Lambers, E.; McCumiskey, E. J.; Taylor, C. R.; Martin, C.; Argibay, Nicolas; Craciun, V.; Tanner, D. B.

    2015-01-17

    Thin ZrC films (<500 nm) were grown on (100) Si substrates at a substrate temperature of 500 °C by the pulsed laser deposition (PLD) technique using a KrF excimer laser under different CH4 pressures. Glancing incidence X-ray diffraction showed that films were nanocrystalline, while X-ray reflectivity studies found out films were very dense and exhibited a smooth surface morphology. Optical spectroscopy data shows that the films have high reflectivity (>90%) in the infrared region, characteristic of metallic behavior. Nanoindentation results indicated that films deposited under lower CH4 pressures exhibited slightly higher nanohardness and Young modulus values than films deposited undermore » higher pressures. As a result, tribological characterization revealed that these films exhibited relatively high wear resistance and steady-state friction coefficients on the order of μ = 0.4.« less

  4. Properties of NiO thin films deposited by intermittent spray pyrolysis process

    NASA Astrophysics Data System (ADS)

    Reguig, B. A.; Khelil, A.; Cattin, L.; Morsli, M.; Bernède, J. C.

    2007-02-01

    NiO thin films have been grown on glass substrates by intermittent spray pyrolysis deposition of NiCl 2·6H 2O diluted in distilled water, using a simple "perfume atomizer". The effect of the solution molarity on their properties was studied and compared to those of NiO thin films deposited with a classical spray system. It is shown that NiO thin films crystallized in the NiO structure are achieved after deposition. Whatever the precursor molarity, the grain size is around 25-30 nm. The crystallites are preferentially oriented along the (1 1 1) direction. All the films are p-type. However, the thickness and the conductivity of the NiO films depend on the precursor contraction. By comparison with the properties of films deposited by classical spray technique, it is shown that the critical precursor concentration, which induces strong thin films properties perturbations, is higher when a perfume atomizer is used. This broader stability domain can be attributed to better chlorides decomposition during the rest time used in the perfume atomizer technique.

  5. Characteristics of CoxTi1-xO2 thin films deposited by MOCVD

    SciTech Connect

    McClure, A.; Kayani, A.; Idzerda, Y.U.; Arenholz, E.; Cruz, E.

    2008-05-09

    This paper deals with the growth and characterization of ferromagnetic cobalt doped TiO{sub 2} thin films deposited by liquid precursor metal organic chemical vapor deposition (MOCVD) using a new combination of the source materials Co(TMHD){sub 3}, tetrahydrofuran (THF), and titanium isopropoxide (TIP). An array of experiments reveals the intrinsic ferromagnetic nature of the grown films, and suggests that the magnetism is not generated by oxygen vacancies.

  6. Substrate dependent structural and magnetic properties of pulsed laser deposited Fe3O4 thin films.

    PubMed

    Goyal, Rajendra N; Kaur, Davinder; Pandey, Ashish K

    2010-12-01

    Nanocrystalline iron oxide thin films have been deposited on various substrates such as quartz, MgO(100), and Si(100) by pulsed laser deposition technique using excimer KrF laser (248 nm). The orientations, crystallite size and lattice parameters were studied using X-ray diffraction. The XRD results show that the films deposited on MgO and Si substrates are highly oriented and show only (400) and (311) reflections respectively. On the other hand, the orientation of the films deposited on quarts substrate changed from (311) to (400) with an increase in the substrate temperature from 400 degrees C to 600 degrees C, indicating thereby that the film growth direction is highly affected with nature of substrate and substrate temperature. The surface morphology of the deposited films was studied using Atomic Force Microscopy (AFM) and spherical ball like regular features of nanometer size grains were obtained. The magnetic properties were studied by Superconducting Quantum Interference Device (SQUID) magnetometer in the magnetic field +/- 6 Tesla. The magnetic field dependent magnetization (M-H) curves of all the Fe3O4 thin films measured at 5 K and 300 K show the ferrimagnetic nature. The electrochemical sensing of dopamine studied for these films shows that the film deposited on MgO substrate can be used as a sensing electrode. PMID:21121292

  7. Suppressed grain-boundary scattering in atomic layer deposited Nb:TiO2 thin films

    NASA Astrophysics Data System (ADS)

    Niemelä, Janne-Petteri; Hirose, Yasushi; Shigematsu, Kei; Sano, Masahito; Hasegawa, Tetsuya; Karppinen, Maarit

    2015-11-01

    We have fabricated high-quality thin films of the transparent conducting anatase Nb:TiO2 on glass substrates through atomic layer deposition, and a subsequent reductive heat treatment of the as-deposited amorphous films. Hall-effect measurements and Drude-fitting of the Vis-NIR spectra indicate that for lightly doped films deposited at temperatures around 170 °C, grain boundary scattering becomes negligible and the mobility is predominately limited by phonon-electron scattering inherent to the anatase lattice and by impurities. Simultaneously, such lighter doping leads to reduced plasma absorption, thereby improving material's performance as a transparent conductor.

  8. Enhanced Bactericidal Activity of Silver Thin Films Deposited via Aerosol-Assisted Chemical Vapor Deposition.

    PubMed

    Ponja, Sapna D; Sehmi, Sandeep K; Allan, Elaine; MacRobert, Alexander J; Parkin, Ivan P; Carmalt, Claire J

    2015-12-30

    Silver thin films were deposited on SiO2-barrier-coated float glass, fluorine-doped tin oxide (FTO) glass, Activ glass, and TiO2-coated float glass via AACVD using silver nitrate at 350 °C. The films were annealed at 600 °C and analyzed by X-ray powder diffraction, X-ray photoelectron spectroscopy, UV/vis/near-IR spectroscopy, and scanning electron microscopy. All the films were crystalline, and the silver was present in its elemental form and of nanometer dimension. The antibacterial activity of these samples was tested against Escherichia coli and Staphylococcus aureus in the dark and under UV light (365 nm). All Ag-deposited films reduced the numbers of E. coli by 99.9% within 6 h and the numbers of S. aureus by 99.9% within only 2 h. FTO/Ag reduced bacterial numbers of E. coli to below the detection limit after 60 min and caused a 99.9% reduction of S. aureus within only 15 min of UV irradiation. Activ/Ag reduced the numbers of S. aureus by 66.6% after 60 min and TiO2/Ag killed 99.9% of S. aureus within 60 min of UV exposure. More remarkably, we observed a 99.9% reduction in the numbers of E. coli within 6 h and the numbers of S. aureus within 4 h in the dark using our novel TiO2/Ag system. PMID:26632854

  9. Investigation of thin films of organic-based magnets grown by physical vapor deposition

    SciTech Connect

    Kao, C. Y.; Lu, Y.; Li, B.; Yoo, J.-W.; Epstein, A. J.

    2014-10-06

    Thin films of organic-based magnet, V[TCNE]{sub x} (TCNE: tetracyanoethylene), were deposited by physical vapor deposition (PVD) based reactive evaporation. The growth conditions were studied in detail. A saturated composition of V[TCNE]{sub ∼1.9} was determined by optimizing the growth condition. Two sets of films with different V to TCNE ratios were characterized. Both films were magnetic ordered up to 400 K and held coercive field of 60 Oe at room temperature. With the presence of excess vanadium within the film, the increase of defects created by PVD results in significant change in electronic property.

  10. Formation and thermal stability of amorphous Cu-Zr thin films deposited by coevaporation

    SciTech Connect

    Minemura, T.; van den Broek, J.J.; Daams, J.L.C.

    1988-05-01

    The formation and thermal stability of amorphous thin films have been characterized by comparing them with those of melt-spun ribbons. The various Cu/sub 1-//sub x/Zr/sub x/ thin films were deposited by coevaporation. The amorphous formation range and the crystallization behavior in the films were investigated with x-ray diffraction and differential scanning calorimetry. The amorphous thin films are formed in the composition range x = 0.20--0.75, which is wider than that found for the melt-spun ribbons. The crystallization temperature and the activation energy for crystallization are lower than those of the melt-spun ribbons, although the composition dependencies show tendencies similar to those of the ribbons. These differences in thermal stability between amorphous films and ribbons might be due to a lower degree of the short-range ordering in the films.

  11. Underpotential deposition-mediated layer-by-layer growth of thin films

    SciTech Connect

    Wang, Jia Xu; Adzic, Radoslav R.

    2015-05-19

    A method of depositing contiguous, conformal submonolayer-to-multilayer thin films with atomic-level control is described. The process involves the use of underpotential deposition of a first element to mediate the growth of a second material by overpotential deposition. Deposition occurs between a potential positive to the bulk deposition potential for the mediating element where a full monolayer of mediating element forms, and a potential which is less than, or only slightly greater than, the bulk deposition potential of the material to be deposited. By cycling the applied voltage between the bulk deposition potential for the mediating element and the material to be deposited, repeated desorption/adsorption of the mediating element during each potential cycle can be used to precisely control film growth on a layer-by-layer basis. This process is especially suitable for the formation of a catalytically active layer on core-shell particles for use in energy conversion devices such as fuel cells.

  12. Centrifugal Deposition of Microgels for the Rapid Assembly of Nonfouling Thin Films

    PubMed Central

    South, Antoinette B.; Whitmire, Rachel E.; García, Andrés J.; Lyon, L. Andrew

    2010-01-01

    Thin films assembled from microgel building blocks have been constructed using a simple, high-throughput, and reproducible centrifugation (or “active”) deposition technique. When compared to a common passive adsorption method (e.g., dip coating), microgels that are actively deposited onto a surface have smaller footprints and are more closely packed. Under both active and passive deposition conditions, the microgel footprint areas decrease during deposition. However, under active deposition, the microgel footprint appears to decrease continually and to a greater degree over the course of the deposition, forming a tightly packed, homogeneous film. Taking advantage of the rapid and uniform assembly of these films, we demonstrate the use of active deposition toward the fabrication of polyelectrolyte multilayers containing anionic microgels and a cationic linear polymer. Microgel multilayers successfully demonstrated effective blocking of the underlying substrate toward macrophage adhesion, which is a highly sought-after property for modulating the inflammatory response to an implanted biomaterial. PMID:20356152

  13. Effect of Post Deposition Annealing Treatments on Properties of AZO Thin Films for Schottky Diode Applications.

    PubMed

    Singh, Shaivalini; Park, Si-Hyun

    2016-01-01

    High-quality aluminum (Al) doped ZnO (AZO) thin films were deposited on silicon substrates by RF sputtering at room temperature. The deposited films were annealed from the temperatures 350 °C to 650 °C in pure nitrogen (N₂) ambient. The effects of annealing on the microstructural, optical and electrical properties of the AZO films were investigated. A detailed analysis by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Four Probe and Hall measurements was performed to study the properties of these AZO thin films. It was observed that all of the as-deposited and annealed AZO films have homogenous surfaces and hexagonal wurtzite structures with good crystalline quality. The study also suggested that there was an intermediate post annealing temperature (450 °C) at which the deposited ZnO film exhibit best surface characteristics. Pd/AZO Schottky devices were fabricated with 450 °C annealed AZO thin films and the parameters of Schottky devices were extracted from I-V characteristics. These results indicated that the Pd/AZO films were very much suitable for various optoelectronics applications particularly for metal semiconductor metal based UV detector application. PMID:27398537

  14. Sputter deposition and characterization of lithium cobalt oxide thin films and their applications in thin-film rechargeable lithium batteries

    SciTech Connect

    Wang, B.; Bates, J.B.; Luck, C.F.; Sales, B.C.; Zuhr, R.A.; Robertson, J.D.

    1996-01-01

    Li Co oxide thin films were deposited by rf magnetron sputtering of a LiCoO{sub 2} target in a 3:1 Ar/O{sub 2} mixture gas. From proton-induced gamma-ray emission analysis and Rutherford backscattering spectrometry, the average composition of these films was determined to be Li{sub 1.15}CoO{sub 2.16}. X-ray powder diffraction patterns of films annealed in air at 500-700 C were consistent with regular rhombohedral structure of crystalline LiCoO{sub 2}. Discharge curves of thin film lithium cells with amoprohous LiCoO{sub 2} showed no obvious structural transition between 4.2 and 1.5 V. Shape of discharge curves of cells with polycrystalline cathodes were consistent with a two-phase voltage plateau at {similar_to}3.9 V with a relatively large capacity and two additional smaller plateaus at higher voltages. Cells with the 700 C annealed cathodes showed a capacity loss of {similar_to} after 1000 cycles between 4.2 and 3.0 V.

  15. [The Influence of Deposition Pressure on the Properties of Hydrogenated Amorphous Silicon Thin Films].

    PubMed

    Yuan, Jun-bao; Yang, Wen; Chen, Xiao-bo; Yang, Pei-zhi; Song, Zhao-ning

    2016-02-01

    Hydrogenated amorphous silicon (a-Si:H) thin films on soda-lime glass substrates were deposited by plasma enhanced chemical vapor deposition (PECVD) using disilane and hydrogen as source gases. To study the influence of deposition pressure on the deposition rate, optical band gap and structure factor, a surface profilometer, an ultraviolet-visible spectrometer, a Fourier transform infrared (FTIR) spectrometer and a scanning electron microscopy (SEM) were used to characterize the deposited thin films. It is found that the deposition rate firstly increased and then decreased and the optical band gap monotonically decreased with the increasing deposition pressure. Moreover, the formation of SiH bond was preferable to the formation of SH₂ or SiH₃ bond when the deposition pressure was less than 210 Pa, while it was opposite when the deposition pressure is higher than 210 Pa. Finally, the deposition pressure in the range of 110~210 Pa was found to be more suitable for the preparation of high quality a-Si:H thin films. PMID:27209724

  16. 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.

  17. Chemical-bath deposition of ZnSe thin films: Process and material characterization

    SciTech Connect

    Dona, J.M.; Herrero, J.

    1995-03-01

    Chemical-bath deposition of ZnSe thin films from NH{sub 3}/NH{sub 2}-NH{sub 2}/SeC(NH{sub 2}){sub 2}/Na{sub 2}SO{sub 3}/ZnSO{sub 4} solutions has been studied. The effect of various process parameters on the growth and the film quality is presented. A first approach to a mechanistic interpretation of the chemical process, based on the influence of the process parameters on the film growth rate, is reported. The structural, optical, chemical, and electrical properties of the ZnSe thin-films deposited by this method have been studied. The electron diffraction (EDS) analysis shows that the films are microcrystalline with mixed cubic and hexagonal structure. EDS analysis has demonstrated that the films are highly stoichiometric. Scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy studies of the ZnSe thin films deposited by this method show that the films are continuous and homogeneous. Optical measurements have allowed the authors to detect the presence of the spin-orbit splitting effect in this material. Electrical conductivity measurements have shown the highly resistive nature of these films ({rho} {approximately} 10{sup 9} {Omega} cm).

  18. Chemical bath deposition of Cu3BiS3 thin films

    NASA Astrophysics Data System (ADS)

    Deshmukh S., G.; Panchal A., K.; Vipul, Kheraj

    2016-05-01

    First time, copper bismuth sulfide (Cu3BiS3) thin films were synthesized on the glass substrate using simple, low-cost chemical bath deposition (CBD) technique. The synthesized parameters such as temperature of bath, pH and concentration of precursors were optimized for the deposition of uniform, well adherent Cu3BiS3 thin films. The optical, surface morphology and structural properties of the Cu3BiS3 thin films were studied using UV-VIS-NIR spectra, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The as- synthesized Cu3BiS3 film exhibits a direct band gap 1.56 to 1.58 eV having absorption coefficient of the order of 105 cm-1. The XRD declares the amorphous nature of the films. SEM images shows films were composed of close-packed fine spherical nanoparticles of 70-80 nm in diameter. The chemical composition of the film was almost stoichiometric. The optical study indicates that the Cu3BiS3 films can be applied as an absorber layer for thin film solar cells.

  19. Thin films of energetic materials by physical vapor deposition: TATB and LLM-105

    NASA Astrophysics Data System (ADS)

    Williamson, David; Gymer, Sue; O'Conner, Colum; Hazelwood, Adam; Jardine, Andrew

    2015-06-01

    Thin films of energetic materials enable a diverse range of characterization measurements: structure, surface energy and adhesion, and even reactivity. Here we present a method to grow thin films by a physical vapor deposition method (sublimation) using a dedicated instrument which can operate at ultra-high vacuum. The approach enables fabrication of thin films of energetic materials that are otherwise difficult to process by traditional methods, for example because of their low solubility. The intention is to use this instrument as a platform for studying pure materials and co-deposited materials grown either as multi-layers or as co-crystals. Examples of TATB and LLM-105 film morphologies grown using this technique are presented.

  20. Structural, optical, and electrical properties of pulsed laser deposition CIGSS thin films

    NASA Astrophysics Data System (ADS)

    Xu, Yan-Bin; Kang, Y. Zhen-Feng; Fan, Yue; Xiao, Ling-ling; Bo, Qing-Rui; Ding, Tie-Zhu

    2015-12-01

    High-quality CuIn0.75Ga0.25(Se0.75S0.25)2 (CIGSS) thin films were synthesized on the soda-lime glass (SLG) substrates by pulsed laser deposition. The structural and optical properties of CIGSS thin films were studied by experiments and theoretical calculations. XRD result reveals that the films are of chalcopyrite structure. The experiments and theory show that CIGSS is a semiconductor with a direct band gap. The direct band gap energy of the deposited CIGSS thin films are in the solar energy range. The band structure and density of states of the CIGSS crystals were studied by the first principles density functional theory. The experimental data and theoretical data have demonstrated good agreement.

  1. Studies on VOx thin films deposited over Si3N4 coated Si substrates

    NASA Astrophysics Data System (ADS)

    Raj, P. Deepak; Gupta, Sudha; Sridharan, M.

    2015-06-01

    Vanadium oxide (VOx) thin films were deposited on to the silicon nitride (Si3N4) coated silicon (Si) substrate using reactive direct current magnetron sputtering at different substrate temperatures (Ts). The deposited films were characterized for their structural, morphological, optical and electrical properties. The average grain size of the deposited films was in the range of 95 to 178 nm and the strain varied from 0.071 to 0.054 %. The optical bandgap values of the films were evaluated using UV-Vis spectroscopy and lies in the range of 2.46 to 3.88 eV. The temperature coefficient of resistance (TCR) for the film deposited at 125 °C was -1.23%/°C with the sheet resistivity of 2.7 Ω.cm.

  2. Induced recrystallization of CdTe thin films deposited by close-spaced sublimation

    SciTech Connect

    Moutinho, H.R.; Dhere, R.G.; Al-Jassim, M.M.; Levi, D.H.; Kazmerski, L.L.; Mayo, B.

    1999-03-01

    We have deposited CdTe thin films by close-spaced sublimation at two different temperature ranges. The films deposited at the lower temperature partially recrystallized after CdCl{sub 2} treatment at 350&hthinsp;{degree}C and completely recrystallized after the same treatment at 400&hthinsp;{degree}C. The films deposited at higher temperature did not recrystallize at these two temperatures. These results confirmed that the mechanisms responsible for changes in physical properties of CdTe films treated with CdCl{sub 2} are recrystallization and grain growth, and provided an alternative method to deposit CSS films using lower temperatures. {copyright} {ital 1999 American Institute of Physics.}

  3. Deposition of highly textured AlN thin films by reactive high power impulse magnetron sputtering

    SciTech Connect

    Moreira, Milena A.; Törndahl, Tobias; Katardjiev, Ilia; Kubart, Tomas

    2015-03-15

    Aluminum nitride thin films were deposited by reactive high power impulse magnetron sputtering (HiPIMS) and pulsed direct-current on Si (100) and textured Mo substrates, where the same deposition conditions were used for both techniques. The films were characterized by x-ray diffraction and atomic force microscopy. The results show a pronounced improvement in the AlN crystalline texture for all films deposited by HiPIMS on Si. Already at room temperature, the HiPIMS films exhibited a strong preferred (002) orientation and at 400 °C, no contributions from other orientations were detected. Despite the low film thickness of only 200 nm, an ω-scan full width at half maximum value of 5.1° was achieved on Si. The results are attributed to the high ionization of sputtered material achieved in HiPIMS. On textured Mo, there was no significant difference between the deposition techniques.

  4. Mössbauer study of electrochemically deposited amorphous iron-sulfide-oxide thin films

    NASA Astrophysics Data System (ADS)

    Ichimura, Masaya; Kajima, Takahiro; Kawai, Shoichi; Mibu, Ko

    2016-03-01

    Iron-sulfide-oxide thin films, which are promising candidates for solar cell materials, were deposited by electrochemical deposition. As-deposited and annealed films were characterized by Mössbauer spectroscopy, X-ray diffraction (XRD), and Raman scattering at room temperature. The as-deposited film is amorphous, and the oxygen content is about 1/4 of the sulfur content (S/Fe ≈ 1.5, O/Fe ≈ 0.4). The Mössbauer spectrum for the as-deposited film is a doublet with a broad line profile having hyperfine parameters similar to those of FeS2 pyrite or marcasite. This indicates that Fe atoms are in the Fe2+ low-spin state, as in FeS2.

  5. Roughness of glancing angle deposited titanium thin films: an experimental and computational study.

    PubMed

    Backholm, Matilda; Foss, Morten; Nordlund, Kai

    2012-09-28

    The characterization of roughness at the nanoscale by the means of atomic force microscopy (AFM) was performed on high aspect ratio glancing angle deposited titanium thin films. With the use of scanning electron microscopy as well as x-ray photoelectron spectroscopy, it was shown that the AFM measurements gave rise to incorrect roughness values for the films consisting of the highest aspect ratio structures. By correcting for this experimental artefact, the difference between the saturated roughness value of a film grown with conventional physical vapour deposition and films grown with a glancing angle of deposition was shown to behave as a power law function of the deposition angle, with a saturated roughness exponent of κ = 7.1 ± 0.2. This power law scaling was confirmed by three-dimensional molecular dynamics simulations of glancing angle deposition, where the saturated roughness exponent was calculated to κ = 6.7 ± 0.4. PMID:22948111

  6. Effects of deposition temperature on the mechanical and physical properties of silicon nitride thin films

    SciTech Connect

    Walmsley, B.A.; Liu, Y.; Hu, X.Z.; Bush, M.B.; Winchester, K.J.; Martyniuk, M.; Dell, J.M.; Faraone, L.

    2005-08-15

    This study investigates the mechanical and physical properties of low-temperature plasma-enhanced chemical-vapor-deposited silicon nitride thin films, with particular respect to the effect of deposition temperature. The mechanical properties of the films were evaluated by both nanoindentation and microcantilever beam-bending techniques. The cantilever beam specimens were fabricated from silicon nitride thin films deposited on (100) silicon wafer by bulk micromachining. The density of the films was determined from quartz crystal microbalance measurements, as well as from the resonant modes of the cantilever beams, which were mechanically excited using an atomic force microscope. It was found that both the Young's modulus and density of the films were significantly reduced with decreasing deposition temperature. The decrease in Young's modulus is attributed to the decreasing material density. The decrease in density with decreasing deposition temperature is believed to be due to the slower diffusion rates of the deposited species, which retarded the densification of the film during the deposition process.

  7. Effects of deposition temperature on the mechanical and physical properties of silicon nitride thin films

    NASA Astrophysics Data System (ADS)

    Walmsley, B. A.; Liu, Y.; Hu, X. Z.; Bush, M. B.; Winchester, K. J.; Martyniuk, M.; Dell, J. M.; Faraone, L.

    2005-08-01

    This study investigates the mechanical and physical properties of low-temperature plasma-enhanced chemical-vapor-deposited silicon nitride thin films, with particular respect to the effect of deposition temperature. The mechanical properties of the films were evaluated by both nanoindentation and microcantilever beam-bending techniques. The cantilever beam specimens were fabricated from silicon nitride thin films deposited on (100) silicon wafer by bulk micromachining. The density of the films was determined from quartz crystal microbalance measurements, as well as from the resonant modes of the cantilever beams, which were mechanically excited using an atomic force microscope. It was found that both the Young's modulus and density of the films were significantly reduced with decreasing deposition temperature. The decrease in Young's modulus is attributed to the decreasing material density. The decrease in density with decreasing deposition temperature is believed to be due to the slower diffusion rates of the deposited species, which retarded the densification of the film during the deposition process.

  8. 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

  9. 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.

  10. Structural and optical characterizations of chemically deposited cadmium selenide thin films

    SciTech Connect

    Khomane, A.S.

    2011-10-15

    Highlights: {yields} CdSe thin films deposited first time using formic acid as a complexing agent. {yields} The deposited thin films were characterized by XRD, SEM, UV-vis-NIR and electrical techniques. {yields} X-ray diffraction analysis shows presence of zinc blende crystal structure. -- Abstract: Synthesis of cadmium selenide thin films by CBD method has been presented. The deposited film samples were subjected to XRD, SEM, UV-vis-NIR and TEP characterization. X-ray diffraction analysis showed that CdSe film sample crystallized in zinc blende or cubic phase structure. SEM studies reveal that the grains are spherical in shape and uniformly distributed all over the surface of the substrates. The optical band gap energy of as deposited film sample was found to be in the order of 1.8 eV. The electrical conductivity of the film sample was found to be 10{sup -6} ({Omega} cm){sup -1} with n-type of conduction mechanism.

  11. Anomalous scaling behavior and surface roughening in molecular thin-film deposition

    SciTech Connect

    Yim, S.; Jones, T. S.

    2006-04-15

    The thin film growth dynamics of a molecular semiconductor, free-base phthalocyanine (H{sub 2}Pc), deposited by organic molecular beam deposition, has been studied by atomic force microscopy (AFM) and height difference correlation function (HDCF) analysis. The measured dynamic scaling components ({alpha}{sub loc}=0.61{+-}0.12, {beta}=1.02{+-}0.08, and 1/z=0.72{+-}0.13) are consistent with rapid surface roughening and anomalous scaling behavior. A detailed analysis of AFM images and simple growth models suggest that this behavior arises from the pronounced upward growth of crystalline H{sub 2}Pc mounds during the initial stages of thin film growth.

  12. Preparation of vanadium oxide thin films modified with Ag using a hybrid deposition configuration

    NASA Astrophysics Data System (ADS)

    Gonzalez-Zavala, F.; Escobar-Alarcón, L.; Solís-Casados, D. A.; Rivera-Rodríguez, C.; Basurto, R.; Haro-Poniatowski, E.

    2016-04-01

    The application of a hybrid deposition configuration, formed by the interaction of a laser ablation plasma with a flux of atomic vapor, to deposit vanadium oxide thin films modified with different amounts of silver, is reported. The effect of the amount of Ag incorporated in the films on their structural, morphological, compositional and optical properties was studied. The obtained results reveal that films with variable Ag content from 11.7 to 24.6 at.% were obtained. Depending on the silver content, the samples show very different surface morphologies. Optical characterization indicates the presence of nanostructures of Ag. Thin films containing silver exhibit better photocatalytic performances than unmodified V2O5 films. Raman spectra reveal that as the silver content is increased, the signals associated with V2O5 disappear and new modes attributed mainly to silver vanadates appear suggesting the formation of ternary compounds.

  13. Photovoltaic properties of ferroelectric BaTiO3 thin films RF sputter deposited on silicon

    NASA Technical Reports Server (NTRS)

    Dharmadhikari, V. S.; Grannemann, W. W.

    1982-01-01

    Ferroelectric thin films of BaTiO3 have been successfully deposited on n-type silicon substrates at temperatures above 500 C by RF sputtering in an O2/Ar atmosphere. Analysis by X-ray diffraction patterns show that films deposited at room temperature are amorphous. At temperatures above 500 C, crystalline BaTiO3 films with a tetragonal structure are obtained. The polarization-electric field (P-E) hysteresis loops and a broad peak in the dielectric constant versus temperature curve at Curie point indicate that the RF sputtered BaTiO3 films are ferroelectric. An anomalous photovoltaic effect is observed in these thin films which is related to the remanent polarization of the material. The results on open-circuit and short-circuit measurements provide an important basis for a better understanding of the role of photovoltaic field, photovoltaic current, and the pyroelectric properties in photoferroelectric domain switching.

  14. Uses of ion bombardment in thin-film deposition

    SciTech Connect

    Erck, R.A.; Fenske, G.R.; Erdemir, A.

    1990-10-01

    Use of plasma- and ion-beam-modified surfaces and surface coatings in continually expanding in engineering disciplines. The purpose of these modifications and treatments is to impart favorable properties, such as wear resistance and lubricity, to the surfaces, while at the same time retaining the strength or toughness of the bulk materials. Energetic-ion bombardment can be used to modify the structural and chemical properties of surfaces or applied coatings. Ion-implantation has been used for many years, and recently, other surface-modification techniques, among them ion-beam mixing and ion-beam-assisted deposition, have attracted attention because they permit application of highly adherent lubricious and wear-resistant films. In this paper, ion-beam techniques are described from the viewpoint of ion-surface interactions, and some avenues for the engineering of tribological surfaces are presented. 100 refs., 4 figs.

  15. MgB 2 thin films by hybrid physical-chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Xi, X. X.; Pogrebnyakov, A. V.; Xu, S. Y.; Chen, K.; Cui, Y.; Maertz, E. C.; Zhuang, C. G.; Li, Qi; Lamborn, D. R.; Redwing, J. M.; Liu, Z. K.; Soukiassian, A.; Schlom, D. G.; Weng, X. J.; Dickey, E. C.; Chen, Y. B.; Tian, W.; Pan, X. Q.; Cybart, S. A.; Dynes, R. C.

    2007-06-01

    Hybrid physical-chemical vapor deposition (HPCVD) has been the most effective technique for depositing MgB 2 thin films. It generates high magnesium vapor pressures and provides a clean environment for the growth of high purity MgB 2 films. The epitaxial pure MgB 2 films grown by HPCVD show higher-than-bulk Tc due to tensile strain in the films. The HPCVD films are the cleanest MgB 2 materials reported, allowing basic research, such as on magnetoresistance, that reveals the two-band nature of MgB 2. The carbon-alloyed HPCVD films demonstrate record-high Hc2 values promising for high magnetic field applications. The HPCVD films and multilayers have enabled the fabrication of high quality MgB 2 Josephson junctions.

  16. Properties of antimony doped ZnO thin films deposited by spray pyrolysis technique

    SciTech Connect

    Sadananda Kumar, N. Bangera, Kasturi V.; Shivakumar, G. K.

    2015-07-15

    Antimony (Sb) doped zinc oxide (ZnO) thin films were deposited on the glass substrate at 450°C using spray pyrolysis technique. Effect of Sb doping on surface morphology structural, optical and electrical properties were studied. X-ray diffraction (XRD) analysis showed that both the undoped and doped ZnO thin films are polycrystalline in nature with (101) preferred orientation. SEM analysis showed a change in surface morphology of Sb doped ZnO thin films. Doping results in a marked increase in conductivity without affecting the transmittance of the films. ZnO films prepared with 3 at % Sb shows the lowest resistivity of 0.185 Ohm cm with a Hall mobility of 54.05 cm{sup 2} V{sup –1} s{sup –1}, and a hole concentration of 6.25 × 10{sup 17} cm{sup –3}.

  17. Amorphous indium gallium zinc oxide thin film grown by pulse laser deposition technique

    NASA Astrophysics Data System (ADS)

    Mistry, Bhaumik V.; Joshi, U. S.

    2016-05-01

    Highly electrically conducting and transparent in visible light IGZO thin film were grown on glass substrate at substrate temperature of 400 C by a pulse laser deposition techniques. Structural, surface, electrical, and optical properties of IGZO thin films were investigated at room temperature. Smooth surface morphology and amorphous nature of the film has been confirmed from the AFM and GIXRD analysis. A resistivity down to 7.7×10-3 V cm was reproducibly obtained while maintaining optical transmission exceeding 70% at wavelengths from 340 to 780 nm. The carrier densities of the film was obtain to the value 1.9×1018 cm3, while the Hall mobility of the IGZO thin film was 16 cm2 V-1S-1.

  18. Epitaxial niobium dioxide thin films by reactive-biased target ion beam deposition

    SciTech Connect

    Wang, Yuhan; Comes, Ryan B.; Kittiwatanakul, Salinporn; Wolf, Stuart A.; Lu, Jiwei

    2015-03-01

    Epitaxial NbO2 thin films were synthesized on Al2O3 (0001) substrates via reactive bias target ion beam deposition. X-ray diffraction and Raman spectra were used to confirm the tetragonal phase of pure NbO2. Through XPS, it was found that there was a ~ 1.3 nm thick Nb2O5 layer on the surface and the bulk of the thin film was NbO2. The epitaxial relationship between NbO2 film and substrate was determined. Electrical transport measurement as a function of temperature showed that the conduction mechanism could be described by variable range hopping mechanism.

  19. Determination of dispersion parameters of thermally deposited CdTe thin film

    NASA Astrophysics Data System (ADS)

    Dhimmar, J. M.; Desai, H. N.; Modi, B. P.

    2016-05-01

    Cadmium Telluride (CdTe) thin film was deposited onto glass substrates under a vacuum of 5 × 10-6 torr by using thermal evaporation technique. The prepared film was characterized for dispersion analysis from reflectance spectra within the wavelength range of 300 nm - 1100 nm which was recorded by using UV-Visible spectrophotometer. The dispersion parameters (oscillator strength, oscillator wavelength, high frequency dielectric constant, long wavelength refractive index, lattice dielectric constant and plasma resonance frequency) of CdTe thin film were investigated using single sellimeir oscillator model.

  20. 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.

  1. Development of aerosol assisted chemical vapor deposition for thin film fabrication

    NASA Astrophysics Data System (ADS)

    Maulana, Dwindra Wilham; Marthatika, Dian; Panatarani, Camellia; Mindara, Jajat Yuda; Joni, I. Made

    2016-02-01

    Chemical vapor deposition (CVD) is widely used to grow a thin film applied in many industrial applications. This paper report the development of an aerosol assisted chemical vapor deposition (AACVD) which is one of the CVD methods. Newly developed AACVD system consists of a chamber of pyrex glass, two wire-heating elements placed to cover pyrex glass, a substrate holder, and an aerosol generator using an air brush sprayer. The temperature control system was developed to prevent condensation on the chamber walls. The control performances such as the overshoot and settling time were obtained from of the developed temperature controller. Wire-heating elements were controlled at certain setting value to heat the injected aerosol to form a thin film in the substrate. The performance of as-developed AACVD system tested to form a thin film where aerosol was sprayed into the chamber with a flow rate of 7 liters/minutes, and vary in temperatures and concentrations of precursor. The temperature control system have an overshoot around 25 °C from the desired set point temperature, very small temperature ripple 2 °C and a settling time of 20 minutes. As-developed AACVD successfully fabricated a ZnO thin film with thickness of below 1 µm. The performances of system on formation of thin films influenced by the generally controlled process such as values of setting temperature and concentration where the aerosol flow rate was fixed. Higher temperature was applied, the more uniform ZnO thin films were produced. In addition, temperature of the substrate also affected on surface roughness of the obtained films, while concentration of ZnO precursor determined the thickness of produce films. It is concluded that newly simple AACVD can be applied to produce a thin film.

  2. Deposition and Characterization of Thin Films on Metallic Substrates

    NASA Technical Reports Server (NTRS)

    Gatica, Jorge E.

    2005-01-01

    A CVD method was successfully developed to produce conversion coatings on aluminum alloys surfaces with reproducible results with a variety of precursors. A well defined protocol to prepare the precursor solutions formulated in a previous research was extended to other additives. It was demonstrated that solutions prepared following such a protocol could be used to systematically generate protective coatings onto aluminum surfaces. Experiments with a variety of formulations revealed that a refined deposition protocol yields reproducible conversion coatings of controlled composition. A preliminary correlation between solution formulations and successful precursors was derived. Coatings were tested for adhesion properties enhancement for commercial paints. A standard testing method was followed and clear trends were identified. Only one precursors was tested systematically. Anticipated work on other precursors should allow a better characterization of the effect of intermetallics on the production of conversion/protective coatings on metals and ceramics. The significance of this work was the practical demonstration that chemical vapor deposition (CVD) techniques can be used to systematically generate protective/conversion coating on non-ferrous surfaces. In order to become an effective approach to replace chromate-based pre- treatment processes, namely in the aerospace or automobile industry, the process parameters must be defined more precisely. Moreover, the feasibility of scale-up designs necessitates a more comprehensive characterization of the fluid flow, transport phenomena, and chemical kinetics interacting in the process. Kinetic characterization showed a significantly different effect of magnesium-based precursors when compared to iron-based precursors. Future work will concentrate on refining the process through computer simulations and further experimental studies on the effect of other transition metals to induce deposition of conversion/protective films

  3. Nanocrystalline CuInSSe thin films by chemical bath deposition technique

    NASA Astrophysics Data System (ADS)

    Shrotriya, Vipin; Rajaram, P.

    2016-05-01

    Crystalline CuInSSe thin films have been deposited on glass substrate by chemical bath deposition technique. The CuCl2, InCl3, thiourea and SeO2 were used as source materials for the Cu2+, In3+, S2- and Se2- ions and the Cu/In ratio was kept at 1.0. EDC was used as a complexing agent. The XRD, Scanning Electron Microscope (SEM), Energy Dispersive Analysis of X-Ray (EDAX) and Optical transmission studies were used for structural analysis, surface morphology, elemental analysis and optical band gap, of the grown thin films respectively. The deposition parameters such as pH, deposition temperature and deposition time were optimized.

  4. Local bonding environment of plasma deposited nitrogen-rich silicon nitride thin films

    NASA Astrophysics Data System (ADS)

    Soh, Martin T. K.; Savvides, N.; Musca, Charles A.; Martyniuk, Mariusz P.; Faraone, Lorenzo

    2005-05-01

    Plasma deposited nitrogen-rich silicon nitride thin films were prepared at temperatures between 80 and 300 °C. The infrared transmission (400-4000cm-1) was measured, and selected absorption bands were quantified through a multiple Lorentzian oscillator parametric analysis. It is observed that the concentration of silicon-centered tetrahedra bonded together through nitrogen atoms increases monotonically with increasing deposition temperature. A qualitative model is presented to highlight the impact of the active adsorption site density on the degree of stepped (ordered) nucleation at the vapor-film interface. The importance of this growth profile, in particular for micro-systems-technology, is discussed in conjunction with measurements of the biaxial modulus and residual stress of the thin films. A mechanism for residual stress controllability is also presented. The atomic concentrations of silicon, nitrogen, and hydrogen in the thin films were calculated using infrared calibration factors derived from the deposition temperature dependent condensation processes. The results for silicon nitride thin films deposited at 300 °C were observed to be similar in composition to silicon diimide. Additional observations of the infrared transmission characteristics are reported, which include the identification of silazane bridge characteristics for the absorption feature around 610cm-1, which is typically associated with Si-H (bending) absorption.

  5. Effects of Buffer Salt Concentration on the Dominated Deposition Mechanism and Optical Characteristics of Chemically Deposited Cadmium Sulfide Thin Films

    NASA Astrophysics Data System (ADS)

    Kakhaki, Z. Makhdoumi; Youzbashi, A.; Sangpour, P.; Kazemzadeh, A.; Naderi, N.; Bazargan, A. M.

    2016-02-01

    Effects of buffer salt concentration on the rate of deposition, dominated deposition mechanism and subsequently the structural, morphological, and optical properties of cadmium sulfide (CdS) thin films deposited by chemical bath deposition (CBD) on glass substrate were investigated. The precursors were chosen to be cadmium chloride (CdCl2) as the cadmium source, thiourea (CS(NH2)2) as the sulfur source, ammonium nitrate (NH4NO3) as the buffer salt and ammonia as the complexing agent and the pH controller. The influence of the NH4NO3 concentration on the structure, morphology, film uniformity, stoichiometry and optical properties of CdS thin films was also studied by X-ray diffractometer (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray (EDX) spectroscope, uv-visible and photoluminescence (PL) spectroscopes. The XRD studies revealed that all the deposited films exhibited a (002)h/(111)c preferred orientation. The crystallite size was increased from 20nm to 30nm by the increase of concentration of NH4NO3 from 0.5M to 2.5M. The morphology of CdS thin films were agglomerated spherical particles consisted of smaller particles. The surface of thin films deposited at the NH4NO3 concentration of 0.5M was compact and smooth. The increase of the concentration of NH4NO3 decreased the packing density of the films. The optical band gap was in the range of 2.25-2.4eV, which was decreased by the decrement of packing density. The PL spectra showed two peaks centered at 400nm and 500nm which are attributed to violet and band-to-band emissions, respectively.

  6. Characterization Of Fe{sub 1-x}Co{sub x}Si Thin Films Deposited Via Pulsed Laser Deposition

    SciTech Connect

    Manyala, N.; Ngom, Balla; Kana-Kana, J. B.; Bucher, Remy; Maaza, M.; Di Tusa, J. F.

    2008-09-23

    We report on the structural and morphological characterization of B20 cubic structure Fe{sub 1-x}Co{sub x}Si thin films grown by pulsed laser deposition for the concentration range 0{<=}x{<=}0.3 deposited on Si (111) substrate. The x-ray diffraction, Rutherford back scattering (RBS), Scanning Electron microscopy (SEM) and Atomic force microscopy (AFM) of the films show that all the films are single phase B20 cubic structure with concentrations close to expected values, very smooth and dense with surface roughness less than 0.8 nm.

  7. The impact of thickness and thermal annealing on refractive index for aluminum oxide thin films deposited by atomic layer deposition.

    PubMed

    Wang, Zi-Yi; Zhang, Rong-Jun; Lu, Hong-Liang; Chen, Xin; Sun, Yan; Zhang, Yun; Wei, Yan-Feng; Xu, Ji-Ping; Wang, Song-You; Zheng, Yu-Xiang; Chen, Liang-Yao

    2015-01-01

    The aluminum oxide (Al2O3) thin films with various thicknesses under 50 nm were deposited by atomic layer deposition (ALD) on silicon substrate. The surface topography investigated by atomic force microscopy (AFM) revealed that the samples were smooth and crack-free. The ellipsometric spectra of Al2O3 thin films were measured and analyzed before and after annealing in nitrogen condition in the wavelength range from 250 to 1,000 nm, respectively. The refractive index of Al2O3 thin films was described by Cauchy model and the ellipsometric spectra data were fitted to a five-medium model consisting of Si substrate/SiO2 layer/Al2O3 layer/surface roughness/air ambient structure. It is found that the refractive index of Al2O3 thin films decrease with increasing film thickness and the changing trend revised after annealing. The phenomenon is believed to arise from the mechanical stress in ALD-Al2O3 thin films. A thickness transition is also found by transmission electron microscopy (TEM) and SE after 900°C annealing. PMID:25852343

  8. The impact of thickness and thermal annealing on refractive index for aluminum oxide thin films deposited by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Wang, Zi-Yi; Zhang, Rong-Jun; Lu, Hong-Liang; Chen, Xin; Sun, Yan; Zhang, Yun; Wei, Yan-Feng; Xu, Ji-Ping; Wang, Song-You; Zheng, Yu-Xiang; Chen, Liang-Yao

    2015-02-01

    The aluminum oxide (Al2O3) thin films with various thicknesses under 50 nm were deposited by atomic layer deposition (ALD) on silicon substrate. The surface topography investigated by atomic force microscopy (AFM) revealed that the samples were smooth and crack-free. The ellipsometric spectra of Al2O3 thin films were measured and analyzed before and after annealing in nitrogen condition in the wavelength range from 250 to 1,000 nm, respectively. The refractive index of Al2O3 thin films was described by Cauchy model and the ellipsometric spectra data were fitted to a five-medium model consisting of Si substrate/SiO2 layer/Al2O3 layer/surface roughness/air ambient structure. It is found that the refractive index of Al2O3 thin films decrease with increasing film thickness and the changing trend revised after annealing. The phenomenon is believed to arise from the mechanical stress in ALD-Al2O3 thin films. A thickness transition is also found by transmission electron microscopy (TEM) and SE after 900°C annealing.

  9. Effects of Post-Deposition Annealing on the Properties of Calcium Manganese Oxide Thin Films

    NASA Astrophysics Data System (ADS)

    Ferrone, Natalie; Chaudhry, Adeel; Hart, Cacie; Lawson, Bridget; Houston, David; Neubauer, Samuel; Johnson, Anthony; Schaefer, David; Kolagani, Rajeswari

    We will present our results on the effects of post-deposition annealing on the structural and electrical properties of CaMnO3-d thin films grown by Pulsed Laser deposition. The thin films are epitaxially grown on (100) LaAlO3 which has larger in-plane lattice parameters than that of bulk CaMnO3, which leads to bi-axial tensile strain in the thin films. Results from our laboratory show that bi-axial tensile strain leads to low resistivity in thinner films, the resistivity increasing with increasing thickness. These results are suggestive of a coupling between strain and oxygen stoichiometry in the thin films. We have investigated the effects of post-deposition annealing in various gas ambients towards the goal of understanding the effects of relaxation and oxygen stoichiometric changes. We will present a comparison of the structural and electrical properties of as-grown and post-annealed films over a range of thicknesses. Support from Towson University Office of Undergraduate Research, Fisher Endowment Grant & Undergraduate Research Grant from the Fisher College of Science & Mathematics, Seed Funding Grant from the School of Emerging technologies, & NSF Grant ECCS 112856.

  10. Ion-beam assisted deposition of thin molybdenum films studied by molecular dynamics simulation

    NASA Astrophysics Data System (ADS)

    Robbemond, Arie; Thijsse, Barend J.

    1997-05-01

    We report results obtained by molecular dynamics simulation of low energy argon-ion assisted growth of thin molybdenum films (≈ 20 Å). The effects of a single ion impact are discussed, but more particularly we consider film growth from a manufacturing viewpoint and examine the properties of the completed films. Results for ion-beam assisted deposition are compared with those for unassisted growth (i.e. physical vapor deposition). Surface orientation, atomic displacements, surface roughness, sputtering, point defects, and the influence of off-normal atom incidence are discussed.

  11. Atomic layer deposition of quaternary oxide (La,Sr)CoO3-δ thin films.

    PubMed

    Ahvenniemi, E; Matvejeff, M; Karppinen, M

    2015-05-01

    A novel atomic layer deposition (ALD) process was developed for fabricating quaternary cobalt oxide (La1-xSrx)CoO3-δ thin films having the eye on future applications of such films in e.g. solid oxide fuel cell cathodes, oxygen separation membranes or thermocouples. The deposition parameters and the conditions of a subsequent annealing step were systematically investigated, and using the thus optimized parameters the cation stoichiometry in the films could be accurately tuned. The most detailed study was conducted for x = 0.7, i.e. the composition with the highest application potential within the (La1-xSrx)CoO3-δ system. PMID:25826428

  12. Metal-organic chemical vapour deposition of polycrystalline tetragonal indium sulphide (InS) thin films

    NASA Technical Reports Server (NTRS)

    Macinnes, Andrew N.; Cleaver, William M.; Barron, Andrew R.; Power, Michael B.; Hepp, Aloysius F.

    1992-01-01

    The dimeric indium thiolate /(t Bu)2In(mu-S sup t Bu)/2 has been used as a single-source precursor for the MOCVD of InS thin films. The dimeric In2S2 core is proposed to account for the formation of the nonequilibrium high-pressure tetragonal phase in the deposited films. Analysis of the deposited films has been obtained by TEM, with associated energy-dispersive X-ray analysis and X-ray photoelectron spectroscopy.

  13. Solution-deposited thin films as passive and active light-guides.

    PubMed

    Ulrich, R; Weber, H P

    1972-02-01

    Light-guiding thin films of various materials have been deposited on glass substrates from liquid solutions by slow evaporation of the solvent. The attenuation of the guided light wave in some of these films is as low as that in the best films prepared by other methods. Film deposition from solution is done at or near room temperature. Therefore, this technique allows us to dope the thin films with organic molecules, e.g., laser dyes. The preparation and light-guiding properties of the doped and undoped films are described. The materials studied were epoxy, lead-silica, polyurethane, and Kodak photoresist KPR. Films of the first and second material have shown losses as low as 0.3 dB/cm at wavelengths of 0.633 microm and 1.064 microm, respectively. Films of polyurethane have been prepared with rhodamine 6G doping. When pumped with a pulsed nitrogen laser, the doped films showed optical gains of up to 100 dB/cm. The KPR films have an attenuation of ~1 dB/cm at 1.064 microm. This low optical loss, in combination with the hotographic sensitivity of the KPR, offers the possibility of fabricating integrated optical circuits directly in the photoresist films. PMID:20111519

  14. Studies on Structural, Morphological and Optical Properties of Chemically Deposited CdS1-xSex Thin Films.

    PubMed

    Deo, Soumya R; Singh, Ajaya K; Deshmukh, Lata; Singh, Narendra Pratap; Aleksandrova, Mariya P

    2016-03-01

    The thin films of CdS1-xSex were successfully deposited over glass substrates by chemical bath deposition technique. Cadmium acetate, thiourea and sodium selenosulfate were used as source materials for Cd(2+), S(2-) and Se(2-) ions, while 2-mercaptoethanol was used as capping agent. The various deposition conditions such as precursor concentration, deposition temperature, pH and deposition time were optimized for the deposition of CdS1-xSex thin films of good quality and the films were annealed at 200° and 300 °C. The structural, morphological, chemical and optical properties were examined by various characterization techniques and discussed in detail. The optical band gap of CdS1-xSex thin film samples were estimated and found in the range from 2.11 to 1.79 eV for as-deposited and annealed thin films. PMID:26634707

  15. Impact of sputter deposition parameters on molybdenum nitride thin film properties

    NASA Astrophysics Data System (ADS)

    Stöber, L.; Konrath, J. P.; Krivec, S.; Patocka, F.; Schwarz, S.; Bittner, A.; Schneider, M.; Schmid, U.

    2015-07-01

    Molybdenum and molybdenum nitride thin films are presented, which are deposited by reactive dc magnetron sputtering. The influence of deposition parameters, especially the amount of nitrogen during film synthesization, to mechanical and electrical properties is investigated. The crystallographic phase and lattice constants are determined by x-ray diffraction analyses. Further information on the microstructure as well as on the biaxial film stress are gained from techniques such as transmission electron microscopy, scanning electron microscopy and the wafer bow. Furthermore, the film resistivity and the temperature coefficient of resistance are measured by the van der Pauw technique starting from room temperature up to 300 °C. Independent of the investigated physical quantity, a dominant dependence on the sputtering gas nitrogen content is observed compared to other deposition parameters such as the plasma power or the sputtering gas pressure in the deposition chamber.

  16. Transparent ferrimagnetic semiconducting CuCr2O4 thin films by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Tripathi, T. S.; Yadav, C. S.; Karppinen, M.

    2016-04-01

    We report the magnetic and optical properties of CuCr2O4 thin films fabricated by atomic layer deposition (ALD) from Cu(thd)2, Cr(acac)3, and ozone; we deposit 200 nm thick films and anneal them at 700 °C in oxygen atmosphere to crystallize the spinel phase. A ferrimagnetic transition at 140 K and a direct bandgap of 1.36 eV are determined for the films from magnetic and UV-vis spectrophotometric measurements. Electrical transport measurements confirm the p-type semiconducting behavior of the films. As the ALD technique allows the deposition of conformal pin-hole-free coatings on complex 3D surfaces, our CuCr2O4 films are interesting material candidates for various frontier applications.

  17. Biomolecular papain thin films grown by matrix assisted and conventional pulsed laser deposition: A comparative study

    NASA Astrophysics Data System (ADS)

    György, E.; Pérez del Pino, A.; Sauthier, G.; Figueras, A.

    2009-12-01

    Biomolecular papain thin films were grown both by matrix assisted pulsed laser evaporation (MAPLE) and conventional pulsed laser deposition (PLD) techniques with the aid of an UV KrF∗ (λ =248 nm, τFWHM≅20 ns) excimer laser source. For the MAPLE experiments the targets submitted to laser radiation consisted on frozen composites obtained by dissolving the biomaterial powder in distilled water at 10 wt % concentration. Conventional pressed biomaterial powder targets were used in the PLD experiments. The surface morphology of the obtained thin films was studied by atomic force microscopy and their structure and composition were investigated by Fourier transform infrared spectroscopy. The possible physical mechanisms implied in the ablation processes of the two techniques, under comparable experimental conditions were identified. The results showed that the growth mode, surface morphology as well as structure of the deposited biomaterial thin films are determined both by the incident laser fluence value as well as target preparation procedure.

  18. Low leakage current gate dielectrics prepared by ion beam assisted deposition for organic thin film transistors

    NASA Astrophysics Data System (ADS)

    Kim, Chang Su; Jo, Sung Jin; Kim, Jong Bok; Ryu, Seung Yoon; Noh, Joo Hyon; Baik, Hong Koo; Lee, Se Jong; Kim, Youn Sang

    2007-12-01

    This communication reports on the fabrication of low operating voltage pentacene thin-film transistors with high-k gate dielectrics by ion beam assisted deposition (IBAD). These densely packed dielectric layers by IBAD show a much lower level of leakage current than those created by e-beam evaporation. These results, from the fact that those thin films deposited with low adatom mobility, have an open structure, consisting of spherical grains with pores in between, that acts as a significant path for leakage current. By contrast, our results demonstrate the potential to limit this leakage. The field effect mobility, on/off current ratio, and subthreshold slope obtained from pentacene thin-film transistors (TFTs) were 1.14 cm2/V s, 105, and 0.41 V/dec, respectively. Thus, the high-k gate dielectrics obtained by IBAD show promise in realizing low leakage current, low voltage, and high mobility pentacene TFTs.

  19. Li-rich Thin Film Cathode Prepared by Pulsed Laser Deposition

    PubMed Central

    Yan, Binggong; Liu, Jichang; Song, Bohang; Xiao, Pengfei; Lu, Li

    2013-01-01

    Li-rich layer-structured cathode thin films are prepared by pulsed laser deposition. X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), X-ray photoelectron spectroscopy (XPS) and electrochemical testing in half battery cells are used to characterize crystal structure, surface morphology, chemical valence states and electrochemical performance of these thin films, respectively. It is observed that partial layer to spinel transformation takes place during post annealing, and the layered structure further gradually transforms to spinel during electrochemical cycling based on the analysis of dQ/dV. Electrochemical measurement shows that the thin film electrode deposited at 350 mTorr and post-annealed at 800°C possesses the best performance. PMID:24276678

  20. Raman spectroscopy of ZnMnO thin films grown by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Orozco, S.; Riascos, H.; Duque, S.

    2016-02-01

    ZnMnO thin films were grown by Pulsed Laser Deposition (PLD) technique onto Silicon (100) substrates at different growth conditions. Thin films were deposited varying Mn concentration, substrate temperature and oxygen pressure. ZnMnO samples were analysed by using Raman Spectroscopy that shows a red shift for all vibration modes. Raman spectra revealed that nanostructure of thin films was the same of ZnO bulk, wurzite hexagonal structure. The structural disorder was manifested in the line width and shape variations of E2(high) and E2(low) modes located in 99 and 434cm-1 respectively, which may be due to the incorporation of Mn ions inside the ZnO crystal lattice. Around 570cm-1 was found a peak associated to E1(LO) vibration mode of ZnO. 272cm-1 suggest intrinsic host lattice defects. Additional mode centred at about 520cm-1 can be overlap of Si and Mn modes.

  1. Epitaxial thin film deposition of magnetostrictive materials and its effect on magnetic anisotropy

    NASA Astrophysics Data System (ADS)

    McClure, Adam Marc

    Magnetostriction means that the dimensions of a material depend on its magnetization. The primary goal of this dissertation was to understand the effect of magnetostriction on the magnetic anisotropy of single crystal magnetostrictive thin films, where the epitaxial pinning of the material to a substrate could inhibit its conversion to new dimensions. In order to address this goal, several Fe-based binary alloys were deposited onto various substrates by molecular beam epitaxy. The samples were characterized by an array of techniques including electron diffraction, Rutherford backscattering, vibrating sample magnetometry, ferromagnetic resonance, and x-ray absorption spectroscopies. The attempted growths of crystalline magnetostrictive thin films resulted in successful depositions of Fe1-xGax and Fe1-x Znx. Depositions onto MgO(001) substrates result in an in-plane cubic magnetic anisotropy, as expected from the cubic symmetry of the Fe-based thin films, and a strong out-of-plane uniaxial anisotropy that forces the magnetization to lie in the plane of the films. Depositions onto ZnSe/GaAs(001) substrates feature an additional in-plane uniaxial anisotropy. The magnitudes and signs of the in-plane anisotropies depend on the Ga content. Furthermore, the cubic anisotropy constant of Fe1-xGax samples deposited onto MgO substrates switches sign at a lower Ga concentration than is seen in bulk Fe1-xGax. The effect on the magnetic anisotropy of depositing a magnetostrictive material as an epitaxial thin film is influenced by the material's magnetostrictive properties and the substrate upon which it is deposited. In particular, pinning a magnetoelastic material to a substrate will modify its cubic anisotropy, and depositions on substrates compliant to an anisotropic strain relaxation may result in a strong in-plane uniaxial anisotropy.

  2. Chemical vapour deposition of thermochromic vanadium dioxide thin films for energy efficient glazing

    SciTech Connect

    Warwick, Michael E.A.; Binions, Russell

    2014-06-01

    Vanadium dioxide is a thermochromic material that undergoes a semiconductor to metal transitions at a critical temperature of 68 °C. This phase change from a low temperature monoclinic structure to a higher temperature rutile structure is accompanied by a marked change in infrared reflectivity and change in resistivity. This ability to have a temperature-modulated film that can limit solar heat gain makes vanadium dioxide an ideal candidate for thermochromic energy efficient glazing. In this review we detail the current challenges to such glazing becoming a commercial reality and describe the key chemical vapour deposition technologies being employed in the latest research. - Graphical abstract: Schematic demonstration of the effect of thermochromic glazing on solar radiation (red arrow represents IR radiation, black arrow represents all other solar radiation). - Highlights: • Vanadium dioxide thin films for energy efficient glazing. • Reviews chemical vapour deposition techniques. • Latest results for thin film deposition for vanadium dioxide.

  3. Investigation on single walled carbon nanotube thin films deposited by Langmuir Blodgett method

    SciTech Connect

    Vishalli, Dharamvir, Keya; Kaur, Ramneek; Raina, K. K.

    2015-05-15

    Langmuir Blodgett is a technique to deposit a homogeneous film with a fine control over thickness and molecular organization. Thin films of functionalized SWCNTs have been prepared by Langmuir Blodgett method. The good surface spreading properties of SWCNTs at air/water interface are indicated by surface pressure-area isotherm and the monolayer formed on water surface is transferred onto the quartz substrate by vertical dipping. A multilayer film is thus obtained in a layer by layer manner. The film is characterized by Atomic Force Microscope (AFM), UV-Vis-NIR spectroscopy and FTIR.AFM shows the surface morphology of the deposited film. UV-Vis-NIR spectroscopy shows the characteristic peaks of semiconducting SWCNTs. The uniformity of LB film can be used further in understanding the optical and electrical behavior of these materials.

  4. Vacancies Ordered in Screw Form (VOSF) and Layered Indium Selenide Thin Film Deposition by Laser Back Ablation

    SciTech Connect

    Beck, Kenneth M.; Wiley, William R.; Venkatasubramanian, Eswaranand; Ohuchi, Fumio S.

    2009-09-30

    Indium selenide thin films are important due to their applications in non-volatile memory and solar cells. In this work, we present an initial study of a new application of deposition-site selective laser back ablation (LBA) for making thin films of In2Se3. In-vacuo annealing and subsequent characterization of the films by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) indicate that control of substrate temperature during deposition and post-deposition annealing temperature is critical in determining the phase and composition of the films. The initial laser fluence and target film thickness determine the amount of material deposited onto the substrate.

  5. Synthesis and Characterization of Molybdenum Doped ZnO Thin Films by SILAR Deposition Method

    NASA Astrophysics Data System (ADS)

    Radha, R.; Sakthivelu, A.; Pradhabhan, D.

    2016-08-01

    Molybdenum (Mo) doped zinc oxide (ZnO) thin films were deposited on the glass substrate by Successive Ionic Layer Adsorption and Reaction (SILAR) deposition method. The effect of Mo dopant concentration of 5, 6.6 and 10 mol% on the structural, morphological, optical and electrical properties of n-type Mo doped ZnO films was studied. The X-ray diffraction (XRD) results confirmed that the Mo doped ZnO thin films were polycrystalline with wurtzite structure. The field emission scanning electron microscopy (FESEM) studies shows that the surface morphology of the films changes with Mo doping. A blue shift of the optical band gap was observed in the optical studies. Effect of Mo dopant concentration on electrical conductivity was studied and it shows comparatively high electrical conductivity at 10 mol% of Mo doping concentration.

  6. Embedded argon as a tool for sampling local structure in thin plasma deposited aluminum oxide films

    SciTech Connect

    Prenzel, Marina; Kortmann, Annika; Keudell, Achim von; Arcos, Teresa de los; Winter, Joerg

    2012-11-15

    Al{sub 2}O{sub 3} thin films, either amorphous or of varying degrees of crystallinity, were deposited by two-frequency radio-frequency magnetron sputtering. Film crystallinity was investigated by Fourier transform infrared spectroscopy and X-ray diffraction (XRD). X-ray photoelectron spectroscopy (XPS) was employed to determine the amount of Ar naturally trapped within the films during the deposition process. A clear correlation was found between the existence of crystalline phases, as determined by XRD, and a shift towards lower binding energy positions of the Ar2p core levels of embedded gas. The shift is due to differences in the local Al{sub 2}O{sub 3} matrix (amorphous or crystalline) of the embedded gas, thus, providing an XPS fingerprint that can be used to qualitatively determine the presence or absence of crystalline phases in very thin films.

  7. Characterization and kinetic investigation of electroless deposition of pure cobalt thin films on silicon substrates

    NASA Astrophysics Data System (ADS)

    Cheng, S. L.; Hsu, T. L.; Lee, T.; Lee, S. W.; Hu, J. C.; Chen, L. T.

    2013-01-01

    We present here the results of studies of the synthesis and growth behaviors of electroless pure Co thin films on Pd-activated Si substrates using hydrazine as the reductant. Using the hydrazine-modified electroless Co plating processes, dense and continuous pure Co films were deposited on (0 0 1)Si for samples plated at 30-45 °C. This electroless plating process could be explained by the electrochemical mechanism. After a series of transmission electron microscopic examinations, the deposited Co films were determined to be polycrystalline with a hexagonal crystal structure and the average Co film thickness at each temperature studied was found to follow a linear relationship with the plating time. The deposition rates of pure Co films increase with the plating temperatures from 7.3 nm/min to 12.6 nm/min. By measuring the Co deposition rates at different plating temperatures, the activation energy for linear growth of the electroless Co thin films on Si substrates derived from an Arrhenius plot is about 32.6 kJ/mol. As the plating temperature was increased to 50 °C or higher, the plating solution became turbid and the formation of dendritic cobalt deposits was observed.

  8. Thin film solar cells grown by organic vapor phase deposition

    NASA Astrophysics Data System (ADS)

    Yang, Fan

    Organic solar cells have the potential to provide low-cost photovoltaic devices as a clean and renewable energy resource. In this thesis, we focus on understanding the energy conversion process in organic solar cells, and improving the power conversion efficiencies via controlled growth of organic nanostructures. First, we explain the unique optical and electrical properties of organic materials used for photovoltaics, and the excitonic energy conversion process in donor-acceptor heterojunction solar cells that place several limiting factors of their power conversion efficiency. Then, strategies for improving exciton diffusion and carrier collection are analyzed using dynamical Monte Carlo models for several nanostructure morphologies. Organic vapor phase deposition is used for controlling materials crystallization and film morphology. We improve the exciton diffusion efficiency while maintaining good carrier conduction in a bulk heterojunction solar cell. Further efficiency improvement is obtained in a novel nanocrystalline network structure with a thick absorbing layer, leading to the demonstration of an organic solar cell with 4.6% efficiency. In addition, solar cells using simultaneously active heterojunctions with broad spectral response are presented. We also analyze the efficiency limits of single and multiple junction organic solar cells, and discuss the challenges facing their practical implementations.

  9. Fabrication of multiferroic GdMnO3 thin film by pulsed laser deposition technique

    NASA Astrophysics Data System (ADS)

    Negi, Puneet; Agrawal, H. M.; Srivastava, R. C.; Asokan, K.

    2012-06-01

    Here, we report the fabrication of GdMnO3 multiferroic thin film on SrTiO3 (110) substrate by pulsed laser deposition (PLD) technique. The target sample was synthesized using modified solgel route. The thickness of the film observed by Talystep profilometer, is about 200 nm. X-ray diffraction and Raman spectroscopic techniques were used to investigate the structure of the target as well as of the film. The surface topography of the film was investigated by atomic force microscopy.

  10. 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.