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Sample records for cds thin films

  1. Optical and structural properties of sputtered CdS films for thin film solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Donguk [School of Electronic and Electrical Engineering, Sungkyunkwan University, Cheoncheon-dong 300, Jangan-gu, Suwon 440-746 (Korea, Republic of); Park, Young [High-Speed Railroad Infrastructure System Research Team, Korea Railroad Research Institute, Uiwang 437-757 (Korea, Republic of); Kim, Minha [School of Electronic and Electrical Engineering, Sungkyunkwan University, Cheoncheon-dong 300, Jangan-gu, Suwon 440-746 (Korea, Republic of); Choi, Youngkwan [Water Facility Research Center, K-water, 125, 1689 Beon-gil, Yuseong-daero, Yuseong-gu, Daejeon 305-730 (Korea, Republic of); Park, Yong Seob [Department of Photoelectronics Information, Chosun College of Science and Technology, Gwangju (Korea, Republic of); Lee, Jaehyoeng, E-mail: jaehyeong@skku.edu [School of Electronic and Electrical Engineering, Sungkyunkwan University, Cheoncheon-dong 300, Jangan-gu, Suwon 440-746 (Korea, Republic of)

    2015-09-15

    Graphical abstract: Photo current–voltage curves (a) and the quantum efficiency (QE) (b) for the solar cell with CdS film grown at 300 °C. - Highlights: • CdS thin films were grown by a RF magnetron sputtering method. • Influence of growth temperature on the properties of CdS films was investigated. • At higher T{sub g}, the crystallinity of the films improved and the grains enlarged. • CdS/CdTe solar cells with efficiencies of 9.41% were prepared at 300 °C. - Abstract: CdS thin films were prepared by radio frequency magnetron sputtering at various temperatures. The effects of growth temperature on crystallinity, surface morphology and optical properties of the films were characterized with X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman spectra, UV–visible spectrophotometry, and photoluminescence (PL) spectra. As the growth temperature was increased, the crystallinity of the sputtered CdS films was improved and the grains were enlarged. The characteristics of CdS/CdTe thin film solar cell appeared to be significantly influenced by the growth temperature of the CdS films. Thin film CdS/CdTe solar cells with efficiencies of 9.41% were prepared at a growth temperature of 300 °C.

  2. Chemical bath deposition of CdS thin films doped with Zn and Cu

    Indian Academy of Sciences (India)

    A I Oliva; J E Corona; R Patiño; A I Oliva-Avilés

    2014-04-01

    Zn- and Cu-doped CdS thin films were deposited onto glass substrates by the chemical bath technique. ZnCl2 and CuCl2 were incorporated as dopant agents into the conventional CdS chemical bath in order to promote the CdS doping process. The effect of the deposition time and the doping concentration on the physical properties of CdS films were investigated. The morphology, thickness, bandgap energy, crystalline structure and elemental composition of Zn- and Cu-doped CdS films were investigated and compared to the undoped CdS films properties. Both Zn- and Cu-doped CdS films presented a cubic crystalline structure with (1 1 1) as the preferential orientation. Lower values of the bandgap energy were observed for the doped CdS films as compared to those of the undoped CdS films. Zn-doped CdS films presented higher thickness and roughness values than those of Cu-doped CdS films. From the photoluminescence results, it is suggested that the inclusion of Zn and Cu into CdS crystalline structure promotes the formation of acceptor levels above the CdS valence band, resulting in lower bandgap energy values for the doped CdS films.

  3. Raman spectroscopy of optical properties in CdS thin films

    Directory of Open Access Journals (Sweden)

    Trajić J.

    2015-01-01

    Full Text Available Properties of CdS thin films were investigated applying atomic force microscopy (AFM and Raman spectroscopy. CdS thin films were prepared by using thermal evaporation technique under base pressure 2 x 10-5 torr. The quality of these films was investigated by AFM spectroscopy. We apply Raman scattering to investigate optical properties of CdS thin films, and reveal existence of surface optical phonon (SOP mode at 297 cm-1. Effective permittivity of mixture were modeled by Maxwell - Garnet approximation. [Projekat Ministarstva nauke Republike Srbije, br. 45003

  4. CdS thin films prepared by laser assisted chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, L.V.; Mendivil, M.I.; Garcia Guillen, G.; Aguilar Martinez, J.A. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Krishnan, B. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Avellaneda, D.; Castillo, G.A.; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, Av. Pedro de Alba s/n, Ciudad Universitaria, San Nicolas de los Garza, Nuevo Leon 66450 (Mexico); CIIDIT – Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

    2015-05-01

    Highlights: • CdS thin films by conventional CBD and laser assisted CBD. • Characterized these films using XRD, XPS, AFM, optical and electrical measurements. • Accelerated growth was observed in the laser assisted CBD process. • Improved dark conductivity and good photocurrent response for the LACBD CdS. - Abstract: In this work, we report the preparation and characterization of CdS thin films by laser assisted chemical bath deposition (LACBD). CdS thin films were prepared from a chemical bath containing cadmium chloride, triethanolamine, ammonium hydroxide and thiourea under various deposition conditions. The thin films were deposited by in situ irradiation of the bath using a continuous laser of wavelength 532 nm, varying the power density. The thin films obtained during deposition of 10, 20 and 30 min were analyzed. The changes in morphology, structure, composition, optical and electrical properties of the CdS thin films due to in situ irradiation of the bath were analyzed by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV–vis spectroscopy. The thin films obtained by LACBD were nanocrystalline, photoconductive and presented interesting morphologies. The results showed that LACBD is an effective synthesis technique to obtain nanocrystalline CdS thin films having good optoelectronic properties.

  5. Structure and property of CdS thin films with different residual chlorine content

    Science.gov (United States)

    Feng, Kai; Wu, Weibing; Shan, Beibei; Nan, Huilin

    2016-10-01

    Two types of CdS thin films were synthesized via chemical bath deposition (CBD) method from solutions of acetate and chloride, respectively. The structural and photoelectric characteristics of both CdS thin films were characterized by XRD, SEM, PL, UV-vis and electrochemical measurements. The pristine films were hexagonal regardless of anion type in CBD solutions. Cl residual was confirmed in the CdS film from the Cl-containing solution. The residual Cl helps to reduce S vacancies and improve the crystallinity during annealing, which is proved by the left shift of peaks in XRD patterns, the increased band gap, and the lower carrier concentration. The present results are significant in choosing suitable anions during the CBD deposition of CdS thin film for improving the device performance of CdTe solar cell.

  6. Structural and Optical Properties of CdS Thin Film Grown by Chemical Bath Deposition

    Directory of Open Access Journals (Sweden)

    S. Rajpal

    2013-07-01

    Full Text Available In this work we report synthesis and optical characterization of CdS thin films coated on glass substrate. The films were deposited using chemical bath deposition method. Scanning Electron microscopy shows a uniform film of CdS film at particular concentration and dipping time. The Energy Dispersive spectroscopy reveals the presence of Cd and S in the CdS film. X-Ray diffraction confirms the cubic structure of CdS deposited on glass and amorphous nature of glass. Optical and photoluminescence studies were done using UV-Visible spectroscopy and Photoluminescence spectroscopy respectively. We have determined bandgap by analyzing UV-Visible spectra results. Wettability studies were done using Optical Contact Angle, which confirms the hydrophobic nature of the CdS films.

  7. Preparation of polycrystalline CdS thin films by chemical bath deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E.A.; Kim, B.S.; Shin, S.H.; Park, J.I.; Park, K.J. [National Industrial Technology Inst., Kwacheon (Korea, Republic of). Div. of Inorganic Chemistry

    1996-12-31

    CdS has been recognized as a promising n-type window material for CdTe/CdS and CuInSe{sub 2}/CdS heterojunction thin film solar cells. The authors prepared CdS thin films from a solution containing cadmium acetate, thiourea, ammonia, and ammonium acetate. They varied fabrication conditions such as the concentrations of reactants, reaction temperature, and heat treatment, to investigate the changes in structural and optical properties of the film. Effects of substrate on the properties were also investigated.

  8. Deposition Methods and Properties of Polycrystalline CdS Thin Films

    Institute of Scientific and Technical Information of China (English)

    LIANG Qian; ZENG Guanggen; LI Bing; WANG Wenwu; JIANG Haibo; ZHANG Jingquan; LI Wei; WU Lili; FENG Lianghuan

    2015-01-01

    CdS thin film was used as a suitable window layer for CdS/CdTe solar cell, and the properties of CdS thin films deposited by pulsed laser deposition (PLD), chemical bath deposition (CBD) and magnetron sputtering (MS) were reported. The experimental results show that the transmittances of PLD-CdS thin films are about 85%and the band gaps are about 2.38-2.42eV. SEM results show that the surface of PLD-CdS thin film is much more compact and uniform. PLD is more suitable to prepare the CdS thin films than CBD and MS. Based on the thorough study, by using totally PLD technique, the FTO/PLD-CdS(150 nm)/CSS-CdTe solar cell (0.0707 cm2) can be prepared with an efficiency of 10.475%.

  9. Structural and Optical Study of Chemical Bath Deposited Nano-Structured CdS Thin Films

    Science.gov (United States)

    Kumar, Suresh; Sharma, Dheeraj; Sharma, Pankaj; Sharma, Vineet; Barman, P. B.; Katyal, S. C.

    2011-12-01

    CdS is commonly used as window layer in polycrystalline solar cells. The paper presents a structural and optical study of CdS nano-structured thin films. High quality CdS thin films are grown on commercial glass by means of chemical bath deposition. It involves an alkaline solution of cadmium salt, a complexant, a chalcogen source and a non-ionic surfactant. The films have been prepared under various process parameters. The chemically deposited films are annealed to estimate its effect on the structural and optical properties of films. These films (as -deposited and annealed) have been characterized by means of XRD, SEM and UV-Visible spectrophotometer. XRD of films show the nano-crystalline nature. The energy gap of films is found to be of direct in nature.

  10. Chemical surface deposition of cds thin films from CdI2 aqueous solution

    Directory of Open Access Journals (Sweden)

    G. Il’chuk

    2009-01-01

    Full Text Available For the first time using CdI2 solution CdS films on glass and ITO coated glass substrates were produced by the method of layerwise chemical surface deposition (ChSD. CdS thin films with the widths from 40 nm to 100 nm were obtained for windows in solar cells based on CdS/CdTe heterojunctions. Changes of the structural and optical properties of CdS films due to air annealing are shown.

  11. Growth and characterization of CdS thin films on polymer substrates for photovoltaic applications.

    Science.gov (United States)

    Park, Yongseob; Kim, Eung Kwon; Lee, Suho; Lee, Jaehyeong

    2014-05-01

    In this work, cadmium sulfide (CdS) films were deposited on flexible polymer substrates such as polycarbonate (PC) and polyethylene terephthalate (PET). The r.f. magnetron sputtering, which is cost-effective scalable technique, was used for the film deposition. The structural and optical properties of the films grown at different sputtering pressures were investigated. When the CdS film was deposited at lower pressure, the crystallinity and the preferred orientation toward c-axis in hexagonal phase was improved. However, the optical transmittance was reduced as the sputtering pressure was decreased. Compared with the glass substrate, CdS films grown on polymer substrates were exhibited some wore structural and optical characteristics. CdTe thin film solar cell applied to sputtered CdS as a window layer showed a maximum efficiency of 11.6%.

  12. A comparative study of CdS thin films deposited by different techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pérez-Hernández, G., E-mail: german.perez@ujat.mx [Universidad Juárez Autónoma de Tabasco, Avenida Universidad s/n, Col. Magisterial, Villahermosa, Tabasco 86040 (Mexico); Pantoja-Enríquez, J. [Centro de Investigación y Desarrollo Tecnológico en Energías Renovables, UNICACH, Libramiento Norte No 1150, Tuxtla Gutiérrez, Chiapas 29039 (Mexico); Escobar-Morales, B. [Instituto Tecnológico de Cancún, Avenida Kábah Km 3, Cancún, Quintana Roo 77500 (Mexico); Martinez-Hernández, D.; Díaz-Flores, L.L.; Ricardez-Jiménez, C. [Universidad Juárez Autónoma de Tabasco, Avenida Universidad s/n, Col. Magisterial, Villahermosa, Tabasco 86040 (Mexico); Mathews, N.R.; Mathew, X. [Centro de Investigación en Energía, Universidad Nacional Autónoma de México, Temixco, Morelos 62580 (Mexico)

    2013-05-01

    Cadmium sulfide thin-films were deposited on glass slides and SnO{sub 2}:F coated glass substrates by chemical bath deposition, sputtering and close-spaced sublimation techniques. The films were studied for the structural and opto-electronic properties after annealing in an ambient identical to that employed in the fabrication of CdTe/CdS devices. Quantum efficiency of the CdTe/CdS solar cells fabricated with CdS buffer films prepared by the three methods were investigated to understand the role of CdS film preparation method on the blue response of the devices. The higher blue response observed for the devices fabricated with chemical bath deposited CdS film is discussed. - Highlights: ► CdS films were prepared by different techniques. ► Role of CdS on the blue response of device was studied. ► Structural and optical properties of CdS were analyzed. ► Chemically deposited CdS has high blue transmittance. ► CdS deposition method influences diffusion of S and Te.

  13. Influence of film thickness and In-doping on physical properties of CdS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Butt, Sajid, E-mail: sajidarif@hotmail.com [Department of Materials Science and Engineering, Institute of Space Technology (IST), Islamabad 44000 (Pakistan); Thermal Transport Laboratory, School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad (Pakistan); Shah, Nazar Abbas [Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Nazir, Adnan [Istituto Italiano di Tecnologia, Via Morego 30, I-16163 Genova (Italy); Ali, Zulfiqar [Optics Laboratories, P. O. Box 1021, Islamabad (Pakistan); Maqsood, Asghri [CESET, Center for Emerging Sciences, Engineering and Technology, Islamabad (Pakistan)

    2014-02-25

    Highlights: • Fabrication of polycrystalline CdS thin films by Close Spaced Sublimation technique. • The direct band gap of 2.44 eV and the electrical resistivity in the order of 10{sup 6}–10{sup 8} Ω cm was measured. • Resistivity was reduced to the order of 10{sup –2}–10{sup 1} Ω m by the thermally diffusion of indium into CdS films. -- Abstract: Polycrystalline CdS thin films were deposited on glass substrates by close spaced sublimation technique. Samples of various thicknesses, ranging from 250 to 940 nm were obtained. The optical and electrical properties of pure CdS thin films were studied as a function of film thickness. The resistivity of as-deposited CdS films was in the order of 10{sup 6}–10{sup 8} Ω cm, depending upon the film thickness. In the high temperature region, carriers are transported over the grain boundaries by thermionic emission. Resistivity was reduced to the order of 10{sup −2}–10{sup 1} Ω cm by the thermally diffusion of indium into CdS films, without changing the type of carriers. The annealing temperature dependence of structural, optical and electrical properties of In-doped CdS films showed that the samples annealed at 350 °C and 400 °C exhibited better results.

  14. Photo current generation in RGO - CdS nanorod thin film device

    Science.gov (United States)

    Chakraborty, Koushik; Chakrabarty, Sankalpita; Ibrahim, Sk.; Pal, Tanusri; Ghosh, Surajit

    2016-05-01

    Herein, we report the synthesis and characterization of reduced graphene oxide (RGO) - cadmium sulfide (CdS) nanocomposite materials. The reduction of GO, formation of CdS and decoration of CdS onto RGO sheets were done in a one- pot solvothermal process. We have observed that the PL intensity for CdS nanorods remarkably quenched after the attachment of RGO, which established the photo induced charge transformation from the CdS nanorod to RGO sheets through the RGO-CdS interface. The optoelectronic transport properties of our fabricated large area thin film device exhibits excellent photo induced charge generation under simulated solar light illumination. The photo sensitivity of the device increases linearly with the increase of illuminated light intensity. The RGO-CdS composite exhibits enhance photocatalytic dye degradation efficiency in compare to control CdS under simulated solar light illumination.

  15. Preparation and properties of CdS thin films grown by ILGAR method

    Institute of Scientific and Technical Information of China (English)

    QIU Jijun; JIN Zhengguo; WU Weibing; LIU Xiaoxin; CHENG Zhijie

    2004-01-01

    CdS thin films were deposited by the ion layer gas reaction (ILGAR) method. Structural, chemical, topographical development as well as optical and electrical properties of as-deposited and annealed thin films were investigated by XRD,SEM, XPS, AFM and UV-VIS. The results showed that the thin films are uniform, compact and good in adhesion to the substrates, and the growth of the films is 2.8 nm/cycle. The evolution of structure undergoes from the cubic structure to the hexagonal one with a preferred orientation along the (002) plane after annealing at 673 K. An amount of C, O and Cl impuriries can be reduced by increasing the drying temperature or by annealing in N2 atmosphere. It was found that the band gap of the CdS films shifts to higher wavelength after annealing or increasing film thickness. The electrical resistivity decreases with increasing annealing temperature and film thickness.

  16. Analysis of chemically deposited CdSe and CdS thin films

    CERN Document Server

    Osuji, R U

    2002-01-01

    We have successfully deposited quality polycrystalline thin films of CdSe and CdS on Corning 7059 glass slides by the electroless chemical bath technique at room temperature (~27 $^\\circ$C). X-ray analysis confirmed the successful deposition of CdSe and CdS thin films. Our grown CdSe film thickness ranged from 0.10 $\\mu$m. to 0.80 $\\pm$ 0.01 $\\mu$m and the CdS film thickness ranged from 0.10 $\\mu$m to 1.00 $\\pm$ 0.01 $\\mu$m. The scanning electron micrograph of the films reveals uniform film surface. The energy gaps, $E_g$ determined for our CdSe and CdS films have average values of 1.70 $\\pm$ 0.04 eV and 2.15 $\\pm$ 0.04 eV respectively. The films have high absorbance in the 0.35 $\\mu$m - 0.85 $\\mu$m range. These qualities make them suitable for use in thin film solar cell technology.

  17. The analysis of CdS thin film at the processes of manufacturing CdS/CdTe solar cells

    Science.gov (United States)

    Chun, S.; Jung, Y.; Kim, J.; Kim, D.

    2011-07-01

    In sequence, the deposited CdS thin film had undergone physical and optical changes by the processes of manufacturing CdS/CdTe solar cells. CdS thin film was manufactured by the Chemical Bath Deposition (CBD) method. The aqueous solution was based on ammonia solution. The temperature of bath system was 75 °C and deposition time was 50 min. The thickness of deposited CdS thin film was about 200 nm. The substrate was the glass coated with SnO 2:F thin film. The following process was the deposition of CdTe thin film by the Closed-Space-Sublimation (CSS) method. The final process was the CdCl 2 heat treatment at N 2+O 2 atmosphere, and the contrast experiment progressed for CdCl 2-CdS thin film after CSS process at N 2 atmosphere. The phase transition of CdS thin film, stress relaxation and optical band gap narrowing were developed by each process. And so, the formation of cadmium oxide was detected after the CdCl 2 heat treatment. It influenced to increase the optical band gap of CdS thin film. The variation in the structure properties, optical properties and residual stresses of CdS thin film was analyzed by X-ray diffractometer (XRD), Raman spectroscopy and ultraviolet (UV)-visible (VIS) spectroscopy.

  18. Solution precursor plasma deposition of nanostructured CdS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Tummala, Raghavender [Department of Mechanical Engineering, University of Michigan, Dearborn, MI 48128 (United States); Guduru, Ramesh K., E-mail: rkguduru@umich.edu [Department of Mechanical Engineering, University of Michigan, Dearborn, MI 48128 (United States); Mohanty, Pravansu S. [Department of Mechanical Engineering, University of Michigan, Dearborn, MI 48128 (United States)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Inexpensive process with capability to produce large scale nanostructured coatings. Black-Right-Pointing-Pointer Technique can be employed to spray the coatings on any kind of substrates including polymers. Black-Right-Pointing-Pointer The CdS coatings developed have good electrical conductivity and optical properties. Black-Right-Pointing-Pointer Coatings possess large amount of particulate boundaries and nanostructured grains. -- Abstract: Cadmium sulfide (CdS) films are used in solar cells, sensors and microelectronics. A variety of techniques, such as vapor based techniques, wet chemical methods and spray pyrolysis are frequently employed to develop adherent CdS films. In the present study, rapid deposition of CdS thin films via plasma spray route using a solution precursor was investigated, for the first time. Solution precursor comprising cadmium chloride, thiourea and distilled water was fed into a DC plasma jet via an axial atomizer to create ultrafine droplets for instantaneous and accelerated thermal decomposition in the plasma plume. The resulting molten/semi-molten ultrafine/nanoparticles of CdS eventually propel toward the substrate to form continuous CdS films. The chemistry of the solution precursor was found to be critical in plasma pyrolysis to control the stoichiometry and composition of the films. X-ray diffraction studies confirmed hexagonal {alpha}-CdS structure. Surface morphology and microstructures were investigated to compare with other synthesis techniques in terms of process mechanism and structural features. Transmission electron microscopy studies revealed nanostructures in the atomized particulates. Optical measurements indicated a decreasing transmittance in the visible light with increasing the film thickness and band gap was calculated to be {approx}2.5 eV. The electrical resistivity of the films (0.243 {+-} 0.188 Multiplication-Sign 10{sup 5} {Omega} cm) was comparable with the literature

  19. Optical and structural properties of chemically deposited CdS thin films on polyethylene naphthalate substrates

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval-Paz, M.G., E-mail: myrnasandoval@udec.cl [Departamento de Fisica, Facultad de Ciencias Fisicas y Matematicas, Universidad de Concepcion, Casilla 160-C, Concepcion (Chile); Ramirez-Bon, R. [Centro de Investigacion y Estudios Avanzados del IPN, Unidad Queretaro, Apdo. Postal 1-798, 76001 Queretaro, Qro. (Mexico)

    2011-11-30

    CdS thin films were deposited on polyethylene naphthalate substrates by means of the chemical bath deposition technique in an ammonia-free cadmium-sodium citrate system. Three sets of CdS films were grown in precursor solutions with different contents of Cd and thiourea maintaining constant the concentration ratios [Cd]/[thiourea] and [Cd]/[sodium citrate] at 0.2 and 0.1 M/M, respectively. The concentrations of cadmium in the reaction solutions were 0.01, 7.5 Multiplication-Sign 10{sup -3} and 6.8 Multiplication-Sign 10{sup -3} M, respectively. The three sets of CdS films were homogeneous, hard, specularly reflecting, yellowish and adhered very well to the plastic substrates, quite similar to those deposited on glass substrates. The structural and optical properties of the CdS films were determined from X-ray diffraction, optical transmission and reflection spectroscopy and atomic force microscopy measurements. We found that the properties of the films depend on both the amount of Cd in the growth solutions and on the deposition time. The increasing of Cd concentration in the reaction solution yield to thicker CdS films with smaller grain size, shorter lattice constant, and higher energy band gap. The energy band gap of the CdS films varied in the range 2.42-2.54 eV depending on the precursor solution. The properties of the films were analyzed in terms of the growth mechanisms during the chemical deposition of CdS layers.

  20. Thermal and structural properties of spray pyrolysed CdS thin film

    Indian Academy of Sciences (India)

    P Raji; C Sanjeeviraja; K Ramachandran

    2005-06-01

    Using photo acoustic technique, the thermal properties of CdS thin films grown by spray pyrolysis are measured. Thermal diffusivity and conductivity in these films decrease at least two orders compared with bulk. These results are compared with our study on nano CdS and the other available literature. The comparison is good. The dependence of thermal diffusivity on the thickness of the layer or the size of the particles on the glass substrate are analysed from the present measurement and discussed. The dependence of thermal diffusivity on the thickness of the layer on the glass substrate is discussed.

  1. Shallow bath chemical deposition of CdS thin film

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Y.S. [Department of Molecule Science and Engineering, National Taipei University of Science and Technology, Taipei, 10617, Taiwan (China); Choubey, R.K. [Department of Applied Physics, Birla Institute of Technology, Mesra, Ranchi, 835 215 (India); Department of Chemical Engineering, National Taiwan University, Taipei, 10617, Taiwan (China); Yu, W.C. [Department of Molecule Science and Engineering, National Taipei University of Science and Technology, Taipei, 10617, Taiwan (China); Hsu, W.T. [Green Energy and Environmental Research Laboratory, Industrial Technology Research Institute, Hsin-Chu, Taiwan (China); Lan, C.W., E-mail: cwlan@ntu.edu.tw [Department of Chemical Engineering, National Taiwan University, Taipei, 10617, Taiwan (China)

    2011-10-31

    Cadmium sulfide thin film was grown by shallow chemical bath deposition technique. This technique used a highly conducted hot plate to heat the substrate, while using a shallow bath for higher thermal gradients. As a result, large area uniformity could be achieved and the homogeneous nucleation was suppressed. More importantly, the solution used was greatly reduced, which is crucial for cost reduction in practice. The effects of temperature and shaking on the growth kinetics and film properties were investigated. The reaction activation energy was obtained to be 0.84 eV, and was not affected much by shaking indicating that the deposition is essentially reaction controlled. Furthermore, the films deposited at low or high temperature conditions had better photoconductivity.

  2. Characterization of CdS Thin-Film in High Efficient CdS/CdTe Solar Cells

    Science.gov (United States)

    Tsuji, Miwa; Aramoto, Tetsuya; Ohyama, Hideaki; Hibino, Takeshi; Omura, Kuniyoshi

    2000-07-01

    Cadmium sulfide (CdS) thin films are the most commonly used window materials for high efficient cadmium telluride (CdTe) and chalcopyrite polycrystalline thin-film photovoltaic devices. High efficient CdS/CdTe solar cells with thin CdS films have been developed using ultrathin CdS films with a thickness of less than 0.1 μm. CdS films were deposited on transparent conductive oxide (TCO)/glass substrates by the metal organic chemical vapor deposition (MOCVD) technique. CdTe films were subsequently deposited by the close-spaced sublimation (CSS) technique. The screen printing and sintering method fabricated carbon and silver electrodes. Cell performance depends primarily on the electrical and optical properties of CdS films. Therefore we started to develop higher-quality CdS films and found clear differences between high- and low-quality CdS films from the analyses of scanning electron microscope (SEM), atomic force microscope (AFM), secondary ion mass spectroscopy (SIMS), thermal desorption spectrometry (TDS) and Fourier transforms-infrared spectrometry (FT-IR) measurements. As a result of controlling the quality of CdS films, a photovoltaic conversion efficiency of 10.5% has been achieved for size of 1376 cm2 of the solar cells under the Air Mass (AM) 1.5 conditions of the Japan Quality Assurance Organization.

  3. Effect of Ag doping on opto-electrical properties of CdS thin films for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Nazir, Adnan, E-mail: adnan.nazir@iit.it [Istituto Italiano di Tecnologia, Via Morego 30, I-16163 Genova (Italy); School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad (Pakistan); Toma, Andrea [Istituto Italiano di Tecnologia, Via Morego 30, I-16163 Genova (Italy); Shah, Nazar Abbas [Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Panaro, Simone [Istituto Italiano di Tecnologia, Via Morego 30, I-16163 Genova (Italy); Butt, Sajid [Department of Materials Science and Engineering, Institute of Space Technology (IST), Islamabad 44000 (Pakistan); School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad (Pakistan); Sagar, Rizwan ur Rehman [Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan); Raja, Waseem [Istituto Italiano di Tecnologia, Via Morego 30, I-16163 Genova (Italy); Rasool, Kamran [Micro and Nano Devices Group, Department of Metallurgy and Materials Engineering Pakistan, Institute of Engineering and Applied Sciences (PIEAS), P.O. Nilore, Islamabad 45650 (Pakistan); Maqsood, Asghari [Department of Physics, Air University, Islamabad (Pakistan)

    2014-10-01

    Highlights: • Polycrystalline CdS thin films are fabricated by means of Close Spaced Sublimation technique. • Ag is doped by simple ion-exchange technique in order to reduce resistivity of CdS thin films. • Remarkable reduction in resistivity without introducing many transparency losses. - Abstract: Cadmium sulfide (CdS) polycrystalline thin films of different thicknesses (ranging from 370 nm to 750 nm) were fabricated on corning glass substrates using Close Spaced Sublimation (CSS) technique. Optical and electrical investigation revealed that CdS thin films show an appreciable transparency (50–70% transmission) in visible range and a highly resistive behavior (10{sup 6} Ω cm). Samples were doped by silver (Ag) at different concentrations, using ion exchange technique, in order to reduce the resistivity of CdS thin films and to improve their efficiency as a window layer for solar cell application. The doping of Ag in pure CdS thin films resulted into an increase of surface roughness and a decrease both in electrical resistivity and in transparency. By optimizing annealing parameters, we were able to properly control the optical properties of the present system. In fact, the Ag doping of pure CdS films has led to a decrease of the sample resistivity by three orders of magnitude (10{sup 3} Ω cm) against a 20% cut in optical transmission.

  4. Improved electrical stability of CdS thin film transistors through Hydrogen-based thermal treatments

    KAUST Repository

    Salas Villaseñor, Ana L.

    2014-06-01

    Thin film transistors (TFTs) with a bottom-gate configuration were fabricated using a photolithography process with chemically bath deposited (CBD) cadmium sulfide (CdS) films as the active channel. Thermal annealing in hydrogen was used to improve electrical stability and performance of the resulting CdS TFTs. Hydrogen thermal treatments results in significant V T instability (V T shift) improvement while increasing the I on/I off ratio without degrading carrier mobility. It is demonstrated that after annealing V T shift and I on/I off improves from 10 V to 4.6 V and from 105 to 10 9, respectively. Carrier mobility remains in the order of 14.5 cm2 V s-1. The reduced V T shift and performance is attributed to a reduction in oxygen species in the CdS after hydrogen annealing, as evaluated by Fourier transform infrared spectroscopy (FTIR). © 2014 IOP Publishing Ltd.

  5. Preparation, structural and optical characterization of nanocrystalline CdS thin film

    Science.gov (United States)

    Abdel-Galil, A.; Balboul, M. R.; Atta, A.; Yahia, I. S.; Sharaf, A.

    2014-08-01

    Nano-structured CdS thin film was deposited onto a glass substrate by an electron beam evaporation technique at room temperature from a powder prepared by a hydrothermal method. The morphology and structural properties of the as-deposited film were characterized using atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques. The AFM morphology study confirms that the CdS thin film has nano-sized grains and a dense morphology. The mean particle size that resulted from XRD analyses was 8.4 nm. Also, the XRD patterns show that CdS powder and thin film have hexagonal wurtzite type structure with a preferred c-axis orientation along (002) plane. The refractive index and the film thickness were obtained using the Swanepoel method from transmission spectrum. The optical band gap was calculated from the absorption spectrum, and was found to be 2.41 eV corresponding to direct optical transition. The dispersion of the refractive index was explained using a single oscillator model. The dielectric relaxation time and the optical conductivity were determined and studied with photon energy.

  6. Characterization of CdS thin film in high efficient CdS/CdTe solar cells

    Science.gov (United States)

    Tsuji, Miwa; Aramoto, Tetsuya; Ohyama, Hideaki; Hibino, Takeshi; Omura, Kuniyoshi

    2000-06-01

    Cadmium sulfide (CdS) thin film is the most commonly used window material for high-efficient cadmium telluride (CdTe) thin-film photovoltaic devices. High-efficient CdS/CdTe solar cells have been developed using ultra-thin CdS films having a thickness of below 0.1 μm. CdS film is deposited on transparent conductive oxide (TCO) film coated glass substrates by the metal organic chemical vapor deposition (MOCVD) technique, CdTe film is subsequently deposited by the close-spaced sublimation (CSS) technique. Finally, carbon and Ag-In electrodes are fabricated by the screen printing and sintering method. Cell performance depends primarily on the electrical and optical properties of CdS film, and hence we started to develop higher quality CdS film and found out clear differences between high- and low-quality CdS films from various analyses: SEM, AFM, SIMS, TDS and FT-IR. As a result of controlling qualities of CdS films, photovoltaic conversion efficiency of 10.5% has been achieved for a size of 1376 cm 2 of the solar module under air mass (AM) 1.5 conditions by the Japan Quality Assurance Organization (JQA).

  7. Properties of CdS thin films grown by CBD as a function of thiourea concentration

    Energy Technology Data Exchange (ETDEWEB)

    Ximello-Quiebras, J.N.; Contreras-Puente, G.; Rueda-Morales, G.; Vigil, O. [Escuela Superior de Fisica y Matematicas-Instituto Politecnico Nacional, Edificio 9, U.P.A.L.M. 07738 DF (Mexico); Santana-Rodriguez, G. [Instituto de Investigaciones en Materiales, UNAM, CP 04510 (Mexico DF); Morales-Acevedo, A. [CINVESTAV-IPN, Depto. Ingenieria Electrica-SEES, Av. IPN 2508,CP 07360 Mexico, DF (Mexico)

    2006-04-14

    This paper reports a study of the growth rate and optical properties of CdS thin films prepared by the chemical bath deposition technique. For the deposition an aqueous solution of cadmium chloride, ammonium chloride, ammonium hydroxide and thiourea were used, the films were deposited on conducting glass (SnO{sub 2}: F). The growth kinetics is relatively fast when the quantity of thiourea is increased in the deposition solution and higher value of band gap is obtained (E{sub g}=2.44eV). The films show good transmittance in the visible region. (author)

  8. Synthesis and characterization of chemically deposited CdS thin films without toxic precursors.

    Science.gov (United States)

    Fernández-Pérez, A.; Sandoval-Paz, M. G.

    2016-05-01

    Al doped and undoped CdS thin films (CdS:Al) were deposited on glass, copper and bronze substrates by chemical bath deposition technique in an ammonia-free cadmium-sodium citrate system. The structural and optical properties of the CdS films were determined by X-ray diffraction (XRD), scanning electron microscope (SEM), and simultaneous transmission- reflection spectroscopy. It was found that the properties of the films depend on the amount of Al in the growth solutions and deposition time. The increase in Al content in the reaction solution led to a smaller crystallite size and higher energy band gap that varies in the range 2.42 eV - 2.59 eV depending on the Al content.

  9. Optical Parameters of Spray-Deposited CdS1-y Te y Thin Films

    Science.gov (United States)

    Ikhmayies, Shadia J.

    2016-11-01

    CdS x Te1-x and CdS1-y Te y solid solutions are usually formed in the interfacial region in CdS/CdTe solar cells during the deposition of the CdTe layer and/or the processing steps of the device. In this work, indium-doped CdS1-y Te y thin films were prepared by first producing CdS:In thin films by the spray pyrolysis technique on glass substrates, then annealing the films in nitrogen atmosphere in the presence of elemental tellurium. The films were characterized by scanning electron microscopy, energy dispersive x-ray spectroscopy, and transmittance measurements. The transmittance was used to deduce the reflectance from which the optical parameters were computed. The extinction coefficient, refractive index, the real and imaginary parts of the dielectric constant, optical conductivity, and energy loss were computed, and their dependence on the composition was investigated. In addition, the dispersion of the refractive index was analyzed by the single oscillator model, and dispersion parameters were investigated.

  10. Optical Parameters of Spray-Deposited CdS1- y Te y Thin Films

    Science.gov (United States)

    Ikhmayies, Shadia J.

    2017-02-01

    CdS x Te1- x and CdS1- y Te y solid solutions are usually formed in the interfacial region in CdS/CdTe solar cells during the deposition of the CdTe layer and/or the processing steps of the device. In this work, indium-doped CdS1- y Te y thin films were prepared by first producing CdS:In thin films by the spray pyrolysis technique on glass substrates, then annealing the films in nitrogen atmosphere in the presence of elemental tellurium. The films were characterized by scanning electron microscopy, energy dispersive x-ray spectroscopy, and transmittance measurements. The transmittance was used to deduce the reflectance from which the optical parameters were computed. The extinction coefficient, refractive index, the real and imaginary parts of the dielectric constant, optical conductivity, and energy loss were computed, and their dependence on the composition was investigated. In addition, the dispersion of the refractive index was analyzed by the single oscillator model, and dispersion parameters were investigated.

  11. Synthesis of nanocrystalline CdS thin film by SILAR and their characterization

    Science.gov (United States)

    Mukherjee, A.; Satpati, B.; Bhattacharyya, S. R.; Ghosh, R.; Mitra, P.

    2015-01-01

    Cadmium sulphide (CdS) thin film was prepared by successive ion layer adsorption and reaction (SILAR) technique using ammonium sulphide as anionic precursor. Characterization techniques of XRD, SEM, TEM, FTIR and EDX were utilized to study the microstructure of the films. Structural characterization by x-ray diffraction reveals the polycrystalline nature of the films. Cubic structure is revealed from X-ray diffraction and selected area diffraction (SAD) patterns. The particle size estimated using X-ray line broadening method is approximately 7 nm. Instrumental broadening was taken into account while particle size estimation. TEM shows CdS nanoparticles in the range 5-15 nm. Elemental mapping using EFTEM reveals good stoichiometric composition of CdS. Characteristic stretching vibration mode of CdS was observed in the absorption band of FTIR spectrum. Optical absorption study exhibits a distinct blue shift in band gap energy value of about 2.56 eV which confirms the size quantization.

  12. Growth of ZnS, CdS and multilayer ZnS/CdS thin films by SILAR technique

    Science.gov (United States)

    Valkonen, Mika P.; Kanniainen, Tapio; Lindroos, Seppo; Leskelä, Markku; Rauhala, Eero

    1997-08-01

    Successive ionic layer adsorption and reaction (SILAR) technique was used to deposit cadmium sulfide (CdS) and zinc sulfide (ZnS) thin films on (100)GaAs. CdS thin films were also grown on ITO-covered glass substrates. Multilayer CdS/ZnS thin films were deposited on glass substrates. The crystallinity of the thin films was characterized by means of X-ray diffraction and they all turned out to be polycrystalline. The thin films looked relatively smooth and homogeneous in scanning electron microscopy (SEM) images. Energy dispersive X-ray analysis (EDX) and Rutherford backscattering spectroscopy (RBS) proved nearly 1 : 1 stoichiometry for the multilayer samples. Thickness of the thin films was measured by RBS and chemical analysis.

  13. Sub-THz thermally activated-electrical conductivity of CdS thin films

    Science.gov (United States)

    Rahman, Rezwanur; Scales, John A.

    2016-08-01

    The electrical conductivity of a CdS thin film controlled by grain structures is essential to enhance its photoconductivity to be able to be fit as a window material in CdS/CdTe heterojunction solar cells. In order to characterize a thin film, electromagnetically, we employed an open cavity resonator with a sub-millimeter Vector Network Analyzer. Our technique is capable of measuring complex dielectric permittivity, ɛ ˜ , of a photovoltaic film as thin as 0.1 μm. We measured the real part of the complex dielectric permittivity, ɛre, and electrical conductivity, σre (derived from the imaginary part, ɛim), of unannealed and annealed CdS films with thicknesses ˜0.15 μm on ˜3 mm thick-borosilicate glass substrates, at room temperature. We obtain the (thermally activated) electrical conductivity between 100 and 312 GHz, which is less in annealed samples than in unannealed ones by ˜2 orders of magnitude. Contrary to our expectations, the carrier concentrations extracted from these data by fitting a Drude model are ˜1016 cm-3 (unannealed) and ˜1014 cm-3 (annealed). We investigate the connection between the grain size and carrier concentration.

  14. CdS thin films growth by fast evaporation with substrate rotation

    Energy Technology Data Exchange (ETDEWEB)

    Castro-Rodriguez, R., E-mail: romano@mda.cinvestav.mx [Applied Physics Department, CINVESTAV-IPN Merida, C.P. 97310, Merida, Yucatan (Mexico); Mendez-Gamboa, J.; Perez-Quintana, I.; Medina-Ezquivel, R. [Yucatan Autonomous University, Faculty of Engineering. AP 150 Cordemex, 97310, Merida, Yucatan (Mexico)

    2011-09-01

    CdS thin films were grown by fast evaporation technique combined with substrate rotation. The source evaporation temperature was maintained at 600 deg. C and the substrate temperature at 350 deg. C with background pressure of 1.0 m Torr. The substrates were corning glass 2947 with dimension of 1 in. x 1 in. rotate at 500 rpm during the growth. In order to verify the quality of the CdS films, the samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and optical measurements. The films shown a flat uniformity thickness with growth rate of {approx}3.5 nm/s, the orientation was in the cubic-(1 1 1) and hexagonal-(0 0 2) plane in dependence of the growth time, grain size {approx}5 nm, roughness uniformity {approx}2.7 nm, transmittance in the visible region spectrum {approx}80%, energy band gap between 2.39 and 2.42 eV and short circuit photocurrent density (J{sub SC}) losses in the CdS films of 4.7 mA/cm{sup 2}.

  15. Decoupling interface effect on the phase stability of CdS thin films by van der Waals heteroepitaxy

    Science.gov (United States)

    Sun, Xin; Wang, Yiping; Seewald, Lucas J.; Chen, Zhizhong; Shi, Jian; Washington, Morris A.; Lu, Toh-Ming

    2017-01-01

    Wurtzite (W) and zinc-blende (ZB) polytypism has long been observed in epitaxial CdS thin films. The present work, based on van der Waals epitaxial CdS thin films, is an attempt to explain which crystal modification, W or ZB, is favored under different growth conditions. In this van der Waals epitaxy system where the substrate influence is considered weak, it is found that the substrate temperature plays a crucial role in determining the crystal modification of CdS, that is, W and ZB CdS are more stable at low and high ends of substrate temperature, respectively. We attribute this temperature effect to the entropy difference (SW benefit in terms of high density of bonding contributed by the substrate-film interface is believed to be too overwhelming for the intrinsic entropy difference to overcome. Furthermore, the deposition rate is found to affect the crystalline quality and strain level in CdS films but not the crystal modification of the CdS films. Last, Raman and photoluminescence spectroscopies reveal the strain behaviors in the films. The phase change from W to ZB CdS is well-correlated with the observed peak shifts in Raman and photoluminescence spectroscopies.

  16. Dependence of electro-optical properties on the deposition conditions of chemical bath deposited CdS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Dona, J.M.; Herrero, J. [CIEMAT, Madrid (Spain). Inst. de Energias Renovables

    1997-11-01

    Lately, there has been a sharp increase in the publication of papers on chemical bath deposition of CdS thin films and related materials due to successful results obtained using this method to fabricate CdS thin-film buffer layers for CuInSe{sub 2}- and CdTe-based polycrystalline thin-film solar cells. Generally, these papers focus on previously proposed methods of studying film characteristics without a systematic study of the influence of deposition conditions on film characteristics. In this paper the authors present an exhaustive study of the chemical bath-deposited CdS thin films electro-optical properties dependence on deposition variables. The authors propose not only a set of conditions for obtaining CdS thin films by this method but additionally, suitable deposition process conditions for certain application requirements, such as buffer layers for thin-film solar cells. The observed electro-optical characteristics dependence on the deposition variables corroborates the chemical mechanism that they proposed previously for this process.

  17. Electrical Response of CdS Thin Film and CdS/Si Heterojunction to Gamma Radiation

    Directory of Open Access Journals (Sweden)

    M. R. Balboul

    2016-01-01

    Full Text Available Gamma irradiation method has been used to change the electrical properties of CdS thin film. A specific dose of γ-irradiation increases the activation energy of CdS thin film. In addition, γ-irradiation was used to change the sign of Hall coefficient, RH, of CdS thin film from negative to positive irrespective of temperature. The Hall mobility mechanism shows noticeable change after γ-irradiation from decreasing to increasing with raising the temperature. In depth, analysis was done using capacitance-voltage measurement in order to realize the modification in the CdS/Si junction band gap after γ-irradiation. Several parameters were also studied such as charge carrier concentration, ND, and flat band potential, Vfb. The γ-irradiation was found to increase the concentration of the deep traps within the band gap of the CdS/Si heterojunction.

  18. Synthesis of nanocrystalline CdS thin films in PVA matrix

    Indian Academy of Sciences (India)

    R Devi; P Purkayastha; P K Kalita; B K Sarma

    2007-04-01

    Nanocrystalline thin films of CdS are deposited on glass substrates by chemical bath deposition technique using polyvinyl alcohol (PVA) matrix solution. Crystallite sizes of the nanocrystalline films are determined from broadening of X-ray diffraction lines and are found to vary from 5.4–10.2 nm. The band gap of the nanocrystalline material is determined from the UV spectrograph. The absorption edge is shifted towards the lower wave length side (i.e. blue shift) and are found to be within the range from 2.48–2.8 eV as grain sizes decrease from 10.2–5.4 nm. This is also supported by the spectral response curves. An increase of molarity decreases the grain size which in turn increases the band gap.

  19. Structural analysis of CdS thin films obtained by multiple dips of oscillating chemical bath

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez Lazos, C.D. [Seccion de Electronica del Estado Solido, Centro de Investigacion y de Estudios Avanzados, Av. Instituto Politecnico Nacional 2508, Col. San Pedro Zacatenco, 07360 Mexico, D.F. (Mexico); Rosendo, E., E-mail: erosendo@siu.buap.m [Centro de Investigacion en Dispositivos Semiconductores, Universidad Autonoma de Puebla, 14 Sur y San Claudio, Col. San Manuel, C.P. 72570, Puebla (Mexico); Ortega, M. [Seccion de Electronica del Estado Solido, Centro de Investigacion y de Estudios Avanzados, Av. Instituto Politecnico Nacional 2508, Col. San Pedro Zacatenco, 07360 Mexico, D.F. (Mexico); Oliva, A.I. [Departamento de Fisica Aplicada, Centro de Investigacion y de Estudios Avanzados, Unidad Merida, A.P. 73 Cordemex, 97310 Merida, Yucatan (Mexico); Tapia, O.; Diaz, T.; Juarez, H.; Garcia, G. [Centro de Investigacion en Dispositivos Semiconductores, Universidad Autonoma de Puebla, 14 Sur y San Claudio, Col. San Manuel, C.P. 72570, Puebla (Mexico); Rubin, M. [Facultad de Ciencias de la Computacion, 14 Sur y San Claudio, Col. San Manuel, C.P. 72570, Puebla (Mexico)

    2009-11-25

    Highly oriented CdS thin films with thicknesses greater than 1 mum were deposited by multiple dips, using oscillating chemical bath deposition (OCBD) at the bath temperature of 75 deg. C, and deposition time ranging from 15 to 75 min for a single dip. Samples with different thickness were prepared by repeating the deposition process for two and three times. The films deposited by a single dip have the alpha-greenockite structure showing the (0 0 2) as preferred orientation, as indicated by the X-ray diffraction measurements. This notable characteristic is preserved in the samples obtained from two or three dips. The crystallite size for the samples deposited by a single dip depends on the deposition time, because it varied from 23 to 37 nm as the deposition time increased. Nevertheless for samples deposited by two and three dips, the grain size shows no noticeable change, being about 22 nm.

  20. Effect of annealing temperature on structural and Raman spectroscopy analysis of nanostructured CdS thin films

    Science.gov (United States)

    Venkata Veera Prasad, M.; Thyagarajan, K.; Kumar, B. Rajesh

    2016-09-01

    Nanocrystalline CdS thin films were deposited on glass substrates using the sol-gel spin coating method. The structural properties and surface morphology of the CdS thin films were characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Atomic force microscopy (AFM). XRD studies revealed that all the films exhibit cubic structure with a (1 1 1) preferential orientation. The diffraction peak (1 1 1) shifts towards higher 20 value with increasing annealing temperature from 150 oC to 350 oC. The Raman spectra shows the intense and broad peaks at ∼302 and ∼603.5cm-1 which are assigned to fundamental optical phonon mode (LO) and first over tone mode (2LO) of CdS.

  1. Cu-doped CdS and its application in CdTe thin film solar cell

    Directory of Open Access Journals (Sweden)

    Yi Deng

    2016-01-01

    Full Text Available Cu is widely used in the back contact formation of CdTe thin film solar cells. However, Cu is easily to diffuse from the back contact into the CdTe absorber layer and even to the cell junction interface CdS/CdTe. This phenomenon is generally believed to be the main factor affecting the CdTe solar cell stability. In this study Cu was intentionally doped in CdS thin film to study its effect on the microstructural, optical and electrical properties of the CdS material. Upon Cu doping, the VCd− and the surface-state-related photoluminescence emissions were dramatically decreased/quenched. The presence of Cu atom hindered the recrystallization/coalescence of the nano-sized grains in the as-deposited CdS film during the air and the CdCl2 annealing. CdTe thin film solar cell fabricated with Cu-doped CdS window layers demonstrated much decreased fill factor, which was induced by the increased space-charge recombination near the p-n junction and the worsened junction crystalline quality. Temperature dependent current-voltage curve measurement indicated that the doped Cu in the CdS window layer was not stable at both room and higher temperatures.

  2. Cu-doped CdS and its application in CdTe thin film solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Yi [School of Automation, Wuhan University of Technology, Wuhan, Hubei 430070 (China); College of Electronic and Information Engineering, Hankou University, Wuhan, Hubei 430212 (China); Yang, Jun; Yang, Ruilong; Shen, Kai; Wang, Dezhao [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Wang, Deliang, E-mail: eedewang@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Key Laboratory of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2016-01-15

    Cu is widely used in the back contact formation of CdTe thin film solar cells. However, Cu is easily to diffuse from the back contact into the CdTe absorber layer and even to the cell junction interface CdS/CdTe. This phenomenon is generally believed to be the main factor affecting the CdTe solar cell stability. In this study Cu was intentionally doped in CdS thin film to study its effect on the microstructural, optical and electrical properties of the CdS material. Upon Cu doping, the V{sub Cd{sup −}} and the surface-state-related photoluminescence emissions were dramatically decreased/quenched. The presence of Cu atom hindered the recrystallization/coalescence of the nano-sized grains in the as-deposited CdS film during the air and the CdCl{sub 2} annealing. CdTe thin film solar cell fabricated with Cu-doped CdS window layers demonstrated much decreased fill factor, which was induced by the increased space-charge recombination near the p-n junction and the worsened junction crystalline quality. Temperature dependent current-voltage curve measurement indicated that the doped Cu in the CdS window layer was not stable at both room and higher temperatures.

  3. Cu-doped CdS and its application in CdTe thin film solar cell

    Science.gov (United States)

    Deng, Yi; Yang, Jun; Yang, Ruilong; Shen, Kai; Wang, Dezhao; Wang, Deliang

    2016-01-01

    Cu is widely used in the back contact formation of CdTe thin film solar cells. However, Cu is easily to diffuse from the back contact into the CdTe absorber layer and even to the cell junction interface CdS/CdTe. This phenomenon is generally believed to be the main factor affecting the CdTe solar cell stability. In this study Cu was intentionally doped in CdS thin film to study its effect on the microstructural, optical and electrical properties of the CdS material. Upon Cu doping, the VCd- and the surface-state-related photoluminescence emissions were dramatically decreased/quenched. The presence of Cu atom hindered the recrystallization/coalescence of the nano-sized grains in the as-deposited CdS film during the air and the CdCl2 annealing. CdTe thin film solar cell fabricated with Cu-doped CdS window layers demonstrated much decreased fill factor, which was induced by the increased space-charge recombination near the p-n junction and the worsened junction crystalline quality. Temperature dependent current-voltage curve measurement indicated that the doped Cu in the CdS window layer was not stable at both room and higher temperatures.

  4. CdS quantum dots sensitized Cu doped ZnO nanostructured thin films for solar cell applications

    Science.gov (United States)

    Poornima, K.; Gopala Krishnan, K.; Lalitha, B.; Raja, M.

    2015-07-01

    ZnO nanorods and Cu doped ZnO nanorods thin films have been prepared by simple hydrothermal method. CdS quantum dots are sensitized with Cu doped ZnO nanorod thin films using successive ionic layer adsorption and reaction (SILAR) method. The X-ray diffraction study reveals that ZnO nanorods, and CdS quantum dot sensitized Cu doped ZnO nanorods exhibit hexagonal structure. The scanning electron microscope image shows the presence of ZnO nanorods. The average diameter and length of the aligned nanorod is 300 nm and 1.5 μm respectively. The absorption spectra shows that the absorption edge of CdS quantum dot sensitized ZnO nanorod thin film is shifted toward longer wavelength region when compared to the absorption edge of ZnO nanorods film. The conversion efficiency of the CdS quantum dot sensitized Cu doped ZnO nanorod thin film solar cell is 1.5%.

  5. Effect of Annealing on the Properties of Nanocrystalline CdS Thin Films Prepared by CBD Method

    Directory of Open Access Journals (Sweden)

    A. Djelloul

    2016-06-01

    Full Text Available The CdS thin films were deposited on glass substrate by chemical bath deposition (CBD. The effect of annealing temperature on the morphological, structural, optical and electrical properties of the crystalline CdS films were investigated for different annealing temperature (as deposited, 300, 400 and 500 °C.The annealing time is 1 h. The materials have been prepared using simple aqueous solutions containing cadmium sulfate, as source of cadmium, and thiourea as source of sulfur and ammonium hydroxide as the complexing agent. The temperature of the bath was maintained at low temperature of 80 °C. The surface morphological properties studied by SEM and AFM respectively. The structural properties of CdS thin film was studied by X-ray diffraction. The optical parameter such as transmittance and energy band gap of the films with thermal annealing temperature was investigated by UV-Visible spectrophotometer. The variation of band gap values of CdS thin film samples were found to be in the range of 2.37 to 2.5 eV. Electrical resistivity measurements were carried out in four-probe Van Der Pauw geometry at room temperature by the Hall measurement. SEM image confirmed that film of smooth surface morphology.

  6. Effect of Annealing on the Properties of Nanocrystalline CdS Thin Films Prepared by CBD Method

    OpenAIRE

    2016-01-01

    The CdS thin films were deposited on glass substrate by chemical bath deposition (CBD). The effect of annealing temperature on the morphological, structural, optical and electrical properties of the crystalline CdS films were investigated for different annealing temperature (as deposited, 300, 400 and 500 °C).The annealing time is 1 h. The materials have been prepared using simple aqueous solutions containing cadmium sulfate, as source of cadmium, and thiourea as source of sulfur and ammoniu...

  7. [Research on the polycrystalline CdS thin films prepared by close-spaced sublimation].

    Science.gov (United States)

    Yang, Ding-Yu; Xia, Geng-Pei; Zheng, Jia-Gui; Feng, Liang-Huan; Cai, Ya-Ping

    2009-01-01

    In the present paper, the factors of influence on the deposition rate of CdS films prepared by close-spaced sublimation (CSS) were first studied systematically, and it was found from the experiments that the deposition rate increased with the raised temperature of sublimation source, while decreased with the raised substrate temperature and the deposition pressure. The structure, morphology and light transmittance of the prepared samples were tested subsequently, and the results show: (1) The CdS films deposited under different oxygen partial pressure all present predominating growth lattice orientation (103), and further more the films will be strengthened after annealed under CdCl2 atmosphere. (2) The AFM images of CdS show that the films are compact and uniform in grain diameter, and the grain size becomes larger with the increased substrate temperature. Along with it, the film roughness was also augmented. (3) The transmittance in the shortwave region of visible light through the CdS films would be enhanced when its thickness is reduced, and that will help improve the shortwave spectral response of CdTe solar cells. Finally, the prepared CdS films were employed to fabricate CdTe solar cells, which have achieved a conversion efficiency of 10.29%, and thus the feasibility of CSS process in the manufacture of CdTe solar cells was validated primarily.

  8. Effect of chlorine doping on the structural, morphological, optical and electrical properties of spray deposited CdS thin films

    Directory of Open Access Journals (Sweden)

    T. Sivaraman

    2015-10-01

    Full Text Available CdS and chlorine doped CdS (CdS:Cl thin films with different Cl-doping levels (0, 2, 4, 6 and 8 at% have been deposited on glass substrates by a spray pyrolysis technique using a perfume atomizer. The effect of Cl doping on the structural, morphological, optical and electrical properties of the films was investigated. XRD patterns revealed that all the films exhibit hexagonal crystal structure with a preferential orientation along the (0 0 2 plane irrespective of the Cl doping level. The particle size value decreases from 22.03 nm to 18.12 nm with increase in Cl concentration. Optical band gap is blue-shifted from 2.48 eV to 2.73 eV with increase in Cl doping concentration. All the films have resistivity in the order of 104 Ω cm. The obtained results confirm that chlorine as an anionic dopant material can enhance the physical properties of CdS thin films to a large extent.

  9. Spin-coating deposition of PbS and CdS thin films for solar cell application

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Jayesh; Mighri, Frej [Laval University, CREPEC, Department of Chemical Engineering, Quebec, QC (Canada); Ajji, Abdellah [Ecole Polytechnique, CREPEC, Chemical Engineering Department, Montreal, QC (Canada); Tiwari, Devendra; Chaudhuri, Tapas K. [Charotar University of Science and Technology (CHARUSAT), Dr. K.C. Patel Research and Development Centre, Anand District, Gujarat (India)

    2014-12-15

    In this work, we describe a simple spin-coating deposition technique for lead sulphide (PbS) and cadmium sulphide (CdS) films from a methanolic metal-thiourea complex. The characterization of the films by X-ray diffraction and X-ray photoelectron spectroscopy techniques revealed that pure cubic phase PbS and CdS layers were formed via this method. As shown by atomic force microscopy and scanning electron microscopy results, both films were homogeneous and presented a smooth surface. Optical properties showed that the energy band gap of PbS and CdS films were around 1.65 and 2.5 eV, respectively. The PbS film is p-type in nature with an electrical conductivity of around 0.8 S/cm. The hole concentration and mobility were 2.35 x 10{sup 18} cm{sup -3} and 2.16 x 10{sup -3} cm{sup 2}/V/s, respectively, as determined from Hall measurement. Both films were used to develop a thin film solar cell device of graphite/PbS/CdS/ITO/glass. Device characterization showed the power conversion efficiency of around 0.24 %. The corresponding open circuit voltage, short circuit current and fill factor were 0.570 V, 1.32 mA/cm{sup 2} and 0.32, respectively. (orig.)

  10. Cd xZn 1- xS solid solution thin films, CdS thin films and CdS/ZnS multilayer thin films grown by SILAR technique

    Science.gov (United States)

    Valkonen, Mika P.; Lindroos, Seppo; Leskelä, Markku

    1998-09-01

    Cd xZn 1- xS solid solution thin films were grown by successive ionic layer adsorption and reaction (SILAR) technique on soda lime glass, ITO-covered glass and polymer substrates. In addition, CdS thin films and CdS/ZnS multilayer thin films were deposited on polymer substrates. The thin films were characterized by X-ray diffraction and energy dispersive X-ray analysis. The Cd xZn 1- xS films were polycrystalline and cubic (111) or hexagonal (002) oriented. The cation/anion ratios were 1 : 1. In XRD, the CdS/ZnS multilayer samples showed not only reflections of CdS, ZnS, but also Cd xZn 1- xS formed in the interface. The Cd xZn 1- xS thin films and CdS/ZnS multilayer thin films could be tailored to a set of various composition and structure.

  11. Substrate temperature dependent studies on properties of chemical spray pyrolysis deposited CdS thin films for solar cell applications

    Science.gov (United States)

    Diwate, Kiran; Pawbake, Amit; Rondiya, Sachin; Kulkarni, Rupali; Waykar, Ravi; Jadhavar, Ashok; Rokade, Avinash; Funde, Adinath; Mohite, Kakasaheb; Shinde, Manish; Pathan, Habib; Devan, Rupesh; Jadkar, Sandesh

    2017-02-01

    Thin films of CdS have been prepared by chemical spray pyrolysis by spraying precursor solution directly onto soda lime glass (SLG) substrates. Influence of substrate temperature on structural, optical, morphological and electrical properties have been investigated by using various techniques such as low angle X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), UV–visible spectroscopy photoluminescence (PL) spectroscopy etc. Formation of CdS has been confirmed by low angle XRD, Raman spectroscopy and XPS analysis. XRD pattern showed that CdS films are polycrystalline, have hexagonal structure and prefer orientation of crystallites shifts from (101) to (002) with increase in substrate temperature. Raman spectroscopy revealed that exciton-phonon coupling depends on substrate temperature and hence on crystallite size. Optical band gap increased from 2.43 to 2.99 eV when substrate temperature increased from 325 to 475 ^\\circ {{C}}. Transmittance of the film also showed an increasing trend from ∼ 52 % to ∼ 80 % with increase in substrate temperature. Such high band gap and transmittance values of CdS films prepared at 475 ^\\circ {{C}} make it a useful window material in CdS/CdTe and CdS/Cu2S heterojunction solar cells. Project supported by the Department of Science and Technology (DST), Ministry of New and Renewable Energy (MNRE), Government of India, New Delhi.

  12. CdS thin films obtained by thermal treatment of cadmium(II) complex precursor deposited by MAPLE technique

    Energy Technology Data Exchange (ETDEWEB)

    Rotaru, Andrei [INFLPR - National Institute for Laser, Plasma and Radiation Physics, PPAM - Lasers Department, 409 Atomistilor Bvd., Magurele RO-077125, Bucharest (Romania); Mietlarek-Kropidlowska, Anna [Gdansk University of Technology, Chemistry Faculty, 11/12 G. Narutowicza Str., PL-90-233 Gdansk (Poland); Constantinescu, Catalin, E-mail: catalin.constantinescu@inflpr.ro [INFLPR - National Institute for Laser, Plasma and Radiation Physics, PPAM - Lasers Department, 409 Atomistilor Bvd., Magurele RO-077125, Bucharest (Romania); Scarisoreanu, Nicu; Dumitru, Marius [INFLPR - National Institute for Laser, Plasma and Radiation Physics, PPAM - Lasers Department, 409 Atomistilor Bvd., Magurele RO-077125, Bucharest (Romania); Strankowski, Michal [Gdansk University of Technology, Chemistry Faculty, 11/12 G. Narutowicza Str., PL-90-233 Gdansk (Poland); Rotaru, Petre [University of Craiova, Faculty of Physics, 13 A.I. Cuza St., Craiova RO-200585, Dolj (Romania); Ion, Valentin [INFLPR - National Institute for Laser, Plasma and Radiation Physics, PPAM - Lasers Department, 409 Atomistilor Bvd., Magurele RO-077125, Bucharest (Romania); Vasiliu, Cristina [INOE 2000 - National Institute for Optoelectronics, 1 Atomistilor Bvd., Magurele RO-077125, Bucharest (Romania); Becker, Barbara [Gdansk University of Technology, Chemistry Faculty, 11/12 G. Narutowicza Str., PL-90-233 Gdansk (Poland); Dinescu, Maria [INFLPR - National Institute for Laser, Plasma and Radiation Physics, PPAM - Lasers Department, 409 Atomistilor Bvd., Magurele RO-077125, Bucharest (Romania)

    2009-05-15

    Thin films of [Cd{l_brace}SSi(O-Bu{sup t}){sub 3}{r_brace}(S{sub 2}CNEt{sub 2})]{sub 2}, precursor for semiconducting CdS layers, were deposited on silicon substrates by Matrix-Assisted Pulsed Laser Evaporation (MAPLE) technique. Structural analysis of the obtained films by Fourier transform infrared spectroscopy (FTIR) confirmed the viability of the procedure. After the deposition of the coordination complex, the layers are manufactured by appropriate thermal treatment of the system (thin film and substrate), according to the thermal analysis of the compound. Surface morphology of the thin films was investigated by atomic force microscopy (AFM) and spectroscopic-ellipsometry (SE) measurements.

  13. S-Rich CdS1−yTey Thin Films Produced by the Spray Pyrolysis Technique

    Directory of Open Access Journals (Sweden)

    Shadia J. Ikhmayies

    2016-03-01

    Full Text Available Understanding the properties of CdSTe ternary alloys is important because they always form at the interface between the CdS window layer and CdTe absorber layer in CdS/CdTe solar cells due to the intermixing. This interdiffusion is necessary because it improves the device performance. Experimental work has been devoted to studying Te rich p-type CdSxTe1−x alloys, but there is a lack of studies on S-rich n-type CdS1−yTey solid solutions. In this work, a review of the structure, morphology, and optical properties of the S-rich n-type CdS1−yTey thin films produced by the spray pyrolysis technique on glass substrates is presented.

  14. Chemical bath deposition of CdS thin films: An approach to the chemical mechanism through study of the film microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Dona, J.M.; Herrero, J. [CIEMAT, Madrid (Spain). Inst. de Energias Renovables

    1997-11-01

    Many papers have been published lately on chemical bath deposition of CdS (CBD-CdS) thin films and related materials due to the promising results obtained using CBD-CdS for the fabrication of thin-film solar cells. In spite of this little of the research proposes a realistic chemical mechanism for the deposition process based on the determination of kinetic parameters. In this paper the authors present an exhaustive study of the CBD-CdS kinetic from which they propose a new chemical mechanism which agrees with the kinetic parameters determined supported by heterogeneous catalysis concepts. Simultaneously, the dependence of the deposited film structure on the kinetic variables is studied and the results obtained corroborate the proposed mechanism. These studies have allowed the authors to establish a standard set of conditions for the fabrication of homogeneous and continuous very thin CdS films.

  15. Physical properties of chemical bath deposited CdS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ximello-Quiebras, J.N.; Contreras-Puente, G.; Aguilar-Hernandez, J. [Escuela Superior de Fisica y Matematicas-Instituto Politecnico Nacional, Edificio 9, U.P.A.L.M. 07738 DF (Mexico); Santana-Rodriguez, G.; Arias-Carbajal Readigos, A. [Facultad de Fisica IMRE, Universidad de la Habana, 10400 La Habana (Cuba)

    2004-05-01

    Cadmium sulfide films of different thicknesses were deposited by chemical bath deposition (CBD) from a bath containing cadmium chloride, ammonium chloride, ammonium hydroxide and thiourea. The XRD patterns show that the films have a hexagonal phase with a preferential (002) orientation. The photoluminescence spectra show a defect structure, characteristics of the CdS films obtained by CBD. The electrical behavior in dark and under illumination, the optical properties and the band gap value reported in this work is in agreement with that reported in the literature.

  16. Temperature-dependent photoluminescence and mechanism of CdS thin film grown on Si nanoporous pillar array

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Ling Ling [Department of Physics and Laboratory of Material Physics, Zhengzhou University, Zhengzhou 450052 (China); College of Physics and Chemistry, Henan Polytechnic University, Jiaozuo 454000 (China); Li, Yan Tao [Department of Physics and Laboratory of Material Physics, Zhengzhou University, Zhengzhou 450052 (China); School of Material Science and Engineering, Henan University of Technology, Zhengzhou 454052 (China); Hu, Chu Xiong [Department of Physics and Laboratory of Material Physics, Zhengzhou University, Zhengzhou 450052 (China); Li, Xin Jian, E-mail: lixj@zzu.edu.cn [Department of Physics and Laboratory of Material Physics, Zhengzhou University, Zhengzhou 450052 (China)

    2015-09-15

    Highlights: • CdS/silicon nanoporous pillar array (CdS/Si-NPA) was prepared by a CBD method. • The PL spectrum of CdS/Si-NPA was measured at different temperatures, from 10 to 300 K. • The PL spectrum was composed of four emission bands, obeying different mechanisms. • The PL degradation with temperature was due to phonon-induced escape of carriers. - Abstract: Si-based cadmium sulfide (CdS) is a prospective semiconductor system in constructing optoelectronic nanodevices, and this makes the study on the factors which may affect its optical and electrical properties be of special importance. Here we report that CdS thin film was grown on Si nanoporous pillar array (Si-NPA) by a chemical bath deposition method, and the luminescent properties of CdS/Si-NPA as well as its mechanism were studied by measuring and analyzing its temperature-dependent photoluminescence (PL) spectrum. The low-temperature measurement disclosed that the PL spectrum of CdS/Si-NPA could be decomposed into four emission bands, a blue band, a green band, a red band and an infrared band. The blue band was due to the luminescence from Si-NPA substrate, and the others originate from the CdS thin film. With temperature increasing, the peak energy, PL intensity and peak profile shape for the PL bands from CdS evolves differently. Through theoretical and fitting analyses, the origins of the green, red and infrared band are attributed to the near band-edge emission, the radiative recombination from surface defects to Cd vacancies and those to S interstitials, respectively. The cause of PL degradation is due to the thermal quenching process, a phonon-induced electron escape but with different activation energies. These results might provide useful information for optimizing the preparing parameters to promote the performance of Si-based CdS optoelectronic devices.

  17. Characterization of CuInSe{sub 2}/CdS thin-film solar cells prepared using CBD

    Energy Technology Data Exchange (ETDEWEB)

    Vidyadharan Pillai, P.K.; Vijayakumar, K.P. [Department of Physics, Cochin University of Science and Technology, Kochi, Kerala (India)

    1997-12-19

    CuInSe{sub 2}/CdS thin-film heterojunction solar cells were fabricated entirely by chemical bath deposition technique. The illuminated J-V characteristics of the devices prepared with different thicknesses of CdS and CuInSe{sub 2} were studied. The typical solar cell parameters obtained for the best cell are: V{sub oc}=365 mV, J{sub sc}=12 mA/cm{sup 2}, FF=61%, and {eta}=3.1% under an illumination of 85 mW/cm{sup 2} on a cell of active area 0.1 cm{sup 2}. The J-V and C-V characteristics under dark condition and the spectral response were also studied for the best cell. The diode quality factor obtained is 1.7

  18. Structural and Photoelectrochemical Properties of Cu-Doped CdS Thin Films Prepared by Ultrasonic Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Rui Xie

    2013-01-01

    Full Text Available Cu-doped CdS thin films of variable doping levels have been deposited on indium tin oxide-coated glass substrate by simple and cost-effective ultrasonic spray pyrolysis. The influences of doping concentration and annealing treatment on the structure and photoelectrochemical properties of the films were investigated. The deposited films were characterized by XRD, SEM, and UV-Vis spectra. Moreover, the films were investigated by electrochemical and photoelectrochemical measurements with regard to splitting water for solar energy conversion. The results showed that the Cu impurity can cause a structural change and red shift of absorption edge. It was found that the photocurrent can be improved by the Cu-doping process for the unannealed films under the weak illumination. The unannealed 5 at.% Cu-doped sample obtained the maximum IPCE, which achieved about 45% at 0.3 V versus SCE potential under 420 nm wavelength photoirradiation. In addition, the p-type CdS was formed with a doping of 4 at.%~10 at.% Cu after 450°C 2 h annealed in vacuum.

  19. Stress and morphological development of CdS and ZnS thin films during the SILAR growth on (1 0 0)GaAs

    Science.gov (United States)

    Laukaitis, Giedrius; Lindroos, Seppo; Tamulevičius, Sigitas; Leskelä, Markku

    2001-12-01

    Cadmium sulfide and zinc sulfide films were grown on (1 0 0)GaAs substrate by successive ionic layer adsorption and reaction (SILAR) technique from aqueous precursor solutions at room temperature and normal pressure. The stress development of the thin films was characterized by laser interferometry as a function of the thickness of the films. The morphology and roughness of the films were monitored by atomic force microscopy. Additionally the crystallinity and crystallite size were analyzed by X-ray diffraction and composition by electron spectroscopy for chemical analysis. The CdS thin films had significantly higher stress level and also better crystallinity compared with ZnS thin films. Both films were polycrystalline and cubic, but the CdS thin films followed the substrate (1 0 0) orientation, whereas the ZnS films were (1 1 1) orientated. The roughness vs. film thickness curves of both films followed each other in shape, but the CdS films consisted of smaller particles.

  20. Improving the optical and crystalline properties on CdS thin films growth on small and large area by using CBD technique

    Energy Technology Data Exchange (ETDEWEB)

    Albor A, M. L.; Flores M, J. M.; Hernandez V, C.; Contreras P, G.; Mejia G, C.; Rueda M, G. [IPN, Escuela Superior de Fisica y Matematicas, Departamento de Fisica, Unidad Profesional Adolfo Lopez Mateos, Zacatenco, 07738 Ciudad de Mexico (Mexico); Gonzalez T, M. A. [IPN, Escuela Superior de Computo, Departamento de Formacion Basica, Unidad Profesional Adolfo Lopez Mateos, 07738 Ciudad de Mexico (Mexico)

    2016-11-01

    CdS polycrystalline thin films have been used as window layer in solar cells; the optical and crystalline quality of the CdS-partner plays and important role in the photovoltaic device performance. CdS thin films were deposited by using Chemical Bath Deposition. The SnO{sub 2}:F substrates used were chemically treated with HCl (0.1 M) and others were thermally annealed in different atmospheres (Ar and O{sub 2}). The physical properties of CdS thin films were influenced by the HCl treatment, position, size and the substrates movement inside the reaction beaker. The CdS samples were deposited in areas of 4 cm{sup 2}, 50 cm{sup 2} and 100 cm{sup 2}. Finally CdS thin films with thickness of 35-300 nm with good optical and crystalline quality on a uniform morphology were obtained. Transmittance values were obtained for all samples about 85-90 % with an average of gap energy of 2.5 eV. The structural characteristics of the samples were determined by the X-ray diffraction patterns, by means of a D-500 Siemens X-ray system. (Author)

  1. Electron Filtering by an Intervening ZnS Thin Film in the Au Nanoparticle-loaded CdS Plasmonic Photocatalyst.

    Science.gov (United States)

    Takayama, Kouichi; Fujiwara, Keigo; Kume, Takahiro; Naya, Shin-Ichi; Tada, Hiroaki

    2016-12-12

    In the gold nanoparticle (Au NP)-loaded CdS film on fluorine-doped tin oxide electrode (Au/CdS/FTO), the localized plasmonic resonance excitation-induced electron injection from Au NP to CdS has been proved by photoelectrochemical measurements. Formation of ZnS thin films between the Au NP and CdS film leads to a drastic increase of the photocurrent under visible-light irradiation ( > 610 nm) in a 0.1 M NaClO4 aqueous electrolyte solution due to the electron filtering effect. The photocurrent strongly depends on the thickness of the ZnS film, and the maximum value is obtained at the thickness of as thin as 2.1 nm. Further, the ZnS overlayer significantly stabilizes the photocurrent of the CdS/FTO electrode in a polysulfide/sulfide electrolyte solution even under the excitation of CdS ( > 430 nm). This work presents important information about the design for the new plasmonic photocatalysts consisting of plasmonic metal NP and chalcogenide semiconductors with high conduction band edge.

  2. Electron Filtering by an Intervening ZnS Thin Film in the Gold Nanoparticle-Loaded CdS Plasmonic Photocatalyst.

    Science.gov (United States)

    Takayama, Kouichi; Fujiwara, Keigo; Kume, Takahiro; Naya, Shin-Ichi; Tada, Hiroaki

    2017-01-05

    In the gold nanoparticle (Au NP)-loaded CdS film on fluorine-doped tin oxide electrode (Au/CdS/FTO), the localized plasmonic resonance excitation-induced electron injection from Au NP to CdS has been proven by photoelectrochemical measurements. Formation of ZnS thin films between the Au NP and CdS film leads to a drastic increase of the photocurrent under visible-light irradiation (λ > 610 nm) in a 0.1 M NaClO4 aqueous electrolyte solution due to the electron filtering effect. The photocurrent strongly depends on the thickness of the ZnS film, and the maximum value is obtained at a thickness as thin as 2.1 nm. Furthermore, the ZnS overlayer significantly stabilizes the photocurrent of the CdS/FTO electrode in a polysulfide/sulfide electrolyte solution even under the excitation of CdS (λ > 430 nm). This work presents important information about the design for new plasmonic photocatalysts consisting of plasmonic metal NPs and chalcogenide semiconductors with high conduction band edge.

  3. Rf sputtering of CdTE and CdS for thin film PV

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, A.D.; Tabory, C.N.; Shao, M.; Fischer, A.; Feng, Z.; Bohn, R.G. (Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States))

    1994-06-30

    In late 1992 we demonstrated the first rf sputtered CdS/CdTe photovoltaic cell with efficiency exceeding 10%. In this cell both CdS and CdTe layers were deposited by rf sputtering. In this paper we report preliminary measurements of (1) optical emission spectroscopy of the rf plasma, (2) the width of the phonon Raman line as a function of deposition temperature for CdS, and (3) studies of oxygen doping during pulsed laser deposition of CdTe.

  4. Structural and optical properties of Ni-doped CdS thin films prepared by chemical bath deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Premarani, R. [Arumugam Pillai SeethaiAmmal College, Thiruppattur-630211 (India); Saravanakumar, S., E-mail: sarophy84@gmail.com; Chandramohan, R. [SreeSevuganAnnamalai College, Devakottai-630303 (India); Mahalingam, T. [Department of Electrical and Computer Engineering, Ajou University, Suwon 443-749 (Korea, Republic of)

    2015-06-24

    The structural and optical behavior of undoped Cadmiun Sulphide (CdS) and Ni-doped CdS thinfilms prepared by Chemical Bath Deposition (CBD) technique is reported. The crystallite sizes of the thinfilms have been characterized by X-ray diffraction pattern (XRD). The particle sizes increase with the increase of Ni content in the CdS thinfilms. Scanning Electron Microscope (SEM) results indicated that CdS thinfilms is made up of aggregate of spherical-like particles. The composition was estimated by Energy Dispersive Analysis of X-ray (EDX) and reported. Spectroscopic studies revealed considerable improvement in transmission and the band gap of the films changes with addition of Ni dopant that is associated with variation in crystallite sizes in the nano regime.

  5. A method to form semiconductor quantum dot (QD) thin films by igniting a flame at air-liquid interface: CdS and WO3.

    Science.gov (United States)

    Jadhav, Aarti H; Patil, Sagar H; Sathaye, Shivaram D; Patil, Kashinath R

    2015-02-01

    We reveal an easy, inexpensive, efficient one stepflame synthesis of semiconductor/metal oxide thin films at air-liquid interface, subsequently, transferred on suitable substrate. The method has been illustrated by the formation of CdS and WO3 QDs thin films. The features of the present method are (1) Growth of thin films consisting of0.5-2.0nm sized Quantum Dots (QDs)/(ultra-small nanoparticles) in a short time, at the air-liquid interface which can be suitably transferred by a well-known Blodgett technique to an appropriate substrate, (2) The method is suitable to apply layer by layer (LbL) technique to increase the film thickness as well as forming various compositions as revealed by AFM measurements. The films are characterized for their structure (SAED), morphology (TEM), optical properties (UV-Vis.) and photoluminescence (PL). Possible mechanism of formation of QDs thin film and effect of capping in case of CdS QDs is discussed.

  6. RETRACTED: Ammonia-free method for synthesis of CdS nanocrystalline thin films through chemical bath deposition technique

    Science.gov (United States)

    Karimi, M.; Rabiee, M.; Moztarzadeh, F.; Bodaghi, M.; Tahriri, M.

    2009-11-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal ( http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief of Solid State Communications as the authors have plagiarized part of a paper that has also appeared in Current Applied Physics: Controlled synthesis, characterization and optical properties of CdS nanocrystalline thin films via chemical bath deposition (CBD) route Meysam Karimi, Mohammad Rabiee, Fathollah Moztarzadeh, Mohammadreza Tahriri and Masoud Bodaghi; Curr. Appl. Phys., 9 (2009) 1263-1268, doi: 10.1016/j.cap.2009.02.006. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

  7. Plasmon resonance-induced photoluminescence enhancement of CdTe/Cds quantum dots thin films

    Science.gov (United States)

    Wang, Hongyu; Xu, Ling; Wu, Yangqing; Xu, Jun; Ma, Zhongyuan; Chen, Kunji

    2016-11-01

    CdTe/CdS quantum dots/Au nano-rods nano-composite films were fabricated on planar Si substrates. The optical properties of all samples were investigated and the corresponding simulations were studied. It was found that the photoluminescence intensity of the CdTe/CdS quantum dots films was enhanced about 9-fold after the incorporation of Au nano-rods, the internal quantum efficiency increased from 24.3% to 35.2% due to the localized surface plasmon resonance. The time-resolved luminescence decay curves showed that the lifetimes of CdTe/CdS quantum dots films decreased to 2.8 ns after interaction with Au nano-rods. The results of finite-difference time-domain simulation indicated that Au nano-rods induced the localization of electric field, which enhanced the PL intensity of quantum dots films in the vicinity of Au nano-rods.

  8. Thermally deposited Ag-doped CdS thin film transistors with high-k rare-earth oxide Nd{sub 2}O{sub 3} as gate dielectric

    Energy Technology Data Exchange (ETDEWEB)

    Gogoi, P., E-mail: paragjyoti_g@rediffmail.com [Sibsagar College, Material Science Laboratory, Department of Physics (India)

    2013-03-15

    The performance of thermally deposited CdS thin film transistors doped with Ag has been reported. Ag-doped CdS thin films have been prepared using chemical method. High dielectric constant rare earth oxide Nd{sub 2}O{sub 3} has been used as gate insulator. The thin film trasistors are fabricated in coplanar electrode structure on ultrasonically cleaned glass substrates with a channel length of 50 {mu}m. The thin film transistors exhibit a high mobility of 4.3 cm{sup 2} V{sup -1} s{sup -1} and low threshold voltage of 1 V. The ON-OFF ratio of the thin film transistors is found as 10{sup 5}. The TFTs also exhibit good transconductance and gain band-width product of 1.15 Multiplication-Sign 10{sup -3} mho and 71 kHz respectively.

  9. Effects of ultraviolet light on B-doped CdS thin films prepared by spray pyrolysis method using perfume atomizer

    Energy Technology Data Exchange (ETDEWEB)

    Novruzov, V.D. [Department of Physics, Recep Tayyip Erdogan University, Rize (Turkey); Keskenler, E.F., E-mail: keskenler@gmail.com [Department of Nanotechnology Engineering, Recep Tayyip Erdogan University, Rize (Turkey); Tomakin, M. [Department of Physics, Recep Tayyip Erdogan University, Rize (Turkey); Kahraman, S. [Department of Physics, Mustafa Kemal University, Hatay (Turkey); Gorur, O. [Department of Physics, Abant Izzet Baysal University, Bolu (Turkey)

    2013-09-01

    Boron doped CdS thin films were deposited by spray pyrolysis method using perfume atomizer. The effects of ultraviolet light on the structural, optical and electrical properties of B-doped CdS thin films were investigated as a function of dopant concentration (B/Cd). X-ray diffraction studies showed that all samples were polycrystalline nature with hexagonal structure. It was determined that the preferred orientation of non-illuminated samples changes from (1 0 1) to (0 0 2) with B concentration. The c lattice constant of films decreases from 6.810 Å to 6.661 Å with boron doping. The XRD peak intensity increased with the illumination for almost all the samples. The lattice parameters of B-doped samples remained nearly constant after illumination. It was found that the optical transmittance, photoluminescence spectra, resistivity and carrier concentration of the B-doped samples are stable after the illumination with UV light. Also the effects of UV light on B-doped CdS/Cu{sub 2}S solar cell were investigated and it was determined that photoelectrical parameters of B-doped solar cell were more durable against the UV light.

  10. Effects of ultraviolet light on B-doped CdS thin films prepared by spray pyrolysis method using perfume atomizer

    Science.gov (United States)

    Novruzov, V. D.; Keskenler, E. F.; Tomakin, M.; Kahraman, S.; Gorur, O.

    2013-09-01

    Boron doped CdS thin films were deposited by spray pyrolysis method using perfume atomizer. The effects of ultraviolet light on the structural, optical and electrical properties of B-doped CdS thin films were investigated as a function of dopant concentration (B/Cd). X-ray diffraction studies showed that all samples were polycrystalline nature with hexagonal structure. It was determined that the preferred orientation of non-illuminated samples changes from (1 0 1) to (0 0 2) with B concentration. The c lattice constant of films decreases from 6.810 Å to 6.661 Å with boron doping. The XRD peak intensity increased with the illumination for almost all the samples. The lattice parameters of B-doped samples remained nearly constant after illumination. It was found that the optical transmittance, photoluminescence spectra, resistivity and carrier concentration of the B-doped samples are stable after the illumination with UV light. Also the effects of UV light on B-doped CdS/Cu2S solar cell were investigated and it was determined that photoelectrical parameters of B-doped solar cell were more durable against the UV light.

  11. Morphological and chemical study of the initial growth of CdS thin films deposited using an ammonia-free chemical process

    Energy Technology Data Exchange (ETDEWEB)

    Mazon-Montijo, D.A.; Sotelo-Lerma, M.; Quevedo-Lopez, M. [Centro de Investigacion en Polimeros y Materiales, Universidad de Sonora, Apdo. Postal 130, 83190 Hermosillo, Son. (Mexico); El-Bouanani, M. [Department of Materials Science and Engineering, University of North Texas, P.O. Box 305310 Denton, TX 76203-5310 (United States); Alshareef, H.N. [SEMATECH, 2706 Montopolis Drive, Austin, TX 78741 (United States); Espinoza-Beltran, F.J. [Centro de Investigacion y Estudios Avanzados del IPN, Unidad Queretaro, Apdo. Postal 1-798, 76001 Queretaro, Qro. (Mexico); Ramirez-Bon, R. [Centro de Investigacion y Estudios Avanzados del IPN, Unidad Queretaro, Apdo. Postal 1-798, 76001 Queretaro, Qro. (Mexico)], E-mail: rrbon@qro.cinvestav.mx

    2007-11-15

    We study the initial growth stages of CdS thin films deposited by an ammonia-free chemical bath deposition process. This ammonia-free process is more environmentally benign because it reduces potential ammonia release to the environment due to its high volatility. Instead of ammonia, sodium citrate was used as the complexing agent. We used atomic force microscopy (AFM), Rutherford backscattering (RBS) and X-ray photoelectron spectroscopy (XPS) to investigate the morphological and chemical modifications at the substrate surface during the first initial stages of the CdS deposition process. Additionally, X-ray diffraction (XRD) and optical transmission spectroscopy measurements were carried out to compliment the study. XPS results show that the first nucleation centers are composed by Cd(OH){sub 2} which agglomerate in patterns of bands, as demonstrated by AFM results. It is also observed that the conversion to CdS (by anionic exchange) of the first nucleus begins before the substrate surface is completely covered by a homogenous film.

  12. Growth, Optical and Electirical Properties of In2S3, In1-xCdxS and CdS Thin Films by the (SILAR) Method

    Science.gov (United States)

    Kundakçi, M.; Akaltun, Y.; Astam, A.; Ateş, A.; Yildirim, M.; Gürbulak, B.

    2007-04-01

    In2S3 and In1-xCdxS and CdS thin films were grown on glass substrates by using Successive Ionic Layer Adsorption and Reaction (SILAR) technique at room temperature. The band gap energies of the films were determined by optical absorption measurements. The optical absorption measurements were done as a function of the in the 10-320 K temperature range. It has been seen that, the band gap energies of the In2S3, In1-xCdxS and CdS are decreasing with in increasing temperature. The electrical characterization was done by current-voltage measurements with two probe method. The electrical resistivity measurements were done as a function of the in the 300-450 K temperature range. The electrical resistivity are decreasing with in increasing temperature. The resistivity were calculated at 300 K and 450 K, as 2×106 Ωcm and 1×104 Ωcm, 1,5×107 and 5,4×103, 1,5×107 and 1,2×104 Ωcm for CdS, In1-xCdxS, In2S3, respectively.

  13. Effect of Annealing Temperature on the Optical Spectra of CdS Thin Films Deposited at Low Solution Concentrations by Chemical Bath Deposition (CBD Technique

    Directory of Open Access Journals (Sweden)

    Zahid Rizwan

    2011-02-01

    Full Text Available Two different concentrations of CdCl2 and (NH22CS were used to prepare CdS thin films, to be deposited on glass substrate by chemical bath deposition (CBD technique. CdCl2 (0.000312 M and 0.000625 M was employed as a source of Cd2+ while (NH22CS (0.00125 M and 0.000625 M for S2− at a constant bath temperature of 70 °C. Adhesion of the deposited films was found to be very good for all the solution concentrations of both reagents. The films were air-annealed at a temperature between 200 °C to 360 °C for one hour. The minimum thickness was observed to be 33.6 nm for film annealed at 320 °C. XRD analyses reveal that the films were cubic along with peaks of hexagonal phase for all film samples. The crystallite size of the films decreased from 41.4 nm to 7.4 nm with the increase of annealing temperature for the CdCl2 (0.000312 M. Optical energy band gap (Eg, Urbach energy (Eu and absorption coefficient (α have been calculated from the transmission spectral data. These parameters have been discussed as a function of annealing temperature and solution concentration. The best transmission (about 97% was obtained for the air-annealed films at higher temperature at CdCl2 (0.000312 M.

  14. Structural, optical and electrical properties of CdS, Cd 0.5In 0.5S and In 2S 3 thin films grown by SILAR method

    Science.gov (United States)

    Kundakci, M.; Ateş, A.; Astam, A.; Yildirim, M.

    2008-01-01

    CdS, Cd 0.5In 0.5S and In 2S 3 thin films were grown by successive ionic layer adsorption and reaction (SILAR) method on a glass substrate at room temperature. These films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Optical and electrical properties of these films have been investigated as a function of temperature. The absorption measurements were carried out in the temperature range 10-320 K with a step of 10 K. The band gap energies ‘ Eg’ for CdS, Cd 0.5In 0.5S and In 2S 3 thin films have been found as 2.38, 2.52 and 2.63 eV at 10 K, respectively. The electrical resistivity of CdS, Cd 0.5In 0.5S and In 2S 3 thin films have been determined using a ‘dc’ two-probe method, in the temperature range of 300-450 K. The electrical resistivity values have been calculated at 300 K, as 2×10 6 Ω cm, 3.5×10 7 Ω cm and 1.5×10 7 Ω cm for CdS, Cd 0.5In 0.5S and In 2S 3, respectively. This is one of the first studies which led to deposition of the CdInS thin films by using the SILAR method.

  15. Photoluminescence study of polycrystalline photovoltaic CdS thin film layers grown by close-spaced sublimation and chemical bath deposition

    Science.gov (United States)

    Abken, Anke E.; Halliday, D. P.; Durose, Ken

    2009-03-01

    Photoluminescence (PL) measurements were used to study the effect of postdeposition treatments by annealing and CdCl2 activation on polycrystalline CdS layer grown by close-spaced sublimation (CSS) and chemical bath deposition (CBD). CdS films were either annealed in a temperature range of 200-600 °C or CdCl2 treated between 300-550 °C. The development of "red," "intermediate orange," "yellow," and "green" luminescence bands is discussed in comparison with PL assignments found in literature. PL spectra from CdS layer grown by CSS are dominated by the yellow band with transitions at 2.08 and 1.96 eV involving (Cdi-A), (VS-A) complex states where A represents an acceptor. Green luminescence bands are observed at 2.429 and 2.393 eV at higher annealing temperature of 500-600 °C or CdCl2 treatment above 450 °C, and these peaks are associated with zero and a longitudinal optical phonon replica of "free-to-bound" transitions. As grown CBD-CdS films show a prominent red band with four main peaks located at 1.43, 1.54, 1.65, and 1.77 eV, believed to be phonon replicas coupled with local vibrational modes. This remains following postdeposition treatment. The red luminescence is associated with VS surface states and in the case of CdCl2 treatment with (VCd-ClS) centers. Postdeposition treatments of CBD and CdS promote the evolution of an intermediate orange band at 2.00 eV, most likely a donor-acceptor pair, and a yellow band at 2.12 eV correlated with (Cdi-VCd) centers. The green luminescence bands observed at 2.25 and 2.34 eV are associated with transitions from deep donor states (e.g., Cdi) to the valence band. These states form due to crystallinity enhancement and lattice conversion during annealing or CdCl2 activation. Observed changes in PL bands provide detailed information about changes in radiative recombination centers in CdS layer, which are suggested to occur during device processing of CdTe/CdS thin film solar cells.

  16. Studies on chemical bath deposited CdS buffer layers for CIGS thin film solar cells%CIGS薄膜太阳能电池缓冲层CdS薄膜的制备研究

    Institute of Scientific and Technical Information of China (English)

    何丽秋

    2016-01-01

    目前CdS材料的制备方法有很多种,但是最常用的是化学水浴法。本文研究了浓度、反应溶液pH值、温度、沉积时间对CdS缓冲层薄膜的影响,对CIGS薄膜太阳能电池缓冲层CdS薄膜的制备方法进行了论述。%At present,the preparation methods of CdS has many kinds,The chemical bath deposition(CBD)is the most commonly method.In this review,the effects of concentration,pH,temperature and deposition time on the CdS buffer layer were studied.The preparation methods of CIGS thin film for CdS thin film solar cells were discussed.

  17. CdS nanoparticles sensitization of Al-doped ZnO nanorod array thin film with hydrogen treatment as an ITO/FTO-free photoanode for solar water splitting.

    Science.gov (United States)

    Hsu, Chih-Hsiung; Chen, Dong-Hwang

    2012-10-25

    Aluminum-doped zinc oxide (AZO) nanorod array thin film with hydrogen treatment possesses the functions of transparent conducting oxide thin film and 1-D nanostructured semiconductor simultaneously. To enhance the absorption in the visible light region, it is sensitized by cadmium sulfide (CdS) nanoparticles which efficiently increase the absorption around 460 nm. The CdS nanoparticles-sensitized AZO nanorod array thin film with hydrogen treatment exhibits significantly improved photoelectrochemical property. After further heat treatment, a maximum short current density of 5.03 mA cm-2 is obtained under illumination. They not only are much higher than those without CdS nanoparticles sensitization and those without Al-doping and/or hydrogen treatment, but also comparable and even slightly superior to some earlier works for the CdS-sensitized zinc oxide nanorod array thin films with indium tin oxide (ITO) or fluorine-doped tin oxide (FTO) as substrates. This demonstrated successfully that the AZO nanorod array thin film with hydrogen treatment is quite suitable as an ITO/FTO-free photoanode and has great potentials in solar water splitting after sensitization by quantum dots capable of visible light absorption.

  18. Effect of annealing temperature on the optical spectra of CdS thin films deposited at low solution concentrations by Chemical Bath Deposition (CBD) Technique.

    Science.gov (United States)

    Rizwan, Zahid; Zakaria, Azmi; Mohd Ghazali, Mohd Sabri; Jafari, Atefeh; Din, Fasih Ud; Zamiri, Reza

    2011-02-22

    Two different concentrations of CdCl(2) and (NH(2))(2)CS were used to prepare CdS thin films, to be deposited on glass substrate by chemical bath deposition (CBD) technique. CdCl(2) (0.000312 M and 0.000625 M) was employed as a source of Cd(2+) while (NH(2))(2)CS (0.00125 M and 0.000625 M) for S(2-) at a constant bath temperature of 70 °C. Adhesion of the deposited films was found to be very good for all the solution concentrations of both reagents. The films were air-annealed at a temperature between 200 °C to 360 °C for one hour. The minimum thickness was observed to be 33.6 nm for film annealed at 320 °C. XRD analyses reveal that the films were cubic along with peaks of hexagonal phase for all film samples. The crystallite size of the films decreased from 41.4 nm to 7.4 nm with the increase of annealing temperature for the CdCl(2) (0.000312 M). Optical energy band gap (E(g)), Urbach energy (E(u)) and absorption coefficient (α) have been calculated from the transmission spectral data. These parameters have been discussed as a function of annealing temperature and solution concentration. The best transmission (about 97%) was obtained for the air-annealed films at higher temperature at CdCl(2) (0.000312 M).

  19. The effect of processing conditions on the structural morphology and physical properties of ZnO and CdS thin films produced via sol-gel synthesis and chemical bath deposition techniques

    Science.gov (United States)

    Salam, Shahzad; Islam, Mohammad; Alam, Mahboob; Akram, Aftab; Ikram, Mujtaba; Mahmood, Asif; Khan, Majid; Mujahid, Mohammad

    2011-12-01

    Cadmium sulfide (CdS) and zinc oxide (ZnO) are used in thin film solar cells as buffer layer and transparent conducting oxide, respectively. The effect of annealing conditions on the morphology and physical properties of CdS and ZnO films prepared using chemical bath deposition and sol-gel synthesis techniques, respectively, was investigated. CdS films obtained from the chemical bath deposition (CBD) process were found to be polycrystalline with dense granular morphology. Electrical characterization of the films annealed at 400 °C for 10 min yielded values of 2.2×10-3 Ω cm and 8.3×1012 cm-3 for resistivity and carrier concentration, respectively. Scanning electron microscopy (SEM) and x-ray diffraction (XRD) studies of intrinsic zinc oxide (i-ZnO) films revealed flake-like morphology and transformation of the as-deposited amorphous structure into a hexagonal wurtzite crystal structure upon annealing at 500 °C for 2 h. Optical and electrical characterization results showed that such films had ~80% transmittance and resistivity values as low as 6.4×102 Ω cm. These films are being explored for fabrication and testing of copper-indium-gallium-(di)selenide (CIGS) thin film solar cells obtained from simple, cost-effective, solution-based synthesis routes.

  20. Investigations of the drift mobility of carriers and density of states in nanocrystalline CdS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Baljinder [Department of Physics, Kurukshetra University, Kurukshetra 136119 (India); Department of Physics, Panjab University, Chandigarh 160014 (India); Singh, Janpreet; Kaur, Jagdish [Department of Physics, Panjab University, Chandigarh 160014 (India); Moudgil, R.K. [Department of Physics, Kurukshetra University, Kurukshetra 136119 (India); Tripathi, S.K., E-mail: surya@pu.ac.in [Department of Physics, Panjab University, Chandigarh 160014 (India)

    2016-06-01

    Nanocrystalline Cadmium Sulfide (nc-CdS) thin films have been prepared on well-cleaned glass substrate at room temperature (300 K) by thermal evaporation technique using inert gas condensation (IGC) method. X-ray diffraction (XRD) analysis reveals that the films crystallize in hexagonal structure with preferred orientation along [002] direction. Scanning electron microscope (SEM) and Transmission electron microscope (TEM) studies reveal that grains are spherical in shape and uniformly distributed over the glass substrates. The optical band gap of the film is estimated from the transmittance spectra. Electrical parameters such as Hall coefficient, carrier type, carrier concentration, resistivity and mobility are determined using Hall measurements at 300 K. Transit time and mobility are estimated from Time of Flight (TOF) transient photocurrent technique in gap cell configuration. The measured values of electron drift mobility from TOF and Hall measurements are of the same order. Constant Photocurrent Method in ac-mode (ac-CPM) is used to measure the absorption spectra in low absorption region. By applying derivative method, we have converted the measured absorption data into a density of states (DOS) distribution in the lower part of the energy gap. The value of Urbach energy, steepness parameter and density of defect states have been calculated from the absorption and DOS spectra.

  1. Studies of heat treated CSS CdS films

    Science.gov (United States)

    Marinskiy, D.; Marinskaya, S.; Viswanathan, V.; Morel, D. L.; Ferekides, C. S.

    1999-03-01

    Cadmium sulfide continues to be the most successful and widely used n-type heterojunction partner in thin film CdTe solar cells. In most cases solar cell performance is enhanced if the CdS films are heat treated prior to the deposition of the CdTe. This paper discusses the effect of H2 annealing on the resistivity of CSS-CdS films and the use of a mobility activation model to explain the observed changes in resistivity. Photoluminescence measurements of CSS CdS films heat-treated in He and in CdCl2 vapor have also been carried out. In all cases the heat treatments lead to an increase in the intensity of a photoluminescence band believed to be associated with sulfur vacancies.

  2. Photoluminescence study of polycrystalline photovoltaic CdS thin film layers grown by close-spaced sublimation and chemical bath deposition.

    OpenAIRE

    Abken, Anke E.; Halliday, D.P.; Durose, Ken

    2009-01-01

    Photoluminescence (PL) measurements were used to study the effect of postdeposition treatments by annealing and CdCl2 activation on polycrystalline CdS layer grown by close-spaced sublimation (CSS) and chemical bath deposition (CBD). CdS films were either annealed in a temperature range of 200–600 °C or CdCl2 treated between 300–550 °C. The development of “red,” “intermediate orange,” “yellow,” and “green” luminescence bands is discussed in comparison with PL assignments found in literature. ...

  3. Analysis of the electrodeposition and surface chemistry of CdTe, CdSe, and CdS thin films through substrate-overlayer surface-enhanced Raman spectroscopy.

    Science.gov (United States)

    Gu, Junsi; Fahrenkrug, Eli; Maldonado, Stephen

    2014-09-02

    The substrate-overlayer approach has been used to acquire surface enhanced Raman spectra (SERS) during and after electrochemical atomic layer deposition (ECALD) of CdSe, CdTe, and CdS thin films. The collected data suggest that SERS measurements performed with off-resonance (i.e. far from the surface plasmonic wavelength of the underlying SERS substrate) laser excitation do not introduce perturbations to the ECALD processes. Spectra acquired in this way afford rapid insight on the quality of the semiconductor film during the course of an ECALD process. For example, SERS data are used to highlight ECALD conditions that yield crystalline CdSe and CdS films. In contrast, SERS measurements with short wavelength laser excitation show evidence of photoelectrochemical effects that were not germane to the intended ECALD process. Using the semiconductor films prepared by ECALD, the substrate-overlayer SERS approach also affords analysis of semiconductor surface adsorbates. Specifically, Raman spectra of benzenethiol adsorbed onto CdSe, CdTe, and CdS films are detailed. Spectral shifts in the vibronic features of adsorbate bonding suggest subtle differences in substrate-adsorbate interactions, highlighting the sensitivity of this methodology.

  4. Influence of deposition parameters on the structural and optical properties of CdS thin films obtained by micro-controlled SILAR deposition

    Science.gov (United States)

    Rao, K. Gowrish; Ashith, V. K.

    2015-02-01

    Polycrystalline CdS films were obtained by a micro-controlled SILAR deposition technique, using aqueous solutions of cadmium acetate and thiourea as precursors. The structural and optical properties of the films were found to be influenced by various deposition parameters such as number of immersion cycles, concentration of the precursors and temperature of the solutions. Contrary to the observations made by some researchers, we found that the thickness of the films increased continuously with number of immersion cycles and also with concentration of the precursor solutions. We also found that the films covered the substrates uniformly, without any voids, unlike the films obtained by others. Effect of deposition parameters on thickness, substrate coverage, grain size, chemical composition, optical band gap and other properties of the films is discussed in detail.

  5. Spectroscopic Analysis of Impurity Precipitates in CdS Films

    Energy Technology Data Exchange (ETDEWEB)

    Webb, J. D.; Keane, J.; Ribelin, R.; Gedvilas, L.; Swartzlander, A.; Ramanathan, K.; Albin, D. S.; Noufi, R.

    1999-10-31

    Impurities in cadmium sulfide (CdS) films are a concern in the fabrication of copper (indium, gallium) diselenide (CIGS) and cadmium telluride (CdTe) photovoltaic devices. Devices incorporating chemical-bath-deposited (CBD) CdS are comparable in quality to devices incorporating purer CdS films grown using vacuum deposition techniques, despite the higher impurity concentrations typically observed in the CBD CdS films. In this paper, we summarize and review the results of Fourier transform infrared (FTIR), Auger, electron microprobe, and X-ray photoelectron spectroscopic (XPS) analyses of the impurities in CBD CdS films. We show that these impurities differ as a function of substrate type and film deposition conditions. We also show that some of these impurities exist as 10{sup 2} micron-scale precipitates.

  6. First principles calculations of point defect diffusion in CdS buffer layers: Implications for Cu(In,Ga)(Se,S)2 and Cu2ZnSn(Se,S)4-based thin-film photovoltaics

    Science.gov (United States)

    Varley, J. B.; Lordi, V.; He, X.; Rockett, A.

    2016-01-01

    We investigate point defects in CdS buffer layers that may arise from intermixing with Cu(In,Ga)Se2 (CIGSe) or Cu2ZnSn(S,Se)4 (CZTSSe) absorber layers in thin-film photovoltaics (PV). Using hybrid functional calculations, we characterize the migration barriers of Cu, In, Ga, Se, Sn, Zn, Na, and K impurities and assess the activation energies necessary for their diffusion into the bulk of the buffer. We find that Cu, In, and Ga are the most mobile defects in CIGS-derived impurities, with diffusion expected to proceed into the buffer via interstitial-hopping and cadmium vacancy-assisted mechanisms at temperatures ˜400 °C. Cu is predicted to strongly favor migration paths within the basal plane of the wurtzite CdS lattice, which may facilitate defect clustering and ultimately the formation of Cu-rich interfacial phases as observed by energy dispersive x-ray spectroscopic elemental maps in real PV devices. Se, Zn, and Sn defects are found to exhibit much larger activation energies and are not expected to diffuse within the CdS bulk at temperatures compatible with typical PV processing temperatures. Lastly, we find that Na interstitials are expected to exhibit slightly lower activation energies than K interstitials despite having a larger migration barrier. Still, we find both alkali species are expected to diffuse via an interstitially mediated mechanism at slightly higher temperatures than enable In, Ga, and Cu diffusion in the bulk. Our results indicate that processing temperatures in excess of ˜400 °C will lead to more interfacial intermixing with CdS buffer layers in CIGSe devices, and less so for CZTSSe absorbers where only Cu is expected to significantly diffuse into the buffer.

  7. First principles calculations of point defect diffusion in CdS buffer layers: Implications for Cu(In,Ga)(Se,S){sub 2} and Cu{sub 2}ZnSn(Se,S){sub 4}-based thin-film photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Varley, J. B.; Lordi, V. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); He, X.; Rockett, A. [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2016-01-14

    We investigate point defects in CdS buffer layers that may arise from intermixing with Cu(In,Ga)Se{sub 2} (CIGSe) or Cu{sub 2}ZnSn(S,Se){sub 4} (CZTSSe) absorber layers in thin-film photovoltaics (PV). Using hybrid functional calculations, we characterize the migration barriers of Cu, In, Ga, Se, Sn, Zn, Na, and K impurities and assess the activation energies necessary for their diffusion into the bulk of the buffer. We find that Cu, In, and Ga are the most mobile defects in CIGS-derived impurities, with diffusion expected to proceed into the buffer via interstitial-hopping and cadmium vacancy-assisted mechanisms at temperatures ∼400 °C. Cu is predicted to strongly favor migration paths within the basal plane of the wurtzite CdS lattice, which may facilitate defect clustering and ultimately the formation of Cu-rich interfacial phases as observed by energy dispersive x-ray spectroscopic elemental maps in real PV devices. Se, Zn, and Sn defects are found to exhibit much larger activation energies and are not expected to diffuse within the CdS bulk at temperatures compatible with typical PV processing temperatures. Lastly, we find that Na interstitials are expected to exhibit slightly lower activation energies than K interstitials despite having a larger migration barrier. Still, we find both alkali species are expected to diffuse via an interstitially mediated mechanism at slightly higher temperatures than enable In, Ga, and Cu diffusion in the bulk. Our results indicate that processing temperatures in excess of ∼400 °C will lead to more interfacial intermixing with CdS buffer layers in CIGSe devices, and less so for CZTSSe absorbers where only Cu is expected to significantly diffuse into the buffer.

  8. Thin Films

    Directory of Open Access Journals (Sweden)

    M. Benmouss

    2003-01-01

    the optical absorption are consistent with the film color changes. Finally, the optical and electrochromic properties of the films prepared by this method are compared with those of our sputtered films already studied and with other works.

  9. Formation of the physical vapor deposited CdS Cu In,Ga Se2 interface in highly efficient thin film solar cells

    OpenAIRE

    Rusu, M.; Glatzel, Th.; Neisser, A.; Kaufmann, C.A.; Sadewasser, S.; Lux Steiner, M. Ch.

    2006-01-01

    We report on the buffer absorber interface formation in highly efficient 14.5 , AM1.5 ZnO CdS Cu In,Ga Se2 solar cells with a physical vapor deposited CdS buffer. For Se decapped Cu In,Ga Se2 CIGSe absorbers we observe sulfur passivation of the CIGSe grain boundaries during CdS growth and at the interface a thermally stimulated formation of a region with a higher band gap than that of the absorber bulk, determining the height of the potential barrier at the CdS CIGSe interface. For air ex...

  10. Pyroelectric coupling in thin film photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Karpov, Victor G.; Shvydka, Diana [Department of Physics and Astronomy, University of Toledo, OH (United States)

    2007-07-15

    We propose a theory of thin film photovoltaics in which one of the polycrystalline films is made of a pyroelectric material grains such as CdS. That film is shown to generate strong polarization improving the device open circuit voltage. Implications and supporting facts for the major photovoltaic types based on CdTe and CuIn(Ga)Se{sub 2} absorber layers are discussed. Band diagram of a pyroelectric (CdS) based PV junction. Arrows represent the charge carrier photo-generation. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Graded-Bandgap Solar Cells Using All-Electrodeposited ZnS, CdS and CdTe Thin-Films

    Directory of Open Access Journals (Sweden)

    Obi K. Echendu

    2015-05-01

    Full Text Available A 3-layer graded-bandgap solar cell with glass/FTO/ZnS/CdS/CdTe/Au structure has been fabricated using all-electrodeposited ZnS, CdS and CdTe thin layers. The three semiconductor layers were electrodeposited using a two-electrode system for process simplification. The incorporation of a wide bandgap amorphous ZnS as a buffer/window layer to form glass/FTO/ZnS/CdS/CdTe/Au solar cell resulted in the formation of this 3-layer graded-bandgap device structure. This has yielded corresponding improvement in all the solar cell parameters resulting in a conversion efficiency >10% under AM1.5 illumination conditions at room temperature, compared to the 8.0% efficiency of a 2-layer glass/FTO/CdS/CdTe/Au reference solar cell structure. These results demonstrate the advantages of the multi-layer graded-bandgap device architecture over the conventional 2-layer structure. In addition, they demonstrate the effective application of the two-electrode system as a simplification to the conventional three-electrode system in the electrodeposition of semiconductors with the elimination of the reference electrode as a possible impurity source.

  12. Hot electron induced NIR detection in CdS films.

    Science.gov (United States)

    Sharma, Alka; Kumar, Rahul; Bhattacharyya, Biplab; Husale, Sudhir

    2016-03-11

    We report the use of random Au nanoislands to enhance the absorption of CdS photodetectors at wavelengths beyond its intrinsic absorption properties from visible to NIR spectrum enabling a high performance visible-NIR photodetector. The temperature dependent annealing method was employed to form random sized Au nanoparticles on CdS films. The hot electron induced NIR photo-detection shows high responsivity of ~780 mA/W for an area of ~57 μm(2). The simulated optical response (absorption and responsivity) of Au nanoislands integrated in CdS films confirms the strong dependence of NIR sensitivity on the size and shape of Au nanoislands. The demonstration of plasmon enhanced IR sensitivity along with the cost-effective device fabrication method using CdS film enables the possibility of economical light harvesting applications which can be implemented in future technological applications.

  13. Effect of low concentration Sn doping on optical properties of CdS films grown by CBD technique.

    Science.gov (United States)

    Jafari, Atefeh; Zakaria, Azmi; Rizwan, Zahid; Mohd Ghazali, Mohd Sabri

    2011-01-01

    Thin and transparent films of doped cadmium sulfide (CdS) were obtained on commercial glass substrates by Chemical Bath Deposition (CBD) technique. The films were doped with low concentration of Sn, and annealed in air at 300 °C for 45 min. The morphological characterization of the films with different amounts of dopant was made using SEM and EDAX analysis. Optical properties of the films were evaluated by measuring transmittance using the UV-vis spectrophotometer. A comparison of the results revealed that lower concentration of Sn doping improves transmittance of CdS films and makes them suitable for application as window layer of CdTe/CIGS solar cells.

  14. Thin film processes II

    CERN Document Server

    Kern, Werner

    1991-01-01

    This sequel to the 1978 classic, Thin Film Processes, gives a clear, practical exposition of important thin film deposition and etching processes that have not yet been adequately reviewed. It discusses selected processes in tutorial overviews with implementation guide lines and an introduction to the literature. Though edited to stand alone, when taken together, Thin Film Processes II and its predecessor present a thorough grounding in modern thin film techniques.Key Features* Provides an all-new sequel to the 1978 classic, Thin Film Processes* Introduces new topics, and sever

  15. Pyrolyzed thin film carbon

    Science.gov (United States)

    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.

  16. Formation of the physical vapor deposited CdS /Cu(In,Ga)Se2 interface in highly efficient thin film solar cells

    Science.gov (United States)

    Rusu, M.; Glatzel, Th.; Neisser, A.; Kaufmann, C. A.; Sadewasser, S.; Lux-Steiner, M. Ch.

    2006-04-01

    We report on the buffer/absorber interface formation in highly efficient (14.5%, air mass 1.5) ZnO /CdS/Cu(In,Ga)Se2 solar cells with a physical vapor deposited CdS buffer. For Se-decapped Cu (In,Ga)Se2 (CIGSe) absorbers we observe sulfur passivation of the CIGSe grain boundaries during CdS growth and at the interface a thermally stimulated formation of a region with a higher band gap than that of the absorber bulk, determining the height of the potential barrier at the CdS /CIGSe interface. For air-exposed CIGSe samples the grain boundary passivation is impeded by a native oxide/adsorbate layer at the CIGSe surface determining the thermal stability of the potential barrier height.

  17. Ceramic Composite Thin Films

    Science.gov (United States)

    Ruoff, Rodney S. (Inventor); Stankovich, Sasha (Inventor); Dikin, Dmitriy A. (Inventor); Nguyen, SonBinh T. (Inventor)

    2013-01-01

    A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.

  18. A composite CdS thin film/TiO2 nanotube structure by ultrafast successive electrochemical deposition toward photovoltaic application

    Science.gov (United States)

    Fu, Han; Liu, Hong; Shen, Wenzhong

    2014-11-01

    Fabricating functional compounds on substrates with complicated morphology has been an important topic in material science and technology, which remains a challenging issue to simultaneously achieve a high growth rate for a complex nanostructure with simple controlling factors. Here, we present a novel simple and successive method based on chemical reactions in an open reaction system manipulated by an electric field. A uniform CdS/TiO2 composite tubular structure has been fabricated in highly ordered TiO2 nanotube arrays in a very short time period (~90 s) under room temperature (RT). The content of CdS in the resultant and its crystalline structure was tuned by the form and magnitude of external voltage. The as-formed structure has shown a quite broad and bulk-like light absorption spectrum with the absorption of photon energy even below that of the bulk CdS. The as-fabricated-sensitized solar cell based on this composite structure has achieved an efficiency of 1.43% without any chemical doping or co-sensitizing, 210% higher than quantum dot-sensitized solar cell (QDSSC) under a similar condition. Hopefully, this method can also easily grow nanostructures based on a wide range of compound materials for energy science and electronic technologies, especially for fast-deploying devices.

  19. A composite CdS thin film/TiO2 nanotube structure by ultrafast successive electrochemical deposition toward photovoltaic application.

    Science.gov (United States)

    Fu, Han; Liu, Hong; Shen, Wenzhong

    2014-01-01

    Fabricating functional compounds on substrates with complicated morphology has been an important topic in material science and technology, which remains a challenging issue to simultaneously achieve a high growth rate for a complex nanostructure with simple controlling factors. Here, we present a novel simple and successive method based on chemical reactions in an open reaction system manipulated by an electric field. A uniform CdS/TiO2 composite tubular structure has been fabricated in highly ordered TiO2 nanotube arrays in a very short time period (~90 s) under room temperature (RT). The content of CdS in the resultant and its crystalline structure was tuned by the form and magnitude of external voltage. The as-formed structure has shown a quite broad and bulk-like light absorption spectrum with the absorption of photon energy even below that of the bulk CdS. The as-fabricated-sensitized solar cell based on this composite structure has achieved an efficiency of 1.43% without any chemical doping or co-sensitizing, 210% higher than quantum dot-sensitized solar cell (QDSSC) under a similar condition. Hopefully, this method can also easily grow nanostructures based on a wide range of compound materials for energy science and electronic technologies, especially for fast-deploying devices.

  20. CdS films deposited by chemical bath under rotation

    Energy Technology Data Exchange (ETDEWEB)

    Oliva-Aviles, A.I., E-mail: aoliva@mda.cinvestav.mx [Centro de Investigacion y de Estudios Avanzados Unidad Merida, Departamento de Fisica Aplicada. A.P. 73-Cordemex, 97310 Merida, Yucatan (Mexico); Patino, R.; Oliva, A.I. [Centro de Investigacion y de Estudios Avanzados Unidad Merida, Departamento de Fisica Aplicada. A.P. 73-Cordemex, 97310 Merida, Yucatan (Mexico)

    2010-08-01

    Cadmium sulfide (CdS) films were deposited on rotating substrates by the chemical bath technique. The effects of the rotation speed on the morphological, optical, and structural properties of the films were discussed. A rotating substrate-holder was fabricated such that substrates can be taken out from the bath during the deposition. CdS films were deposited at different deposition times (10, 20, 30, 40 and 50 min) onto Corning glass substrates at different rotation velocities (150, 300, 450, and 600 rpm) during chemical deposition. The chemical bath was composed by CdCl{sub 2}, KOH, NH{sub 4}NO{sub 3} and CS(NH{sub 2}){sub 2} as chemical reagents and heated at 75 deg. C. The results show no critical effects on the band gap energy and the surface roughness of the CdS films when the rotation speed changes. However, a linear increase on the deposition rate with the rotation energy was observed, meanwhile the stoichiometry was strongly affected by the rotation speed, resulting a better 1:1 Cd/S ratio as speed increases. Rotation effects may be of interest in industrial production of CdTe/CdS solar cells.

  1. Thin Film & Deposition Systems (Windows)

    Data.gov (United States)

    Federal Laboratory Consortium — Coating Lab: Contains chambers for growing thin film window coatings. Plasma Applications Coating Lab: Contains chambers for growing thin film window coatings. Solar...

  2. Subatomic deformation driven by vertical piezoelectricity from CdS ultrathin films.

    Science.gov (United States)

    Wang, Xuewen; He, Xuexia; Zhu, Hongfei; Sun, Linfeng; Fu, Wei; Wang, Xingli; Hoong, Lai Chee; Wang, Hong; Zeng, Qingsheng; Zhao, Wu; Wei, Jun; Jin, Zhong; Shen, Zexiang; Liu, Jie; Zhang, Ting; Liu, Zheng

    2016-07-01

    Driven by the development of high-performance piezoelectric materials, actuators become an important tool for positioning objects with high accuracy down to nanometer scale, and have been used for a wide variety of equipment, such as atomic force microscopy and scanning tunneling microscopy. However, positioning at the subatomic scale is still a great challenge. Ultrathin piezoelectric materials may pave the way to positioning an object with extreme precision. Using ultrathin CdS thin films, we demonstrate vertical piezoelectricity in atomic scale (three to five space lattices). With an in situ scanning Kelvin force microscopy and single and dual ac resonance tracking piezoelectric force microscopy, the vertical piezoelectric coefficient (d 33) up to 33 pm·V(-1) was determined for the CdS ultrathin films. These findings shed light on the design of next-generation sensors and microelectromechanical devices.

  3. Subatomic deformation driven by vertical piezoelectricity from CdS ultrathin films

    Science.gov (United States)

    Wang, Xuewen; He, Xuexia; Zhu, Hongfei; Sun, Linfeng; Fu, Wei; Wang, Xingli; Hoong, Lai Chee; Wang, Hong; Zeng, Qingsheng; Zhao, Wu; Wei, Jun; Jin, Zhong; Shen, Zexiang; Liu, Jie; Zhang, Ting; Liu, Zheng

    2016-01-01

    Driven by the development of high-performance piezoelectric materials, actuators become an important tool for positioning objects with high accuracy down to nanometer scale, and have been used for a wide variety of equipment, such as atomic force microscopy and scanning tunneling microscopy. However, positioning at the subatomic scale is still a great challenge. Ultrathin piezoelectric materials may pave the way to positioning an object with extreme precision. Using ultrathin CdS thin films, we demonstrate vertical piezoelectricity in atomic scale (three to five space lattices). With an in situ scanning Kelvin force microscopy and single and dual ac resonance tracking piezoelectric force microscopy, the vertical piezoelectric coefficient (d33) up to 33 pm·V−1 was determined for the CdS ultrathin films. These findings shed light on the design of next-generation sensors and microelectromechanical devices. PMID:27419234

  4. Investigation of annealing temperature effect on magnetron sputtered cadmium sulfide thin film properties

    Science.gov (United States)

    Akbarnejad, E.; Ghorannevis, Z.; Abbasi, F.; Ghoranneviss, M.

    2016-12-01

    Cadmium sulfide (CdS) thin films are deposited on the fluorine doped tin oxide coated glass substrate using the radio frequency magnetron sputtering setup. The effects of annealing in air on the structural, morphological, and optical properties of CdS thin film are studied. Optimal annealing temperature is investigated by annealing the CdS thin film at different annealing temperatures of 300, 400, and 500 °C. Thin films of CdS are characterized by X-ray diffractometer analysis, field emission scanning electron microscopy, atomic force microscopy, UV-Vis-NIR spectrophotometer and four point probe. The as-grown CdS films are found to be polycrystalline in nature with a mixture of cubic and hexagonal phases. By increasing the annealing temperature to 500 °C, CdS film showed cubic phase, indicating the phase transition of CdS. It is found from physical characterizations that the heat treatment in air increased the mean grain size, the transmission, and the surface roughness of the CdS thin film, which are desired to the application in solar cells as a window layer material.

  5. Thermal evaporation and characterization of Sb2Se3 thin film for substrate Sb2Se3/CdS solar cells.

    Science.gov (United States)

    Liu, Xinsheng; Chen, Jie; Luo, Miao; Leng, Meiying; Xia, Zhe; Zhou, Ying; Qin, Sikai; Xue, Ding-Jiang; Lv, Lu; Huang, Han; Niu, Dongmei; Tang, Jiang

    2014-07-09

    Sb2Se3 is a promising absorber material for photovoltaic cells because of its optimum band gap, strong optical absorption, simple phase and composition, and earth-abundant and nontoxic constituents. However, this material is rarely explored for photovoltaic application. Here we report Sb2Se3 solar cells fabricated from thermal evaporation. The rationale to choose thermal evaporation for Sb2Se3 film deposition was first discussed, followed by detailed characterization of Sb2Se3 film deposited onto FTO with different substrate temperatures. We then studied the optical absorption, photosensitivity, and band position of Sb2Se3 film, and finally a prototype photovoltaic device FTO/Sb2Se3/CdS/ZnO/ZnO:Al/Au was constructed, achieving an encouraging 2.1% solar conversion efficiency.

  6. Biomimetic thin film synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Graff, G.L.; Campbell, A.A.; Gordon, N.R.

    1995-05-01

    The purpose of this program is to develop a new process for forming thin film coatings and to demonstrate that the biomimetic thin film technology developed at PNL is useful for industrial applications. In the biomimetic process, mineral deposition from aqueous solution is controlled by organic functional groups attached to the underlying substrate surface. The coatings process is simple, benign, inexpensive, energy efficient, and particularly suited for temperature sensitive substrate materials (such as polymers). In addition, biomimetic thin films can be deposited uniformly on complex shaped and porous substrates providing a unique capability over more traditional line-of-sight methods.

  7. Optical properties of CdS sintered film

    Indian Academy of Sciences (India)

    D Patidar; R Sharma; N Jain; T P Sharma; N S Saxena

    2006-02-01

    Chemical method has been used to prepare cadmium sulphide by using cadmium, hydrochloric acid and H2S. The reflection spectra of covered and uncovered sintered films of CdS have been recorded by ‘Hitachi spectrophotometer’ over the wavelength range 300–700 nm. The energy band gaps of these films have been calculated from reflection spectra. It is found that the energy band gap of both films is same as 2.41 eV. It is indicated that energy band gap of these films does not change. This value of band gap is in good agreement with the value reported by other workers. The measurement of photocurrent has also been carried out using Keithley High Resistance meter/ Electrometer. This film shows the high photosensitivity and high photocurrent decay. Thus so obtained films are suitable for fabrication of photo detectors and solar cells.

  8. Structural properties of dopping metallic impurities on CdS thin layers

    Directory of Open Access Journals (Sweden)

    S. Ghasemzadeh

    2016-12-01

    Full Text Available (Cu,Zn-dopped CdS thin layers were deposited on glass substrates by chemical bath deposition technique. The effects of the doping on the structural properties of CdS thin layers were studied by SEM and EDAX analysis. Hetero junction layers were produced with different nano structures and different fraction of voids and metallic ions.

  9. Structural properties of dopping metallic impurities on CdS thin layers

    OpenAIRE

    S. Ghasemzadeh; H. kangarlou

    2016-01-01

    (Cu,Zn)-dopped CdS thin layers were deposited on glass substrates by chemical bath deposition technique. The effects of the doping on the structural properties of CdS thin layers were studied by SEM and EDAX analysis. Hetero junction layers were produced with different nano structures and different fraction of voids and metallic ions.

  10. Study of the defect levels, electrooptics, and interface properties of polycrystalline CdTe and CdS thin films and their junction

    Energy Technology Data Exchange (ETDEWEB)

    Abulfotuh, F.A.; Balcioglu, A.; Wangensteen, T.; Moutinho, H.R.; Hassoon, F.; Kazmerski, L.L. [National Renewable Energy Lab., Golden, CO (United States); Al-Douri, A.; Alnajjar, A. [United Arab Emirates Univ., Al-Ain (United Arab Emirates). Physics Dept.

    1997-12-31

    In this study, the electrical behavior of CdS/CdTe junctions was investigated using deep-level transient spectroscopy (DLTS) and capacitance-voltage (c-v) measurements. The results were then correlated to chemical composition and optical properties (measured by using a wavelength-scanning ellipsometer) of the CdTe film and the dominant defect states were determined by photoluminescence (PL) emission measured before and after post-deposition CdCl{sub 2} treatments. CdTe films used in this study were prepared by electrochemical deposition (ED), close-spaced sublimation (CSS), and physical vapor deposition (PVD). The chemical and heat treatments are shown to decrease Cd-vacancy levels (PL measurements), which determine various parameters crucial to the device performance such as the type and concentration of the dominant defects and deep levels, greatly affect the device performance by controlling open-circuit voltage.

  11. Thin film device applications

    CERN Document Server

    Kaur, Inderjeet

    1983-01-01

    Two-dimensional materials created ab initio by the process of condensation of atoms, molecules, or ions, called thin films, have unique properties significantly different from the corresponding bulk materials as a result of their physical dimensions, geometry, nonequilibrium microstructure, and metallurgy. Further, these characteristic features of thin films can be drasti­ cally modified and tailored to obtain the desired and required physical characteristics. These features form the basis of development of a host of extraordinary active and passive thin film device applications in the last two decades. On the one extreme, these applications are in the submicron dimensions in such areas as very large scale integration (VLSI), Josephson junction quantum interference devices, magnetic bubbles, and integrated optics. On the other extreme, large-area thin films are being used as selective coatings for solar thermal conversion, solar cells for photovoltaic conver­ sion, and protection and passivating layers. Ind...

  12. Multifunctional thin film surface

    Energy Technology Data Exchange (ETDEWEB)

    Brozik, Susan M.; Harper, Jason C.; Polsky, Ronen; Wheeler, David R.; Arango, Dulce C.; Dirk, Shawn M.

    2015-10-13

    A thin film with multiple binding functionality can be prepared on an electrode surface via consecutive electroreduction of two or more aryl-onium salts with different functional groups. This versatile and simple method for forming multifunctional surfaces provides an effective means for immobilization of diverse molecules at close proximities. The multifunctional thin film has applications in bioelectronics, molecular electronics, clinical diagnostics, and chemical and biological sensing.

  13. Role of the buffer solution in the chemical deposition of CdS films for CIGS solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sooho; Kim, Donguk; Baek, Dohyun; Hong, Byoungyou; Yi, Junsin; Lee, Jaehyeong [Sungkyunkwan University, Suwon (Korea, Republic of); Park, Yongseob [Chosun College of Science and and Technology, Gwangju (Korea, Republic of); Choi, Wonseok [Hanbat National University, Daejeon (Korea, Republic of)

    2014-05-15

    In this work, the effects of NH{sub 4}Ac on the structural and the electro-optical properties of CdS films were investigated. CdS thin films were deposited on soda-lime glass and indium-tin-oxide (ITO) coated glass from a chemical bath containing 0.025 M cadmium acetate, 0 M ∼ 0.2 M ammonium acetate, 0.5 M thiourea, and ammonia. Cadmium acetate was the cadmium source, ammonium acetate served as a buffer, ammonia was the complexing agent, and thiourea was the source of sulfur. A commonly- available chemical bath deposition system was successfully modified to obtain precise control over the pH of the solution at 75 .deg. C during the deposition. Chemically deposited CdS films were studied by using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), optical transmittance, and electrical resistivity measurements.

  14. CDS

    Science.gov (United States)

    Allen, Mark

    2015-12-01

    The Centre de Donnees de Strasbourg (CDS) is a reference data centre for Astronomy. The CDS services; SIMBAD, Vizier, Aladin and X-Match, provide added value to scientific content in order to support the astronomy research community. Data and information are curated from refereed journals, major surveys, observatories and missions with a strong emphasis on maintaining a high level of quality. The current status and plans of the CDS will be presented, highlighting how the recent innovations of the HiPS (Hierarchical Progressive surveys) and MOC (Multi-Order Coverage map) systems enable the visualisation of hundreds of surveys and data sets, and brings new levels of interoperability between catalogues, surveys images and data cubes.

  15. Effect of Low Concentration Sn Doping on Optical Properties of CdS Films Grown by CBD Technique

    Directory of Open Access Journals (Sweden)

    Mohd Sabri Mohd Ghazali

    2011-09-01

    Full Text Available Thin and transparent films of doped cadmium sulfide (CdS were obtained on commercial glass substrates by Chemical Bath Deposition (CBD technique. The films were doped with low concentration of Sn, and annealed in air at 300 °C for 45 min. The morphological characterization of the films with different amounts of dopant was made using SEM and EDAX analysis. Optical properties of the films were evaluated by measuring transmittance using the UV-vis spectrophotometer. A comparison of the results revealed that lower concentration of Sn doping improves transmittance of CdS films and makes them suitable for application as window layer of CdTe/CIGS solar cells.

  16. Thin film superfluid optomechanics

    CERN Document Server

    Baker, Christopher G; McAuslan, David L; Sachkou, Yauhen; He, Xin; Bowen, Warwick P

    2016-01-01

    Excitations in superfluid helium represent attractive mechanical degrees of freedom for cavity optomechanics schemes. Here we numerically and analytically investigate the properties of optomechanical resonators formed by thin films of superfluid $^4$He covering micrometer-scale whispering gallery mode cavities. We predict that through proper optimization of the interaction between film and optical field, large optomechanical coupling rates $g_0>2\\pi \\times 100$ kHz and single photon cooperativities $C_0>10$ are achievable. Our analytical model reveals the unconventional behaviour of these thin films, such as thicker and heavier films exhibiting smaller effective mass and larger zero point motion. The optomechanical system outlined here provides access to unusual regimes such as $g_0>\\Omega_M$ and opens the prospect of laser cooling a liquid into its quantum ground state.

  17. Biomimetic thin film deposition

    Science.gov (United States)

    Rieke, P. C.; Campbell, A. A.; Tarasevich, B. J.; Fryxell, G. E.; Bentjen, S. B.

    1991-04-01

    Surfaces derivatized with organic functional groups were used to promote the deposition of thin films of inorganic minerals. These derivatized surfaces were designed to mimic the nucleation proteins that control mineral deposition during formation of bone, shell, and other hard tissues in living organisms. By the use of derivatized substrates control was obtained over the phase of mineral deposited, the orientation of the crystal lattice and the location of deposition. These features are of considerable importance in many technically important thin films, coatings, and composite materials. Methods of derivatizing surfaces are considered and examples of controlled mineral deposition are presented.

  18. Thin film ceramic thermocouples

    Science.gov (United States)

    Gregory, Otto (Inventor); Fralick, Gustave (Inventor); Wrbanek, John (Inventor); You, Tao (Inventor)

    2011-01-01

    A thin film ceramic thermocouple (10) having two ceramic thermocouple (12, 14) that are in contact with each other in at least on point to form a junction, and wherein each element was prepared in a different oxygen/nitrogen/argon plasma. Since each element is prepared under different plasma conditions, they have different electrical conductivity and different charge carrier concentration. The thin film thermocouple (10) can be transparent. A versatile ceramic sensor system having an RTD heat flux sensor can be combined with a thermocouple and a strain sensor to yield a multifunctional ceramic sensor array. The transparent ceramic temperature sensor that could ultimately be used for calibration of optical sensors.

  19. Thin films for material engineering

    Science.gov (United States)

    Wasa, Kiyotaka

    2016-07-01

    Thin films are defined as two-dimensional materials formed by condensing one by one atomic/molecular/ionic species of matter in contrast to bulk three-dimensional sintered ceramics. They are grown through atomic collisional chemical reaction on a substrate surface. Thin film growth processes are fascinating for developing innovative exotic materials. On the basis of my long research on sputtering deposition, this paper firstly describes the kinetic energy effect of sputtered adatoms on thin film growth and discusses on a possibility of room-temperature growth of cubic diamond crystallites and the perovskite thin films of binary compound PbTiO3. Secondly, high-performance sputtered ferroelectric thin films with extraordinary excellent crystallinity compatible with MBE deposited thin films are described in relation to a possible application for thin-film MEMS. Finally, the present thin-film technologies are discussed in terms of a future material science and engineering.

  20. Thin film metal-oxides

    CERN Document Server

    Ramanathan, Shriram

    2009-01-01

    Presents an account of the fundamental structure-property relations in oxide thin films. This title discusses the functional properties of thin film oxides in the context of applications in the electronics and renewable energy technologies.

  1. Rare Earth Oxide Thin Films

    CERN Document Server

    Fanciulli, Marco

    2007-01-01

    Thin rare earth (RE) oxide films are emerging materials for microelectronic, nanoelectronic, and spintronic applications. The state-of-the-art of thin film deposition techniques as well as the structural, physical, chemical, and electrical properties of thin RE oxide films and of their interface with semiconducting substrates are discussed. The aim is to identify proper methodologies for the development of RE oxides thin films and to evaluate their effectiveness as innovative materials in different applications.

  2. NMR characterization of thin films

    Science.gov (United States)

    Gerald, II, Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela

    2008-11-25

    A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.

  3. Selective inorganic thin films

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, M.L.F.; Weisenbach, L.A.; Anderson, M.T. [Sandia National Laboratories, Albuquerque, NM (United States)] [and others

    1995-05-01

    This project is developing inorganic thin films as membranes for gas separation applications, and as discriminating coatings for liquid-phase chemical sensors. Our goal is to synthesize these coatings with tailored porosity and surface chemistry on porous substrates and on acoustic and optical sensors. Molecular sieve films offer the possibility of performing separations involving hydrogen, air, and natural gas constituents at elevated temperatures with very high separation factors. We are focusing on improving permeability and molecular sieve properties of crystalline zeolitic membranes made by hydrothermally reacting layered multicomponent sol-gel films deposited on mesoporous substrates. We also used acoustic plate mode (APM) oscillator and surface plasmon resonance (SPR) sensor elements as substrates for sol-gel films, and have both used these modified sensors to determine physical properties of the films and have determined the sensitivity and selectivity of these sensors to aqueous chemical species.

  4. Defect control in room temperature deposited cadmium sulfide thin films by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Como, N. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Martinez-Landeros, V. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Centro de Investigación en Materiales Avanzados, Monterrey, Nuevo Leon, 66600, México (Mexico); Mejia, I. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States); Aguirre-Tostado, F.S. [Centro de Investigación en Materiales Avanzados, Monterrey, Nuevo Leon, 66600, México (Mexico); Nascimento, C.D.; Azevedo, G. de M; Krug, C. [Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, 91509-900 (Brazil); Quevedo-Lopez, M.A., E-mail: mquevedo@utdallas.edu [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX, 75080 (United States)

    2014-01-01

    The control of defects in cadmium sulfide thin films and its impact on the resulting CdS optical and electrical characteristics are studied. Sulfur vacancies and cadmium interstitial concentrations in the CdS films are controlled using the ambient pressure during pulsed laser deposition. CdS film resistivities ranging from 10{sup −1} to 10{sup 4} Ω-cm are achieved. Hall Effect measurements show that the carrier concentration ranges from 10{sup 19} to 10{sup 13} cm{sup −3} and is responsible for the observed resistivity variation. Hall mobility varies from 2 to 12 cm{sup 2}/V-s for the same pressure regime. Although the energy bandgap remains unaffected (∼ 2.42 eV), the optical transmittance is reduced due to the increase of defects in the CdS films. Rutherford back scattering spectroscopy shows the dependence of the CdS films stoichiometry with deposition pressure. The presence of CdS defects is attributed to more energetic species reaching the substrate, inducing surface damage in the CdS films during pulsed laser deposition. - Highlights: • CdS thin films deposited by pulsed laser deposition at room temperature. • The optical, electrical and structural properties were evaluated. • Carrier concentration ranged from 10{sup 19} to 10{sup 13} cm{sup −3}. • The chemical composition was studied by Rutherford back scattering. • The density of sulfur vacancies and cadmium interstitial was varied.

  5. [Spectral emissivity of thin films].

    Science.gov (United States)

    Zhong, D

    2001-02-01

    In this paper, the contribution of multiple reflections in thin film to the spectral emissivity of thin films of low absorption is discussed. The expression of emissivity of thin films derived here is related to the thin film thickness d and the optical constants n(lambda) and k(lambda). It is shown that in the special case d-->infinity the emissivity of thin films is equivalent to that of the bulk material. Realistic numerical and more precise general numerical results for the dependence of the emissivity on d, n(lambda) and k(lambda) are given.

  6. Thin film superconductor magnetic bearings

    Science.gov (United States)

    Weinberger, Bernard R.

    1995-12-26

    A superconductor magnetic bearing includes a shaft (10) that is subject to a load (L) and rotatable around an axis of rotation, a magnet (12) mounted to the shaft, and a stator (14) in proximity to the shaft. The stator (14) has a superconductor thin film assembly (16) positioned to interact with the magnet (12) to produce a levitation force on the shaft (10) that supports the load (L). The thin film assembly (16) includes at least two superconductor thin films (18) and at least one substrate (20). Each thin film (18) is positioned on a substrate (20) and all the thin films are positioned such that an applied magnetic field from the magnet (12) passes through all the thin films. A similar bearing in which the thin film assembly (16) is mounted on the shaft (10) and the magnet (12) is part of the stator (14) also can be constructed.

  7. Carbon Superatom Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Canning, A. [Cray Research, PSE, EPFL, 1015 Lausanne (Switzerland); Canning, A.; Galli, G. [Institut Romand de Recherche Numerique en Physique des Materiaux (IRRMA), IN-Ecublens, 1015 Lausanne (Switzerland); Kim, J. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States)

    1997-06-01

    We report on quantum molecular dynamics simulations of C{sub 28} deposition on a semiconducting surface. Our results show that under certain deposition conditions C{sub 28} {close_quote}s act as building blocks on a nanometer scale to form a thin film of nearly defect-free molecules. The C{sub 28} {close_quote}s behave as carbon superatoms, with the majority of them being threefold or fourfold coordinated, similar to carbon atoms in amorphous systems. The microscopic structure of the deposited film supports recent suggestions about the stability of a new form of carbon, the hyperdiamond solid. {copyright} {ital 1997} {ital The American Physical Society}

  8. Chiral atomically thin films

    Science.gov (United States)

    Kim, Cheol-Joo; Sánchez-Castillo, A.; Ziegler, Zack; Ogawa, Yui; Noguez, Cecilia; Park, Jiwoong

    2016-06-01

    Chiral materials possess left- and right-handed counterparts linked by mirror symmetry. These materials are useful for advanced applications in polarization optics, stereochemistry and spintronics. In particular, the realization of spatially uniform chiral films with atomic-scale control of their handedness could provide a powerful means for developing nanodevices with novel chiral properties. However, previous approaches based on natural or grown films, or arrays of fabricated building blocks, could not offer a direct means to program intrinsic chiral properties of the film on the atomic scale. Here, we report a chiral stacking approach, where two-dimensional materials are positioned layer-by-layer with precise control of the interlayer rotation (θ) and polarity, resulting in tunable chiral properties of the final stack. Using this method, we produce left- and right-handed bilayer graphene, that is, a two-atom-thick chiral film. The film displays one of the highest intrinsic ellipticity values (6.5 deg μm-1) ever reported, and a remarkably strong circular dichroism (CD) with the peak energy and sign tuned by θ and polarity. We show that these chiral properties originate from the large in-plane magnetic moment associated with the interlayer optical transition. Furthermore, we show that we can program the chiral properties of atomically thin films layer-by-layer by producing three-layer graphene films with structurally controlled CD spectra.

  9. Luminescence properties of Eu3+/CDs/PVA composite applied in light conversion film

    Science.gov (United States)

    He, Jiangling; He, Youling; Zhuang, Jianle; Zhang, Haoran; Lei, Bingfu; Liu, Yingliang

    2016-12-01

    In this work, blue-light-emitting carbon dots (CDs) were composited with red-light-emitting europium ions (Eu3+) solutions under the synergistic reaction of polyvinyl alcohol (PVA) to prepare the light conversion film. The formation mechanism of Eu3+/CDs/PVA film was detailedly discussed. It is the first report that this composite was synthesized through direct recombination of CDs and Eu3+ solutions instead of traditional methods based on Eu3+ coordination compound. Furthermore, tunable photoluminescence property can be successfully achieved by controlling the ratio of CDs to doped Eu3+, this property can meet the variable light component requirements for different species of plants.

  10. Biomimetic thin film deposition

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Synthesis of CdS nanocrystals in polymeric films studied by in-situ GID and GISAXS

    KAUST Repository

    Di Luccio, Tiziana

    2015-07-07

    In this work, we describe the synthesis of CdS nanocrystals in thin polymeric films by in-situ Grazing Incidence Diffraction (GID) and Grazing Incidence Small Angle Scattering (GISAXS). The 2D GISAXS patterns indicate how the precursor structure is altered as the temperature is varied from 25°C to 300°C. At 150°C, the CdS nanocrystals start to arrange themselves in a hexagonal lattice with a lattice parameter of 27 A. The diffraction intensity from the hexagonal lattice reaches a maximum at 170"C and decreases steadily upon further heating above 220°C indicating loss of symmetry. Correspondingly, the GID scans at 170°C show strong crystalline peaks from cubic CdS nanocrystals that are about 2 nm size. The results indicate that a temperature of 170°C is sufficient to synthesize CdS nanocrystals without degradation of the polymer matrix (Topas) in thin films (about 30nm). © 2015 Materials Research Society.

  12. Thin film processes

    CERN Document Server

    Vossen, John L

    1978-01-01

    Remarkable advances have been made in recent years in the science and technology of thin film processes for deposition and etching. It is the purpose of this book to bring together tutorial reviews of selected filmdeposition and etching processes from a process viewpoint. Emphasis is placed on the practical use of the processes to provide working guidelines for their implementation, a guide to the literature, and an overview of each process.

  13. Handbook of thin film technology

    CERN Document Server

    Frey, Hartmut

    2015-01-01

    “Handbook of Thin Film Technology” covers all aspects of coatings preparation, characterization and applications. Different deposition techniques based on vacuum and plasma processes are presented. Methods of surface and thin film analysis including coating thickness, structural, optical, electrical, mechanical and magnetic properties of films are detailed described. The several applications of thin coatings and a special chapter focusing on nanoparticle-based films can be found in this handbook. A complete reference for students and professionals interested in the science and technology of thin films.

  14. Thin film interconnect processes

    Science.gov (United States)

    Malik, Farid

    Interconnects and associated photolithography and etching processes play a dominant role in the feature shrinkage of electronic devices. Most interconnects are fabricated by use of thin film processing techniques. Planarization of dielectrics and novel metal deposition methods are the focus of current investigations. Spin-on glass, polyimides, etch-back, bias-sputtered quartz, and plasma-enhanced conformal films are being used to obtain planarized dielectrics over which metal films can be reliably deposited. Recent trends have been towards chemical vapor depositions of metals and refractory metal silicides. Interconnects of the future will be used in conjunction with planarized dielectric layers. Reliability of devices will depend to a large extent on the quality of the interconnects.

  15. Influence of annealing on the properties of CdS polycrystalline thin films deposited by close-spaced sublimation%后处理对近空间升华法制备CdS薄膜性能影响研究

    Institute of Scientific and Technical Information of China (English)

    曾广根; 黎兵; 郑家贵; 蔡亚平; 张静全; 武莉莉; 李卫; 冯良桓

    2011-01-01

    In this paper, the CdS thin films deposited by close-spaced sublimation have been annealed. The properties of films were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and the relationship of dark conductivities ~ temperature (σ~T). The results showed that (002) preferred direction of crystalline grains still exists after annealing > the treatment can promote recrystalliza-tion and grain growth; With the annealing temperatures increasing, the dark conductivities(σ-dark) increase while the dark conductivity activation energy (Ea) decreases. Finally, an optimization anneal condition has been achieved and the CdS thin films as windows layers of CdTe solar cells have been obtained.%将近空间升华法(CSS)沉积所得的CdS薄膜进行退火处理,利用XRD、SEM、暗电导温度关系研究不同退火条件对CdS多晶薄膜性能的影响.结果表明退火后CdS多晶薄膜在(002)面上具有择优取向;退火促使再结晶并促进晶粒长大;暗电导(dark-σ)随退火温度增加而增加,暗电导激活能(Ea)随退火温度的增加而减少.最后得到较优化的退火条件,获得适合作为CdTe太阳电池窗口层的CdS薄膜.

  16. Investigation on Silicon Thin Film Solar Cells

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The preparation, current status and trends are investigated for silicon thin film solar cells. The advantages and disadvantages of amorphous silicon thin film, polycrystalline silicon thin film and mono-crystalline silicon thin film solar cells are compared. The future development trends are pointed out. It is found that polycrystalline silicon thin film solar cells will be more promising for application with great potential.

  17. Nonlinear optical thin films

    Science.gov (United States)

    Leslie, Thomas M.

    1993-01-01

    A focused approach to development and evaluation of organic polymer films for use in optoelectronics is presented. The issues and challenges that are addressed include: (1) material synthesis, purification, and the tailoring of the material properties; (2) deposition of uniform thin films by a variety of methods; (3) characterization of material physical properties (thermal, electrical, optical, and electro-optical); and (4) device fabrication and testing. Photonic materials, devices, and systems were identified as critical technology areas by the Department of Commerce and the Department of Defense. This approach offers strong integration of basic material issues through engineering applications by the development of materials that can be exploited as the active unit in a variety of polymeric thin film devices. Improved materials were developed with unprecedented purity and stability. The absorptive properties can be tailored and controlled to provide significant improvement in propagation losses and nonlinear performance. Furthermore, the materials were incorporated into polymers that are highly compatible with fabrication and patterning processes for integrated optical devices and circuits. By simultaneously addressing the issues of materials development and characterization, keeping device design and fabrication in mind, many obstacles were overcome for implementation of these polymeric materials and devices into systems. We intend to considerably improve the upper use temperature, poling stability, and compatibility with silicon based devices. The principal device application that was targeted is a linear electro-optic modulation etalon. Organic polymers need to be properly designed and coupled with existing integrated circuit technology to create new photonic devices for optical communication, image processing, other laser applications such as harmonic generation, and eventually optical computing. The progression from microscopic sample to a suitable film

  18. Cadmium Sulfide Thin Films Deposited onto MWCNT/Polysulfone Substrates by Chemical Bath Deposition

    Directory of Open Access Journals (Sweden)

    M. Moreno

    2016-01-01

    Full Text Available Cadmium sulfide (CdS thin films were deposited by chemical bath deposition (CBD onto polymeric composites with electric field-aligned multiwall carbon nanotubes (MWCNTs. MWCNT/polysulfone composites were prepared by dispersing low concentrations of MWCNTs within dissolved polysulfone (PSF. An alternating current electric field was “in situ” applied to align the MWCNTs within the dissolved polymer along the field direction until the solvent was evaporated. 80 μm thick solid MWCNT/PSF composites with an electrical conductivity 13 orders of magnitude higher than the conductivity of the neat PSF were obtained. The MWCNT/PSF composites were subsequently used as flexible substrates for the deposition of CdS thin films by CBD. Transparent and adherent CdS thin films with an average thickness of 475 nm were obtained. The values of the energy band gap, average grain size, rms roughness, crystalline structure, and preferential orientation of the CdS films deposited onto the polymeric substrate were very similar to the corresponding values of the CdS deposited onto glass (conventional substrate. These results show that the MWCNT/PSF composites with electric field-tailored MWCNTs represent a suitable option to be used as flexible conducting substrate for CdS thin films, which represents an important step towards the developing of flexible systems for photovoltaic applications.

  19. Host thin films incorporating nanoparticles

    Science.gov (United States)

    Qureshi, Uzma

    The focus of this research project was the investigation of the functional properties of thin films that incorporate a secondary nanoparticulate phase. In particular to assess if the secondary nanoparticulate material enhanced a functional property of the coating on glass. In order to achieve this, new thin film deposition methods were developed, namely use of nanopowder precursors, an aerosol assisted transport technique and an aerosol into atmospheric pressure chemical vapour deposition system. Aerosol assisted chemical vapour deposition (AACVD) was used to deposit 8 series of thin films on glass. Five different nanoparticles silver, gold, ceria, tungsten oxide and zinc oxide were tested and shown to successfully deposit thin films incorporating nanoparticles within a host matrix. Silver nanoparticles were synthesised and doped within a titania film by AACVD. This improved solar control properties. A unique aerosol assisted chemical vapour deposition (AACVD) into atmospheric pressure chemical vapour deposition (APCVD) system was used to deposit films of Au nanoparticles and thin films of gold nanoparticles incorporated within a host titania matrix. Incorporation of high refractive index contrast metal oxide particles within a host film altered the film colour. The key goal was to test the potential of nanopowder forms and transfer the suspended nanopowder via an aerosol to a substrate in order to deposit a thin film. Discrete tungsten oxide nanoparticles or ceria nanoparticles within a titanium dioxide thin film enhanced the self-cleaning and photo-induced super-hydrophilicity. The nanopowder precursor study was extended by deposition of zinc oxide thin films incorporating Au nanoparticles and also ZnO films deposited from a ZnO nanopowder precursor. Incorporation of Au nanoparticles within a VO: host matrix improved the thermochromic response, optical and colour properties. Composite VC/TiC and Au nanoparticle/V02/Ti02 thin films displayed three useful

  20. Facile method to prepare CdS nanostructure based on the CdTe films

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ligang; Chen, Yuehui; Wei, Zelu; Cai, Hongling; Zhang, Fengming; Wu, Xiaoshan, E-mail: xswu@nju.edu.cn

    2015-09-15

    Graphical abstract: - Highlights: • CdS nanostructure is directly fabricated on CdTe film only by heating treatment under H{sub 2}S/N{sub 2} mixed atmosphere at a relatively low temperature (450 °C) with gold layer as the intermediate. • Nanostructure of CdS layer, varying from nanowires to nanosheets, may be controlled by the thickness of gold film. • The change of morphology adjusts its luminescence properties. - Abstract: Nanostructured cadmium sulfide (CdS) plays critical roles in electronics and optoelectronics. In this paper, we report a method to fabricate CdS nanostructure directly on CdTe film, via a thermal annealing method in H{sub 2}S/N{sub 2} mixed gas flow at a relatively low temperature (450 °C). The microstructure and optical properties of CdS nanostructure are investigated by X-ray diffraction, transmission electron microscopy, Raman, and photoluminescence. The morphology of CdS nanostructure, evolving from nanowires to nanosheets, can be controlled by the thickness of Au film deposited on the CdTe film. And CdS nanostructures are single crystalline with the hexagonal wurtzite structure. Raman spectroscopy under varying the excitation wavelengths confirm that synthesized CdS-CdTe films contain two layers, i.e., CdS nanostructure (top) and CdTe layer (bottom). The change of morphology modifies its luminescence properties. Obviously, through simply thermal annealing in H{sub 2}S/N{sub 2} mixed gas, fabricating CdS nanostructure on CdTe film can open up the new possibility for obtaining high efficient CdTe solar cell.

  1. Recent advances in thin film CdTe solar cells

    Science.gov (United States)

    Ferekides, Chris S.; Ceekala, Vijaya; Dugan, Kathleen; Killian, Lawrence; Oman, Daniel; Swaminathan, Rajesh; Morel, Don

    1996-01-01

    CdTe thin film solar cells have been fabricated on a variety of glass substrates (borosilicate and soda lime). The CdS films were deposited to a thickness of 500-2000 Å by the chemical bath deposition (CBD), rf sputtering, or close spaced sublimation (CSS) processes. The CdTe films were deposited by CSS in the temperature range of 450-625 °C. The main objective of this work is to fabricate high efficiency solar cells using processes that can meet low cost manufacturing requirements. In an attempt to enhance the blue response of the CdTe cells, ZnS films have also been prepared (CBD, rf sputtering, CSS) as an alternative window layer to CdS. Device behavior has been found to be consistent with a recombination model.

  2. Thin Film Inorganic Electrochemical Systems.

    Science.gov (United States)

    1995-07-01

    determined that thin film cathodes of LiCoO2 can be readily performed by either spray pyrolysis or spin coating . These cathodes are electrochemically...active. We have also determined that thin film anodes of Li4Ti5O12 can be prepared by spray pyrolysis or spin coating . These anodes are also

  3. Characterization of chemical bath deposited buffer layers for thin film solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, D.; Efstathiadis, H.; Haldar, P. [College of Nanoscale Science and Engineering, University at Albany - State University of New York, 257 Fuller Rd., Albany, NY 12203 (United States); Sun, R. [Angstrom Sun Technologies Inc., 33 Nagog Park, Acton, MA 01720 (United States)

    2010-10-15

    Cadmium sulfide (CdS), indium sulfide (In{sub 2}S{sub 3}) and zinc sulfide (ZnS) thin films have been deposited by chemical bath deposition (CBD) for buffer layer applications in Cu-chalcopyrite-based thin film solar cells. Films were characterized by scanning electron microscopy (SEM), UV-Vis transmission, X-ray photoelectron spectroscopy (XPS), grazing-incidence X-ray diffraction (GIXRD), and spectroscopic ellipsometry. Results indicate CdS can be deposited with low oxygen content and high light transmission over 245-1700 nm. CBD-ZnS and CBD-InS both exhibit 5-10% less light transmission than CdS in the same thickness range. In terms of light transmission and degree of impurities CdS appears to be a better buffer material than CBD-ZnS or CBD-InS. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  4. Thin film cadmium telluride photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, A.; Bohn, R. (Toledo Univ., OH (United States))

    1992-04-01

    This report describes research to develop to vacuum-based growth techniques for CdTe thin-film solar cells: (1) laser-driven physical vapor deposition (LDPVD) and (2) radio-frequency (rf) sputtering. The LDPVD process was successfully used to deposit thin films of CdS, CdTe, and CdCl{sub 2}, as well as related alloys and doped semiconductor materials. The laser-driven deposition process readily permits the use of several target materials in the same vacuum chamber and, thus, complete solar cell structures were fabricated on SnO{sub 2}-coated glass using LDPVD. The rf sputtering process for film growth became operational, and progress was made in implementing it. Time was also devoted to enhancing or implementing a variety of film characterization systems and device testing facilities. A new system for transient spectroscopy on the ablation plume provided important new information on the physical mechanisms of LDPVD. The measurements show that, e.g., Cd is predominantly in the neutral atomic state in the plume but with a fraction that is highly excited internally ({ge} 6 eV), and that the typical neutral Cd translational kinetic energies perpendicular to the target are 20 eV and greater. 19 refs.

  5. Modification of optical and electrical properties of chemical bath deposited CdS using plasma treatments

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, G. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); Krishnan, B. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); CIIDIT, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico); Avellaneda, D.; Castillo, G. Alan; Das Roy, T.K. [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); Shaji, S., E-mail: sshajis@yahoo.com [Facultad de Ingenieria Mecanica y Electrica, Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Nuevo Leon, C.P 66450 (Mexico); CIIDIT, Universidad Autonoma de Nuevo Leon, Apodaca, Nuevo Leon (Mexico)

    2011-08-31

    Cadmium sulphide (CdS) is a well known n-type semiconductor that is widely used in solar cells. Here we report preparation and characterization of chemical bath deposited CdS thin films and modification of their optical and electrical properties using plasma treatments. CdS thin films were prepared from a chemical bath containing Cadmium chloride, Triethanolamine and Thiourea under various deposition conditions. Good quality thin films were obtained during deposition times of 5, 10 and 15 min. CdS thin films prepared for 10 min. were treated using a glow discharge plasma having nitrogen and argon carrier gases. The changes in morphology, optical and electrical properties of these plasma treated CdS thin films were analyzed in detail. The results obtained show that plasma treatment is an effective technique in modification of the optical and electrical properties of chemical bath deposited CdS thin films.

  6. Polyimide Aerogel Thin Films

    Science.gov (United States)

    Meador, Mary Ann; Guo, Haiquan

    2012-01-01

    Polyimide aerogels have been crosslinked through multifunctional amines. This invention builds on "Polyimide Aerogels With Three-Dimensional Cross-Linked Structure," and may be considered as a continuation of that invention, which results in a polyimide aerogel with a flexible, formable form. Gels formed from polyamic acid solutions, end-capped with anhydrides, and cross-linked with the multifunctional amines, are chemically imidized and dried using supercritical CO2 extraction to give aerogels having density around 0.1 to 0.3 g/cubic cm. The aerogels are 80 to 95% porous, and have high surface areas (200 to 600 sq m/g) and low thermal conductivity (as low as 14 mW/m-K at room temperature). Notably, the cross-linked polyimide aerogels have higher modulus than polymer-reinforced silica aerogels of similar density, and can be fabricated as both monoliths and thin films.

  7. Effect of indium doping level on certain physical properties of CdS films deposited using an improved SILAR technique

    Energy Technology Data Exchange (ETDEWEB)

    Ravichandran, K., E-mail: kkr1365@yahoo.com [P.G. and Research Department of Physics, AVVM Sri Pushpam College (Autonomous), Poondi, Thanjavur-613 503, Tamil Nadu (India); Senthamilselvi, V. [P.G. and Research Department of Physics, AVVM Sri Pushpam College (Autonomous), Poondi, Thanjavur-613 503, Tamil Nadu (India); Department of Physics, Kunthavai Naachiyaar Government College for Women (Autonomous), Thanjavur-613 007, Tamil Nadu (India)

    2013-04-01

    The influence of indium (In) doping levels (0, 2, …, 8 at.%) on certain physical properties of cadmium sulphide (CdS) thin films deposited using an improved successive ionic layer adsorption and reaction (ISILAR) method has been studied. In this improved SILAR technique, a fresh anionic solution was introduced after a particular number of dipping cycles in order to achieve good stoichiometry. All the deposited films exhibited cubic phase with (1 1 1) plane as preferential orientation. The calculated crystallite size values are found to be decreased from 54.80 nm to 23.65 nm with the increase in In doping level. The optical study confirmed the good transparency (80%) of the film. A most compact and pinhole free smooth surface was observed for the CdS films with 8 at.% of In doping level. The perceived photoluminescence (PL) bands endorsed the lesser defect crystalline nature of the obtained CdS:In films. The chemical composition analysis (EDAX) showed the near stoichiometric nature of this ISILAR deposited CdS:In films.

  8. Impact of Gate Dielectric in Carrier Mobility in Low Temperature Chalcogenide Thin Film Transistors for Flexible Electronics

    KAUST Repository

    Salas-Villasenor, A. L.

    2010-06-29

    Cadmium sulfide thin film transistors were demonstrated as the n-type device for use in flexible electronics. CdS thin films were deposited by chemical bath deposition (70° C) on either 100 nm HfO2 or SiO2 as the gate dielectrics. Common gate transistors with channel lengths of 40-100 μm were fabricated with source and drain aluminum top contacts defined using a shadow mask process. No thermal annealing was performed throughout the device process. X-ray diffraction results clearly show the hexagonal crystalline phase of CdS. The electrical performance of HfO 2 /CdS -based thin film transistors shows a field effect mobility and threshold voltage of 25 cm2 V-1 s-1 and 2 V, respectively. Improvement in carrier mobility is associated with better nucleation and growth of CdS films deposited on HfO2. © 2010 The Electrochemical Society.

  9. Thin-film cadmium telluride solar cells

    Science.gov (United States)

    Chu, T. L.

    1986-08-01

    The major objective of this work was to demonstrate CdTe devices grown by chemical vapor deposition (CVD) with a total area greater than 1 cm2 and photovoltic efficiencies of at least 13%. During the period covered, various processing steps were investigated for the preparation of thin-film CdTe heterojunction solar cells of the inverted configuration. Glass coated with fluorine-doped tin oxide was used as the substrate. Thin-film heterojunction solar cells were prepared by depositing p-CdTe films on substrates using CVD and close-spaced sublimation (CSS). Cells prepared from CSS CdTe usually have a higher conversion efficiency than those prepared from CVD CdTe, presumably due to the chemical interaction between CdS and CdTe at the interface during the CVD process. The best cell, about 1.2 sq cm in area, had an AM 1.5 (global) efficiency of 10.5%, and further improvements are expected by optimizing the process parameters.

  10. Thin-film solar cell

    NARCIS (Netherlands)

    Metselaar, J.W.; Kuznetsov, V.I.

    1998-01-01

    The invention relates to a thin-film solar cell provided with at least one p-i-n junction comprising at least one p-i junction which is at an angle alpha with that surface of the thin-film solar cell which collects light during operation and at least one i-n junction which is at an angle beta with t

  11. CdZnS thin films sublimated by closed space using mechanical mixing: A new approach

    Science.gov (United States)

    Mahmood, Waqar; Shah, Nazar Abbas

    2014-06-01

    Cadmium sulfide (CdS) is a prominent material for its tunable band gap used as a window layer in II-VI semiconductor solar cells. The light trapping capability of window layer is one of the powerful tools to enhance the efficiency of the cell. CdS and zinc (Zn) powders were mixed mechanically with different weight percents to make CdZnS (CZS) powder. CZS was deposited onto an ultrasonically cleaned glass substrate using close spaced sublimation (CSS) technique. CZS as-deposited thin films were characterized for structural, surface morphology with energy dispersive X-rays (EDX) and optical properties for the use of window layer in CdS/CdTe based solar cells. The different Zn concentrations in CZS played a vital role on crystallite size in structural analysis and optical properties e.g. transmission, absorption coefficient and energy band gap, etc. The crystallite size of as-deposited CZS thin films were increased as Zn concentration was increased up to certain value. The energy band gap varies from 2.42 eV to 2.57 eV for as-deposited CZS thin films with increasing Zn concentrations and surface morphology changes also. These changes were occurred due to zinc diffusion in CdS thin films. An angle resolved transmission data was taken to check the behavior of CdS and CZS thin film at different angles. A comparative study was carried out between CdS thin films and CZS thin films for the use of good window layer material.

  12. Size effects in thin films

    CERN Document Server

    Tellier, CR; Siddall, G

    1982-01-01

    A complete and comprehensive study of transport phenomena in thin continuous metal films, this book reviews work carried out on external-surface and grain-boundary electron scattering and proposes new theoretical equations for transport properties of these films. It presents a complete theoretical view of the field, and considers imperfection and impurity effects.

  13. Thin film corrosion. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Raut, M.K.

    1980-06-01

    Corrosion of chromium/gold (Cr/Au) thin films during photolithography, prebond etching, and cleaning was evaluated. Vapors of chromium etchant, tantalum nitride etchant, and especially gold etchant were found to corrosively attack chromium/gold films. A palladium metal barrier between the gold and chromium layers was found to reduce the corrosion from gold etchant.

  14. Interfacial Properties of CZTS Thin Film Solar Cell

    Directory of Open Access Journals (Sweden)

    N. Muhunthan

    2014-01-01

    Full Text Available Cu-deficient CZTS (copper zinc tin sulfide thin films were grown on soda lime as well as molybdenum coated soda lime glass by reactive cosputtering. Polycrystalline CZTS film with kesterite structure was produced by annealing it at 500°C in Ar atmosphere. These films were characterized for compositional, structural, surface morphological, optical, and transport properties using energy dispersive X-ray analysis, glancing incidence X-ray diffraction, Raman spectroscopy, scanning electron microscopy, atomic force microscopy, UV-Vis spectroscopy, and Hall effect measurement. A CZTS solar cell device having conversion efficiency of ~0.11% has been made by depositing CdS, ZnO, ITO, and Al layers over the CZTS thin film deposited on Mo coated soda lime glass. The series resistance of the device was very high. The interfacial properties of device were characterized by cross-sectional SEM and cross-sectional HRTEM.

  15. [Preparation and spectral characterization of CdS(y)Te(1-y) thin films].

    Science.gov (United States)

    Li, Wei; Feng, Liang-Huan; Wu, Li-Li; Zhang, Jing-Quan; Li, Bing; Lei, Zhi; Cai, Ya-Ping; Zheng, Jia-Gui; Cai, Wei; Zhang, Dong-Min

    2008-03-01

    CdS(y)Te(1-y) (0 thin films were prepared on glass substrates by co-evaporation of powders of CdTe and CdS. For the characterization of the structure and composition of the CdS(y)Te(1-y) thin films the X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) were used. The results indicate that the values of sulfur content y detected and controlled by the quartz wafer detector show good agreement with the EDS results. The films were found to be cubic for x or = 0.3. The 20-50 nm of grain sizes for CdS(y)Te(1-y) thin films were calculated using a method of XRD analysis. Finally, the optical properties of CdS(y)Te(1-y) thin films were characterized by UV-Vis-NIR spectroscopy alone. According to a method from Swanepoel, together with the first-order Sellmeier model, the thickness, of d-535 nm, energy gap of E(g)-1.41 eV, absorption coefficient, alpha(lambda) and refractive index, n(lambda) of CdS(0.22) Te(0.78) thin films were determined from the transmittance at normal incidence of light in the wavelength range 300-2 500 nm. The results also indicate that the CdS(y)Te(1-y) thin films with any composition (0 thin films can be implemented for other semiconductor thin films.

  16. Thin Film Deposition Techniques (PVD)

    Science.gov (United States)

    Steinbeiss, E.

    The most interesting materials for spin electronic devices are thin films of magnetic transition metals and magnetic perovskites, mainly the doped La-manganites [1] as well as several oxides and metals for passivating and contacting the magnetic films. The most suitable methods for the preparation of such films are the physical vapor deposition methods (PVD). Therefore this report will be restricted to these deposition methods.

  17. Thin Films with Low Zn Content Prepared by Chemical Bath Deposition

    Directory of Open Access Journals (Sweden)

    Caijuan Tian

    2012-01-01

    Full Text Available Chemical bath deposition (CBD was used for the growth of thin films with low Zn content. The influence of preparation conditions, such as pH, temperature, and concentration, on film properties was investigated. The chemical growth mechanism of thin films was analyzed, and optimized growth conditions for the thin films were established. The fill factor and short-circuit current were improved while was used to replace CdS as the window layer in CdTe solar cells.

  18. On the yellow-band emission in CdS films

    Energy Technology Data Exchange (ETDEWEB)

    Lozada-Morales, R. [Departamento de Optoelectronica, FCFM-BUAP, Puebla (Mexico); Zelaya-Angel, O. [Dept. de Fisica, CINVESTAV-IPN, Mexico (Mexico); Torres-Delgado, G. [Lab. de Investigacion en Materiales, CINVESTAV-IPN, Queretaro (Mexico)

    2001-07-01

    CdS polycrystalline thin films were prepared by the chemical bath deposition (CBD) method on glass substrates. X-ray diffraction (XRD) studies show that the films grow in the cubic zinc-blende crystalline phase. Upon thermal annealing (TA) in Ar+S{sub 2} flux at normal pressure in the temperature range 240-510 C, the evolution of the transformation into the hexagonal wurtzite phase is observed. This hexagonal crystalline structure is the stable phase. From XRD diagrams the phase transition can be appreciated to occur upon TA at approximately 300 C. Photoluminescence (PL) data prove that the green-emission band is present for well-defined phases - cubic or hexagonal ones. A second band located at 2.2 eV appears for samples near the transition region. This band at 2.2 eV, called the yellow band, has already been reported to be associated with interstitial Cd atoms. A model for this yellow-band-mechanism formation, arising during the phase transformation, has been proposed based on Frenkel-pair creation. (orig.)

  19. PbS Thin Films for Photovoltaic Applications Obtained by Non-Traditional Chemical Bath Deposition

    OpenAIRE

    2015-01-01

    To optimize cost-efficiency relation for thin film solar cells, we explore the recently developed versions of chemical deposition of semiconductor films, together with classic CBD (Chemical Bath Deposition): SILAR (Successive Ionic Layer Adsorption and Reaction) and PCBD (Photo Chemical Bath Deposition), all of them ammonia-free and ecologically friendly. The films of CdS and PbS were made, and experimental solar cells with CdS window layer and PbS absorber elaborated. We found that band gap ...

  20. Thin-film metal hydrides.

    Science.gov (United States)

    Remhof, Arndt; Borgschulte, Andreas

    2008-12-01

    The goal of the medieval alchemist, the chemical transformation of common metals into nobel metals, will forever be a dream. However, key characteristics of metals, such as their electronic band structure and, consequently, their electric, magnetic and optical properties, can be tailored by controlled hydrogen doping. Due to their morphology and well-defined geometry with flat, coplanar surfaces/interfaces, novel phenomena may be observed in thin films. Prominent examples are the eye-catching hydrogen switchable mirror effect, the visualization of solid-state diffusion and the formation of complex surface morphologies. Thin films do not suffer as much from embrittlement and/or decrepitation as bulk materials, allowing the study of cyclic absorption and desorption. Therefore, thin-metal hydride films are used as model systems to study metal-insulator transitions, for high throughput combinatorial research or they may be used as indicator layers to study hydrogen diffusion. They can be found in technological applications as hydrogen sensors, in electrochromic and thermochromic devices. In this review, we discuss the effect of hydrogen loading of thin niobium and yttrium films as archetypical examples of a transition metal and a rare earth metal, respectively. Our focus thereby lies on the hydrogen induced changes of the electronic structure and the morphology of the thin films, their optical properties, the visualization and the control of hydrogen diffusion and on the study of surface phenomena and catalysis.

  1. Photodecomposition of methylene blue by amorphous TiO2, CdS and TiO2-CdS films

    OpenAIRE

    F.G. Nieto-Caballero; E. Sánchez-Mora; J. M. Gracia-Jiménez; N.R. Silva-González; A.G. Rodríguez

    2007-01-01

    TiO2is one of the most widely studied oxide materials for applications related to photocatalytic processes. It has been reported that TiO2combined with CdS produces an improvement in the photocatalytic efficiency. This work focuses on the obtainment of TiO2, CdS and TiO2-CdSin situthin films by the sol-gel/dip coating method. After deposition on glass, each film was calcined at 300oC in an argon atmospherefor 30 min. The films were characterized by SEM, UV-Vis, XRD and micro-Raman. The TiO...

  2. Birefringent non-polarizing thin film design

    Institute of Scientific and Technical Information of China (English)

    QI Hongji; HONG Ruijin; HE Hongbo; SHAO Jianda; FAN Zhengxiu

    2005-01-01

    In this paper, 2×2 characteristic matrices of uniaxially anisotropic thin film for extraordinary and ordinary wave are deduced at oblique incidence. Furthermore, the reflectance and transmittance of thin films are calculated separately for two polarizations, which provide a new concept for designing non-polarizing thin films at oblique incidence. Besides, using the multilayer birefringent thin films, non-polarizing designs, such as beam splitter thin film at single wavelength, edge filter and antireflection thin film over visible spectral region are obtained at oblique incidence.

  3. Drying of thin colloidal films

    Science.gov (United States)

    Routh, Alexander F.

    2013-04-01

    When thin films of colloidal fluids are dried, a range of transitions are observed and the final film profile is found to depend on the processes that occur during the drying step. This article describes the drying process, initially concentrating on the various transitions. Particles are seen to initially consolidate at the edge of a drying droplet, the so-called coffee-ring effect. Flow is seen to be from the centre of the drop towards the edge and a front of close-packed particles passes horizontally across the film. Just behind the particle front the now solid film often displays cracks and finally the film is observed to de-wet. These various transitions are explained, with particular reference to the capillary pressure which forms in the solidified region of the film. The reasons for cracking in thin films is explored as well as various methods to minimize its effect. Methods to obtain stratified coatings through a single application are considered for a one-dimensional drying problem and this is then extended to two-dimensional films. Different evaporative models are described, including the physical reason for enhanced evaporation at the edge of droplets. The various scenarios when evaporation is found to be uniform across a drying film are then explained. Finally different experimental techniques for examining the drying step are mentioned and the article ends with suggested areas that warrant further study.

  4. 13.4% efficient thin-film CdS/CdTe solar cells

    Science.gov (United States)

    Chu, T. L.; Chu, S. S.; Ferekides, C.; Wu, C. Q.; Britt, J.; Wang, C.

    1991-12-01

    Cadmium telluride is a promising thin-film photovoltaic material as shown by the more than 10% efficient CdS/CdTe heterojunction solar cells. In this work, thin-film CdS/CdTe solar cells have been prepared using CdS films grown from an aqueous solution and p-CdTe films deposited by close-spaced sublimation (CSS). The properties of CdS films deposited from an ammonical solution of a Cd-salt, an ammonium salt, and thiourea have been controlled by optimizing the temperature and composition of the solution. The solution-grown CdS films have a high photoconductivity ratio, and its optical transmission is superior to that of vacuum evaporated CdS films. The properties of p-CdTe films deposited by CSS have been optimized by controlling the temperature and composition of the source material, and the substrate temperature. The properties of CdS/CdTe heterojunctions have been studied; junction photovoltage spectroscopy is used for the qualitative comparison of junction characteristics. Solar cells of 1-cm2 area with an AM 1.5 efficiency of 13.4% are reported.

  5. Thin-film forces in pseudoemulsion films

    Energy Technology Data Exchange (ETDEWEB)

    Bergeron, V.; Radke, C.J. [California Univ., Berkeley, CA (United States). Dept. of Chemical Engineering]|[Lawrence Berkeley Lab., CA (United States)

    1991-06-01

    Use of foam for enhanced oil recovery (EOR) has shown recent success in steam-flooding field applications. Foam can also provide an effective barrier against gas coning in thin oil zones. Both of these applications stem from the unique mobility-control properties a stable foam possesses when it exists in porous media. Unfortunately, oil has a major destabilizing effect on foam. Therefore, it is important for EOR applications to understand how oil destroys foam. Studies all indicate that stabilization of the pseudoemulsion film is critical to maintain foam stability in the presence of oil. Hence, to aid in design of surfactant formulations for foam insensitivity to oil the authors pursue direct measurement of the thin-film or disjoining forces that stabilize pseudoemulsion films. Experimental procedures and preliminary results are described.

  6. Thin films under chemical stress

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    The goal of work on this project has been develop a set of experimental tools to allow investigators interested in transport, binding, and segregation phenomena in composite thin film structures to study these phenomena in situ. Work to-date has focuses on combining novel spatially-directed optical excitation phenomena, e.g. waveguide eigenmodes in thin dielectric slabs, surface plasmon excitations at metal-dielectric interfaces, with standard spectroscopies to understand dynamic processes in thin films and at interfaces. There have been two main scientific thrusts in the work and an additional technical project. In one thrust we have sought to develop experimental tools which will allow us to understand the chemical and physical changes which take place when thin polymer films are placed under chemical stress. In principle this stress may occur because the film is being swelled by a penetrant entrained in solvent, because interfacial reactions are occurring at one or more boundaries within the film structure, or because some component of the film is responding to an external stimulus (e.g. pH, temperature, electric field, or radiation). However all work to-date has focused on obtaining a clearer understanding penetrant transport phenomena. The other thrust has addressed the kinetics of adsorption of model n-alkanoic acids from organic solvents. Both of these thrusts are important within the context of our long-term goal of understanding the behavior of composite structures, composed of thin organic polymer films interspersed with Langmuir-Blodgett (LB) and self-assembled monolayers. In addition there has been a good deal of work to develop the local technical capability to fabricate grating couplers for optical waveguide excitation. This work, which is subsidiary to the main scientific goals of the project, has been successfully completed and will be detailed as well. 41 refs., 10 figs.

  7. Thin-film solar cell

    OpenAIRE

    Metselaar, J.W.; Kuznetsov, V. I.

    1998-01-01

    The invention relates to a thin-film solar cell provided with at least one p-i-n junction comprising at least one p-i junction which is at an angle alpha with that surface of the thin-film solar cell which collects light during operation and at least one i-n junction which is at an angle beta with the light-collecting surface. In this context, the relationships 45 < alpha < 135 degrees and 45 < beta < 135 degrees apply. The invention also relates to a panel provided with a plurality of such t...

  8. Deposition of Cadmium Sulphide Thin Films by Photochemical Deposition and Characterization

    Directory of Open Access Journals (Sweden)

    H.L. Pushpalatha

    2015-03-01

    Full Text Available Deposition of cadmium sulphide (CdS thin films on glass substrates in acidic medium by photochemical deposition (PCD and studies by several characterizations are presented. The structural characterization of the thin films was carried out by XRD. The elemental composition of the thin films was carried out by EDAX. The optical properties have been studied in the wavelength range 200-900 nm and the optical transition has been found to be direct and allowed. The morphological properties are studied by AFM and electrical properties are studied by four probe technique.

  9. Shielding superconductors with thin films

    CERN Document Server

    Posen, Sam; Catelani, Gianluigi; Liepe, Matthias U; Sethna, James P

    2015-01-01

    Determining the optimal arrangement of superconducting layers to withstand large amplitude AC magnetic fields is important for certain applications such as superconducting radiofrequency cavities. In this paper, we evaluate the shielding potential of the superconducting film/insulating film/superconductor (SIS') structure, a configuration that could provide benefits in screening large AC magnetic fields. After establishing that for high frequency magnetic fields, flux penetration must be avoided, the superheating field of the structure is calculated in the London limit both numerically and, for thin films, analytically. For intermediate film thicknesses and realistic material parameters we also solve numerically the Ginzburg-Landau equations. It is shown that a small enhancement of the superheating field is possible, on the order of a few percent, for the SIS' structure relative to a bulk superconductor of the film material, if the materials and thicknesses are chosen appropriately.

  10. Ferroelectric Thin Film Development

    Science.gov (United States)

    2003-12-10

    less. The film temper- ature is monitored by thermocouple sensors. Process gases pass through the chamber during the process. An advantage of RTP is the...semiconductor InSe ,” J. Appl. Phys., vol. 86, pp. 5687–5691, November 1999. 37. R. Mollers and R. Memming Ber. Bunsenges. Phys. Chem., vol. 76, 1972. 38. M

  11. Ultrafast charge carrier relaxation and charge transfer processes in CdS/CdTe thin films.

    Science.gov (United States)

    Pandit, Bill; Dharmadasa, Ruvini; Dharmadasa, I M; Druffel, Thad; Liu, Jinjun

    2015-07-14

    Ultrafast transient absorption pump-probe spectroscopy (TAPPS) has been employed to investigate charge carrier relaxation in cadmium sulfide/cadmium telluride (CdS/CdTe) nanoparticle (NP)-based thin films and electron transfer (ET) processes between CdTe and CdS. Effects of post-growth annealing treatments to ET processes have been investigated by carrying out TAPPS experiments on three CdS/CdTe samples: as deposited, heat treated, and CdCl2 treated. Clear evidence of ET process in the treated thin films has been observed by comparing transient absorption (TA) spectra of CdS/CdTe thin films to those of CdS and CdTe. Quantitative comparison between ultrafast kinetics at different probe wavelengths unravels the ET processes and enables determination of its rate constants. Implication of the photoinduced dynamics to photovoltaic devices is discussed.

  12. Thin-Film Metamaterials called Sculptured Thin Films

    CERN Document Server

    Lakhtakia, Akhlesh

    2010-01-01

    Morphology and performance are conjointed attributes of metamaterials, of which sculptured thin films (STFs) are examples. STFs are assemblies of nanowires that can be fabricated from many different materials, typically via physical vapor deposition onto rotating substrates. The curvilinear--nanowire morphology of STFs is determined by the substrate motions during fabrication. The optical properties, especially, can be tailored by varying the morphology of STFs. In many cases prototype devices have been fabricated for various optical, thermal, chemical, and biological applications.

  13. Blacking of nano-CdS thin film from gas/liquid interface for enhanced photoelectrochemical performances

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xiaoqing; Yin, Xiangle; Pu, Fang; Xia, Yue, E-mail: xiayue_chem@126.com; Huang, Wei; Li, Zelin, E-mail: lizelin@hunnu.edu.cn

    2014-09-15

    Graphical abstract: Thin films of CdS nanoparticles prepared rapidly at gas/liquid interface became black under visible light irradiation and exhibited enhanced photoelectrochemical performance in splitting water for hydrogen production in alkaline solution of methanol. - Highlights: • Thin films of CdS nanoparticles were facilely obtained at gas/liquid interface. • It involved reaction between CdCl{sub 2} and Na{sub 2}S and assembly of CdS nanoparticles. • The film became black under visible light irradiation in methanol alkaline solution. • The phase composition of the black film was characterized by HRTEM and XRD. • The black film exhibited enhanced PEC performance for H{sub 2}-production from water. - Abstract: Thin films of CdS nanoparticles were prepared rapidly at gas/liquid interface by dropping Na{sub 2}S ethanol solution onto CdCl{sub 2} solution surface with the help of a surfactant (dodecyl sulfate). The photoelectrochemical cell that comprised of the prepared thin film photoanode of CdS nanoparticles and a Pt cathode generated a photocurrent density as high as 2.8 mA cm{sup −2} at a bias voltage of 0.6 V under visible light illumination of 100 mW cm{sup −2} in an alkaline solution of methanol, which was larger than that in other solutions under investigation. It can be ascribed to methanol-assisted transformation of CdS nanoparticles into black Cd/Cd(OH){sub 2}/CdS nanocomposites. At 2.8 mA, the decrease of bias voltage reached 2.49 V for hydrogen production with a solar-to-electricity efficiency of 4.65%.

  14. Selective inorganic thin films

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, M.L.F.; Pohl, P.I.; Brinker, C.J. [Sandia National Labs., Albuquerque, NM (United States)

    1997-04-01

    Separating light gases using membranes is a technology area for which there exists opportunities for significant energy savings. Examples of industrial needs for gas separation include hydrogen recovery, natural gas purification, and dehydration. A membrane capable of separating H{sub 2} from other gases at high temperatures could recover hydrogen from refinery waste streams, and facilitate catalytic dehydrogenation and the water gas shift (CO + H{sub 2}O {yields} H{sub 2} + CO{sub 2}) reaction. Natural gas purification requires separating CH{sub 4} from mixtures with CO{sub 2}, H{sub 2}S, H{sub 2}O, and higher alkanes. A dehydrating membrane would remove water vapor from gas streams in which water is a byproduct or a contaminant, such as refrigeration systems. Molecular sieve films offer the possibility of performing separations involving hydrogen, natural gas constituents, and water vapor at elevated temperatures with very high separation factors. It is in applications such as these that the authors expect inorganic molecular sieve membranes to compete most effectively with current gas separation technologies. Cryogenic separations are very energy intensive. Polymer membranes do not have the thermal stability appropriate for high temperature hydrogen recovery, and tend to swell in the presence of hydrocarbon natural gas constituents. The authors goal is to develop a family of microporous oxide films that offer permeability and selectivity exceeding those of polymer membranes, allowing gas membranes to compete with cryogenic and adsorption technologies for large-scale gas separation applications.

  15. Thin films of soft matter

    CERN Document Server

    Kalliadasis, Serafim

    2007-01-01

    A detailed overview and comprehensive analysis of the main theoretical and experimental advances on free surface thin film and jet flows of soft matter is given. At the theoretical front the book outlines the basic equations and boundary conditions and the derivation of low-dimensional models for the evolution of the free surface. Such models include long-wave expansions and equations of the boundary layer type and are analyzed via linear stability analysis, weakly nonlinear theories and strongly nonlinear analysis including construction of stationary periodic and solitary wave and similarity solutions. At the experimental front a variety of very recent experimental developments is outlined and the link between theory and experiments is illustrated. Such experiments include spreading drops and bubbles, imbibitions, singularity formation at interfaces and experimental characterization of thin films using atomic force microscopy, ellipsometry and contact angle measurements and analysis of patterns using Minkows...

  16. Polycrystalline thin films : A review

    Energy Technology Data Exchange (ETDEWEB)

    Valvoda, V. [Charles Univ., Prague (Czech Republic). Faculty of Mathematics and Physics

    1996-09-01

    Polycrystalline thin films can be described in terms of grain morphology and in terms of their packing by the Thornton`s zone model as a function of temperature of deposition and as a function of energy of deposited atoms. Grain size and preferred grain orientation (texture) can be determined by X-ray diffraction (XRD) methods. A review of XRD analytical methods of texture analysis is given with main attention paid to simple empirical functions used for texture description and for structure analysis by joint texture refinement. To illustrate the methods of detailed structure analysis of thin polycrystalline films, examples of multilayers are used with the aim to show experiments and data evaluation to determine layer thickness, periodicity, interface roughness, lattice spacing, strain and the size of diffraction coherent volumes. The methods of low angle and high angle XRD are described and discussed with respect to their complementary information content.

  17. Photoconductivity of thin organic films

    Science.gov (United States)

    Tkachenko, Nikolai V.; Chukharev, Vladimir; Kaplas, Petra; Tolkki, Antti; Efimov, Alexander; Haring, Kimmo; Viheriälä, Jukka; Niemi, Tapio; Lemmetyinen, Helge

    2010-04-01

    Thin organic films were deposited on silicon oxide surfaces with golden interdigitated electrodes (interelectrode gap was 2 μm), and the film resistivities were measured in dark and under white light illumination. The compounds selected for the measurements include molecules widely used in solar cell applications, such as polythiophene ( PHT), fullerene ( C60), pyrelene tetracarboxylic diimide ( PTCDI) and copper phthalocyanine ( CuPc), as well as molecules potentially interesting for photovoltaic applications, e.g. porphyrin-fullerene dyads. The films were deposited using thermal evaporation (e.g. for C60 and CuPc films), spin coating for PHT, and Langmuir-Schaeffer for the layer-by-layer deposition of porphyrin-fullerene dyads. The most conducting materials in the series are films of PHT and CuPc with resistivities 1.2 × 10 3 Ω m and 3 × 10 4 Ω m, respectively. Under light illumination resistivity of all films decreases, with the strongest light effect observed for PTCDI, for which resistivity decreases by 100 times, from 3.2 × 10 8 Ω m in dark to 3.1 × 10 6 Ω m under the light.

  18. Photoconductivity of thin organic films

    Energy Technology Data Exchange (ETDEWEB)

    Tkachenko, Nikolai V. [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere (Finland); Chukharev, Vladimir, E-mail: Vladimir.Chukharev@tut.fi [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere (Finland); Kaplas, Petra; Tolkki, Antti; Efimov, Alexander [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere (Finland); Haring, Kimmo; Viheriaelae, Jukka; Niemi, Tapio [Optoelectronics Research Centre, Tampere University of Technology, P.O. Box 692, FIN-33101 Tampere (Finland); Lemmetyinen, Helge [Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, FIN-33101 Tampere (Finland)

    2010-04-01

    Thin organic films were deposited on silicon oxide surfaces with golden interdigitated electrodes (interelectrode gap was 2 {mu}m), and the film resistivities were measured in dark and under white light illumination. The compounds selected for the measurements include molecules widely used in solar cell applications, such as polythiophene (PHT), fullerene (C{sub 60}), pyrelene tetracarboxylic diimide (PTCDI) and copper phthalocyanine (CuPc), as well as molecules potentially interesting for photovoltaic applications, e.g. porphyrin-fullerene dyads. The films were deposited using thermal evaporation (e.g. for C{sub 60} and CuPc films), spin coating for PHT, and Langmuir-Schaeffer for the layer-by-layer deposition of porphyrin-fullerene dyads. The most conducting materials in the series are films of PHT and CuPc with resistivities 1.2 x 10{sup 3} {Omega} m and 3 x 10{sup 4} {Omega} m, respectively. Under light illumination resistivity of all films decreases, with the strongest light effect observed for PTCDI, for which resistivity decreases by 100 times, from 3.2 x 10{sup 8} {Omega} m in dark to 3.1 x 10{sup 6} {Omega} m under the light.

  19. Flexible thin film magnetoimpedance sensors

    Energy Technology Data Exchange (ETDEWEB)

    Kurlyandskaya, G.V., E-mail: galina@we.lc.ehu.es [Universidad del País Vasco, UPV/EHU, Departamento de Electricidad y Electrónica, P.O. Box 644, Bilbao 48080 (Spain); Ural Federal University, Laboratory of Magnetic sensoric, Lenin Ave. 51, 620083 Ekaterinburg (Russian Federation); Fernández, E. [BCMaterials UPV-EHU, Vizcaya Science and Technology Park, 48160 Derio (Spain); Svalov, A. [Universidad del País Vasco, UPV/EHU, Departamento de Electricidad y Electrónica, P.O. Box 644, Bilbao 48080 (Spain); Ural Federal University, Laboratory of Magnetic sensoric, Lenin Ave. 51, 620083 Ekaterinburg (Russian Federation); Burgoa Beitia, A. [Universidad del País Vasco, UPV/EHU, Departamento de Electricidad y Electrónica, P.O. Box 644, Bilbao 48080 (Spain); García-Arribas, A. [Universidad del País Vasco, UPV/EHU, Departamento de Electricidad y Electrónica, P.O. Box 644, Bilbao 48080 (Spain); BCMaterials UPV-EHU, Vizcaya Science and Technology Park, 48160 Derio (Spain); Larrañaga, A. [SGIker, Servicios Generales de Investigación, Universidad del País Vasco (UPV/EHU), 48080 Bilbao (Spain)

    2016-10-01

    Magnetically soft thin film deposited onto polymer substrates is an attractive option for flexible electronics including magnetoimpedance (MI) applications. MI FeNi/Ti based thin film sensitive elements were designed and prepared using the sputtering technique by deposition onto rigid and flexible substrates at different deposition rates. Their structure, magnetic properties and MI were comparatively analyzed. The main structural features were sufficiently accurately reproduced in the case of deposition onto cyclo olefine polymer substrates compared to glass substrates for the same conditions. Although for the best condition (28 nm/min rate) of the deposition onto polymer a significant reduction of the MI field sensitivity was found satisfactory for sensor applications sensitivity: 45%/Oe was obtained for a frequency of 60 MHz. - Highlights: • [FeNi/Ti]{sub 3}/Cu/[FeNi/Ti]{sub 3} films were prepared by sputtering at different deposition rates. • Polymer substrates insure sufficiently accurate reproducibility of the film structure. • High deposition rate of 28 nm/min insures the highest values of the magnetoimpedance sensitivity. • Deposition onto polymer results in the satisfactory magnetoimpedance sensitivity of 45%/Oe.

  20. Selective epitaxial growth for YBCO thin films

    NARCIS (Netherlands)

    Damen, C.A.J.; Smilde, H.-J.H.; Blank, D.H.A.; Rogalla, H.

    1998-01-01

    A novel selective epitaxial growth (SEG) technique for (YBCO) thin films is presented. The method involves the deposition of a thin (about 10 nm) metal layer, in the desired pattern, on a substrate before the deposition of the superconducting thin film. During growth the metal reacts with the YBCO,

  1. Thin film CdS/Cu/sub 2/S solar cells by chemical spraying

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, J.F.

    1976-12-15

    This project involves further work on a process developed to make very thin film CdS/Cu/sub 2/S solar cells. The process is adapted to the float glass process and consists of spraying suitable chemicals on a moving ribbon of glass which floats on a bath of molten metal. The spraying produces the necessary thin films (with suitable optical and electrical properties) of SnO/sub 2/, CdS and Cu/sub 2/S. The CdS films produced are two to three microns thick, thus conserving the use of cadmium. The estimated cost per peak watt is approximately 7 cents (1975 costs) at 5 percent efficiency and an output of 37.6 x 10/sup 6/ square meters annually. The cells are blackwall cells. A float glass plant modified for the process is shown schematically. Research progress is described.

  2. Thin films for emerging applications v.16

    CERN Document Server

    Francombe, Maurice H

    1992-01-01

    Following in the long-standing tradition of excellence established by this serial, this volume provides a focused look at contemporary applications. High Tc superconducting thin films are discussed in terms of ion beam and sputtering deposition, vacuum evaporation, laser ablation, MOCVD, and other deposition processes in addition to their ultimate applications. Detailed treatment is also given to permanent magnet thin films, lateral diffusion and electromigration in metallic thin films, and fracture and cracking phenomena in thin films adhering to high-elongation substrates.

  3. Enhanced charge collection and photocatalysis performance of CdS and PbS nanoclusters co-sensitized TiO{sub 2} porous film

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Miao; Xu, Yanyan; Gong, Zezhou; Tao, Jiajia [School of Physics & Material Science, Anhui University, Hefei 230601 (China); Sun, Zhaoqi, E-mail: szq@ahu.edu.cn [School of Physics & Material Science, Anhui University, Hefei 230601 (China); Lv, Jianguo [School of Electronic & Information Engineering, Hefei Normal University, Hefei, 230601 (China); National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Chen, Xiaoshuang [National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 (China); Jiang, Xishun [School of Physics & Material Science, Anhui University, Hefei 230601 (China); School of Mechanical & Electronic Engineering, Chuzhou University, Chuzhou, 239000 (China); He, Gang; Wang, Peihong; Meng, Fanming [School of Physics & Material Science, Anhui University, Hefei 230601 (China)

    2015-11-15

    A novel translucent TiO{sub 2} porous film was prepared through etched method. The CdS, PbS and CdS/PbS nanoclusters were imbedded on TiO{sub 2} porous film by successive ionic layer adsorption and reaction method. Microstructure, morphology, optical and photoelectron-chemical properties of the as-synthesized thin films were investigated systematically. XRD and morphology analysis showed that PbS or CdS nanoclusters have been attached to the TiO{sub 2} porous films. It was found that the energy band gap of TiO{sub 2} porous film decreased from 3.46 to 3.2 eV after sensitized with nanoclusters. The photocurrent density of ITO/TiO{sub 2} photoelectrode increased from 0.017 to 0.28 mA/cm{sup 2} after co-sensitized with CdS and PbS nanoclusters. Besides, the photoelectrode sensitized with two sorts of nanoclusters showed evident higher photocurrent density than which sensitized just one sort of nanoclusters. The photocurrent density of ITO/TiO{sub 2}/PbS and TO/TiO{sub 2}/CdS photoelectrode was 0.11 mA/cm{sup 2} and 0.22 mA/cm{sup 2} respectively. 0.28 mA/cm{sup 2} can be obtained by ITO/TiO{sub 2}/CdS/PbS photoelectrode. The results showed that the optical and photoelectrochemistry properties and phtotcatalysis performance of TiO{sub 2} porous film were greatly improved by co-sensitized with CdS and PbS nanoclusters. - Graphical abstract: When CdS and PbS were brought in the cascade structure, such a Fermi level alignment causes upward and downward shifts of the band edges for PbS and CdS, respectively. Therefore the resulting band edges for the ITO/TiO{sub 2}/CdS/PbS devices are inferred to have a stepwise structure. The elevated conduction band edge of PbS provides a higher driving force for the injection of photogenerated electrons from PbS to CdS as well as the injection of excited holes from CdS to PbS. Such a structure offers efficient separation and transport of the excited electrons and holes. - Highlights: • Ti films were obtained from direct current

  4. Thin film fuel cell electrodes.

    Science.gov (United States)

    Asher, W. J.; Batzold, J. S.

    1972-01-01

    Earlier work shows that fuel cell electrodes prepared by sputtering thin films of platinum on porous vycor substrates avoid diffusion limitations even at high current densities. The presented study shows that the specific activity of sputtered platinum is not unusually high. Performance limitations are found to be controlled by physical processes, even at low loadings. Catalyst activity is strongly influenced by platinum sputtering parameters, which seemingly change the surface area of the catalyst layer. The use of porous nickel as a substrate shows that pore size of the substrate is an important parameter. It is noted that electrode performance increases with increasing loading for catalyst layers up to two microns thick, thus showing the physical properties of the sputtered layer to be different from platinum foil. Electrode performance is also sensitive to changing differential pressure across the electrode. The application of sputtered catalyst layers to fuel cell matrices for the purpose of obtaining thin total cells appears feasible.

  5. Low Temperature Electrical Resistivity Studies in Lead Thin Films

    Directory of Open Access Journals (Sweden)

    A.W. Manjunath

    2013-07-01

    Full Text Available Thin lead films of thickness, 100 nm, 150 nm, 200 nm and 250 nm have been deposited using electron beam evaporation technique at room temperature onto glass substrates under high vacuum conditions. Films were investigated for electrical resistivity at low temperatures from 77 K to 300 K. Resistivity variation with temperature indicates transition from metallic to semiconductor behavior. Transition tem-perature increased with increasing film thickness. Temperature coefficient of resistance in the metallic re-gion has been determined for all the four films. Using Arrhenius relation, activation energy for conduction in metallic region has been determined. Mott’s small polaron hopping model has been employed to deter-mine activation energy in the semiconducting region. In a film of 250 nm thick, deviation from Mott’s small polaron hopping model for below 100 K was noted and that has been considered under Mott’s variable range hopping model. The complete understanding of electrical properties of Pb films has been necessitat-ed by the fact that the band gap in CdS decreases when Pb is incorporated into it, which in turn can be used to fabricated large efficient solar cells. It is for the first time that lead films of the present thickness have been investigated for low temperature resistivity.

  6. Thin liquid films dewetting and polymer flow

    CERN Document Server

    Blossey, Ralf

    2012-01-01

    This book is a treatise on the thermodynamic and dynamic properties of thin liquid films at solid surfaces and, in particular, their rupture instabilities. For the quantitative study of these phenomena, polymer thin films haven proven to be an invaluable experimental model system.   What is it that makes thin film instabilities special and interesting, warranting a whole book? There are several answers to this. Firstly, thin polymeric films have an important range of applications, and with the increase in the number of technologies available to produce and to study them, this range is likely to expand. An understanding of their instabilities is therefore of practical relevance for the design of such films.   Secondly, thin liquid films are an interdisciplinary research topic. Interdisciplinary research is surely not an end to itself, but in this case it leads to a fairly heterogeneous community of theoretical and experimental physicists, engineers, physical chemists, mathematicians and others working on the...

  7. CdS nanofilms: Effect of film thickness on morphology and optical band gap

    Science.gov (United States)

    Kumar, Suresh; Kumar, Santosh; Sharma, Pankaj; Sharma, Vineet; Katyal, S. C.

    2012-12-01

    CdS nanofilms of varying thickness (t) deposited by chemical bath deposition technique have been studied for structural changes using x-ray diffractometer (XRD) and transmission electron microscope (TEM). XRD analysis shows polycrystalline nature in deposited films with preferred orientation along (002) reflection plane also confirmed by selected area diffraction pattern of TEM. Uniform and smooth surface morphology observed using field emission scanning electron microscope. The surface topography has been studied using atomic force microscope. The optical constants have been calculated from the analysis of %T and %R spectra in the wavelength range 300 nm-900 nm. CdS nanofilms show a direct transition with red shift. The optical band gap decreases while the refractive index increases with increase in thickness of nanofilms.

  8. Ellipsometric Studies on Silver Telluride Thin Films

    Directory of Open Access Journals (Sweden)

    M. Pandiaraman

    2011-01-01

    Full Text Available Silver telluride thin films of thickness between 45 nm and 145 nm were thermally evaporated on well cleaned glass substrates at high vacuum better than 10 – 5 mbar. Silver telluride thin films are polycrystalline with monoclinic structure was confirmed by X-ray diffractogram studies. AFM and SEM images of these films are also recorded. The phase ratio and amplitude ratio of these films were recorded in the wavelength range between 300 nm and 700 nm using spectroscopic ellipsometry and analysed to determine its optical band gap, refractive index, extinction coefficient, and dielectric functions. High absorption coefficient determined from the analysis of recorded spectra indicates the presence of direct band transition. The optical band gap of silver telluride thin films is thickness dependent and proportional to square of reciprocal of thickness. The dependence of optical band gap of silver telluride thin films on film thickness has been explained through quantum size effect.

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

    Science.gov (United States)

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

    2009-01-01

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

  10. PbS Thin Films for Photovoltaic Applications Obtained by Non-Traditional Chemical Bath Deposition

    Directory of Open Access Journals (Sweden)

    Pérez-García Claudia Elena

    2015-01-01

    Full Text Available To optimize cost-efficiency relation for thin film solar cells, we explore the recently developed versions of chemical deposition of semiconductor films, together with classic CBD (Chemical Bath Deposition: SILAR (Successive Ionic Layer Adsorption and Reaction and PCBD (Photo Chemical Bath Deposition, all of them ammonia-free and ecologically friendly. The films of CdS and PbS were made, and experimental solar cells with CdS window layer and PbS absorber elaborated. We found that band gap of PbS films can be monitored by deposition process due to porosity-induced quantum confinement which depends on the parameters of the process. We expect that the techniques employed can be successfully used for production of optoelectronic devices.

  11. Electrostatic thin film chemical and biological sensor

    Science.gov (United States)

    Prelas, Mark A.; Ghosh, Tushar K.; Tompson, Jr., Robert V.; Viswanath, Dabir; Loyalka, Sudarshan K.

    2010-01-19

    A chemical and biological agent sensor includes an electrostatic thin film supported by a substrate. The film includes an electrostatic charged surface to attract predetermined biological and chemical agents of interest. A charge collector associated with said electrostatic thin film collects charge associated with surface defects in the electrostatic film induced by the predetermined biological and chemical agents of interest. A preferred sensing system includes a charge based deep level transient spectroscopy system to read out charges from the film and match responses to data sets regarding the agents of interest. A method for sensing biological and chemical agents includes providing a thin sensing film having a predetermined electrostatic charge. The film is exposed to an environment suspected of containing the biological and chemical agents. Quantum surface effects on the film are measured. Biological and/or chemical agents can be detected, identified and quantified based on the measured quantum surface effects.

  12. Intrinsically conductive polymer thin film piezoresistors

    DEFF Research Database (Denmark)

    Lillemose, Michael; Spieser, Martin; Christiansen, N.O.

    2008-01-01

    We report on the piezoresistive effect in the intrinsically conductive polymer, polyaniline. A process recipe for indirect patterning of thin film polyaniline has been developed. Using a specially designed chip, the polyaniline thin films have been characterised with respect to resistivity...

  13. Stability Effect In Photoconducting Studies of Some Chemically Deposited CdS, (Cd-Pb)S and (Cd-Zn)S Films

    OpenAIRE

    2008-01-01

    Stability effects in photoconductivity (PC) rise and decay have been studied over a period of 2 years in thin films of (Cd-Pb)S:LiF, La/Pr and (Cd-Zn)S: LiF,La/Pr and have been found quite stable; however, those of CdS are not that stable. Results of annealing effect are also included, which present more stable values. XRD studies show prominent lines of base materials. Further, XRD and SEM studies show the particle sizes are in the nanometer range. Results of optical absorption sp...

  14. The structural properties of CdS deposited by chemical bath deposition and pulsed direct current magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Lisco, F., E-mail: F.Lisco@lboro.ac.uk [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Kaminski, P.M.; Abbas, A.; Bass, K.; Bowers, J.W.; Claudio, G. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom); Losurdo, M. [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR, via Orabona 4, 70126 Bari (Italy); Walls, J.M. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire, LE11 3TU (United Kingdom)

    2015-05-01

    Cadmium sulphide (CdS) thin films were deposited by two different processes, chemical bath deposition (CBD), and pulsed DC magnetron sputtering (PDCMS) on fluorine doped-tin oxide coated glass to assess the potential advantages of the pulsed DC magnetron sputtering process. The structural, optical and morphological properties of films obtained by CBD and PDCMS were investigated using X-ray photoelectron spectroscopy, X-ray diffraction, scanning and transmission electron microscopy, spectroscopic ellipsometry and UV-Vis spectrophotometry. The as-grown films were studied and comparisons were drawn between their morphology, uniformity, crystallinity, and the deposition rate of the process. The highest crystallinity is observed for sputtered CdS thin films. The absorption in the visible wavelength increased for PDCMS CdS thin films, due to the higher density of the films. The band gap measured for the as-grown CBD-CdS is 2.38 eV compared to 2.34 eV for PDCMS-CdS, confirming the higher density of the sputtered thin film. The higher deposition rate for PDCMS is a significant advantage of this technique which has potential use for high rate and low cost manufacturing. - Highlights: • Pulsed DC magnetron sputtering (PDCMS) of CdS films • Chemical bath deposition of CdS films • Comparison between CdS thin films deposited by chemical bath and PDCMS techniques • High deposition rate deposition for PDCMS deposition • Uniform, pinhole free CdS thin films.

  15. High rate deposition of thin film cadmium sulphide by pulsed direct current magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Lisco, F., E-mail: F.Lisco@lboro.ac.uk [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Kaminski, P.M.; Abbas, A.; Bowers, J.W.; Claudio, G. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Losurdo, M. [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR, via Orabona 4, 70126 Bari (Italy); Walls, J.M. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom)

    2015-01-01

    Cadmium Sulphide (CdS) is an important n-type semiconductor widely used as a window layer in thin film photovoltaics Copper Indium Selenide, Copper Indium Gallium (di)Selenide, Copper Zinc Tin Sulphide and Cadmium Telluride (CdTe). Cadmium Sulphide has been deposited using a number of techniques but these techniques can be slow (chemical bath deposition and Radio Frequency sputtering) or the uniformity and the control of thickness can be relatively difficult (close space sublimation). In this paper we report on the development of a process using pulsed Direct Current magnetron sputtering which allows nanometre control of thin film thickness using time only. The CdS thin films deposited in this process are highly uniform and smooth. They exhibit the preferred hexagonal structure at room temperature deposition and they have excellent optical properties. Importantly, the process is highly stable despite the use of a semi-insulating magnetron target. Moreover, the process is very fast. The deposition rate using 1.5 kW of power to a 6-inch circular magnetron was measured to be greater than 8 nm/s. This makes the process suitable for industrial deployment. - Highlights: • Pulsed DC magnetron sputtering of CdS • High deposition rate deposition • Uniform, pinhole free films.

  16. A monolithic thin film electrochromic window

    Energy Technology Data Exchange (ETDEWEB)

    Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K. (Tufts Univ., Medford, MA (United States). Electro-Optics Technology Center); Wei, G. (Mobil Solar Energy Corp., Billerica, MA (United States)); Yu, P.C. (PPG Industries, Inc., Monroeville, PA (United States))

    1991-01-01

    Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors' institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

  17. A monolithic thin film electrochromic window

    Energy Technology Data Exchange (ETDEWEB)

    Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K. [Tufts Univ., Medford, MA (United States). Electro-Optics Technology Center; Wei, G. [Mobil Solar Energy Corp., Billerica, MA (United States); Yu, P.C. [PPG Industries, Inc., Monroeville, PA (United States)

    1991-12-31

    Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors` institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

  18. Magnetostrictive thin films for microwave spintronics.

    Science.gov (United States)

    Parkes, D E; Shelford, L R; Wadley, P; Holý, V; Wang, M; Hindmarch, A T; van der Laan, G; Campion, R P; Edmonds, K W; Cavill, S A; Rushforth, A W

    2013-01-01

    Multiferroic composite materials, consisting of coupled ferromagnetic and piezoelectric phases, are of great importance in the drive towards creating faster, smaller and more energy efficient devices for information and communications technologies. Such devices require thin ferromagnetic films with large magnetostriction and narrow microwave resonance linewidths. Both properties are often degraded, compared to bulk materials, due to structural imperfections and interface effects in the thin films. We report the development of epitaxial thin films of Galfenol (Fe81Ga19) with magnetostriction as large as the best reported values for bulk material. This allows the magnetic anisotropy and microwave resonant frequency to be tuned by voltage-induced strain, with a larger magnetoelectric response and a narrower linewidth than any previously reported Galfenol thin films. The combination of these properties make epitaxial thin films excellent candidates for developing tunable devices for magnetic information storage, processing and microwave communications.

  19. Nanostructured thin films and coatings functional properties

    CERN Document Server

    Zhang, Sam

    2010-01-01

    The second volume in ""The Handbook of Nanostructured Thin Films and Coatings"" set, this book focuses on functional properties, including optical, electronic, and electrical properties, as well as related devices and applications. It explores the large-scale fabrication of functional thin films with nanoarchitecture via chemical routes, the fabrication and characterization of SiC nanostructured/nanocomposite films, and low-dimensional nanocomposite fabrication and applications. The book also presents the properties of sol-gel-derived nanostructured thin films as well as silicon nanocrystals e

  20. Carbon nanotube based transparent conductive thin films.

    Science.gov (United States)

    Yu, X; Rajamani, R; Stelson, K A; Cui, T

    2006-07-01

    Carbon nanotube (CNT) based optically transparent and electrically conductive thin films are fabricated on plastic substrates in this study. Single-walled carbon nanotubes (SWNTs) are chemically treated with a mixture of concentrated sulfuric acid and nitric acid before being dispersed in aqueous surfactant-contained solutions. SWNT thin films are prepared from the stable SWNT solutions using wet coating techniques. The 100 nm thick SWNT thin film exhibits a surface resistivity of 6 kohms/square nanometer with an average transmittance of 88% on the visible light range, which is three times better than the films prepared from the high purity as-received SWNTs.

  1. PREPARATION AND CHARACTERIZATION OF POLY-CRYSTALLINE SILICON THIN FILM

    Institute of Scientific and Technical Information of China (English)

    Y.F. Hu; H. Shen; Z.Y. Liu; L.S. Wen

    2003-01-01

    Poly-crystalline silicon thin film has big potential of reducing the cost of solar cells.In this paper the preparation of thin film is introduced, and then the morphology of poly-crystalline thin film is discussed. On the film we developed poly-crystalline silicon thin film solar cells with efficiency up to 6. 05% without anti-reflection coating.

  2. Photoluminescence and electrical properties of polyvinyl alcohol films doped with CdS nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Z.I.; Hosni, H.M.; Saleh, H.H.; Ghazy, O.A. [Atomic Energy Authority, National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt)

    2016-05-15

    In situ preparation of polyvinyl alcohol (PVA) films doped with cadmium sulfide (CdS) nanoparticles was conducted by gamma radiation. The films were characterized in terms of photoluminescence and electrical conductivity. The photoluminescence results indicated the existence of two emission peaks around 470 and 530 nm, which are due to electron-hole recombination of CdS nanoparticles and surface trapped emission due to the PVA capping, respectively. DC electrical conductivity (σ {sub DC}) measurement in the temperature range from 303 up to 373 K reveals an increase in its value with increasing both Cd{sup 2+} ion molar concentration and irradiation dose. AC electrical conductivity (σ {sub AC}) measurement over the same temperature range at an applied field frequency of 10, 100, 500 and 1000 kHz shows an increase behavior with increasing temperature, frequency, Cd{sup 2+} ion molar concentration and irradiation dose. Dielectric constant (ε {sub 1}) exhibits an increase with temperature, whereas it shows reduced values with increasing frequency, Cd{sup 2+} ion molar concentration and irradiation dose. Also, the dielectric loss tangent (tan δ) follows an increasing trend with increasing temperature, Cd{sup 2+} ion molar concentration and irradiation dose while it has an opposite trend with increasing frequency. The CdS/PVA nanocomposite films behavior could be explained on the basis of formation of charge-transfer complexes (CTCs) by the CdS nanoparticles doped into the PVA matrix and the role of radiation in enhancing the charge carrier mobility of such CTCs. (orig.)

  3. High flux pinning efficiency by columnar defects dispersed in three directions in YBCO thin films

    Science.gov (United States)

    Sueyoshi, Tetsuro; Nishimura, Takahiro; Fujiyoshi, Takanori; Mitsugi, Fumiaki; Ikegami, Tomoaki; Ishikawa, Norito

    2016-10-01

    A systematic investigation of flux pinning by widely direction-dispersed columnar defects (CDs) in YBa2Cu3O y thin films was carried out by using heavy-ion irradiation: a parallel configuration of CDs aligned along the c-axis, and two trimodal splay configurations composed of CDs crossing at 0° and ± 45° relative to the c-axis, where the splay plane defined by the three irradiation angles is perpendicular (trimodal-A) or parallel (trimodal-B) to the transport current direction. The trimodal configurations show high pinning efficiency over a wide range of magnetic field orientations compared to the parallel one at low magnetic field. In particular, trimodal-B shows the higher critical current density of the two trimodal configurations. The crossed CDs at ± 45° in the trimodal configurations provide uncorrelated flux pinning at B || c due to the large tilting angle off the c-axis, which effectively reinforce the flux pinning of CDs parallel to the c-axis. This assist effect is more remarkable for trimodal-B: a kink sliding motion of flux lines along the CDs is more effectively reduced by the splay plane, not only at B || c but also at inclined magnetic fields off the c-axis.

  4. Thermal Expansion Coefficients of Thin Crystal Films

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The formulas for atomic displacements and Hamiltonian of a thin crystal film in phonon occupation number representation are obtained with the aid of Green's function theory. On the basis of these results, the formulas for thermal expansion coefficients of the thin crystal film are derived with the perturbation theory, and the numerical calculations are carried out. The results show that the thinner films have larger thermal expansion coefficients.

  5. BDS thin film damage competition

    Energy Technology Data Exchange (ETDEWEB)

    Stolz, C J; Thomas, M D; Griffin, A J

    2008-10-24

    A laser damage competition was held at the 2008 Boulder Damage Symposium in order to determine the current status of thin film laser resistance within the private, academic, and government sectors. This damage competition allows a direct comparison of the current state-of-the-art of high laser resistance coatings since they are all tested using the same damage test setup and the same protocol. A normal incidence high reflector multilayer coating was selected at a wavelength of 1064 nm. The substrates were provided by the submitters. A double blind test assured sample and submitter anonymity so only a summary of the results are presented here. In addition to the laser resistance results, details of deposition processes, coating materials, and layer count will also be shared.

  6. Thin film bioreactors in space

    Science.gov (United States)

    Hughes-Fulford, M.; Scheld, H. W.

    Studies from the Skylab, SL-3 and D-1 missions have demonstrated that biological organisms grown in microgravity have changes in basic cellular functions such as DNA, mRNA and protein synthesis, cytoskeleton synthesis, glucose utilization and cellular differentiation. Since microgravity could affect prokaryotic and eukaryotic cells at a subcellular and molecular level, space offers us an opportunity to learn more about basic biological systems with one important variable removed. The thin film bioreactor will facilitate the handling of fluids in microgravity, under constant temperature and will allow multiple samples of cells to be grown with variable conditions. Studies on cell cultures grown in microgravity would enable us to identify and quantify changes in basic biological function in microgravity which are needed to develop new applications of orbital research and future biotechnology.

  7. Thin film bioreactors in space

    Science.gov (United States)

    Hughes-Fulford, M.; Scheld, H. W.

    1989-01-01

    Studies from the Skylab, SL-3 and D-1 missions have demonstrated that biological organisms grown in microgravity have changes in basic cellular functions such as DNA, mRNA and protein synthesis, cytoskeleton synthesis, glucose utilization, and cellular differentiation. Since microgravity could affect prokaryotic and eukaryotic cells at a subcellular and molecular level, space offers an opportunity to learn more about basic biological systems with one inmportant variable removed. The thin film bioreactor will facilitate the handling of fluids in microgravity, under constant temperature and will allow multiple samples of cells to be grown with variable conditions. Studies on cell cultures grown in microgravity would make it possible to identify and quantify changes in basic biological function in microgravity which are needed to develop new applications of orbital research and future biotechnology.

  8. Sputtered Zn(O,S) for junction formation in chalcopyrite-based thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Grimm, A.; Just, J.; Kieven, D.; Lauermann, I.; Rissom, T.; Klenk, R. [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Berlin (Germany); Palm, J. [AVANCIS GmbH and Co. KG, Munich (Germany); Neisser, A. [Sulfurcell Solartechnik GmbH, Berlin (Germany)

    2010-06-15

    In an effort to eliminate the standard CdS buffer layer from chalcopyrite-based thin film solar cells we have investigated sputtered Zn(O,S) films. They were prepared by partially reactive sputtering from a ZnS target in an argon/oxygen mixture. Single phase, polycrystalline films were achieved for substrate temperatures of at least 100 C. Test devices prepared in a completely dry process showed superior blue response and active area conversion efficiencies up to 13.7%. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. High-refractive Index Nanocomposite Films Of Polyvinyl-pyrolidone And CdS Nanoparticles By In-Situ Thermolysis

    Science.gov (United States)

    Chaudhuri, Tapas K.; Patel, Mitesh G.

    2010-12-01

    A simple and rapid process for deposition of high refractive index films of CdS/PVP nanocomposite is described. CdS/PVP films are prepared on glass substrate by dip coating a precursor film from methanolic solution of thio-organic complex of cadmium and PVP and subsequent heating at 180° C in air for 10 min. The transmission spectra of the films (thickness ˜700 nm) in the wavelength range 300 to 1000 nm showed an absorption edge near 500 nm due to CdS and high transmission of 85% beyond 500 nm. The refractive index is found to be 1.74 by Swanepoel method, which is between that of PVP (1.48) and CdS (2.5). Transmission Electron Microscopy showed that PVP matrix contains 5 to 10 nm CdS nanocrystals. X-ray and electron diffraction revealed the formation of cubic CdS nanoparticles in PVP. Fourier Transform Infrared spectroscopy of the composite showed that there is a strong interaction between CdS nanocrystals and PVP.

  10. Magnetization in permalloy thin films

    Indian Academy of Sciences (India)

    Rachana Gupta; Mukul Gupta; Thomas Gutberlet

    2008-11-01

    Thin films of permalloy (Ni80Fe20) were prepared using an Ar+N2 mixture with magnetron sputtering technique at ambient temperature. The film prepared with only Ar gas shows reflections corresponding to the permalloy phase in X-ray diffraction (XRD) pattern. The addition of nitrogen during sputtering results in broadening of the peaks in XRD pattern, which finally leads to an amorphous phase. The - loop for the sample prepared with only Ar gas is matching well with the values obtained for the permalloy. For the samples prepared with increased nitrogen partial pressure the magnetic moment decreased rapidly and the values of coercivity increased. The polarized neutron reflectivity measurements (PNR) were performed in the sample prepared with only Ar gas and with nitrogen partial pressure of 5 and 10%. It was found that the spin-up and spin-down reflectivities show exactly similar reflectivity for the sample prepared with Ar gas alone, while PNR measurements on 5 and 10% sample show splitting in the spin-up and spin-down reflectivity.

  11. Micromotors using magnetostrictive thin films

    Science.gov (United States)

    Claeyssen, Frank; Le Letty, Ronan; Barillot, Francois; Betz, Jochen; MacKay, Ken; Givord, Dominique; Bouchilloux, Philippe

    1998-07-01

    This study deals with a micromotor based on the use of magnetostrictive thin films. This motor belongs to the category of the Standing Wave Ultrasonic Motors. The active part of the motor is the rotor, which is a 100 micrometers thick ring vibrating in a flexural mode. Teeth (300 micrometers high) are placed on special positions of the rotor and produce an oblique motion which can induce the relative motion of any object in contact with them. The magnetic excitation field is radial and uses the transverse coupling of the 4 micrometers thick magnetostrictive film. The film, deposited by sputtering on the ring, consists of layers of different rare-earth/iron alloys and was developed during a European Brite-Euram project. The finite element technique was used in order to design a prototype of the motor and to optimize the active rotor and the energizer coil. The prototype we built delivered a speed of 30 turns per minute with a torque of 2 (mu) N.m (without prestress applied on the rotor). Our experimental results show that the performance of this motor could easily be increased by a factor of 5. The main advantage of this motor is the fact that it is remotely powered and controlled. The excitation coil, which provides both power and control, can be placed away from the active rotor. Moreover, the rotor is completely wireless and is not connected to its support or to any other part. It is interesting to note that it would not be possible to build this type of motor using piezoelectric technology. Medical applications of magnetostrictive micromotors could be found for internal microdistributors of medication (the coil staying outside the body). Other applications include remote control micropositioning, micropositioning of optical components, and for the actuation of systems such as valves, electrical switches, and relays.

  12. Minimum entropy principle-based solar cell operation without a pn-junction and a thin CdS layer to extract the holes from the emitter

    Science.gov (United States)

    Böer, Karl W.

    2016-10-01

    The solar cell does not use a pn-junction to separate electrons from holes, but uses an undoped CdS layer that is p-type inverted when attached to a p-type collector and collects the holes while rejecting the backflow of electrons and thereby prevents junction leakage. The operation of the solar cell is determined by the minimum entropy principle of the cell and its external circuit that determines the electrochemical potential, i.e., the Fermi-level of the base electrode to the operating (maximum power point) voltage. It leaves the Fermi level of the metal electrode of the CdS unchanged, since CdS does not participate in the photo-emf. All photoelectric actions are generated by the holes excited from the light that causes the shift of the quasi-Fermi levels in the generator and supports the diffusion current in operating conditions. It is responsible for the measured solar maximum power current. The open circuit voltage (Voc) can approach its theoretical limit of the band gap of the collector at 0 K and the cell increases the efficiency at AM1 to 21% for a thin-film CdS/CdTe that is given as an example here. However, a series resistance of the CdS forces a limitation of its thickness to preferably below 200 Å to avoid unnecessary reduction in efficiency or Voc. The operation of the CdS solar cell does not involve heated carriers. It is initiated by the field at the CdS/CdTe interface that exceeds 20 kV/cm that is sufficient to cause extraction of holes by the CdS that is inverted to become p-type. Here a strong doubly charged intrinsic donor can cause a negative differential conductivity that switches-on a high-field domain that is stabilized by the minimum entropy principle and permits an efficient transport of the holes from the CdTe to the base electrode. Experimental results of the band model of CdS/CdTe solar cells are given and show that the conduction bands are connected in the dark, where the electron current must be continuous, and the valence bands are

  13. TiO2 thin film photocatalyst

    Institute of Scientific and Technical Information of China (English)

    YU Jiaguo

    2004-01-01

    It is well known that the photocatalytic activity of TiO2 thin films strongly depends on the preparing methods and post-treatment conditions, since they have a decisive influence on the chemical and physical properties of TiO2 thin films.Therefore, it is necessary to elucidate the influence of the preparation process and post-treatment conditions on the photocatalytic activity and surface microstructures of the films. This review deals with the preparation of TiO2 thin film photocatalysts by wet-chemical methods (such as sol-gel, reverse micellar and liquid phase deposition) and the comparison of various preparation methods as well as their advantage and disadvantage. Furthermore, it is discussed that the advancement of photocatalytic activity, super-hydrophilicity and bactericidal activity of TiO2 thin film photocatalyst in recent years.

  14. High-efficiency thin-film cadmium telluride photovoltaic cells. Annual technical report, January 20, 1996--January 19, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, A D; Bohn, R G; Contreras-Puente, G [Univ. of Toledo, OH (United States)

    1997-08-01

    The University of Toledo photovoltaics group has been instrumental in developing rf sputtering for CDs/CdTe thin-film solar cells. During the third phase of the present contract our work focussed on efforts to determine factors which limit the efficiency in our {open_quotes}all-sputtered{close_quotes} thin-film CdTe solar cells on soda-lime glass. We find that our all-sputtered cells, which are deposited at substantially lower temperature than those by sublimation or vapor deposition, require less aggressive CdCl{sub 2} treatments than do other deposition techniques and this is presumably related to CDs/CdTe interdiffusion. The CDs/CdTe interdiffusion process has been studied by several methods, including photoluminescence and capacitance-voltage measurements. Furthermore, we have deposited special thin bilayer films on quartz and borosilicate glass. Interdiffusion in these thin bilayers have been probed by Rutherford backscattering, with collaborators at Case Western Reserve University, and grazing incidence x-ray scattering (GIXS), with collaborators at the University at Buffalo and Brookhaven National Lab. Also, in order better to understand the properties of the ternary alloy material, we used laser physical vapor deposition to prepare a series of CdS{sub x}Te{sub 1-x} films on borosilicate glass. The composition of the alloy films was determined by wavelength dispersive x-ray spectroscopy at NREL. These films are currently being investigated by us and other groups at NREL and IEC.

  15. Plasmonic modes in thin films: quo vadis?

    Directory of Open Access Journals (Sweden)

    Antonio ePolitano

    2014-07-01

    Full Text Available Herein, we discuss the status and the prospect of plasmonic modes in thin films. Plasmons are collective longitudinal modes of charge fluctuation in metal samples excited by an external electric field. Surface plasmons (SPs are waves that propagate along the surface of a conductor with applications in magneto-optic data storage, optics, microscopy, and catalysis. In thin films the electronic response is influenced by electron quantum confinement. Confined electrons modify the dynamical screening processes at the film/substrate interface by introducing novel properties with potential applications and, moreover, they affect both the dispersion relation of SP frequency and the damping processes of the SP.Recent calculations indicate the emergence of acoustic surface plasmons (ASP in Ag thin films exhibiting quantum well states and in graphene films. The slope of the dispersion of ASP decreases with film thickness. We also discuss open issues in research on plasmonic modes in graphene/metal interfaes.

  16. Interfacial Effects on Pentablock Ionomer Thin Films

    Science.gov (United States)

    Etampawala, Thusitha; Ratnaweera, Dilru; Osti, Naresh; Shrestha, Umesh; Perahia, Dvora; Majewski, Jaroslaw

    2011-03-01

    The interfacial behavior of multi block copolymer thin films results from a delicate balance between inherent phase segregation due to incompatibility of the blocks and the interactions of the individual blocks with the interfaces. Here in we report a study of thin films of ABCBA penta block copolymers, anionically synthesized, comprising of centered randomly sulfonated polystyrene block to which rubbery poly-ethylenebutalene is connected, terminated by blocks of poly-t-butylstyrene, kindly provided by Kraton. AFM and neutron reflectometry studies have shown that the surface structure of pristine films depends on film thickness and ranges from trapped micelles to thin layered films. Annealing above Tg for the styrene block results in rearrangements into relatively featureless air interface. Neutron reflectivity studies have shown that annealed films forms layers whose plane are parallel to the solid substrate with the bulky block at the air interface and the ionic block at the solid interface.

  17. Occurrence of single-electron phenomenon in CdS nanoclusters in Langmuir-Blodgett films of -octadecyl succinic acid

    Indian Academy of Sciences (India)

    G Hemakanthi; Aruna Dhathathreyan

    2002-10-01

    Cadmium complex of -octadecyl succinic acid (ODSA) in Langmuir films at air/water interface has been studied using surface pressure-molecular area ( - ) and surface potential-molecular area ( - ) isotherms. The metal complex formed, transferred as LB film onto solid substrates, was analysed using FT-IR and was subjected to sulphidation reaction. Antisymmetric and symmetric carboxylate stretching vibrations have been used to determine the nature of the ODSA/cation complexes. CdS formed after sulphidation of the cadmium complex (ODSACd) showed possible single-electron phenomenon indicating the nanosized nature of clusters formed. Atomic Force Microscopy (AFM) measurements carried out confirmed the size of these CdS clusters.

  18. High efficiency thin film cadmium telluride solar cells

    Science.gov (United States)

    Chu, T. L.; Chu, Shirley S.; Britt, J.; Chen, G.; Ferekides, C.; Schultz, N.; Wang, C.; Wu, C. Q.

    1992-12-01

    Cadmium sulfide (CdS), grown from an aqueous solution, and zinc oxide (ZnO), cadmium zinc sulfide (Cd1-xZnxS), and zinc selenide (ZnSe), deposited by metalorganic chemical vapor deposition (MOCVD), have been used as the window for thin film cadmium telluride (CdTe) solar cells. Thin film solar cells were prepared by the successive deposition of the window and p-CdTe (by MOCVD and close-spaced sublimation, CSS) on SnO2:F/glass substrates. CdS/CdTe(CSS) solar cells show considerably better characteristics than CdS/CdTe(MOCVD) solar cells because of the better microstructure of CSS CdTe films. Total area conversion efficiency of 14.6%, verified by the National Renewable Energy Laboratory, has been achieved for solar cells of about 1 cm2 area. Solar cell prepared by using ZnO, ZnSe, or Cd1-xZnxS as window have significantly lower photovoltage than CdS/CdTe solar cells.

  19. Microreactor-Assisted Solution Deposition for Compound Semiconductor Thin Films

    Directory of Open Access Journals (Sweden)

    Chang-Ho Choi

    2014-05-01

    Full Text Available State-of-the-art techniques for the fabrication of compound semiconductors are mostly vacuum-based physical vapor or chemical vapor deposition processes. These vacuum-based techniques typically operate at high temperatures and normally require higher capital costs. Solution-based techniques offer opportunities to fabricate compound semiconductors at lower temperatures and lower capital costs. Among many solution-based deposition processes, chemical bath deposition is an attractive technique for depositing semiconductor films, owing to its low temperature, low cost and large area deposition capability. Chemical bath deposition processes are mainly performed using batch reactors, where all reactants are fed into the reactor simultaneously and products are removed after the processing is finished. Consequently, reaction selectivity is difficult, which can lead to unwanted secondary reactions. Microreactor-assisted solution deposition processes can overcome this limitation by producing short-life molecular intermediates used for heterogeneous thin film synthesis and quenching the reaction prior to homogeneous reactions. In this paper, we present progress in the synthesis and deposition of semiconductor thin films with a focus on CdS using microreactor-assisted solution deposition and provide an overview of its prospect for scale-up.

  20. Anisotropic Heisenberg model in thin film geometry

    Energy Technology Data Exchange (ETDEWEB)

    Akıncı, Ümit

    2014-01-01

    The effect of the anisotropy in the exchange interaction on the phase diagrams and magnetization behavior of the Heisenberg thin film has been investigated with effective field formulation in a two spin cluster using the decoupling approximation. Phase diagrams and magnetization behaviors have been obtained for several different cases, by grouping the systems in accordance with, whether the surfaces/interior of the film has anisotropic exchange interaction or not. - Highlights: • Phase diagrams of the anisotropic Heisenberg model on the thin film obtained • Dependence of the critical properties on the film thickness obtained • Effect of the anisotropy on the magnetic properties obtained.

  1. Insect thin films as solar collectors.

    Science.gov (United States)

    Heilman, B D; Miaoulis, L N

    1994-10-01

    A numerical method for simulation of microscale radiation effects in insect thin-film structures is described. Accounting for solar beam and diffuse radiation, the model calculates the reflectivity and emissivity of such structures. A case study examines microscale radiation effects in butterfuly wings, and results reveal a new function of these multilayer thin films: thermal regulation. For film thicknesses of the order of 0.10 µm, solar absorption levels vary by as much as 25% with small changes in film thickness; for certain existing structures, absorption levels reach 96%., This is attributed to the spectral distribution of the reflected radiation, which consists of a singular reflectance peak within the solar spectrum.

  2. Realizing near stoichiometric and highly transparent CdS:Mo thin films by a low-cost improved SILAR technique

    Energy Technology Data Exchange (ETDEWEB)

    Ravichandran, K. [P.G. and Research Department of Physics, AVVM Sri Pushpam College (Autonomous), Poondi, Thanjavur 613503, Tamil Nadu (India); Nisha Banu, N. [P.G. and Research Department of Physics, AVVM Sri Pushpam College (Autonomous), Poondi, Thanjavur 613503, Tamil Nadu (India); Research Department of Physics, Kunthavai Naachiyaar Government Arts College for Women (Autonomous), Thanjavur 613007, Tamil Nadu (India); Baneto, M. [CUER-UL, Universite de Lome, BP 1515, Lome (Togo); Senthamil Selvi, V. [Research Department of Physics, Kunthavai Naachiyaar Government Arts College for Women (Autonomous), Thanjavur 613007, Tamil Nadu (India)

    2016-02-15

    Undoped and molybdenum doped CdS thin films were deposited on glass substrates using Improved Successive Ionic Layer Adsorption and Reaction (ISILAR) technique. The Mo doping level was varied from 0 to 15 at.% in steps of 5 at.%. The XRD analysis shows that all the films are polycrystalline with cubic structure and grow preferentially along the (111) plane. The crystallite size increases gradually with the increase in Mo doping level up to 10 at.% and decreases with further doping. The morphological studies reveal that Mo doping significantly affects the grains size. Qualitative and quantitative compositional analysis show that near stoichiometric undoped and Mo doped CdS thin films can be achieved using this ISILAR technique. All the films exhibit high transparency in the visible region with an average transmittance in the range of 85-95%. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Ferromagnetic properties of fcc Gd thin films

    Energy Technology Data Exchange (ETDEWEB)

    Bertelli, T. P., E-mail: tambauh@gmail.com; Passamani, E. C.; Larica, C.; Nascimento, V. P.; Takeuchi, A. Y. [Universidade Federal do Espírito Santo, Departamento de Física, Vitória/ES 29075-910 (Brazil); Pessoa, M. S. [Universidade Federal do Espírito Santo, Departamento de Ciências Naturais, São Mateus/ES 29932-540 (Brazil)

    2015-05-28

    Magnetic properties of sputtered Gd thin films grown on Si (100) substrates kept at two different temperatures were investigated using X-ray diffraction, ac magnetic susceptibility, and dc magnetization measurements. The obtained Gd thin films have a mixture of hcp and fcc structures, but with their fractions depending on the substrate temperature T{sub S} and film thickness x. Gd fcc samples were obtained when T{sub S} = 763 K and x = 10 nm, while the hcp structure was stabilized for lower T{sub S} (300 K) and thicker film (20 nm). The fcc structure is formed on the Ta buffer layer, while the hcp phase grows on the fcc Gd layer as a consequence of the lattice relaxation process. Spin reorientation phenomenon, commonly found in bulk Gd species, was also observed in the hcp Gd thin film. This phenomenon is assumed to cause the magnetization anomalous increase observed below 50 K in stressed Gd films. Magnetic properties of fcc Gd thin films are: Curie temperature above 300 K, saturation magnetization value of about 175 emu/cm{sup 3}, and coercive field of about 100 Oe at 300 K; features that allow us to classify Gd thin films, with fcc structure, as a soft ferromagnetic material.

  4. Highly stretchable wrinkled gold thin film wires

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joshua, E-mail: joshuk7@uci.edu; Park, Sun-Jun; Nguyen, Thao [Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697 (United States); Chu, Michael [Department of Biomedical Engineering, University of California, Irvine, California 92697 (United States); Pegan, Jonathan D. [Department of Materials and Manufacturing Technology, University of California, Irvine, California 92697 (United States); Khine, Michelle, E-mail: mkhine@uci.edu [Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697 (United States); Department of Biomedical Engineering, University of California, Irvine, California 92697 (United States)

    2016-02-08

    With the growing prominence of wearable electronic technology, there is a need to improve the mechanical reliability of electronics for more demanding applications. Conductive wires represent a vital component present in all electronics. Unlike traditional planar and rigid electronics, these new wearable electrical components must conform to curvilinear surfaces, stretch with the body, and remain unobtrusive and low profile. In this paper, the piezoresistive response of shrink induced wrinkled gold thin films under strain demonstrates robust conductive performance in excess of 200% strain. Importantly, the wrinkled metallic thin films displayed negligible change in resistance of up to 100% strain. The wrinkled metallic wires exhibited consistent performance after repetitive strain. Importantly, these wrinkled thin films are inexpensive to fabricate and are compatible with roll to roll manufacturing processes. We propose that these wrinkled metal thin film wires are an attractive alternative to conventional wires for wearable applications.

  5. Thin films for geothermal sensing: Final report

    Energy Technology Data Exchange (ETDEWEB)

    1987-09-01

    The report discusses progress in three components of the geothermal measurement problem: (1) developing appropriate chemically sensitive thin films; (2) discovering suitably rugged and effective encapsulation schemes; and (3) conducting high temperature, in-situ electrochemical measurements. (ACR)

  6. Manganese ferrite thin films Part II: Properties

    NARCIS (Netherlands)

    Hulscher, W.S.

    1972-01-01

    Some properties of evaporated manganese ferrite thin films are investigated, e.g. resistivity, magnetization reversal, Curie temperature, Faraday rotation and optical absorption. The properties are partly related to the partial oxygen pressure present during a preceding annealing process.

  7. Thin solid-lubricant films in space

    Science.gov (United States)

    Roberts, E. W.

    Low-friction films of thickness as low as 1 micron, created through sputter-deposition of low shear strength materials, are required in spacecraft applications requiring low power dissipation, such as cryogenic devices, and low torque noise, such as precision-pointing mechanisms. Due to their thinness, these coatings can be applied to high precision-machined tribological components without compromising their functional accuracy. Attention is here given to the cases of thin solid films for ball bearings, gears, and journal bearings.

  8. Studies in thin film flows

    CERN Document Server

    McKinley, I S

    2000-01-01

    the general case of non-zero capillary number numerically. Using the lubrication approximation to the Navier-Stokes equations we investigate the evolution and stability of a thin film of incompressible Newtonian fluid on a planar substrate subjected to a jet of air blowing normally to the substrate. For the simple model of the air jet we adopt, the initially axisymmetric problems we study are identical to those of a drop spreading on a turntable rotating at constant angular velocity (the simplest model for spin coating). We consider both drops without a dry patch (referred to as 'non-annular') and drops with a dry patch at their centre (referred to as 'annular'). First, both symmetric two-dimensional and axisymmetric three-dimensional drops are considered in the quasi-static limit of small capillary number. The evolution of both non-annular and annular drops and the stability of equilibrium solutions to small perturbations with zero wavenumber are determined. Using a specially developed finite-difference code...

  9. Epitaxy, thin films and superlattices

    Energy Technology Data Exchange (ETDEWEB)

    Jagd Christensen, Morten

    1997-05-01

    This report is the result of structural investigations of 3d transition metal superlattices consisting of Fe/V, Cr/Mn, V/Mn and Fe/Mn, and a structural and magnetic study of a series of Ho/Pr alloys. The work includes preparation and characterization of substrates as well as growth of thin films and Fe/V superlattices by molecular beam epitaxy, including in-situ characterization by reflection high energy electron diffraction and Auger electron spectroscopy. Structural characterization has been done by x-ray diffraction and neutron diffraction. The x-ray diffraction experiments have been performed on the rotating copper anode at Risoe, and at synchrotron facilities in Hamburg and Brookhaven, and the neutron scattering was done at the Danish research reactor DR3 at Risoe. In addition to longitudinal scans, giving information about the structural parameters in the modulation direction, non-specular scans were also performed. This type of scans gives information about in-plane orientation and lattice parameters. From the analysis, structural information is obtained about lattice parameters, epitaxial strain, coherence lengths and crystallographic orientation for the superlattice systems, except Fe/Mn superlattices, which could not be modelled. For the Ho/Pr alloys, x-ray magnetic scattering was performed, and the crystal and magnetic structure was investigated. (au) 14 tabs.; 58 ills., 96 refs.

  10. Carbon Nanotube Thin-Film Antennas.

    Science.gov (United States)

    Puchades, Ivan; Rossi, Jamie E; Cress, Cory D; Naglich, Eric; Landi, Brian J

    2016-08-17

    Multiwalled carbon nanotube (MWCNT) and single-walled carbon nanotube (SWCNT) dipole antennas have been successfully designed, fabricated, and tested. Antennas of varying lengths were fabricated using flexible bulk MWCNT sheet material and evaluated to confirm the validity of a full-wave antenna design equation. The ∼20× improvement in electrical conductivity provided by chemically doped SWCNT thin films over MWCNT sheets presents an opportunity for the fabrication of thin-film antennas, leading to potentially simplified system integration and optical transparency. The resonance characteristics of a fabricated chlorosulfonic acid-doped SWCNT thin-film antenna demonstrate the feasibility of the technology and indicate that when the sheet resistance of the thin film is >40 ohm/sq no power is absorbed by the antenna and that a sheet resistance of antenna. The dependence of the return loss performance on the SWCNT sheet resistance is consistent with unbalanced metal, metal oxide, and other CNT-based thin-film antennas, and it provides a framework for which other thin-film antennas can be designed.

  11. Synthesis and characterization of CdS-polyelectrolyte-Bi2S3 thin film by SILAR

    Science.gov (United States)

    Desale, Dipalee J.; Shaikh, Shaheed; Siddiqui, Farha; AnilGhule, Ravikiran Birajadar; Sharma, Ramphal

    2012-06-01

    CdS-Polyelectrolyte-Bi2S3 was grown by cost effective successive ionic layer adsorption and reaction method (SILAR) on glass substrate. The polyelectrolyte used as a protecting layer for excessive ionic loss during the exchange reaction between the cation and anions of the reactants. Thin films was characterized for structural, morphological and an I-V characteristic. The X-ray diffraction pattern (XRD) pattern shows that, CdS-Polyelectrolyte-Bi2S3 thin films have mixed phase of hexagonal and orthorhombic crystal structures corresponding to CdS and Bi2S3 respectively. Scanning electron microscopy (SEM) corresponds deposition of the material along with the presence of bundle like shape is observed in thin film. The I-V measurement under dark and illumination to 100 mW/cm2 shows increase in photoconductivity.

  12. Photophysical properties of Alq3 thin films

    Science.gov (United States)

    Zawadzka, A.; Płóciennik, P.; Strzelecki, J.; Łukasiak, Z.; Sahraoui, B.

    2013-11-01

    This work contains investigation results of the photophysical properties of aluminum (III) tris(8-hydroxyquinoline) thin films. The Alq3 thin films were successfully fabricated by Physical Vapor Deposition technique. The films were grown on transparent: (quartz and glass) and semiconductor (n-type silica) substrates kept at room temperature during the deposition process. Selected films were annealed after fabrication in ambient atmosphere for 12 h at the temperature equal to 100 °C and 150 °C. Morphology of the films was investigated by AFM technique. Photophysical properties were characterized via photoluminescence, transmission, second and third harmonic generation measurements. The thin films exhibit high structural quality regardless of the annealing process, but the stability of the film can be improved by using an appropriate temperature during the annealing process. Photoluminescence of Alq3 films obtained in air were efficient and stable. The measurements of transmission, SHG and THG spectra allowed us to determine optical constant of the films. We find that the photophysical properties were strictly connected with the morphology and the annealing process significantly changes the structural properties of the films.

  13. Production method of thin film solar cell; Hakumaku taiyo denchi no seizo hoho

    Energy Technology Data Exchange (ETDEWEB)

    Oki, K.; Watanabe, T.; Matsui, M.

    1996-01-23

    This invention relates to the film formation of chalcopyrite type compound semiconductor used for thin film solar cell. In the case of CuInS2 thin film, heteromorphic phases such as CuIn5S8, Cu2S, and In2S3 are formed on the top surface together with the CuInS2 phase, resulting in the decrease in junction property when n-type semiconductor layer such as CdS layer is formed on it. According to the invention, p-type semiconductor layer made of chalcopyrite type compound semiconductor is dipped into an ammonia water before being laminated with n-type semiconductor layer. Although higher concentration and higher temperature of the ammonia water accelerates the heteromorphic phase film removal velocity, it also gives rise to higher evaporation rate of ammonia. The preferable concentration and temperature are, therefore, 0.01 - 50% and 5 - 80{degree}C, respectively. In this way, the chalcopyrite type compound semiconductor thin film free from heteromorphic phases on its surface can be produced. The thin film solar cell produced by using such thin film has a high conversion efficiency because of a good junction property with n-type semiconductor. 1 fig.

  14. An optimized multilayer structure of CdS layer for CdTe solar cells application

    Energy Technology Data Exchange (ETDEWEB)

    Han Junfeng, E-mail: pkuhjf@gmail.com [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Road Yiheyuan 5, Beijing 100871 (China); Institute of Materials Science, Darmstadt University of Technology, Petersenstr. 23, 64287 Darmstadt (Germany); Liao Cheng, E-mail: Cliao@pku.edu.cn [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Road Yiheyuan 5, Beijing 100871 (China); Jiang Tao [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Road Yiheyuan 5, Beijing 100871 (China); Spanheimer, C.; Haindl, G.; Fu, Ganhua; Krishnakumar, V. [Institute of Materials Science, Darmstadt University of Technology, Petersenstr. 23, 64287 Darmstadt (Germany); Zhao Kui [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Road Yiheyuan 5, Beijing 100871 (China); Klein, A.; Jaegermann, W. [Institute of Materials Science, Darmstadt University of Technology, Petersenstr. 23, 64287 Darmstadt (Germany)

    2011-04-28

    Research highlights: > Two different methods to prepare CdS films for CdTe solar cells. > A new multilayer structure of window layer for the CdTe solar cell. > Thinner CdS window layer for the solar cell than the standard CdS layer. > Higher performance of solar cells based on the new multilayer structure. - Abstract: CdS layers grown by 'dry' (close space sublimation) and 'wet' (chemical bath deposition) methods are deposited and analyzed. CdS prepared with close space sublimation (CSS) has better crystal quality, electrical and optical properties than that prepared with chemical bath deposition (CBD). The performance of CdTe solar cell based on the CSS CdS layer has higher efficiency than that based on CBD CdS layer. However, the CSS CdS suffers from the pinholes. And consequently it is necessary to prepare a 150 nm thin film for CdTe/CdS solar cell. To improve the performance of CdS/CdTe solar cells, a thin multilayer structure of CdS layer ({approx}80 nm) is applied, which is composed of a bottom layer (CSS CdS) and a top layer (CBD CdS). That bi-layer film can allow more photons to pass through it and significantly improve the short circuit current of the CdS/CdTe solar cells.

  15. Thin-film crystalline silicon solar cells

    CERN Document Server

    Brendel, Rolf

    2011-01-01

    This introduction to the physics of silicon solar cells focuses on thin cells, while reviewing and discussing the current status of the important technology. An analysis of the spectral quantum efficiency of thin solar cells is given as well as a full set of analytical models. This is the first comprehensive treatment of light trapping techniques for the enhancement of the optical absorption in thin silicon films.

  16. A thin-film magnetoresistive angle detector

    NARCIS (Netherlands)

    Eijkel, Kees J.M.; Wieberdink, Johan W.; Fluitman, Jan H.J; Popma, Theo J.A.; Groot, Peter; Leeuwis, Henk

    1990-01-01

    An overview is given of the results of our research on a contactless angle detector based on the anisotropic magnetoresistance effect (AMR effect) in a permalloy thin film. The results of high-temperature annealing treatment of the pemalloy film are discussed. Such a treatment suppresses the effects

  17. Liquid phase deposition of electrochromic thin films

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Adhesion and friction of thin metal films

    Science.gov (United States)

    Buckley, D. H.

    1976-01-01

    Sliding friction experiments were conducted in vacuum with thin films of titanium, chromium, iron, and platinum sputter deposited on quartz or mica substrates. A single crystal hemispherically tipped gold slider was used in contact with the films at loads of 1.0 to 30.0 and at a sliding velocity of 0.7 mm/min at 23 C. Test results indicate that the friction coefficient is dependent on the adhesion of two interfaces, that between the film and its substrate and the slider and the film. There exists a relationship between the percent d bond character of metals in bulk and in thin film form and the friction coefficient. Oxygen can increase adhesive bonding of a metal film (platinum) to a substrate.

  19. Polymer surfaces, interfaces and thin films

    Energy Technology Data Exchange (ETDEWEB)

    Stamm, M. [Max-Planck-Institut fuer Polymerforschung, Mainz (Germany)

    1996-11-01

    Neutron reflectometry can be used in various ways to investigate surfaces, interfaces and thin films of polymers. Its potential comes mostly from the possibilities offered by selective deuteration, where a particular component can be made visible with respect to its activity at the interface. In addition the depth resolution is much better than with most other direct techniques, and details of the profiles may be resolved. Several examples will be discussed including the segment diffusion at the interface between two polymer films, the determination of the narrow interfaces between incompatible polymer blends and the development of order in thin diblock copolymer films. (author) 10 figs., 2 tabs., 38 refs.

  20. NLO properties of functionalized DNA thin films

    Energy Technology Data Exchange (ETDEWEB)

    Krupka, Oksana [University d' Angers, Laboratoire POMA CNRS UMR 6136, France, 2 Bd. Lavoisier, 49045 (France)], E-mail: okrupka@mail.ru; El-ghayoury, Abdelkrim [University d' Angers, UFR Sciences, Laboratoire CIMMA UMR CNRS 6200, 2 Bd. Lavoisier, 49045 (France); Rau, Ileana; Sahraoui, Bouchta [University d' Angers, Laboratoire POMA CNRS UMR 6136, France, 2 Bd. Lavoisier, 49045 (France); Grote, James G. [Air Force Research Laboratory Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, 3005 Hobson Way, Dayton, OH 45433-7707 (United States); Kajzar, Francois [University d' Angers, Laboratoire POMA CNRS UMR 6136, France, 2 Bd. Lavoisier, 49045 (France)

    2008-10-31

    In this paper we investigate the third-order nonlinear optical properties of spin deposited thin films of DNA-based complexes using the optical third harmonic generation (THG) technique at a fundamental wavelength of 1064 nm. We found that the third-order susceptibility, {chi}{sup (3)}(- 3{omega};{omega},{omega},{omega}), of DNA-based films was about one order of magnitude larger than that of our reference, a pure silica slab. In thin films doped with 5% of the chromophore disperse red 1 (DR1), a two order of magnitude larger value of {chi}{sup (3)}(- 3{omega};{omega},{omega},{omega}) was observed.

  1. Thin Ice Films at Mineral Surfaces.

    Science.gov (United States)

    Yeşilbaş, Merve; Boily, Jean-François

    2016-07-21

    Ice films formed at mineral surfaces are of widespread occurrence in nature and are involved in numerous atmospheric and terrestrial processes. In this study, we studied thin ice films at surfaces of 19 synthetic and natural mineral samples of varied structure and composition. These thin films were formed by sublimation of thicker hexagonal ice overlayers mostly produced by freezing wet pastes of mineral particles at -10 and -50 °C. Vibration spectroscopy revealed that thin ice films contained smaller populations of strongly hydrogen-bonded water molecules than in hexagonal ice and liquid water. Thin ice films at the surfaces of the majority of minerals considered in this work [i.e., metal (oxy)(hydr)oxides, phyllosilicates, silicates, volcanic ash, Arizona Test Dust] produced intense O-H stretching bands at ∼3400 cm(-1), attenuated bands at ∼3200 cm(-1), and liquid-water-like bending band at ∼1640 cm(-1) irrespective of structure and composition. Illite, a nonexpandable phyllosilicate, is the only mineral that stabilized a form of ice that was strongly resilient to sublimation in temperatures as low as -50 °C. As mineral-bound thin ice films are the substrates upon which ice grows from water vapor or aqueous solutions, this study provides new constraints from which their natural occurrences can be understood.

  2. Carrier lifetimes in thin-film photovoltaics

    Science.gov (United States)

    Baek, Dohyun

    2015-09-01

    The carrier lifetimes in thin-film solar cells are reviewed and discussed. Shockley-Read-Hall recombination is dominant at low carrier density, Auger recombination is dominant under a high injection condition and high carrier density, and surface recombination is dominant under any conditions. Because the surface photovoltage technique is insensitive to the surface condition, it is useful for bulk lifetime measurements. The photoconductance decay technique measures the effective recombination lifetime. The time-resolved photoluminescence technique is very useful for measuring thin-film semiconductor or solar-cell materials lifetime, because the sample is thin, other techniques are not suitable for measuring the lifetime. Many papers have provided time-resolved photoluminescence (TRPL) lifetimes for copper-indium-gallium-selenide (CIGS) and CdTe thin-film solar cell. The TRPL lifetime strongly depends on open-circuit voltage and conversion efficiency; however, the TRPL life time is insensitive to the short-circuit current.

  3. Study of the Thin Film Pulse Transformer

    Institute of Scientific and Technical Information of China (English)

    LIU Bao-yuan; SHI Yu; WEN Qi-ye

    2005-01-01

    A new thin film pulse transformer for using in ISND and model systems is fabricated by a mask sputtering process. This novel pulse transformer consists of four I-shaped CoZrRe nanometer crystal magnetic-film cores and a Cu thin film coil, deposited on the micro-crystal glass substrate directly. The thickness of thin film core is between 1 and 3 μm, and the area is between 4mm×6 mm and 12mm×6 mm. The coils provide a relatively high induce of 0.8 μm and can be well operated in a frequency range of 0.001~20 MHz.

  4. Magnetoelectric thin film composites with interdigital electrodes

    Science.gov (United States)

    Piorra, A.; Jahns, R.; Teliban, I.; Gugat, J. L.; Gerken, M.; Knöchel, R.; Quandt, E.

    2013-07-01

    Magnetoelectric (ME) thin film composites on silicon cantilevers are fabricated using Pb(Zr0.52Ti0.45)O3 (PZT) films with interdigital transducer electrodes on the top side and FeCoSiB amorphous magnetostrictive thin films on the backside. These composites without any direct interface between the piezoelectric and magnetostrictive phase are superior to conventional plate capacitor-type thin film ME composites. A limit of detection of 2.6 pT/Hz1/2 at the mechanical resonance is determined which corresponds to an improvement of a factor of approximately 2.8 compared to the best plate type sensor using AlN as the piezoelectric phase and even a factor of approximately 4 for a PZT plate capacitor.

  5. Tungsten-doped thin film materials

    Science.gov (United States)

    Xiang, Xiao-Dong; Chang, Hauyee; Gao, Chen; Takeuchi, Ichiro; Schultz, Peter G.

    2003-12-09

    A dielectric thin film material for high frequency use, including use as a capacitor, and having a low dielectric loss factor is provided, the film comprising a composition of tungsten-doped barium strontium titanate of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3, where X is between about 0.5 and about 1.0. Also provided is a method for making a dielectric thin film of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3 and doped with W, where X is between about 0.5 and about 1.0, a substrate is provided, TiO.sub.2, the W dopant, Ba, and optionally Sr are deposited on the substrate, and the substrate containing TiO.sub.2, the W dopant, Ba, and optionally Sr is heated to form a low loss dielectric thin film.

  6. MOF thin films: existing and future applications.

    Science.gov (United States)

    Shekhah, O; Liu, J; Fischer, R A; Wöll, Ch

    2011-02-01

    The applications and potentials of thin film coatings of metal-organic frameworks (MOFs) supported on various substrates are discussed in this critical review. Because the demand for fabricating such porous coatings is rather obvious, in the past years several synthesis schemes have been developed for the preparation of thin porous MOF films. Interestingly, although this is an emerging field seeing a rapid development a number of different applications on MOF films were either already demonstrated or have been proposed. This review focuses on the fabrication of continuous, thin porous films, either supported on solid substrates or as free-standing membranes. The availability of such two-dimensional types of porous coatings opened the door for a number of new perspectives for functionalizing surfaces. Also for the porous materials themselves, the availability of a solid support to which the MOF-films are rigidly (in a mechanical sense) anchored provides access to applications not available for the typical MOF powders with particle sizes of a few μm. We will also address some of the potential and applications of thin films in different fields like luminescence, QCM-based sensors, optoelectronics, gas separation and catalysis. A separate chapter has been devoted to the delamination of MOF thin films and discusses the potential to use them as free-standing membranes or as nano-containers. The review also demonstrates the possibility of using MOF thin films as model systems for detailed studies on MOF-related phenomena, e.g. adsorption and diffusion of small molecules into MOFs as well as the formation mechanism of MOFs (101 references).

  7. Cosolvent approach for solution-processable electronic thin films.

    Science.gov (United States)

    Lin, Zhaoyang; He, Qiyuan; Yin, Anxiang; Xu, Yuxi; Wang, Chen; Ding, Mengning; Cheng, Hung-Chieh; Papandrea, Benjamin; Huang, Yu; Duan, Xiangfeng

    2015-04-28

    Low-temperature solution-processable electronic materials are of considerable interest for large-area, low-cost electronics, thermoelectrics, and photovoltaics. Using a soluble precursor and suitable solvent to formulate a semiconductor ink is essential for large-area fabrication of semiconductor thin films. To date, it has been shown that hydrazine can be used as a versatile solvent to process a wide range of inorganic semiconductors. However, hydrazine is highly toxic and not suitable for large-scale manufacturing. Here we report a binary mixed solvent of amine and thiol for effective dispersion and dissolution of a large number of inorganic semiconductors including Cu2S, Cu2Se, In2S3, In2Se3, CdS, SnSe, and others. The mixed solvent is significantly less toxic and safer than hydrazine, while at the same time offering the comparable capability of formulating diverse semiconductor ink with a concentration as high as >200 mg/mL. We further show that such ink material can be readily processed into high-performance semiconducting thin films (Cu2S and Cu2Se) with the highest room-temperature conductivity among solution-based materials. Furthermore, we show that complex semiconductor alloys with tunable band gaps, such as CuIn(S(x)Se(1-x))2 (0 ≤ x ≤ 1), can also be readily prepared by simply mixing Cu2S, Cu2Se, In2S3, and In2Se3 ink solutions in a proper ratio. Our study outlines a general strategy for the formulation of inorganic semiconductor ink for low-temperature processing of large-area electronic thin films on diverse substrates and can greatly impact diverse areas including flexible electronics, thermoelectrics, and photovoltaics.

  8. Energy band alignment in chalcogenide thin film solar cells from photoelectron spectroscopy.

    Science.gov (United States)

    Klein, Andreas

    2015-04-10

    Energy band alignment plays an important role in thin film solar cells. This article presents an overview of the energy band alignment in chalcogenide thin film solar cells with a particular focus on the commercially available material systems CdTe and Cu(In,Ga)Se2. Experimental results from two decades of photoelectron spectroscopy experiments are compared with density functional theory calculations taken from literature. It is found that the experimentally determined energy band alignment is in good agreement with theoretical predictions for many interfaces. These alignments, in particular the theoretically predicted alignments, can therefore be considered as the intrinsic or natural alignments for a given material combination. The good agreement between experiment and theory enables a detailed discussion of the interfacial composition of Cu(In,Ga)Se2/CdS interfaces in terms of the contribution of ordered vacancy compounds to the alignment of the energy bands. It is furthermore shown that the most important interfaces in chalcogenide thin film solar cells, those between Cu(In,Ga)Se2 and CdS and between CdS and CdTe are quite insensitive to the processing of the layers. There are plenty of examples where a significant deviation between experimentally-determined band alignment and theoretical predictions are evident. In such cases a variation of band alignment of sometimes more than 1 eV depending on interface preparation can be obtained. This variation can lead to a significant deterioration of device properties. It is suggested that these modifications are related to the presence of high defect concentrations in the materials forming the contact. The particular defect chemistry of chalcogenide semiconductors, which is related to the ionicity of the chemical bond in these materials and which can be beneficial for material and device properties, can therefore cause significant device limitations, as e.g. in the case of the CuInS2 thin film solar cells or for new

  9. Effect of thermal annealing on structural and optical properties of In2S3 thin films

    Science.gov (United States)

    Choudhary, Sonu

    2015-08-01

    There is a highly need of an alternate of toxic materials CdS for solar cell applications and indium sulfide is found the most suitable candidate to replace CdS due to its non-toxic and environmental friendly nature. In this paper, the effect of thermal annealing on the structural and optical properties of indium sulfide (In2S3) thin films is undertaken. The indium sulfide thin films of 121 nm were deposited on glass substrates employing thermal evaporation method. The films were subjected to the X-ray diffractometer and UV-Vis spectrophotometer respectively for structural and optical analysis. The XRD pattern show that the as-deposited thin film was amorphous in nature and crystallinity is found to be varied with annealing temperature. The optical analysis reveals that the optical band gap is varied with annealing. The optical parameters like absorption coefficient, extinction coefficient and refractive index were calculated. The results are in good agreement with available literature.

  10. Sprayed lanthanum doped zinc oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Bouznit, Y., E-mail: Bouznit80@gmail.com [Laboratory of Materials Study, Jijel University, Jijel 18000 (Algeria); Beggah, Y. [Laboratory of Materials Study, Jijel University, Jijel 18000 (Algeria); Ynineb, F. [Laboratory of Thin Films and Interface, University Mentouri, Constantine 25000 (Algeria)

    2012-01-15

    Lanthanum doped zinc oxide thin films were deposited on soda-lime glass substrates using a pneumatic spray pyrolysis technique. The films were prepared using different lanthanum concentrations at optimum deposition parameters. We studied the variations in structural, morphological and optical properties of the samples due to the change of doping concentration in precursor solutions. X-ray diffraction (XRD) patterns show that pure and La-doped ZnO thin films are highly textured along c-axis perpendicular to the surface of the substrate. Scanning electron micrographs show that surface morphology of ZnO films undergoes a significant change according to lanthanum doping. All films exhibit a transmittance higher than 80% in the visible region.

  11. Sprayed lanthanum doped zinc oxide thin films

    Science.gov (United States)

    Bouznit, Y.; Beggah, Y.; Ynineb, F.

    2012-01-01

    Lanthanum doped zinc oxide thin films were deposited on soda-lime glass substrates using a pneumatic spray pyrolysis technique. The films were prepared using different lanthanum concentrations at optimum deposition parameters. We studied the variations in structural, morphological and optical properties of the samples due to the change of doping concentration in precursor solutions. X-ray diffraction (XRD) patterns show that pure and La-doped ZnO thin films are highly textured along c-axis perpendicular to the surface of the substrate. Scanning electron micrographs show that surface morphology of ZnO films undergoes a significant change according to lanthanum doping. All films exhibit a transmittance higher than 80% in the visible region.

  12. Thermal conductivity of nanoscale thin nickel films

    Institute of Scientific and Technical Information of China (English)

    YUAN Shiping; JIANG Peixue

    2005-01-01

    The inhomogeneous non-equilibrium molecular dynamics (NEMD) scheme is applied to model phonon heat conduction in thin nickel films. The electronic contribution to the thermal conductivity of the film is deduced from the electrical conductivity through the use of the Wiedemann-Franz law. At the average temperature of T = 300 K, which is lower than the Debye temperature ()D = 450 K,the results show that in a film thickness range of about 1-11 nm, the calculated cross-plane thermal conductivity decreases almost linearly with the decreasing film thickness, exhibiting a remarkable reduction compared with the bulk value. The electrical and thermal conductivities are anisotropic in thin nickel films for the thickness under about 10 nm. The phonon mean free path is estimated and the size effect on the thermal conductivity is attributed to the reduction of the phonon mean free path according to the kinetic theory.

  13. Magnetowetting of Ferrofluidic Thin Liquid Films

    Science.gov (United States)

    Tenneti, Srinivas; Subramanian, Sri Ganesh; Chakraborty, Monojit; Soni, Gaurav; Dasgupta, Sunando

    2017-03-01

    An extended meniscus of a ferrofluid solution on a silicon surface is subjected to axisymmetric, non-uniform magnetic field resulting in significant forward movement of the thin liquid film. Image analyzing interferometry is used for accurate measurement of the film thickness profile, which in turn, is used to determine the instantaneous slope and the curvature of the moving film. The recorded video, depicting the motion of the film in the Lagrangian frame of reference, is analyzed frame by frame, eliciting accurate information about the velocity and acceleration of the film at any instant of time. The application of the magnetic field has resulted in unique changes of the film profile in terms of significant non-uniform increase in the local film curvature. This was further analyzed by developing a model, taking into account the effect of changes in the magnetic and shape-dependent interfacial force fields.

  14. Processing and modeling issues for thin-film solar cell devices. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Birkmire, R.W.; Phillips, J.E. [Univ. of Delaware, Newark, DE (United States). Institute of Energy Conversion

    1997-11-01

    During the third phase of the subcontract, IEC researchers have continued to provide the thin film PV community with greater depth of understanding and insight into a wide variety of issues including: the deposition and characterization of CuIn{sub 1-x}Ga{sub x}Se{sub 2}, a-Si, CdTe, CdS, and TCO thin films; the relationships between film and device properties; and the processing and analysis of thin film PV devices. This has been achieved through the systematic investigation of all aspects of film and device production and through the analysis and quantification of the reaction chemistries involved in thin film deposition. This methodology has led to controlled fabrications of 15% efficient CuIn{sub 1-x}Ga{sub x}Se{sub 2} solar cells over a wide range of Ga compositions, improved process control of the fabrication of 10% efficient a-Si solar cells, and reliable and generally applicable procedures for both contacting and doping films. Additional accomplishments are listed below.

  15. Optical Constants of Cadmium Telluride Thin Film

    Science.gov (United States)

    Nithyakalyani, P.; Pandiaraman, M.; Pannir, P.; Sanjeeviraja, C.; Soundararajan, N.

    2008-04-01

    Cadmium Telluride (CdTe) is II-VI direct band gap semiconductor compound with potential application in Solar Energy conversion process. CdTe thin film of thickness 220 mn was prepared by thermal evaporation technique at a high vacuum better than 10-5 m.bar on well cleaned glass substrates of dimensions (l cm×3 cm). The transmittance spectrum and the reflectance spectrum of the prepared CdTc thin film was recorded using UV-Vis Spectrophotometer in the wavelength range between 300 nm and 900 nm. These spectral data were analyzed and the optical band and optical constants of CdTe Thin film have been determined by adopting suitable relations. The optical band gap of CdTe thin film is found to be 1.56 eV and this value is also agreeing with the published works of CdTe thin film prepared by various techniques. The absorption coefficient (α) has been higher than 106 cm-1. The Refractive index (n) and the Extinction Coefficient (k) are found to be varying from 3.0 to 4.0 and 0.1 Cm-1 to 0.5 Cm-1 respectively by varying the energy from l.0 eV to 4.0 eV. These results are also compared with the literature.

  16. Pulsed laser deposition of ferroelectric thin films

    Science.gov (United States)

    Sengupta, Somnath; McKnight, Steven H.; Sengupta, Louise C.

    1997-05-01

    It has been shown that in bulk ceramic form, the barium to strontium ratio in barium strontium titanium oxide (Ba1- xSrxTiO3, BSTO) affects the voltage tunability and electronic dissipation factor in an inverse fashion; increasing the strontium content reduces the dissipation factor at the expense of lower voltage tunability. However, the oxide composites of BSTO developed at the Army Research Laboratory still maintain low electronic loss factors for all compositions examined. The intent of this study is to determine whether such effects can be observed in the thin film form of the oxide composites. The pulsed laser deposition (PLD) method has been used to deposit the thin films. The different compositions of the compound (with 1 wt% of the oxide additive) chosen were: Ba0.3Sr0.7TiO3, Ba0.4Sr0.6TiO3, Ba0.5Sr0.5TiO3, Ba0.6Sr0.4TiO3, and Ba0.7Sr0.3TiO3. The electronic properties investigated in this study were the dielectric constant and the voltage tunability. The morphology of the thin films were examined using the atomic force microscopy. Fourier transform Raman spectroscopy was also utilized for optical characterization of the thin films. The electronic and optical properties of the thin films and the bulk ceramics were compared. The results of these investigations are discussed.

  17. Photoluminescence Study of Copper Selenide Thin Films

    Science.gov (United States)

    Urmila, K. S.; Asokan, T. Namitha; Pradeep, B.

    2011-10-01

    Thin films of Copper Selenide of composition of composition Cu7Se4 with thickness 350 nm are deposited on glass substrate at a temperature of 498 K±5 K and pressure of 10-5 mbar using reactive evaporation, a variant of Gunther's three temperature method with high purity Copper (99.999%) and Selenium (99.99%) as the elemental starting material. The deposited film is characterized structurally using X-ray Diffraction. The structural parameters such as lattice constant, particle size, dislocation density; number of crystallites per unit area and strain in the film are evaluated. Photoluminescence of the film is analyzed at room temperature using Fluoro Max-3 Spectrofluorometer.

  18. Organic thin films and surfaces directions for the nineties

    CERN Document Server

    Ulman, Abraham

    1995-01-01

    Physics of Thin Films has been one of the longest running continuing series in thin film science consisting of 20 volumes since 1963. The series contains some of the highest quality studies of the properties ofvarious thin films materials and systems.In order to be able to reflect the development of todays science and to cover all modern aspects of thin films, the series, beginning with Volume 20, will move beyond the basic physics of thin films. It will address the most important aspects of both inorganic and organic thin films, in both their theoretical as well as technological aspects. Ther

  19. Thin film calorimetry of polymer films

    Science.gov (United States)

    Zhang, Wenhua; Rafailovich, Miriam; Sokolov, Jonathan; Salamon, William

    2000-03-01

    Polystryene and polymethylmethacrylate films for thicknesses ranging from 50nm to 500nm using a direct calorimetric technique (Lai et al, App. Phys. Lett. 67, p9(1995)). Samples were deposited on Ni foils(2-2.5um) and placed in a high vacuum oven. Calibrated heat pulses were input to the polymer films by current pulses to the Ni substrate and temperature changes were determined from the change in Ni resistance. Pulses producing temperature jumps of 3-8K were used and signal averaging over pulses reduced noise levels enough to identify glass transitions down to 50nm. Molecular weight dependence of thick films Tg was used as a temperature calibration.

  20. Thin Film Solar Cells: Organic, Inorganic and Hybrid

    Science.gov (United States)

    Dankovich, John

    2004-01-01

    Thin film solar cells are an important developing resource for hundreds of applications including space travel. In addition to being more cost effective than traditional single crystal silicon cells, thin film multi-crystaline cells are plastic and light weight. The plasticity of the cells allows for whole solar panels to be rolled out from reams. Organic layers are being investigated in order to increase the efficiency of the cells to create an organic / inorganic hybrid cell. The main focus of the group is a thin film inorganic cell made with the absorber CuInS2. So far the group has been successful in creating the layer from a single-source precursor. They also use a unique method of film deposition called chemical vapor deposition for this. The general makeup of the cell is a molybdenum back contact with the CuInS2 layer, then CdS, ZnO and aluminum top contacts. While working cells have been produced, the efficiency so far has been low. Along with quantum dot fabrication the side project of this that is currently being studied is adding a polymer layer to increase efficiency. The polymer that we are using is P3OT (Poly(3-octylthiopene-2,5-diyll), retroregular). Before (and if) it is added to the cell, it must be understood in itself. To do this simple diodes are being constructed to begin to look at its behavior. The P3OT is spin coated onto indium tin oxide and silver or aluminum contacts are added. This method is being studied in order to find the optimal thickness of the layer as well as other important considerations that may later affect the composition of the finished solar cell. Because the sun is the most abundant renewable, energy source that we have, it is important to learn how to harness that energy and begin to move away from our other depleted non-renewable energy sources. While traditional silicon cells currently create electricity at relatively high efficiencies, they have drawbacks such as weight and rigidness that make them unattractive

  1. Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Chu, T.L. (University of South Florida, Tampa, FL (United States))

    1992-04-01

    This report describes research to demonstrate (1) thin film cadmium telluride solar cells with a quantum efficiency of 75% or higher at 0. 44 {mu}m and a photovoltaic efficiency of 11.5% or greater, and (2) thin film zinc telluride and mercury zinc telluride solar cells with a transparency to sub-band-gap radiation of 65% and a photovoltaic conversion efficiency of 5% and 8%, respectively. Work was directed at (1) depositing transparent conducting semiconductor films by solution growth and metal-organic chemical vapor deposition (MOCVD) technique, (2) depositing CdTe films by close-spaced sublimation (CSS) and MOCVD techniques, (3) preparing and evaluating thin film CdTe solar cells, and (4) preparing and characterizing thin film ZnTe, CD{sub 1-x}Zn{sub 1-x}Te, and Hg{sub 1-x}Zn{sub x}Te solar cells. The deposition of CdS films from aqueous solutions was investigated in detail, and their crystallographic, optical, and electrical properties were characterized. CdTe films were deposited from DMCd and DIPTe at 400{degrees}C using TEGa and AsH{sub 3} as dopants. CdTe films deposited by CSS had significantly better microstructures than those deposited by MOCVD. Deep energy states in CdTe films deposited by CSS and MOCVD were investigated. Thin films of ZnTe, Cd{sub 1- x}Zn{sub x}Te, and Hg{sub 1-x}Zn{sub x}Te were deposited by MOCVD, and their crystallographic, optical, and electrical properties were characterized. 67 refs.

  2. Thin film cadmium telluride, zinc telluride, and mercury zinc telluride solar cells

    Science.gov (United States)

    Chu, T. L.

    1992-04-01

    This report describes research to demonstrate (1) thin film cadmium telluride solar cells with a quantum efficiency of 75 percent or higher at 0.44 microns and a photovoltaic efficiency of 11.5 percent or greater, and (2) thin film zinc telluride and mercury zinc telluride solar cells with a transparency to sub-band-gap radiation of 65 percent and a photovoltaic conversion efficiency of 5 percent and 8 percent, respectively. Work was directed at (1) depositing transparent conducting semiconductor films by solution growth and metal-organic chemical vapor deposition (MOCVD) technique, (2) depositing CdTe films by close-spaced sublimation (CSS) and MOCVD techniques, (3) preparing and evaluating thin film CdTe solar cells, and (4) preparing and characterizing thin film ZnTe, CD(1-x)Zn(1-x)Te, and Hg(1-x)Zn(x)Te solar cells. The deposition of CdS films from aqueous solutions was investigated in detail, and their crystallographic, optical, and electrical properties were characterized. CdTe films were deposited from DMCd and DIPTe at 400 C using TEGa and AsH3 as dopants. CdTe films deposited by CSS had significantly better microstructures than those deposited by MOCVD. Deep energy states in CdTe films deposited by CSS and MOCVD were investigated. Thin films of ZnTe, Cd(1-x)Zn(x)Te, and Hg(1-x)Zn(x)Te were deposited by MOCVD, and their crystallographic, optical, and electrical properties were characterized.

  3. Nanostructured and wide bandgap CdS:O thin films grown by reactive RF sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M. A.; Rahman, K. S.; Haque, F.; Rashid, M. J.; Akhtaruzzaman, M.; Sopian, K.; Sulaiman, Y. [Solar Energy Research Institute (SERI), National University of Malaysia, 43600 Bangi (Malaysia); Amin, N. [Solar Energy Research Institute (SERI), National University of Malaysia, 43600 Bangi (Malaysia); Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, National University of Malaysia, 43600 Bangi (Malaysia)

    2015-05-15

    In this study, CdS:O thin films were prepared from a 99.999% CdS target by reactive sputtering in a Ar:O{sub 2} (99:1) ambient with different RF power at room temperature. The deposited films were studied by means of XRD, SEM, EDX, Hall Effect and UV-Vis spectrometry. The incorporations of O{sub 2} into the films were observed to increase with the decrease of deposition power. The cryatallinity of the films were reduced, whereas the band gaps of the films were increased by the increase of O{sub 2} content on the films. The films were found in nano-structured grains with a compact surface. It has been seen that the highest carrier density is observed in the film with O{sub 2} at.% 21.10, while the values decreased with the further increase or decrease of O{sub 2} content on the films; indicating that specific amount of donor like O{sub 2} atoms substitute to the S atoms can improve the carrier density of the CdS:O thin film.

  4. Vibration welding system with thin film sensor

    Science.gov (United States)

    Cai, Wayne W; Abell, Jeffrey A; Li, Xiaochun; Choi, Hongseok; Zhao, Jingzhou

    2014-03-18

    A vibration welding system includes an anvil, a welding horn, a thin film sensor, and a process controller. The anvil and horn include working surfaces that contact a work piece during the welding process. The sensor measures a control value at the working surface. The measured control value is transmitted to the controller, which controls the system in part using the measured control value. The thin film sensor may include a plurality of thermopiles and thermocouples which collectively measure temperature and heat flux at the working surface. A method includes providing a welder device with a slot adjacent to a working surface of the welder device, inserting the thin film sensor into the slot, and using the sensor to measure a control value at the working surface. A process controller then controls the vibration welding system in part using the measured control value.

  5. Nanostructured thin films and coatings mechanical properties

    CERN Document Server

    2010-01-01

    The first volume in "The Handbook of Nanostructured Thin Films and Coatings" set, this book concentrates on the mechanical properties, such as hardness, toughness, and adhesion, of thin films and coatings. It discusses processing, properties, and performance and provides a detailed analysis of theories and size effects. The book presents the fundamentals of hard and superhard nanocomposites and heterostructures, assesses fracture toughness and interfacial adhesion strength of thin films and hard nanocomposite coatings, and covers the processing and mechanical properties of hybrid sol-gel-derived nanocomposite coatings. It also uses nanomechanics to optimize coatings for cutting tools and explores various other coatings, such as diamond, metal-containing amorphous carbon nanostructured, and transition metal nitride-based nanolayered multilayer coatings.

  6. Domains in Ferroic Crystals and Thin Films

    CERN Document Server

    Tagantsev, Alexander K; Fousek, Jan

    2010-01-01

    Domains in Ferroic Crystals and Thin Films presents experimental findings and theoretical understanding of ferroic (non-magnetic) domains developed during the past 60 years. It addresses the situation by looking specifically at bulk crystals and thin films, with a particular focus on recently-developed microelectronic applications and methods for observation of domains with techniques such as scanning force microscopy, polarized light microscopy, scanning optical microscopy, electron microscopy, and surface decorating techniques. Domains in Ferroic Crystals and Thin Films covers a large area of material properties and effects connected with static and dynamic properties of domains, which are extremely relevant to materials referred to as ferroics. In most solid state physics books, one large group of ferroics is customarily covered: those in which magnetic properties play a dominant role. Numerous books are specifically devoted to magnetic ferroics and cover a wide spectrum of magnetic domain phenomena. In co...

  7. Thin Film Photovoltaic/Thermal Solar Panels

    Institute of Scientific and Technical Information of China (English)

    David JOHNSTON

    2008-01-01

    A solar panel is described.in which thin films of semiconductor are deposited onto a metal substrate.The semiconductor-metal combination forms a thin film photovoltaic cell,and also acts as a reflector,absorber tandem, which acts as a solar selective surface,thus enhancing the solar thermal performance of the collector plate.The use of thin films reduces the distance heat is required to flow from the absorbing surface to the metal plate and heat exchange conduits.Computer modelling demonstrated that,by suitable choice of materials,photovohaic efficiency call be maintained,with thermal performance slishtly reduced,compared to that for thermal-only panels.By grading the absorber layer-to reduce the band gap in the lower region-the thermal performance can be improved,approaching that for a thermal-only solar panel.

  8. Multifractal characteristics of titanium nitride thin films

    Directory of Open Access Journals (Sweden)

    Ţălu Ştefan

    2015-09-01

    Full Text Available The study presents a multi-scale microstructural characterization of three-dimensional (3-D micro-textured surface of titanium nitride (TiN thin films prepared by reactive DC magnetron sputtering in correlation with substrate temperature variation. Topographical characterization of the surfaces, obtained by atomic force microscopy (AFM analysis, was realized by an innovative multifractal method which may be applied for AFM data. The surface micromorphology demonstrates that the multifractal geometry of TiN thin films can be characterized at nanometer scale by the generalized dimensions Dq and the singularity spectrum f(α. Furthermore, to improve the 3-D surface characterization according with ISO 25178-2:2012, the most relevant 3-D surface roughness parameters were calculated. To quantify the 3-D nanostructure surface of TiN thin films a multifractal approach was developed and validated, which can be used for the characterization of topographical changes due to the substrate temperature variation.

  9. Solid surfaces, interfaces and thin films

    CERN Document Server

    Lüth, Hans

    2015-01-01

    This book emphasises both experimental and theoretical aspects of surface, interface and thin-film physics. As in previous editions the preparation of surfaces and thin films, their atomic and morphological structure, their vibronic and electronic properties as well as fundamentals of adsorption are treated. Because of their importance in modern information technology and nanostructure research, particular emphasis is paid to electronic surface and interface states, semiconductor space charge layers and heterostructures. A special chapter of the book is devoted to collective phenomena at interfaces and in thin films such as superconductivity and magnetism. The latter topic includes the meanwhile important issues giant magnetoresistance and spin-transfer torque mechanism, both effects being of high interest in information technology. In this new edition, for the first time, the effect of spin-orbit coupling on surface states is treated. In this context the class of the recently detected topological insulators,...

  10. Solid Surfaces, Interfaces and Thin Films

    CERN Document Server

    Lüth, Hans

    2010-01-01

    This book emphasises both experimental and theoretical aspects of surface, interface and thin film physics. As in previous editions the preparation of surfaces and thin films, their atomic and morphological, their vibronic and electronic properties as well as fundamentals of adsorption are treated. Because of their importance in modern information technology and nanostructure physics particular emphasis is paid to electronic surface and interface states, semiconductor space charge layers and heterostructures as well as to superconductor/semiconductor interfaces and magnetic thin films. The latter topic was significantly extended in this new edition by more details about the giant magnetoresistance and a section about the spin-transfer torque mechanism including one new problem as exercise. Two new panels about Kerr-effect and spin-polarized scanning tunnelling microscopy were added, too. Furthermore, the meanwhile important group III-nitride surfaces and high-k oxide/semiconductor interfaces are shortly discu...

  11. Magnetically actuated peel test for thin films

    Energy Technology Data Exchange (ETDEWEB)

    Ostrowicki, G.T.; Sitaraman, S.K., E-mail: suresh.sitaraman@me.gatech.edu

    2012-03-30

    Delamination along thin film interfaces is a prevalent failure mechanism in microelectronic, photonic, microelectromechanical systems, and other engineering applications. Current interfacial fracture test techniques specific to thin films are limited by either sophisticated mechanical fixturing, physical contact near the crack tip, or complicated stress fields. Moreover, these techniques are generally not suitable for investigating fatigue crack propagation under cyclical loading. Thus, a fixtureless and noncontact experimental test technique with potential for fatigue loading is proposed and implemented to study interfacial fracture toughness for thin film systems. The proposed test incorporates permanent magnets surface mounted onto micro-fabricated released thin film structures. An applied external magnetic field induces noncontact loading to initiate delamination along the interface between the thin film and underlying substrate. Characterization of the critical peel force and peel angle is accomplished through in situ deflection measurements, from which the fracture toughness can be inferred. The test method was used to obtain interfacial fracture strength of 0.8-1.9 J/m{sup 2} for 1.5-1.7 {mu}m electroplated copper on natively oxidized silicon substrates. - Highlights: Black-Right-Pointing-Pointer Non-contact magnetic actuation test for interfacial fracture characterization. Black-Right-Pointing-Pointer Applied load is determined through voltage applied to the driving electromagnet. Black-Right-Pointing-Pointer Displacement and delamination propagation is measured using an optical profiler. Black-Right-Pointing-Pointer Critical peel force and peel angle is measured for electroplated Cu thin-film on Si. Black-Right-Pointing-Pointer The measured interfacial fracture energy of Cu/Si interface is 0.8-1.9 J/m{sup 2}.

  12. Capillary instabilities in thin films. I. Energetics

    Energy Technology Data Exchange (ETDEWEB)

    Srolovitz, D.J.; Safran, S.A.

    1986-07-01

    A stability theory is presented which describes the conditions under which thin films rupture. It is found that holes in the film will either grow or shrink, depending on whether their initial radius is larger or smaller than a critical value. If the holes grow large enough, they impinge to form islands; the size of which are determined by the surface energies. The formation of grooves where the grain boundary meets the free surface is a potential source of holes which can lead to film rupture. Equilibrium grain boundary groove depths are calculated for finite grain sizes. Comparison of groove depth and film thickness yields microstructural conditions for film rupture. In addition, pits which form at grain boundary vertices, where three grains meet, are another source of film instability.

  13. Tailoring electronic structure of polyazomethines thin films

    Directory of Open Access Journals (Sweden)

    J. Weszka

    2010-09-01

    Full Text Available Purpose: The aim of this work is to show how electronic properties of polyazomethine thin films deposited by chemical vapor deposition method (CVD can be tailored by manipulating technological parameters of pristine films preparation as well as modifying them while the as-prepared films put into iodine atmosphere.Design/methodology/approach: The recent achievements in the field of designing and preparation methods to be used while preparing polymer photovoltaic solar cells or optoelectronic devices.Findings: The method used allow for pure pristine polymer thin films to be prtepared without any unintentional doping taking place during prepoaration methods. This is a method based on polycondensation process, where polymer chain developing is running directly due to chemical reaction between molecules of bifunctional monomers. The method applied to prepare thin films of polyazomethines takes advantage of monomer transporting by mreans of neutral transport agent as pure argon is.Research limitations/implications: The main disadvantage of alternately conjugated polymers seems to be quite low mobility of charge carrier that is expected to be a consequence of their backbone being built up of sp2 hybridized carbon and nitrogen atoms. Varying technological conditions towards increasing reagents mass transport to the substrate is expected to give such polyazomethine thin films organization that phenylene rin stacking can result in special π electron systems rather than linear ones as it is the case.Originality/value: Our results supply with original possibilities which can be useful in ooking for good polymer materials for optoelectronic and photovoltaic applications. These results have been gained on polyazomethine thin films but their being isoelectronic counterpart to widely used poly p-phenylene vinylene may be very convenient to develop high efficiency polymer solar cells

  14. Magnetite thin films: A simulational approach

    Energy Technology Data Exchange (ETDEWEB)

    Mazo-Zuluaga, J. [Grupo de Estado Solido y Grupo de Instrumentacion Cientifica y Microelectronica, Universidad de Antioquia, A.A. 1226 Medellin (Colombia)]. E-mail: jomazo@fisica.udea.edu.co; Restrepo, J. [Grupo de Estado Solido y Grupo de Instrumentacion Cientifica y Microelectronica, Universidad de Antioquia, A.A. 1226 Medellin (Colombia)

    2006-10-01

    In the present work the study of the magnetic properties of magnetite thin films is addressed by means of the Monte Carlo method and the Ising model. We simulate LxLxd magnetite thin films (d being the film thickness and L the transversal linear dimension) with periodic boundary conditions along transversal directions and free boundary conditions along d direction. In our model, both the three-dimensional inverse spinel structure and the interactions scheme involving tetrahedral and octahedral sites have been considered in a realistic way. Results reveal a power-law dependence of the critical temperature with the film thickness accordingly by an exponent {nu}=0.81 and ruled out by finite-size scaling theory. Estimates for the critical exponents of the magnetization and the specific heat are finally presented and discussed.

  15. Thin Film Electrodes for Rare Event Detectors

    Science.gov (United States)

    Odgers, Kelly; Brown, Ethan; Lewis, Kim; Giordano, Mike; Freedberg, Jennifer

    2017-01-01

    In detectors for rare physics processes, such as neutrinoless double beta decay and dark matter, high sensitivity requires careful reduction of backgrounds due to radioimpurities in detector components. Ultra pure cylindrical resistors are being created through thin film depositions onto high purity substrates, such as quartz glass or sapphire. By using ultra clean materials and depositing very small quantities in the films, low radioactivity electrodes are produced. A new characterization process for cylindrical film resistors has been developed through analytic construction of an analogue to the Van Der Pauw technique commonly used for determining sheet resistance on a planar sample. This technique has been used to characterize high purity cylindrical resistors ranging from several ohms to several tera-ohms for applications in rare event detectors. The technique and results of cylindrical thin film resistor characterization will be presented.

  16. Environmentally stable sputter-deposited thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, D.J.

    1978-03-01

    Accelerated corrosion data are presented for the titanium-silver and chrome-gold thin film metallization systems presently used at Sandia Laboratories. Improvements in corrosion, hence reliability, as a result of interposing a thin intermediate layer of either platinum or palladium are shown. Potentiometric measurements showing the alteration of corrosion potential with the use of palladium for the titanium-silver system are also presented.

  17. Micro-sensor thin-film anemometer

    Science.gov (United States)

    Sheplak, Mark (Inventor); McGinley, Catherine B. (Inventor); Spina, Eric F. (Inventor); Stephens, Ralph M. (Inventor); Hopson, Jr., Purnell (Inventor); Cruz, Vincent B. (Inventor)

    1996-01-01

    A device for measuring turbulence in high-speed flows is provided which includes a micro-sensor thin-film probe. The probe is formed from a single crystal of aluminum oxide having a 14.degree. half-wedge shaped portion. The tip of the half-wedge is rounded and has a thin-film sensor attached along the stagnation line. The bottom surface of the half-wedge is tilted upward to relieve shock induced disturbances created by the curved tip of the half-wedge. The sensor is applied using a microphotolithography technique.

  18. Feasibility Study of Thin Film Thermocouple Piles

    Science.gov (United States)

    Sisk, R. C.

    2001-01-01

    Historically, thermopile detectors, generators, and refrigerators based on bulk materials have been used to measure temperature, generate power for spacecraft, and cool sensors for scientific investigations. New potential uses of small, low-power, thin film thermopiles are in the area of microelectromechanical systems since power requirements decrease as electrical and mechanical machines shrink in size. In this research activity, thin film thermopile devices are fabricated utilizing radio frequency sputter coating and photoresist lift-off techniques. Electrical characterizations are performed on two designs in order to investigate the feasibility of generating small amounts of power, utilizing any available waste heat as the energy source.

  19. Emittance Theory for Thin Film Selective Emitter

    Science.gov (United States)

    Chubb, Donald L.; Lowe, Roland A.; Good, Brian S.

    1994-01-01

    Thin films of high temperature garnet materials such as yttrium aluminum garnet (YAG) doped with rare earths are currently being investigated as selective emitters. This paper presents a radiative transfer analysis of the thin film emitter. From this analysis the emitter efficiency and power density are calculated. Results based on measured extinction coefficients for erbium-YAG and holmium-YAG are presented. These results indicated that emitter efficiencies of 50 percent and power densities of several watts/sq cm are attainable at moderate temperatures (less than 1750 K).

  20. Advances in thin-film solar cells

    CERN Document Server

    Dharmadasa, I M

    2012-01-01

    This book concentrates on the latest developments in our understanding of solid-state device physics. The material presented is mainly experimental and based on CdTe thin-film solar cells. It extends these new findings to CIGS thin-film solar cells and presents a new device design based on graded bandgap multilayer solar cells. This design has been experimentally tested using the well-researched GaAs/AlGaAs system and initial devices have shown impressive device parameters. These devices are capable of absorbing all radiation (UV, visible, and infra-red) within the solar spectrum and combines

  1. Electrical analysis of niobium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Graça, M.P.F., E-mail: mpfg@ua.pt [I3N & Physics Department, Aveiro University, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Saraiva, M. [I3N & Physics Department, Aveiro University, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Freire, F.N.A. [Mechanics Engineering Department, Ceará Federal University, Fortaleza (Brazil); Valente, M.A.; Costa, L.C. [I3N & Physics Department, Aveiro University, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal)

    2015-06-30

    In this work, a series of niobium oxide thin films was deposited by reactive magnetron sputtering. The total pressure of Ar/O{sub 2} was kept constant at 1 Pa, while the O{sub 2} partial pressure was varied up to 0.2 Pa. The depositions were performed in a grounded and non-intentionally heated substrate, resulting in as-deposited amorphous thin films. Raman spectroscopy confirmed the absence of crystallinity. Dielectric measurements as a function of frequency (40 Hz–110 MHz) and temperature (100 K–360 K) were performed. The dielectric constant for the film samples with thickness (d) lower than 650 nm decreases with the decrease of d. The same behaviour was observed for the conductivity. These results show a dependence of the dielectric permittivity with the thin film thickness. The electrical behaviour was also related with the oxygen partial pressure, whose increment promotes an increase of the Nb{sub 2}O{sub 5} stoichiometry units. - Highlights: • Niobium oxide thin films were deposited by reactive magnetron sputtering. • XRD showed a phase change with the increase of the P(O{sub 2}). • Raman showed that increasing P(O{sub 2}), Nb{sub 2}O{sub 5} amorphous increases. • Conductivity tends to decrease with the increase of P(O{sub 2}). • Dielectric analysis indicates the inexistence of preferential grow direction.

  2. Nanostructured p-type CZTS thin films prepared by a facile solution process for 3D p-n junction solar cells.

    Science.gov (United States)

    Park, Si-Nae; Sung, Shi-Joon; Sim, Jun-Hyoung; Yang, Kee-Jeong; Hwang, Dae-Kue; Kim, JunHo; Kim, Gee Yeong; Jo, William; Kim, Dae-Hwan; Kang, Jin-Kyu

    2015-07-07

    Nanoporous p-type semiconductor thin films prepared by a simple solution-based process with appropriate thermal treatment and three-dimensional (3D) p-n junction solar cells fabricated by depositing n-type semiconductor layers onto the nanoporous p-type thin films show considerable photovoltaic performance compared with conventional thin film p-n junction solar cells. Spin-coated p-type Cu2ZnSnS4 (CZTS) thin films prepared using metal chlorides and thiourea show unique nanoporous thin film morphology, which is composed of a cluster of CZTS nanograins of 50-500 nm, and the obvious 3D p-n junction structure is fabricated by the deposition of n-type CdS on the nanoporous CZTS thin films by chemical bath deposition. The photovoltaic properties of 3D p-n junction CZTS solar cells are predominantly affected by the scale of CZTS nanograins, which is easily controlled by the sulfurization temperature of CZTS precursor films. The scale of CZTS nanograins determines the minority carrier transportation within the 3D p-n junction between CZTS and CdS, which are closely related with the photocurrent of series resistance of 3D p-n junction solar cells. 3D p-n junction CZTS solar cells with nanograins below 100 nm show power conversion efficiency of 5.02%, which is comparable with conventional CZTS thin film solar cells.

  3. Perovskite Thin Films via Atomic Layer Deposition

    KAUST Repository

    Sutherland, Brandon R.

    2014-10-30

    © 2014 Wiley-VCH Verlag GmbH & Co. KGaA. (Graph Presented) A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3NH3PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm-1.

  4. Silver buffer layers for YBCO thin films

    Energy Technology Data Exchange (ETDEWEB)

    Azoulay, J. [Tel Aviv Univ. (Israel). Center for Technol. Education Holon

    1999-09-01

    A simple economical conventional vacuum system was used for evaporation of YBCO thin films on as-deposited unbuffered Ag layers on MgO substrates. The subsequent heat treatment was carried out in low oxygen partial pressure at a relative low temperature and short dwelling time. The films thus obtained were characterized for electrical properties using dc four probe electrical measurements and inspected for structural properties and chemical composition by scanning electron microscopy (SEM). (orig.)

  5. Perovskite thin films via atomic layer deposition.

    Science.gov (United States)

    Sutherland, Brandon R; Hoogland, Sjoerd; Adachi, Michael M; Kanjanaboos, Pongsakorn; Wong, Chris T O; McDowell, Jeffrey J; Xu, Jixian; Voznyy, Oleksandr; Ning, Zhijun; Houtepen, Arjan J; Sargent, Edward H

    2015-01-01

    A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3 NH3 PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm(-1) .

  6. Thin multilayer CdS/ZnS films grown by SILAR technique

    Science.gov (United States)

    Valkonen, Mika P.; Lindroos, Seppo; Kanniainen, Tapio; Leskelä, Markku; Tapper, Unto; Kauppinen, Esko

    1997-11-01

    Multilayer ZnS/CdS thin films were grown on glass, ITO-covered glass and (100)GaAs substrates by successive ionic layer adsorption and reaction (SILAR) technique at room temperature and ambient pressure. The layers in multilayer thin film structures were nominally 1-6 nm thick and the amount of layers varied so that the total thickness of 100-120 nm was achieved. The films were polycrystalline according to X-ray diffraction analysis and scanning electron microscopy. The interfaces between the separate cadmium sulfide (CdS) and zinc sulfide (ZnS) layers were not sharp, but contained thin Cd xZn 1- xS solid solution layers. Annealing enhanced the mixing of the different layers and after 50 h at 300°C no separate CdS and ZnS X-ray reflections could be detected. About 20 nm thick layers could be detected as separate fields by scanning electron microscopy.

  7. Workshop on thin film thermal conductivity measurements

    Science.gov (United States)

    Feldman, Albert; Balzaretti, Naira M.; Guenther, Arthur H.

    1998-04-01

    On a subject of considerable import to the laser-induced damage community, a two day workshop on the topic, Thin Film Thermal Conductivity Measurement was held as part of the 13th Symposium on Thermophysical Properties at the University of Colorado in Boulder CO, June 25 and 26, 1997. The Workshop consisted of 4 sessions of 17 oral presentations and two discussion sessions. Two related subjects of interest were covered; 1) methods and problems associated with measuring thermal conductivity ((kappa) ) of thin films, and 2) measuring and (kappa) of chemical vapor deposited (CVD) diamond. On the subject of thin film (kappa) measurement, several recently developed imaginative techniques were reviewed. However, several authors disagreed on how much (kappa) in a film differs from (kappa) in a bulk material of the same nominal composition. A subject of controversy was the definition of an interface. In the first discussion session, several questions were addressed, a principal one being, how do we know that the values of (kappa) we obtain are correct and is there a role for standards in thin film (kappa) measurement. The second discussion session was devoted to a round-robin interlaboratory comparison of (kappa) measurements on a set of CVD diamond specimens and several other specimens of lower thermal conductivity. Large interlaboratory differences obtained in an earlier round robin had been attributed to specimen inhomogeneity. Unfortunately, large differences were also observed in the second round robin even though the specimens were more homogenous. There was good consistency among the DC measurements, however, the AC measurements showed much greater variability. There was positive feedback from most of the attenders regarding the Workshop with nearly all respondents recommending another Workshop in three or fewer years. There was general recognition that thin film thermal conductivity measurements are important for predicting the resistance of optical coating

  8. YBCO thin films in ac and dc films

    CERN Document Server

    Shahzada, S

    2001-01-01

    We report studies on the dc magnetization of YBCO thin films in simultaneously applied dc and ac fields. The effect of the ac fields is to decrease the irreversible magnetization drastically leading to complete collapse of the hysteresis loops for relatively small ac fields (250e). The magnitude of the decrease depends on the component of the ac field parallel to the c-axis. The decrease is non-linear with ac amplitude and is explained in the framework of the critical state response of ultra thin films in perpendicular geometry. The ac fields increase the relaxation rapidly at short times while the long time response appears unaffected. (author)

  9. Study of iron mononitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Tayal, Akhil, E-mail: mgupta@csr.res.in; Gupta, Mukul, E-mail: mgupta@csr.res.in; Phase, D. M., E-mail: mgupta@csr.res.in; Reddy, V. R., E-mail: mgupta@csr.res.in; Gupta, Ajay, E-mail: mgupta@csr.res.in [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore,-452001 (India)

    2014-04-24

    In this work we have studied the crystal structural and local ordering of iron and nitrogen in iron mononitride thin films prepared using dc magnetron sputtering at sputtering power of 100W and 500W. The films were sputtered using pure nitrogen to enhance the reactivity of nitrogen with iron. The x-ray diffraction (XRD), conversion electron Mössbauer spectroscopy (CEMS) and soft x-ray absorption spectroscopy (SXAS) studies shows that the film crystallizes in ZnS-type crystal structure.

  10. Epitaxy of layered semiconductor thin films

    Science.gov (United States)

    Brahim Otsmane, L.; Emery, J. Y.; Jouanne, M.; Balkanski, M.

    1993-03-01

    Epilayers of InSe on InSe(00.1) and GaSe(00.1) have been grown by the molecular beam epitaxy (MBE) technique. Raman spectroscopy was used for a characterization of the structure and crystallinity in InSe/InSe(00.1) (homoepitaxy) and InSe/GaSe(00.1) (heteroepitaxy). The Raman spectra of the InSe thin films are identical to those of polytype γ-InSe. An activation of the E(LO) mode at 211 cm -1 is observed in these films here. Scanning electron microscopy (SEM) is also used to investigate surfaces of these films.

  11. Growth Induced Magnetic Anisotropy in Crystalline and Amorphous Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, Frances

    1998-10-03

    OAK B204 Growth Induced Magnetic Anisotropy in Crystalline and Amorphous Thin Films. The work in the past 6 months has involved three areas of magnetic thin films: (1) amorphous rare earth-transition metal alloys, (2) epitaxial Co-Pt and hTi-Pt alloy thin films, and (3) collaborative work on heat capacity measurements of magnetic thin films, including nanoparticles and CMR materials.

  12. Thin films for micro solid oxide fuel cells

    Science.gov (United States)

    Beckel, D.; Bieberle-Hütter, A.; Harvey, A.; Infortuna, A.; Muecke, U. P.; Prestat, M.; Rupp, J. L. M.; Gauckler, L. J.

    Thin film deposition as applied to micro solid oxide fuel cell (μSOFC) fabrication is an emerging and highly active field of research that is attracting greater attention. This paper reviews thin film (thickness ≤1 μm) deposition techniques and components relevant to SOFCs including current research on nanocrystalline thin film electrolyte and thin-film-based model electrodes. Calculations showing the geometric limits of μSOFCs and first results towards fabrication of μSOFCs are also discussed.

  13. Structure and optical properties of CdS:O thin films

    Energy Technology Data Exchange (ETDEWEB)

    Asaba, Ryo; Wakita, Kazuki [Department of Electrical, Electronics and Computer Engineering, Chiba Institute of Technology, Chiba (Japan); Kitano, Atsushi; Shim, YongGu [Department of Physics and Electronics, Osaka Prefecture University, Sakai, Osaka (Japan); Mamedov, Nazim; Bayramov, Ayaz; Huseynov, Emil; Hasanov, Ilham [Institute of Physics, Azerbaijan National Academy of Science, Baku (Azerbaijan)

    2013-08-15

    We have studied structure and optical properties of CdS:O thin films deposited on soda lime glass substrates by rf magnetron sputtering in the atmosphere of oxygen/argon gases. According to X-ray diffraction and confocal Raman scattering data, the films deposited under oxygen partial pressure below 3% show crystalline structure of CdS. On the other hand, X-ray diffraction, confocal Raman scattering, TEM (transmission electron microscopy) and XPS (X-ray photoelectron spectroscopy) data are indicative of amorphization, nano-crystallization, and inclusion of CdO{sub 2} in CdS:O thin films obtained under oxygen partial pressure of 5%. The last films have shown significantly increased transmittance in a spectral range above the energy gap of CdS. The origin of this transmittance is discussed by taking into account redistribution of electronic density-of-states in amorphous phase, quantum size effect and contribution of CdO{sub 2}. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Annealing effects on the chemical deposited CdS films and the electrical properties of CdS/CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Han, Junfeng [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Institute of Materials Science, Darmstadt University of Technology, Petersenstr. 23, 64287 Darmstadt (Germany); Liao, Cheng, E-mail: Cliao@pku.edu.cn [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Jiang, Tao [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Fu, Ganhua; Krishnakumar, V.; Spanheimer, C.; Haindl, G. [Institute of Materials Science, Darmstadt University of Technology, Petersenstr. 23, 64287 Darmstadt (Germany); Zhao, Kui [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Klein, A.; Jaegermann, W. [Institute of Materials Science, Darmstadt University of Technology, Petersenstr. 23, 64287 Darmstadt (Germany)

    2011-02-15

    Graphical abstract: From XPS core level spectras, compared with as-depositing CdS (sample A), the Fermi level is shifting closer to the conduction band after annealing treatment in the oxygen (sample B) while it is shifting closer to the valence band after annealing treatment in the argon-hydrogen (sample C). That might be the main reason of the different performance of the final devices. The open circuit voltage of the CdS/CdTe solar cell increases when the CBD CdS is annealed with oxygen, while the performance of the solar cell decreases when the CBD CdS is annealed with argon-hydrogen. Research highlights: {yields} Two different methods (oxidation and reduction) were used to anneal CdS films for CdTe solar cells. {yields} Electrical properties were analyzed by XPS (Fermi levels of CdS films). {yields} Annealing treatment in oxidation atmosphere could shift Fermi level of CdS film to higher position and consequently improve the CdS/CdTe junction and performance of solar cells. -- Abstract: CdS layers grown by chemical bath deposition (CBD) are annealed in the oxygen and argon-hydrogen atmosphere respectively. It has been found that the open circuit voltage of the CdS/CdTe solar cell increases when the CBD CdS is annealed with oxygen before the deposition of CdTe by close spaced sublimation (CSS), while the performance of the solar cell decreases when the CBD CdS is annealed with argon-hydrogen. Electronic properties of the CdS films are investigated using X-ray photo-electron spectroscopy (XPS), which indicates that the Fermi level is shifting closer to the conduction band after annealing in the oxygen and consequently a higher open circuit voltage of the solar cell can be obtained.

  15. Correlated dewetting patterns in thin polystyrene films

    Energy Technology Data Exchange (ETDEWEB)

    Neto, Chiara [Department of Applied Physics, University of Ulm, Albert Einstein Allee 11, D-89069 Ulm (Germany); Jacobs, Karin [Department of Applied Physics, University of Ulm, Albert Einstein Allee 11, D-89069 Ulm (Germany); Seemann, Ralf [Department of Applied Physics, University of Ulm, Albert Einstein Allee 11, D-89069 Ulm (Germany); Blossey, Ralf [Centre for Bioinformatics, Saarland University, PO Box 151150, D-66041 Saarbruecken (Germany); Becker, Juergen [Institute of Applied Mathematics, University of Bonn, Beringstr. 6, D-53115 Bonn (Germany); Gruen, Guenther [Institute of Applied Mathematics, University of Bonn, Beringstr. 6, D-53115 Bonn (Germany)

    2003-01-15

    We describe preliminary results of experiments and simulations concerned with the dewetting of thin polystyrene films (thickness < 7 nm) on top of silicon oxide wafers. In the experiments we scratched an initially flat film with an atomic force microscopy (AFM) tip, producing dry channels in the film. Dewetting of the films was imaged in situ using AFM and a correlated pattern of holes ('satellite holes') was observed along the rims bordering the channels. The development of this complex film rupture process was simulated and the results of experiments and simulations are in good agreement. On the basis of these results, we attempt to explain the appearance of satellite holes and their positions relative to pre-existing holes.

  16. Correlated dewetting patterns in thin polystyrene films

    CERN Document Server

    Neto, C; Seemann, R; Blossey, R; Becker, J; Grün, G

    2003-01-01

    We describe preliminary results of experiments and simulations concerned with the dewetting of thin polystyrene films (thickness < 7 nm) on top of silicon oxide wafers. In the experiments we scratched an initially flat film with an atomic force microscopy (AFM) tip, producing dry channels in the film. Dewetting of the films was imaged in situ using AFM and a correlated pattern of holes ('satellite holes') was observed along the rims bordering the channels. The development of this complex film rupture process was simulated and the results of experiments and simulations are in good agreement. On the basis of these results, we attempt to explain the appearance of satellite holes and their positions relative to pre-existing holes.

  17. Humidity sensing characteristics of hydrotungstite thin films

    Indian Academy of Sciences (India)

    G V Kunte; S A Shivashankar; A M Umarji

    2008-11-01

    Thin films of the hydrated phase of tungsten oxide, hydrotungstite (H2WO4.H2O), have been grown on glass substrates using a dip-coating technique. The -axis oriented films have been characterized by X-ray diffraction and scanning electron microscopy. The electrical conductivity of the films is observed to vary with humidity and selectively show high sensitivity to moisture at room temperature. In order to understand the mechanism of sensing, the films were examined by X-ray diffraction at elevated temperatures and in controlled atmospheres. Based on these observations and on conductivity measurements, a novel sensing mechanism based on protonic conduction within the surface layers adsorbed onto the hydrotungstite film is proposed.

  18. Ternary compound thin film solar cells

    Science.gov (United States)

    Kazmerski, L. L.

    1975-01-01

    A group of ternary compound semiconductor (I-III-VI2) thin films for future applications in photovoltaic devices is proposed. The consideration of these materials (CuInSe2, CuInTe2 and especially CuInS2) for long range device development is emphasized. Much of the activity to date has been concerned with the growth and properties of CuInX2 films. X-ray and electron diffraction analyses, Hall mobility and coefficient, resistivity and carrier concentration variations with substrate and film temperature as well as grain size data have been determined. Both p- and n-type films of CuInS2 and CuInSe2 have been produced. Single and double source deposition techniques have been utilized. Some data have been recorded for annealed films.

  19. Stabilized thin film heterostructure for electrochemical applications

    DEFF Research Database (Denmark)

    2015-01-01

    The invention provides a method for the formation of a thin film multi-layered heterostructure upon a substrate, said method comprising the steps of: a. providing a substrate; b. depositing a buffer layer upon said substrate, said buffer layer being a layer of stable ionic conductor (B); c. depos...

  20. Bilaterally Microstructured Thin Polydimethylsiloxane Film Production

    DEFF Research Database (Denmark)

    Vudayagiri, Sindhu; Yu, Liyun; Hassouneh, Suzan Sager;

    2015-01-01

    Thin PDMS films with complex microstructures are used in the manufacturing of dielectric electro active polymer (DEAP) actuators, sensors and generators, to protect the metal electrode from large strains and to assure controlled actuation. The current manufacturing process at Danfoss Polypower A/...

  1. Bauschinger effect in unpassivated freestanding thin films

    NARCIS (Netherlands)

    Shishvan, S.S.; Nicola, L.; Van der Giessen, E.

    2010-01-01

    Two-dimensional (2D) discrete dislocation plasticity simulations are carried out to investigate the Bauschinger effect (BE) in freestanding thin films. The BE in plastic flow of polycrystalline materials is generally understood to be caused by inhomogeneous deformation during loading, leading to res

  2. Flexoelectricity in barium strontium titanate thin film

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Seol Ryung; Huang, Wenbin; Yuan, Fuh-Gwo; Jiang, Xiaoning, E-mail: xjiang5@ncsu.edu [Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Shu, Longlong [Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Electronic Materials Research Laboratory, International Center for Dielectric Research, Xi' an Jiao Tong University, Xi' an, Shaanxi 710049 (China); Maria, Jon-Paul [Department of Material Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2014-10-06

    Flexoelectricity, the linear coupling between the strain gradient and the induced electric polarization, has been intensively studied as an alternative to piezoelectricity. Especially, it is of interest to develop flexoelectric devices on micro/nano scales due to the inherent scaling effect of flexoelectric effect. Ba{sub 0.7}Sr{sub 0.3}TiO{sub 3} thin film with a thickness of 130 nm was fabricated on a silicon wafer using a RF magnetron sputtering process. The flexoelectric coefficients of the prepared thin films were determined experimentally. It was revealed that the thin films possessed a transverse flexoelectric coefficient of 24.5 μC/m at Curie temperature (∼28 °C) and 17.44 μC/m at 41 °C. The measured flexoelectric coefficients are comparable to that of bulk BST ceramics, which are reported to be 10–100 μC/m. This result suggests that the flexoelectric thin film structures can be effectively used for micro/nano-sensing devices.

  3. Amperometric Noise at Thin Film Band Electrodes

    DEFF Research Database (Denmark)

    Larsen, Simon T.; Heien, Michael L.; Taboryski, Rafael

    2012-01-01

    Background current noise is often a significant limitation when using constant-potential amperometry for biosensor application such as amperometric recordings of transmitter release from single cells through exocytosis. In this paper, we fabricated thin-film electrodes of gold and conductive...

  4. Recent progress in thin film organic photodiodes

    NARCIS (Netherlands)

    Inganäs, Olle; Roman, Lucimara S.; Zhang, Fengling; Johansson, D.M.; Andersson, M.R.; Hummelen, J.C.

    2001-01-01

    We review current developments in organic photodiodes, with special reference to multilayer thin film optics, and modeling of organic donor-acceptor photodiodes. We indicate possibilities to enhance light absorption in devices by nanopatterning as well as by blending, and also discuss materials scie

  5. Flexible thin-film NFC tags

    NARCIS (Netherlands)

    Myny, K.; Tripathi, A.K.; Steen, J.L. van der; Cobb, B.

    2015-01-01

    Thin-film transistor technologies have great potential to become the key technology for leafnode Internet of Things by utilizing the NFC protocol as a communication medium. The main requirements are manufacturability on flexible substrates at a low cost while maintaining good device performance char

  6. Welding Wires To Thin Thermocouple Films

    Science.gov (United States)

    Holanda, Raymond; Kim, Walter S.; Danzey, Gerald A.; Pencil, Eric; Wadel, Mary

    1993-01-01

    Parallel-gap resistance welding yields joints surviving temperatures of about 1,000 degrees C. Much faster than thermocompression bonding. Also exceeds conductive-paste bonding and sputtering thin films through porous flame-sprayed insulation on prewelded lead wires. Introduces no foreign material into thermocouple circuit and does not require careful control of thickness of flame-sprayed material.

  7. Quasifree Mg–H thin films

    NARCIS (Netherlands)

    Baldi, A.; Palmisano, V.; Gonzalez-Silveira, M.; Pivak, Y.; Slaman, M.; Schreuders, H.; Dam, B.; Griessen, R.

    2009-01-01

    The thermodynamics of hydrogen absorption in Pd-capped Mg films are strongly dependent on the magnesium thickness. In the present work, we suppress such dependency by inserting a thin Ti layer between Mg and Pd. By means of optical measurements, we show that the surface energy contribution to the de

  8. Tailored piezoelectric thin films for energy harvester

    NARCIS (Netherlands)

    Wan, X.

    2013-01-01

    Piezoelectric materials are excellent materials to transfer mechanical energy into electrical energy, which can be stored and used to power other devices. PiezoMEMS is a good way to combine silicon wafer processing and piezoelectric thin film technology and lead to a variety of miniaturized and prem

  9. Incipient plasticity in metallic thin films

    NARCIS (Netherlands)

    Soer, W. A.; De Hosson, J. Th. M.; Minor, A. M.; Shan, Z.; Asif, S. A. Syed; Warren, O. L.

    2007-01-01

    The authors have compared the incipient plastic behaviors of Al and Al-Mg thin films during indentation under load control and displacement control. In Al-Mg, solute pinning limits the ability of dislocations to propagate into the crystal and thus substantially affects the appearance of plastic inst

  10. Intelligent Processing of Ferroelectric Thin Films

    Science.gov (United States)

    1994-05-31

    unsatisfactory. To detect the electroopic effects of thin films deposited on opaque substrates a waveguide refractometry of category 3 was reported. An advantage...of the waveguide refractometry is its capability of resolving the change in ordinary index from the change in the extraordinary index. Some successes

  11. Polarization Fatigue in Ferroelectric Thin Films

    Institute of Scientific and Technical Information of China (English)

    王忆; K.H.WONG; 吴文彬

    2002-01-01

    The fatigue problem in ferroelectric thin films is investigated based on the switched charge per unit area versus switching cycles. The temperature, dielectric permittivity, voltage bias, frequency and defect valence dependent switching polarization properties are calculated quantitatively with an extended Dawber-Scott model. The results are in agreement with the recent experiments.

  12. Amorphous silicon for thin-film transistors

    NARCIS (Netherlands)

    Schropp, Rudolf Emmanuel Isidore

    1987-01-01

    Hydrogenated amorphous silicon (a-Si:H) has considerable potential as a semiconducting material for large-area photoelectric and photovoltaic applications. Moreover, a-Si:H thin-film transistors (TFT’s) are very well suited as switching devices in addressable liquid crystal display panels and addres

  13. Thin-Film Solid Oxide Fuel Cells

    Science.gov (United States)

    Chen, Xin; Wu, Nai-Juan; Ignatiev, Alex

    2009-01-01

    The development of thin-film solid oxide fuel cells (TFSOFCs) and a method of fabricating them have progressed to the prototype stage. This can result in the reduction of mass, volume, and the cost of materials for a given power level.

  14. Electrostatic Discharge Effects in Thin Film Transistors

    NARCIS (Netherlands)

    Golo, Natasa

    2002-01-01

    Although amorphous silicon thin film transistors (α-Si:H TFT’s) have a very low electron mobility and pronounced instabilities of their electrical characteristics, they are still very useful and they have found their place in the semiconductors industry, as they possess some very good properties: th

  15. Reliability growth of thin film resistors contact

    Directory of Open Access Journals (Sweden)

    Lugin A. N.

    2010-10-01

    Full Text Available Necessity of resistive layer growth under the contact and in the contact zone of resistive element is shown in order to reduce peak values of current flow and power dissipation in the contact of thin film resistor, thereby to increase the resistor stability to parametric and catastrophic failures.

  16. Surface roughness evolution of nanocomposite thin films

    NARCIS (Netherlands)

    Turkin, A; Pei, Y.T.; Shaha, K.P.; Chen, C.Q.; Vainchtein, David; Hosson, J.Th.M. De

    2009-01-01

    An analysis of dynamic roughening and smoothening mechanisms of thin films grown with pulsed-dc magnetron sputtering is presented. The roughness evolution has been described by a linear stochastic equation, which contains the second- and fourth-order gradient terms. Dynamic smoothening of the growin

  17. Practical design and production of optical thin films

    CERN Document Server

    Willey, Ronald R

    2002-01-01

    Fundamentals of Thin Film Optics and the Use of Graphical Methods in Thin Film Design Estimating What Can Be Done Before Designing Fourier Viewpoint of Optical Coatings Typical Equipment for Optical Coating Production Materials and Process Know-How Process Development Monitoring and Control of Thin Film Growth Appendix: Metallic and Semiconductor Material Graphs Author IndexSubject Index

  18. Nonlocal thin films in calculations of the Casimir force

    NARCIS (Netherlands)

    Esquivel-Sirvent, R.; Svetovoy, V.B.

    2005-01-01

    The Casimir force is calculated between plates with thin metallic coating. Thin films are described with spatially dispersive (nonlocal) dielectric functions. For thin films the nonlocal effects are more relevant than for half-spaces. However, it is shown that even for film thickness smaller than th

  19. Growth induced magnetic anisotropy in crystalline and amorphous thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, F.

    1998-07-20

    The work in the past 6 months has involved three areas of magnetic thin films: (1) amorphous rare earth-transition metal alloys, (2) epitaxial Co-Pt and Ni-Pt alloy thin films, and (3) collaborative work on heat capacity measurements of magnetic thin films, including nanoparticles and CMR materials. A brief summary of work done in each area is given.

  20. Potentiostatic Deposition and Characterization of Cuprous Oxide Thin Films

    OpenAIRE

    2013-01-01

    Electrodeposition technique was employed to deposit cuprous oxide Cu2O thin films. In this work, Cu2O thin films have been grown on fluorine doped tin oxide (FTO) transparent conducting glass as a substrate by potentiostatic deposition of cupric acetate. The effect of deposition time on the morphologies, crystalline, and optical quality of Cu2O thin films was investigated.

  1. Monte Carlo simulation of magnetic nanostructured thin films

    Institute of Scientific and Technical Information of China (English)

    Guan Zhi-Qiang; Yutaka Abe; Jiang Dong-Hua; Lin Hai; Yoshitake Yamazakia; Wu Chen-Xu

    2004-01-01

    @@ Using Monte Carlo simulation, we have compared the magnetic properties between nanostructured thin films and two-dimensional crystalline solids. The dependence of nanostructured properties on the interaction between particles that constitute the nanostructured thin films is also studied. The result shows that the parameters in the interaction potential have an important effect on the properties of nanostructured thin films at the transition temperatures.

  2. CZTSSe thin film solar cells: Surface treatments

    Science.gov (United States)

    Joglekar, Chinmay Sunil

    Chalcopyrite semiconducting materials, specifically CZTS, are a promising alternative to traditional silicon solar cell technology. Because of the high absorption coefficient; films of the order of 1 micrometer thickness are sufficient for the fabrication of solar cells. Liquid based synthesis methods are advantageous because they are easily scalable using the roll to roll manufacturing techniques. Various treatments are explored in this study to enhance the performance of the selenized CZTS film based solar cells. Thiourea can be used as a sulfur source and can be used to tune band gap of CZTSSe. Bromine etching can be used to manipulate the thickness of sintered CZTSSe film. The etching treatment creates recombination centers which lead to poor device performance. Various after treatments were used to improve the performance of the devices. It was observed that the performance of the solar cell devices could not be improved by any of the after treatment steps. Other surface treatment processes are explored including KCN etching and gaseous H2S treatments. Hybrid solar cells which included use of CIGS nanoparticles at the interface between CZTSSe and CdS are also explored.

  3. MISSE 5 Thin Films Space Exposure Experiment

    Science.gov (United States)

    Harvey, Gale A.; Kinard, William H.; Jones, James L.

    2007-01-01

    The Materials International Space Station Experiment (MISSE) is a set of space exposure experiments using the International Space Station (ISS) as the flight platform. MISSE 5 is a co-operative endeavor by NASA-LaRC, United Stated Naval Academy, Naval Center for Space Technology (NCST), NASA-GRC, NASA-MSFC, Boeing, AZ Technology, MURE, and Team Cooperative. The primary experiment is performance measurement and monitoring of high performance solar cells for U.S. Navy research and development. A secondary experiment is the telemetry of this data to ground stations. A third experiment is the measurement of low-Earth-orbit (LEO) low-Sun-exposure space effects on thin film materials. Thin films can provide extremely efficacious thermal control, designation, and propulsion functions in space to name a few applications. Solar ultraviolet radiation and atomic oxygen are major degradation mechanisms in LEO. This paper is an engineering report of the MISSE 5 thm films 13 months space exposure experiment.

  4. Chemical bath deposition of thin semiconductor films for use as buffer layers in CuInS sub 2 thin film solar cells

    CERN Document Server

    Kaufmann, C A

    2002-01-01

    different growth phases, layer morphology and solar cell performance were sought and an improved deposition process was developed. As a result, Cd-free CulnS sub 2 thin film solar cells with efficiencies of up to 10.6%) (total area) could be produced. Overall the substitution of CdS is shown to be possible by different alternative compounds, such as Zn(OH,O) sub x S sub y or In(OH,O) sub x S sub y. In the case of In(OH,O) sub x S sub y , an understanding of the CBD process and the effect of different growth phases on the resulting solar cell characteristics could be developed. A CulnS sub 2 thin film solar cell is a multilayered semiconductor device. The solar cells discussed have a layer sequence Mo/CulnS sub 2 /buffer/i-ZnO/ZnO:Ga, where a heterojunction establishes between the p-type absorber and the n-type front contact. Conventionally the buffer consists of CdS, deposited by chemical bath deposition (CBD). Apart from providing process oriented benefits the buffer layer functions as a tool for engineering...

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

    Science.gov (United States)

    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. Thin-film semiconductor rectifier has improved properties

    Science.gov (United States)

    1966-01-01

    Cadmium selenide-zinc selenide film is used as a thin film semiconductor rectifier. The film is vapor-deposited in a controlled concentration gradient into a glass substrate to form the required junctions between vapor-deposited gold electrodes.

  7. Thin blend films of cellulose and polyacrylonitrile

    Science.gov (United States)

    Lu, Rui; Zhang, Xin; Mao, Yimin; Briber, Robert; Wang, Howard

    Cellulose is the most abundant renewable, biocompatible and biodegradable natural polymer. Cellulose exhibits excellent chemical and mechanical stability, which makes it useful for applications such as construction, filtration, bio-scaffolding and packaging. To further expand the potential applications of cellulose materials, their alloying with synthetic polymers has been investigated. In this study, thin films of cotton linter cellulose (CLC) and polyacrylonitrile (PAN) blends with various compositions spanning the entire range from neat CLC to neat PAN were spun cast on silicon wafers from common solutions in dimethyl sulfoxide / ionic liquid mixtures. The morphologies of thin films were characterized using optical microscopy, atomic force microscopy, scanning electron microscopy and X-ray reflectivity. Morphologies of as-cast films are highly sensitive to the film preparation conditions; they vary from featureless smooth films to self-organized ordered nano-patterns to hierarchical structures spanning over multiple length scales from nanometers to tens of microns. By selectively removing the PAN-rich phase, the structures of blend films were studied to gain insights in their very high stability in hot water, acid and salt solutions.

  8. Photoelectrochemical and Raman characterization of In2O3 mesoporous films sensitized by CdS nanoparticles

    Directory of Open Access Journals (Sweden)

    Mikalai V. Malashchonak

    2013-04-01

    Full Text Available The method of successive ion layer adsorption and reaction was applied for the deposition of CdS nanoparticles onto a mesoporous In2O3 substrate. The filling of the nanopores in In2O3 films with CdS particles mainly occurs during the first 30 cycles of the SILAR deposition. The surface modification of In2O3 with CdS nanoparticles leads to the spectral sensitization of photoelectrochemical processes that manifests itself in a red shift of the long-wavelength edge in the photocurrent spectrum by 100–150 nm. Quantum-confinement effects lead to an increase of the bandgap from 2.49 to 2.68 eV when decreasing the number of SILAR cycles from 30 to 10. The spectral shift and the widening of the Raman line belonging to CdS evidences the lattice stress on the CdS/In2O3 interfaces and confirms the formation of a close contact between the nanoparticles.

  9. Annealing Effects on the Photoluminescence and Optical Properties of In-Doped CdS Films

    Directory of Open Access Journals (Sweden)

    Seniye KARAKAYA

    2014-07-01

    Full Text Available Among the II–IV semiconductor compounds, CdS (band gap 2.43 eV have large applications as photoconductors, in semiconductor lasers, nonlinear optical devices and photovoltaic solar cells. In this work; In-doped CdS (CdS:In

  10. Thin Film Electrochemical Power Cells

    Science.gov (United States)

    1991-01-01

    Anion Intercalating Polymer Cathode", proceedings of symposium on Lithium Batteries, The Electrochemical Society , Hollywood, Florida. K. Naoi, W.H...of symposium on Lithium Batteries, The Electrochemical Society , Hollywood, Florida. M. Lien and W.H. Smyrl, "An Impedance Study of Polyvinylferrocene...Films", in Transient Techniques in Corrosion Science and Engineering, eds. W.H. Smyrl, et al., Electrochemical Society , 1989. K, Naoi, M.M. Lien and

  11. Thin film bismuth iron oxides useful for piezoelectric devices

    Energy Technology Data Exchange (ETDEWEB)

    Zeches, Robert J.; Martin, Lane W.; Ramesh, Ramamoorthy

    2016-05-31

    The present invention provides for a composition comprising a thin film of BiFeO.sub.3 having a thickness ranging from 20 nm to 300 nm, a first electrode in contact with the BiFeO.sub.3 thin film, and a second electrode in contact with the BiFeO.sub.3 thin film; wherein the first and second electrodes are in electrical communication. The composition is free or essentially free of lead (Pb). The BFO thin film is has the piezoelectric property of changing its volume and/or shape when an electric field is applied to the BFO thin film.

  12. Thin film heterojunction CdS/Cu ternary alloys solar cells with minority carrier mirrors

    Science.gov (United States)

    Kwietniak, M.; Loferski, J. J.; Beaulieu, R.; Arya, R. R.; Vera, E.; Kazmerski, L.

    A new concept in the fabrication of thin film solar cells with a multilayer structure in which the base region contains a minority carrier mirror (MCM) is reported. The theory of heterojunctions employing CdS as a wide bandgap window and layers of CulnSe2 and CuGaSe(0.9)Te(1.1) with MCM as the photovoltaically active semiconductor is presented. A first cell of this type was made by rf-sputtering the successive layers; its AM1 efficiency was about 4 percent.

  13. Real time spectroscopic ellipsometry for analysis and control of thin film polycrystalline semiconductor deposition in photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Koirala, Prakash; Attygalle, Dinesh; Aryal, Puruswottam; Pradhan, Puja; Chen, Jie [Center for Photovoltaics Innovation and Commercialization and Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Marsillac, Sylvain [Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23529 (United States); Ferlauto, Andre S.; Podraza, Nikolas J.; Collins, Robert W. [Center for Photovoltaics Innovation and Commercialization and Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States)

    2014-11-28

    Real time spectroscopic ellipsometry (RTSE) from the near-infrared to ultraviolet has been applied for analysis of the deposition of polycrystalline thin films that form the basis of two key photovoltaic heterojunction configurations, superstrate SnO{sub 2}/CdS/CdTe and substrate Mo/Cu(In{sub 1−x}Ga{sub x})Se{sub 2}/CdS. The focus of this work is to develop capabilities for monitoring and controlling the key steps in the fabrication of these device structures. Analysis of RTSE data collected during sputter deposition of CdS on a rough SnO{sub 2} transparent top contact provides the time evolution of the CdS effective thickness, or film volume per unit substrate area. This thickness includes interface, bulk, and surface roughness layer components and affects the CdS/CdTe heterojunction performance and the quantum efficiency of the solar cell in the blue region of the solar spectrum. Similarly, analysis of RTSE data collected during co-evaporation of Cu(In{sub 1−x}Ga{sub x})Se{sub 2} (CIGS; x ∼ 0.3) on a rough Mo back contact provides the evolution of a second phase of Cu{sub 2−x}Se within the CIGS layer. During the last stage of CIGS deposition, the In, Ga, and Se co-evaporants convert this Cu{sub 2−x}Se phase to CIGS, and RTSE identifies the endpoint, specifically the time at which complete conversion occurs and single-phase, large-grain CIGS is obtained in this key stage. - Highlights: • Real time spectroscopic ellipsometry (RTSE) study of CdS and CuIn{sub 1−x}Ga{sub x}Se{sub 2} (CIGS) films. • RTSE during CdS deposition provides the evolution of the CdS effective thickness. • RTSE for CIGS film enables to measure and control the composition and thickness. • The work leads to the development of optical models for processing steps.

  14. Physical Vapor Deposition of Thin Films

    Science.gov (United States)

    Mahan, John E.

    2000-01-01

    A unified treatment of the theories, data, and technologies underlying physical vapor deposition methods With electronic, optical, and magnetic coating technologies increasingly dominating manufacturing in the high-tech industries, there is a growing need for expertise in physical vapor deposition of thin films. This important new work provides researchers and engineers in this field with the information they need to tackle thin film processes in the real world. Presenting a cohesive, thoroughly developed treatment of both fundamental and applied topics, Physical Vapor Deposition of Thin Films incorporates many critical results from across the literature as it imparts a working knowledge of a variety of present-day techniques. Numerous worked examples, extensive references, and more than 100 illustrations and photographs accompany coverage of: * Thermal evaporation, sputtering, and pulsed laser deposition techniques * Key theories and phenomena, including the kinetic theory of gases, adsorption and condensation, high-vacuum pumping dynamics, and sputtering discharges * Trends in sputter yield data and a new simplified collisional model of sputter yield for pure element targets * Quantitative models for film deposition rate, thickness profiles, and thermalization of the sputtered beam

  15. Polycrystalline thin film materials and devices

    Energy Technology Data Exchange (ETDEWEB)

    Baron, B.N.; Birkmire, R.W.; Phillips, J.E.; Shafarman, W.N.; Hegedus, S.S.; McCandless, B.E. (Delaware Univ., Newark, DE (United States). Inst. of Energy Conversion)

    1992-10-01

    Results of Phase II of a research program on polycrystalline thin film heterojunction solar cells are presented. Relations between processing, materials properties and device performance were studied. The analysis of these solar cells explains how minority carrier recombination at the interface and at grain boundaries can be reduced by doping of windows and absorber layers, such as in high efficiency CdTe and CuInSe{sub 2} based solar cells. The additional geometric dimension introduced by the polycrystallinity must be taken into consideration. The solar cells are limited by the diode current, caused by recombination in the space charge region. J-V characteristics of CuInSe{sub 2}/(CdZn)S cells were analyzed. Current-voltage and spectral response measurements were also made on high efficiency CdTe/CdS thin film solar cells prepared by vacuum evaporation. Cu-In bilayers were reacted with Se and H{sub 2}Se gas to form CuInSe{sub 2} films; the reaction pathways and the precursor were studied. Several approaches to fabrication of these thin film solar cells in a superstrate configuration were explored. A self-consistent picture of the effects of processing on the evolution of CdTe cells was developed.

  16. Energetic deposition of thin metal films

    CERN Document Server

    Al-Busaidy, M S K

    2001-01-01

    deposited films. The primary aim of this thesis was to study the physical effect of energetic deposition metal thin films. The secondary aim is to enhance the quality of the films produced to a desired quality. Grazing incidence X-ray reflectivity (GIXR) measurements from a high-energy synchrotron radiation source were carried out to study and characterise the samples. Optical Profilers Interferometery, Atomic Force Microscope (AFM), Auger electron spectroscopy (AES), Medium energy ion spectroscopy (MEIS), and the Electron microscope studies were the other main structural characterisation tools used. AI/Fe trilayers, as well as multilayers were deposited using a Nordico planar D.C. magnetron deposition system at different voltage biases and pressures. The films were calibrated and investigated. The relation between energetic deposition variation and structural properties was intensely researched. Energetic deposition refers to the method in which the deposited species possess higher kinetic energy and impact ...

  17. When are thin films of metals metallic?

    Science.gov (United States)

    Plummer, E. W.; Dowben, P. A.

    1993-04-01

    There is an increasing body of experimental information suggesting that very thin films of materials, normally considered to be metals, exhibit behavior characteristic of a nonmetal. In almost all cases, there is a nonmetal-to-metal transition as a function of film density or thickness, frequently accompanied by a structural transition. Amazingly, this behavior seems to occur for metal films on metal substrates, as well as for metals on semiconductors. The identification of this phenomena and the subsequent explanation has been slow in developing, due to the inability to directly measure the conductivity of a submonolayer film. This paper will discuss the evidence accumulated from variety of spectroscopic experimental techniques for three systems: a Mott-Hubbard transition, a Peierls-like distortion, and a Wilson transition.

  18. Cathodoluminescence degradation of PLD thin films

    Science.gov (United States)

    Swart, H. C.; Coetsee, E.; Terblans, J. J.; Ntwaeaborwa, O. M.; Nsimama, P. D.; Dejene, F. B.; Dolo, J. J.

    2010-12-01

    The cathodoluminescence (CL) intensities of Y2SiO5:Ce3+, Gd2O2S:Tb3+ and SrAl2O4:Eu2+,Dy3+ phosphor thin films that were grown by pulsed laser deposition (PLD) were investigated for possible application in low voltage field emission displays (FEDs) and other infrastructure applications. Several process parameters (background gas, laser fluence, base pressure, substrate temperature, etc.) were changed during the deposition of the thin films. Atomic force microscopy (AFM) was used to determine the surface roughness and particle size of the different films. The layers consist of agglomerated nanoparticle structures. Samples with good light emission were selected for the electron degradation studies. Auger electron spectroscopy (AES) and CL spectroscopy were used to monitor changes in the surface chemical composition and luminous efficiency of the thin films. AES and CL spectroscopy were done with 2 keV energy electrons. Measurements were done at 1×10-6 Torr oxygen pressure. The formation of different oxide layers during electron bombardment was confirmed with X-ray photoelectron spectroscopy (XPS). New non-luminescent layers that formed during electron bombardment were responsible for the degradation in light intensity. The adventitious C was removed from the surface in all three cases as volatile gas species, which is consistent with the electron stimulated surface chemical reaction (ESSCR) model. For Y2SiO5:Ce3+ a luminescent SiO2 layer formed during the electron bombardment. Gd2O3 and SrO thin films formed on the surfaces of Gd2O2S:Tb3+ and SrAl2O4:Eu2+,Dy3+, respectively, due to ESSCRs.

  19. Thin film CdS/CdTe solar cells: Research perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Acevedo, Arturo [CINVESTAV del IPN, Department of Electrical Engineering, Avenida IPN No. 2508, 07360 Mexico DF (Mexico)

    2006-06-15

    Polycrystalline thin film CdTe continues to be a leading material for the development of cost effective and reliable photovoltaics. The two key properties of this material are its band gap (1.5eV), close to the ideal for photovoltaic conversion efficiency (1.45eV), and its high optical absorption coefficient. Thin film CdTe solar cells are typically hetero-junctions with CdS being the n-type partner, or window layer. Efficiencies as high as 16.5% have been achieved, but still there is some potential for increasing them. We make an analysis of the typical CdS/CdTe superstrate solar cell, and from it we establish critical issues and different lines of research in order to improve the current efficiencies. We also show that present record efficiencies are very close to the practical efficiency limit for a CdS/CdTe hetero-junction cell. (author)

  20. Optical thin films and coatings from materials to applications

    CERN Document Server

    Flory, Francois

    2013-01-01

    Optical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. This book provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas.$bOptical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. Optical thin films and coatings provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas. Part one explores the design and manufacture of optical coatings. Part two highlights unconventional features of optical thin films including scattering properties of random structures in thin films, optical properties of thin film materials at short wavelengths, thermal properties and colour effects. Part three focusses on novel materials for optical thin films and coatings...

  1. Thin Films for Coating Nanomaterials

    Institute of Scientific and Technical Information of China (English)

    S.M.Mukhopadhyay; P.Joshi; R.V.Pulikollu

    2005-01-01

    For nano-structured solids (those with one or more dimensions in the 1-100 nm range), attempts of surface modification can pose significant and new challenges. In traditional materials, the surface coating could be several hundreds nanometers in thickness, or even microns and millimeters. In a nano-structured material, such as particle or nanofibers, the coating thickness has to be substantially smaller than the bulk dimensions (100 nm or less), yet be durable and effective. In this paper, some aspects of effective nanometer scale coatings have been discussed. These films have been deposited by a non-line of sight (plasma)techniques; and therefore, they are capable of modifying nanofibers, near net shape cellular foams, and other high porosity materials. Two types of coatings will be focused upon: (a) those that make the surface inert and (b) those designed to enhance surface reactivity and bonding. The former has been achieved by forming 1-2 nm layer of -CF2- (and/or CF3) groups on the surface, and the latter by creating a nanolayer of SiO2-type compound. Nucleation and growth studies of the plasma-generated film indicate that they start forming as 2-3 nm high islands that grow laterally, and eventually completely cover the surface with 2-3nm film. Contact angle measurements indicate that these nano-coatings are fully functional even before they have achieved complete coverage of 2-3 nm. They should therefore be applicable to nano-structural solids.This is corroborated by application of these films on vapor grown nanofibers of carbon, and on graphitic foams. Coated and uncoated materials are infiltrated with epoxy matrix to form composites and their microstructure, as well as mechanical behaviors are compared. The results show that the nano-oxide coating can significantly enhance bond formation between carbon and organic phases, thereby enhancing wettability,dispersion, and composite behavior. The fluorocarbon coating, as expected, reduces bond formation, and

  2. MOCVD of thin film photovoltaic solar cells—Next-generation production technology?

    Science.gov (United States)

    Irvine, S. J. C.; Barrioz, V.; Lamb, D.; Jones, E. W.; Rowlands-Jones, R. L.

    2008-11-01

    This paper will review the chalcogenide thin film photovoltaic (PV) solar cells, based on cadmium telluride (CdTe) and copper indium diselenide (CIS) and discuss the potential for metalorganic chemical vapour deposition (MOCVD) to enable more advanced devices in the second generation of CdTe module production. The current generation of production methods is based on physical vapour deposition (PVD) or close-spaced sublimation (CSS). This paper concentrates on the less well-known topic of MOCVD of thin film chalcogenide cells, and in particular that of CdTe. Efficient CdTe PV solar cells (>10% AM1.5) have been demonstrated from deposition of the CdS, CdTe and CdCl 2 films in a single MOCVD chamber. The CdTe layer was doped with As and an additional high As concentration CdTe layer provides effective low resistance contacting without the need for wet etching the surface. The high level of flexibility in using MOCVD has been demonstrated where the CdS window layer has been alloyed with Zn to improve the blue response of the PV device and improve AM1.5 efficiency to 13.3%.

  3. Structural studies of thin films of semiconducting nanoparticles in polymer matrices

    Energy Technology Data Exchange (ETDEWEB)

    Di Luccio, Tiziana [ENEA, Centro Ricerche Brindisi, SS7 Appia Km 706, I-72100 Brindisi (Italy)], E-mail: tiziana.diluccio@portici.enea.it; Piscopiello, Emanuela; Laera, Anna Maria [ENEA, Centro Ricerche Brindisi, SS7 Appia Km 706, I-72100 Brindisi (Italy); Antisari, Marco Vittori [ENEA, Centro Ricerche Casaccia, Via Anguillarese 301, I-00060 S. Maria di Galeria (Roma) (Italy)

    2007-09-15

    Ordered films of nanoscale materials are issue of wide interest for applications in several fields, such as optics, catalysis, and bioelectronics. In particular, semiconducting nanoparticles incorporation in a processable polymer film is an easy way to manipulate such materials for their application. We deposited thin layers of cadmium sulphide (CdS) and zinc sulphide (ZnS) nanoparticles embedded in a thermoplastic cyclo-olephin copolymer (COC) with elevated optical transparency and highly bio-compatible. The nanoparticles were obtained by thiolate precursors previously dispersed in the polymer upon thermal treatment at temperatures ranging between 200 and 300 deg. C depending on the desired size. The precursor/polymer solutions were spin-coated in order to get thin films. The spinning conditions were changed in order to optimise the layer thickness and uniformity. The samples were mainly characterised by X-ray reflectivity (XRR) and by high-resolution transmission electron microscopy (HRTEM) analyses. The thinnest layer we have deposited is 8 nm thick, as evaluated by XRR. The HRTEM measurements showed that the nanoparticles have quasi-spherical shape without evident microstructural defects. The size of the nanoparticles depends on the annealing temperature, e.g. at 232 deg. C the size of the CdS nanoparticles is about 4-5 nm.

  4. Deposition and characterization of CuInS2 thin films deposited over copper thin films

    Science.gov (United States)

    Thomas, Titu; Kumar, K. Rajeev; Kartha, C. Sudha; Vijayakumar, K. P.

    2015-06-01

    Simple, cost effective and versatile spray pyrolysis method is effectively combined with vacuum evaporation for the deposition of CuIns2 thin films for photovoltaic applications. In the present study In2s3 was spray deposited over vacuum evaporated Cu thin films and Cu was allowed to diffuse in to the In2S3 layer to form CuInS2. To analyse the dependence of precursor volume on the formation of CuInS2 films structural, electrical and morphological analzes are carried out. Successful deposition of CuInS2thin films with good crystallinity and morphology with considerably low resistivity is reported in this paper.

  5. Fabrication and characterization of high-mobility solution-based chalcogenide thin-film transistors

    KAUST Repository

    Mejia, Israel I.

    2013-01-01

    We report device and material considerations for the fabrication of high-mobility thin-film transistors (TFTs) compatible with large-area and inexpensive processes. In particular, this paper reports photolithographically defined n-type TFTs (n-TFTs) based on cadmium sulfide (CdS) films deposited using solution-based techniques. The integration process consists of four mask levels with a maximum processing temperature of 100 °C. The TFT performance was analyzed in terms of the CdS semiconductor thickness and as a function of postdeposition annealing in a reducing ambient. The IonI off ratios are ∼107 with field-effect mobilities of ∼5.3 and ∼4.7cm2V̇s for Al and Au source-drain contacts, respectively, using 70 nm of CdS. Transmission electron microscopy and electron energy loss spectroscopy were used to analyze the CdS-metal interfaces. © 1963-2012 IEEE.

  6. Metal nanoparticles for thin film solar cells

    DEFF Research Database (Denmark)

    Gritti, Claudia

    Among the different renewable ways to produce energy, photovoltaic cells have a big potential and the research is now focusing on getting higher efficiency and at the same time saving the manufacturing costs improving the performance of thin film solar cells. The spectral distribution...... a change from ZEP resist to double layer of PMMA and always requires preliminary exposure dose-tests and final particular attention for lift-off step. EBL resulted to be more suitable for silver NPs, since the deposition of gold (on top of an adhesion thin titanium layer) leads to a variation and non...

  7. PLD-grown thin film saturable absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Tellkamp, Friedjof

    2012-11-01

    The subject of this thesis is the preparation and characterization of thin films made of oxidic dielectrics which may find their application as saturable absorber in passively Q-switched lasers. The solely process applied for fabrication of the thin films was the pulsed laser deposition (PLD) which stands out against other processes by its flexibility considering the composition of the systems to be investigated. Within the scope of this thesis the applied saturable absorbers can be divided into two fundamentally different kinds of functional principles: On the one hand, saturable absorption can be achieved by ions embedded in a host medium. Most commonly applied bulk crystals are certain garnets like YAG (Y{sub 3}Al{sub 5}O{sub 12}) or the spinel forsterite (Mg{sub 2}SiO{sub 4}), in each case with chromium as dopant. Either of these media was investigated in terms of their behavior as PLD-grown saturable absorber. Moreover, experiments with Mg{sub 2}GeO{sub 4}, Ca{sub 2}GeO{sub 4}, Sc{sub 2}O{sub 3}, and further garnets like YSAG or GSGG took place. The absorption coefficients of the grown films of Cr{sup 4+}:YAG were determined by spectroscopic investigations to be one to two orders of magnitude higher compared to commercially available saturable absorbers. For the first time, passive Q-switching of a Nd:YAG laser at 1064 nm with Cr{sup 4+}:YAG thin films could be realized as well as with Cr:Sc{sub 2}O{sub 3} thin films. On the other hand, the desirable effect of saturable absorption can also be generated by quantum well structures. For this purpose, several layer system like YAG/LuAG, Cu{sub 2}O/MgO, and ZnO/corumdum were investigated. It turned out that layer systems with indium oxide (In{sub 2}O{sub 3}) did not only grew in an excellent way but also showed up a behavior regarding their photo luminescence which cannot be explained by classical considerations. The observed luminescence at roughly 3 eV (410 nm) was assumed to be of excitonic nature and its

  8. INVESTIGATION OF PHOTOELECTROCHROMIC THIN FILM AND DEVICE

    Institute of Scientific and Technical Information of China (English)

    M.J. Chen; H. Shen

    2005-01-01

    Photoelectrochromic device is a combination of dye-sensitized solar cells and electrochromic WO3 layers. Ectrochroelmic WO3 layer and TiO2 layer had been prepared by the sol-gel process, then be assembled to pohotoelectrochromic device. The effects of heating temperature on photoelectrochromic were investigated. The results showed that thin films prepared by dip-coating and spin-coating had good film quality and the device made by the method mentioned in the paper had good photoelectrochromie properties.

  9. Thermoviscoelastic models for polyethylene thin films

    DEFF Research Database (Denmark)

    Li, Jun; Kwok, Kawai; Pellegrino, Sergio

    2016-01-01

    This paper presents a constitutive thermoviscoelastic model for thin films of linear low-density polyethylene subject to strains up to yielding. The model is based on the free volume theory of nonlinear thermoviscoelasticity, extended to orthotropic membranes. An ingredient of the present approach...... is that the experimentally inaccessible out-of-plane material properties are determined by fitting the model predictions to the measured nonlinear behavior of the film. Creep tests, uniaxial tension tests, and biaxial bubble tests are used to determine the material parameters. The model has been validated experimentally...

  10. Thin film cadmium telluride solar cells

    Science.gov (United States)

    Chu, T. L.; Chu, Shirley S.; Ang, S. T.; Mantravadi, M. K.

    1987-08-01

    Thin-film p-CdTe/CdS/SnO2:F/glass solar cells of the inverted configuration were prepared by the deposition of p-type CdTe films onto CdS/SnO2:F/glass substrates using CVD or close-spaced sublimation (CSS) techniques based on the procedures of Chu et al. (1983) and Nicholl (1963), respectively. The deposition rates of p-CdTe films deposited by CSS were higher than those deposited by the CVD technique (4-5 min were sufficient), and the efficiencies higher than 10 percent were obtained. However, the resistivity of films prepared by CSS was not as readily controlled as that of the CVD films. The simplest technique to reduce the resistivity of the CSS p-CdTe films was to incorporate a dopant, such as As or Sb, into the reaction mixture during the preparation of the source material. The films with resistivities in the range of 500-1000 ohm cm were deposited in this manner.

  11. Electrochromism in copper oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, T.J.; Slack, J.L.; Rubin, M.D.

    2000-08-15

    Transparent thin films of copper(I) oxide prepared on conductive SnO2:F glass substrates by anodic oxidation of sputtered copper films or by direct electrodeposition of Cu2O transformed reversibly to opaque metallic copper films when reduced in alkaline electrolyte. In addition, the same Cu2O films transform reversibly to black copper(II) oxide when cycled at more anodic potentials. Copper oxide-to-copper switching covered a large dynamic range, from 85% and 10% photopic transmittance, with a coloration efficiency of about 32 cm2/C. Gradual deterioration of the switching range occurred over 20 to 100 cycles. This is tentatively ascribed to coarsening of the film and contact degradation caused by the 65% volume change on conversion of Cu to Cu2O. Switching between the two copper oxides (which have similar volumes) was more stable and more efficient (CE = 60 cm2/C), but covered a smaller transmittance range (60% to 44% T). Due to their large electrochemical storage capacity and tolerance for alkaline electrolytes, these cathodically coloring films may be useful as counter electrodes for anodically coloring electrode films such as nickel oxide or metal hydrides.

  12. Cowrie-shell architectures: Low temperature growth of Ni doped CdS film

    Energy Technology Data Exchange (ETDEWEB)

    Thool, Gautam Sheel; Sraveen, K. [Inorganic and Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad 500007 (India); Singh, Ajaya Kumar [Department of Chemistry, Govt. VYT PG. Autonomous College, Durg 491001, Chhattisgarh (India); Pal, Ujjwal [Central Mechanical Engineering Research Institute, M. G. Avenue, Durgapur 713209 (India); Singh, Surya Prakash, E-mail: spsingh@iict.res.in [Inorganic and Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad 500007 (India)

    2015-11-15

    In this work, we report the synthesis of Ni doped CdS cowrie-shell architectures and submicron balls like structures via low temperature chemical bath deposition method. The as-synthesized materials were systematically characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDAX), Raman spectroscopy and FTIR spectra. XRD results revealed the existence of cubic phase of CdS based material. SEM pictures depicted the growth of well define morphologies i.e. cowries-shell and submicron balls. Deposition time and dopant played significant role in the growth of CdS based different architectures. The EDAX spectra confirmed the presence of Ni into the CdS lattice. Surface structure of synthesized material was derived by FTIR analysis. - Highlights: • Ni doped CdS cowrie-shell like architectures were synthesized using low temperature aqueous solution method. • We demonstrated the deposition time and dopant played significant role in the growth of CdS based different architectures. • The formation of Ni doped CdS submicron balls has taken place by simple over growth on cowrie-shell particles. • FTIR spectra showed that the surface Cd{sup 2+} ions probably coordinated to triethanol amine molecules.

  13. Polycrystalline thin films FY 1992 project report

    Energy Technology Data Exchange (ETDEWEB)

    Zweibel, K. [ed.

    1993-01-01

    This report summarizes the activities and results of the Polycrystalline Thin Film Project during FY 1992. The purpose of the DOE/NREL PV (photovoltaic) Program is to facilitate the development of PV that can be used on a large enough scale to produce a significant amount of energy in the US and worldwide. The PV technologies under the Polycrystalline Thin Film project are among the most exciting ``next-generation`` options for achieving this goal. Over the last 15 years, cell-level progress has been steady, with laboratory cell efficiencies reaching levels of 15 to 16%. This progress, combined with potentially inexpensive manufacturing methods, has attracted significant commercial interest from US and international companies. The NREL/DOE program is designed to support the efforts of US companies through cost-shared subcontracts (called ``government/industry partnerships``) that we manage and fund and through collaborative technology development work among industry, universities, and our laboratory.

  14. Polycrystalline thin films FY 1992 project report

    Energy Technology Data Exchange (ETDEWEB)

    Zweibel, K. (ed.)

    1993-01-01

    This report summarizes the activities and results of the Polycrystalline Thin Film Project during FY 1992. The purpose of the DOE/NREL PV (photovoltaic) Program is to facilitate the development of PV that can be used on a large enough scale to produce a significant amount of energy in the US and worldwide. The PV technologies under the Polycrystalline Thin Film project are among the most exciting next-generation'' options for achieving this goal. Over the last 15 years, cell-level progress has been steady, with laboratory cell efficiencies reaching levels of 15 to 16%. This progress, combined with potentially inexpensive manufacturing methods, has attracted significant commercial interest from US and international companies. The NREL/DOE program is designed to support the efforts of US companies through cost-shared subcontracts (called government/industry partnerships'') that we manage and fund and through collaborative technology development work among industry, universities, and our laboratory.

  15. EBSD analysis of electroplated magnetite thin films

    Science.gov (United States)

    Koblischka-Veneva, A.; Koblischka, M. R.; Teng, C. L.; Ryan, M. P.; Hartmann, U.; Mücklich, F.

    2010-05-01

    By means of electron backscatter diffraction (EBSD), we analyse the crystallographic orientation of electroplated magnetite thin films on Si/copper substrates. Varying the voltage during the electroplating procedure, the resulting surface properties are differing considerably. While a high voltage produces larger but individual grains on the surface, the surfaces become smoother on decreasing voltage. Good quality Kikuchi patterns could be obtained from all samples; even on individual grains, where the surface and the edges could be measured. The spatial resolution of the EBSD measurement could be increased to about 10 nm; thus enabling a detailed analysis of single magnetite grains. The thin film samples are polycrystalline and do not exhibit a preferred orientation. EBSD reveals that the grain size changes depending on the processing conditions, while the detected misorientation angles stay similar.

  16. Electrostatic Discharge Effects on Thin Film Resistors

    Science.gov (United States)

    Sampson, Michael J.; Hull, Scott M.

    1999-01-01

    Recently, open circuit failures of individual elements in thin film resistor networks have been attributed to electrostatic discharge (ESD) effects. This paper will discuss the investigation that came to this conclusion and subsequent experimentation intended to characterize design factors that affect the sensitivity of resistor elements to ESD. The ESD testing was performed using the standard human body model simulation. Some of the design elements to be evaluated were: trace width, trace length (and thus width to length ratio), specific resistivity of the trace (ohms per square) and resistance value. However, once the experiments were in progress, it was realized that the ESD sensitivity of most of the complex patterns under evaluation was determined by other design and process factors such as trace shape and termination pad spacing. This paper includes pictorial examples of representative ESD failure sites, and provides some options for designing thin film resistors that are ESD resistant. The risks of ESD damage are assessed and handling precautions suggested.

  17. Multiferroic oxide thin films and heterostructures

    Science.gov (United States)

    Lu, Chengliang; Hu, Weijin; Tian, Yufeng; Wu, Tom

    2015-06-01

    Multiferroic materials promise a tantalizing perspective of novel applications in next-generation electronic, memory, and energy harvesting technologies, and at the same time they also represent a grand scientific challenge on understanding complex solid state systems with strong correlations between multiple degrees of freedom. In this review, we highlight the opportunities and obstacles in growing multiferroic thin films with chemical and structural integrity and integrating them in functional devices. Besides the magnetoelectric effect, multiferroics exhibit excellent resistant switching and photovoltaic properties, and there are plenty opportunities for them to integrate with other ferromagnetic and superconducting materials. The challenges include, but not limited, defect-related leakage in thin films, weak magnetism, and poor control on interface coupling. Although our focuses are Bi-based perovskites and rare earth manganites, the insights are also applicable to other multiferroic materials. We will also review some examples of multiferroic applications in spintronics, memory, and photovoltaic devices.

  18. Multiferroic oxide thin films and heterostructures

    KAUST Repository

    Lu, Chengliang

    2015-05-26

    Multiferroic materials promise a tantalizing perspective of novel applications in next-generation electronic, memory, and energy harvesting technologies, and at the same time they also represent a grand scientific challenge on understanding complex solid state systems with strong correlations between multiple degrees of freedom. In this review, we highlight the opportunities and obstacles in growing multiferroic thin films with chemical and structural integrity and integrating them in functional devices. Besides the magnetoelectric effect, multiferroics exhibit excellent resistant switching and photovoltaic properties, and there are plenty opportunities for them to integrate with other ferromagnetic and superconducting materials. The challenges include, but not limited, defect-related leakage in thin films, weak magnetism, and poor control on interface coupling. Although our focuses are Bi-based perovskites and rare earth manganites, the insights are also applicable to other multiferroic materials. We will also review some examples of multiferroic applications in spintronics, memory, and photovoltaic devices.

  19. High efficiency cadmium telluride and zinc telluride based thin-film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rohatgi, A.; Sudharsanan, R.; Ringel, S.A.; Chou, H.C. (Georgia Inst. of Tech., Atlanta, GA (United States))

    1992-10-01

    This report describes work to improve the basic understanding of CdTe and ZnTe alloys by growing and characterizing these films along with cell fabrication. The major objective was to develop wide-band-gap (1.6--1.8 eV) material for the top cell, along with compatible window material and transparent ohmic contacts, so that a cascade cell design can be optimized. Front-wall solar cells were fabricated with a glass/SnO{sub 2}/CdS window, where the CdS film is thin to maximize transmission and current. Wide-band-gap absorber films (E{sub g} = 1.75 eV) were grown by molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD) techniques, which provided excellent control for tailoring the film composition and properties. CdZnTe films were grown by both MBE and MOCVD. All the as-grown films were characterized by several techniques (surface photovoltage spectroscopy, Auger electron spectroscopy (AES), and x-ray photoelectron spectroscopy (XPS)) for composition, bulk uniformity, thickness, and film and interface quality. Front-wall-type solar cells were fabricated in collaboration with Ametek Materials Research Laboratory using CdTe and CdZnTe polycrystalline absorber films. The effects of processing on ternary film were studied by AES and XPS coupled with capacitance voltage and current voltage measurements as a function of temperature. Bias-dependent spectral response and electrical measurements were used to test some models in order to identify and quantify dominant loss mechanisms.

  20. Investigations on microstructural and optical properties of CdS films fabricated by a low-cost, simplified spray technique using perfume atomizer for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Ravichandran, K.; Philominathan, P. [PG and Research Department of Physics, AVVM, Sri Pushpam College, Poondi, Thanjavur District, Tamil Nadu (India)

    2008-11-15

    Good quality CdS films were fabricated by employing a simplified spray pyrolysis technique using perfume atomizer. CdS films have been deposited from aqueous solutions of sulphur and cadmium, keeping the molar concentrations of S:Cd = 0.01:0.01, 0.02:0.02, 0.04:0.04 and 0.06:0.06 in the starting solutions. The structural studies reveal that the S:Cd concentration has a strong influence on the microstructural characteristics of the sprayed CdS films. It was found that there is a transition in the preferred orientation from (0 0 2) plane to (1 0 1) plane when S:Cd molar concentration increases. The SEM images depict that the films are uniform and homogeneous. All the films have high optical transmittance (>80%) in the visible range. The optical band gap values are found to be in the range of 2.46-2.52 eV. CdS films fabricated by this simple and economic spray technique without using any carrier gas are found to be good in structural and optical properties which are desirable for photovoltaic applications. Hence, this simplified version of spray technique can be considered as an economic alternative to conventional spray pyrolysis (using carrier gas), for the mass production of low-cost, large area CdS coatings for solar cell applications. (author)

  1. Rechargeable thin-film lithium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Bates, J.B.; Gruzalski, G.R.; Dudney, N.J.; Luck, C.F.; Yu, Xiaohua

    1993-08-01

    Rechargeable thin-film batteries consisting of lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have recently been developed. The batteries, which are typically less than 6-{mu}m thick, can be fabricated to any specified size, large or small, onto a variety of substrates including ceramics, semiconductors, and plastics. The cells that have been investigated include Li-TiS{sub 2}, Li-V{sub 2}O{sub 5}, and Li-Li{sub x}Mn{sub 2}O{sub 4}, with open circuit voltages at full charge of about 2.5, 3.6, and 4.2, respectively. The development of these batteries would not have been possible without the discovery of a new thin-film lithium electrolyte, lithium phosphorus oxynitride, that is stable in contact with metallic lithium at these potentials. Deposited by rf magnetron sputtering of Li{sub 3}PO{sub 4} in N{sub 2}, this material has a typical composition of Li{sub 2.9}PO{sub 3.3}N{sub 0.46} and a conductivity at 25{degrees}C of 2 {mu}S/cm. The maximum practical current density obtained from the thin-film cells is limited to about 100 {mu}A/cm{sup 2} due to a low diffusivity of Li{sup +} ions in the cathodes. In this work, the authors present a short review of their work on rechargeable thin-film lithium batteries.

  2. Surface morphology of thin films polyoxadiazoles

    OpenAIRE

    J. Weszka; M.M. Szindler; M. Chwastek-Ogierman; BRUMA M.; P. Jarka; Tomiczek, B.

    2011-01-01

    urpose: The purpose of this paper was to analyse the surface morphology of thin films polyoxadiazoles. Design/methodology/approach: SSix different polymers which belong to the group of polyoxadiazoles were dissolved in the solvent NMP. Each of these polymer was deposited on a glass substrate and a spin coating method was applied with a spin speed of 1000, 2000 and 3000 rev/min. Changes in surface topography and roughness were observed. An atomic force microscope AFM Park System has been used....

  3. Quantized Nanocrystalline CdTe Thin Films

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Nanocrystalline CdTe thin films were prepared by asymmetric rectangular pulse electrodeposition in organic solution at 110°C. STM image shows a porous network morphology constructed by interconnected spherical CdTe crystallites with a mean diameter of 4.2 nm. A pronounced size quantization was indicated in the action and absorption spectra. Potentials dependence dual conductive behavior was revealed in the photocurrent-potential (I-V) curves.

  4. Incoherent and Laser Photodeposition on Thin Films.

    Science.gov (United States)

    1980-09-01

    mixing system. Both a carbon dioxide and dry chemical fire extinguisher were on hand in case a fire was initiated by the compounds. The dimethvlzinc was...summarizes three months of experimental effort devoted toward the production of thin films by the photodissociation of organometallic molecules containing the...that the threshold wavelength for the photodissociation of both Zn- 0 and Se- (CH3 )2 was approximately 2420A. Consequently, these laser photodeposition

  5. Design and characterization of thin film microcoolers

    Science.gov (United States)

    LaBounty, Chris; Shakouri, Ali; Bowers, John E.

    2001-04-01

    Thin film coolers can provide large cooling power densities compared to bulk thermoelectrics due to the close spacing of hot and cold junctions. Important parameters in the design of such coolers are investigated theoretically and experimentally. A three-dimensional (3D) finite element simulator (ANSYS) is used to model self-consistently thermal and electrical properties of a complete device structure. The dominant three-dimensional thermal and electrical spreading resistances acquired from the 3D simulation are also used in a one-dimensional model (MATLAB) to obtain faster, less rigorous results. Heat conduction, Joule heating, thermoelectric and thermionic cooling are included in these models as well as nonideal effects such as contact resistance, finite thermal resistance of the substrate and the heat sink, and heat generation in the wire bonds. Simulations exhibit good agreement with experimental results from InGaAsP-based thin film thermionic emission coolers which have demonstrated maximum cooling of 1.15 °C at room temperature. With the nonideal effects minimized, simulations predict that single stage thin film coolers can provide up to 20-30 °C degrees centigrade cooling with cooling power densities of several 1000 W/cm2.

  6. Titanium diffusion in gold thin films

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, William E. [Materials Department, University of California, Santa Barbara, CA 93106-5050 (United States); Gregori, Giuliano, E-mail: g.gregori@fkf.mpg.d [California NanoSystems Institute, University of California, Santa Barbara, CA 93106-5050 (United States); Mates, Thomas [Materials Department, University of California, Santa Barbara, CA 93106-5050 (United States)

    2010-03-01

    In the present study, diffusion phenomena in titanium/gold (Ti/Au) thin films occurring at temperatures ranging between 200 and 400 {sup o}C are investigated. The motivation is twofold: the first objective is to characterize Ti diffusion into Au layer as an effect of different heat-treatments. The second goal is to prove that the implementation of a thin titanium nitride (TiN) layer between Ti and Au can remarkably reduce Ti diffusion. It is observed that Ti atoms can fully diffuse through polycrystalline Au thin films (260 nm thick) already at temperatures as a low as 250 {sup o}C. Starting from secondary ion mass spectroscopy data, the overall diffusion activation energy {Delta}E = 0.66 eV and the corresponding pre-exponential factor D{sub 0} = 5 x 10{sup -11} cm{sup 2}/s are determined. As for the grain boundary diffusivity, both the activation energy range 0.54 < {Delta}E{sub gb} < 0.66 eV and the pre-exponential factor s{sub 0}D{sub gb0} = 1.14 x 10{sup -8} cm{sup 2}/s are obtained. Finally, it is observed that the insertion of a thin TiN layer (40 nm) between gold and titanium acts as an effective diffusion barrier up to 400 {sup o}C.

  7. Tuning the Band Gap of Cu₂ZnSn(S,Se)₄ Thin Films via Lithium Alloying.

    Science.gov (United States)

    Yang, Yanchun; Kang, Xiaojiao; Huang, Lijian; Pan, Daocheng

    2016-03-02

    Alkali metal doping plays a crucial role in fabricating high-performance Cu(In,Ga)(S,Se)2 and Cu2ZnSn(S,Se)4 (CZTSSe) thin film solar cells. In this study, we report the first experimental observation and characterizations of the alloyed Li(x)Cu(2-x)ZnSn(S,Se)4 thin films. It is found that Cu(+) ions in Cu2ZnSn(S,Se)4 thin films can be substituted with Li(+) ions, forming homogeneous Li(x)Cu(2-x)ZnSn(S,Se)4 (0 ≤ x ≤ 0.29) alloyed thin films. Consequently, the band gap, conduction band minimum, and valence band maximum of Li(x)Cu(2-x)ZnSn(S,Se)4 thin films are profoundly affected by Li/Cu ratios. The band alignment at the Li(x)Cu(2-x)ZnSn(S,Se)4/CdS interface can be tuned by changing the Li/Cu ratio. We found that the photovoltaic parameters of the Li(x)Cu(2-x)ZnSn(S,Se)4 solar cell devices are strongly influenced by the Li/Cu ratios. Besides, the lattice constant, carrier concentration, and crystal growth of Li(x)Cu(2-x)ZnSn(S,Se)4 thin films were studied in detail.

  8. Use of a Fabry-Perot resonator at millimeter wave frequencies in the determination of thin-film resistivities

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, S. J.

    1979-08-01

    A novel contact-free method of measuring resistivity of thin semiconducting films on highly conductive substrates is described. The material structure studied is commonly encountered in thin-film solar cell development. The microwave technique that involves using a semiconfocal Fabry-Perot cavity at a wavelength of 3 mm is discussed in detail. The sample consists o a thin film of CdS on a brass substrate and is mounted on the flat reflector of the cavity. Using field perturbation methods, an expression is derived that relates the film resistivity to the cavity quality factor Q. The cavity quality factor is an easily measured parameter and, by comparing measurements of Q with and without the sample mounted, an accurate measure of the resistivity is obtained. Accuracy of measurements and necessary sample constraints are discussed in detail. Three samples of CdS were measured on brass substrates spanning an order of magnitude in resistivity difference. The results of the method described agree with those of another method that involves current voltage measurement after application of a metallic contact. Unlike the latter method, however, the new technique provides a nondestructive way of measuring the resistivity of semiconductor films on conducting substrates and is amenable to automation.

  9. Recent technical advances in thin-film CdS/CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Omura, K.; Hanahusa, A.; Arita, T.; Higuchi, H.; Aramoto, T.; Nishio, T.; Sibutani, S.; Kumazawa, S.; Murozono, M. [Matsushita Battery Industrial Co., Ltd., Osaka (Japan). PV Research and Development Center; Yabuuchi, Y. [Matsushita Technoresearch Inc., Osaka (Japan); Takakura, H. [Toyama Prefectural University, Toyama (Japan)

    1996-05-01

    CeS/CdTe solar cells have attracted attention recently for their potential as low-cost, high-efficiency solar cells of the future. It is because the CdTe layer (used for photoelectric conversion) has a bandgap energy of 1.51 eV, which corresponds well to sunlight spectra, and the direct transition type energy band structure enables formation of thinner films. We have already industrialized CdS/CdTe solar cells in mass production stage using a printing-sintering process, as large-area modules for electric power generation (Higuchi et al., 1993, Omura et al., 1991), and as cells for indoor applications (primarily in calculators, Suyama et al., 1986). However, this solar cell has a conversion efficiency of approximately 6%. Recently, there has been considerable research into thin-film CdS/CdTe solar cells which have a thinner CdS film formed by CVD or CBD (Britt et al., 1993) process, and thus are photosensitive to light with wavelengths of 500 nm or less. At present stage of our art, in solar cells formed by the CSS with a CdTe film on CVD CdS, a conversion efficiency of 15.05% has been obtained in cells with an area of 1 cm{sup 2}(verified at JQA). (author)

  10. Preparation and properties of antimony thin film anode materials

    Institute of Scientific and Technical Information of China (English)

    SU Shufa; CAO Gaoshao; ZHAO Xinbing

    2004-01-01

    Metallic antimony thin films were deposited by magnetron sputtering and electrodeposition. Electrochemical properties of the thin film as anode materials for lithium-ion batteries were investigated and compared with those of antimony powder. It was found that both magnetron sputtering and electrodeposition are easily controllable processes to deposit antimony films with fiat charge/discharge potential plateaus. The electrochemical performances of antimony thin films, especially those prepared with magnetron sputtering, are better than those of antimony powder. The reversible capacities of the magnetron sputtered antimony thin film are above 400 mA h g-1 in the first 15 cycles.

  11. Dynamic Characterization of Thin Film Magnetic Materials

    Science.gov (United States)

    Gu, Wei

    A broadband dynamic method for characterizing thin film magnetic material is presented. The method is designed to extract the permeability and linewidth of thin magnetic films from measuring the reflection coefficient (S11) of a house-made and short-circuited strip line testing fixture with or without samples loaded. An adaptive de-embedding method is applied to remove the parasitic noise of the housing. The measurements were carried out with frequency up to 10GHz and biasing magnetic fields up to 600 Gauss. Particular measurement setup and 3-step experimental procedures are described in detail. The complex permeability of a 330nm thick continuous FeGaB, 435nm thick laminated FeGaB film and a 100nm thick NiFe film will be induced dynamically in frequency-biasing magnetic field spectra and compared with a theoretical model based on Landau-Lifshitz-Gilbert (LLG) equations and eddy current theories. The ferromagnetic resonance (FMR) phenomenon can be observed among these three magnetic materials investigated in this thesis.

  12. Electrical resistivity of thin metal films

    CERN Document Server

    Wissmann, Peter

    2007-01-01

    The aim of the book is to give an actual survey on the resistivity of thin metal and semiconductor films interacting with gases. We discuss the influence of the substrate material and the annealing treatment of the films, presenting our experimental data as well as theoretical models to calculate the scattering cross section of the conduction electrons in the frame-work of the scattering hypothesis. Main emphasis is laid on the comparison of gold and silver films which exhibit nearly the same lattice structure but differ in their chemical activity. In conclusion, the most important quantity for the interpretation is the surface charging z while the correlation with the optical data or the frustrated IR vibrations seems the show a more material-specific character. Z can be calculated on the basis of the density functional formalism or the self-consistent field approximation using Mulliken’s population analysis.

  13. Sulfated cellulose thin films with antithrombin affinity

    Directory of Open Access Journals (Sweden)

    2009-11-01

    Full Text Available Cellulose thin films were chemically modified by in situ sulfation to produce surfaces with anticoagulant characteristics. Two celluloses differing in their degree of polymerization (DP: CEL I (DP 215–240 and CEL II (DP 1300–1400 were tethered to maleic anhydride copolymer (MA layers and subsequently exposed to SO3•NMe3 solutions at elevated temperature. The impact of the resulting sulfation on the physicochemical properties of the cellulose films was investigated with respect to film thickness, atomic composition, wettability and roughness. The sulfation was optimized to gain a maximal surface concentration of sulfate groups. The scavenging of antithrombin (AT by the surfaces was determined to conclude on their potential anticoagulant properties.

  14. Optical properties of thin polymer films

    Science.gov (United States)

    Kasarova, Stefka N.; Sultanova, Nina G.; Petrova, Tzveta; Dragostinova, Violeta; Nikolov, Ivan

    2009-10-01

    In this report three types of optical polymer thin films deposited on glass substrates are investigated. Transmission spectra of the polymer samples are obtained in the range from 400 nm to 1500 nm. A laser microrefractometer has been used to measure the refractive indices of the examined materials at 406, 656, 910 and 1320 nm. Dispersion properties of the polymer films are analyzed on the base of the Cauchy-Schott's and Sellmeier`s approximations. Dispersion coefficients are calculated and dispersion charts in the visible and near infrared spectral regions are presented and compared. Abbe numbers of mean and partial dispersion of the polymer films are obtained. Calculation of refractive indices at many laser emission wavelengths in the considered spectral range is accomplished.

  15. Characterization of Sulfur Bonding in CdS:O Buffer Layers for CdTe-based Thin-Film Solar Cells.

    Science.gov (United States)

    Duncan, Douglas A; Kephart, Jason M; Horsley, Kimberly; Blum, Monika; Mezher, Michelle; Weinhardt, Lothar; Häming, Marc; Wilks, Regan G; Hofmann, Timo; Yang, Wanli; Bär, Marcus; Sampath, Walajabad S; Heske, Clemens

    2015-08-05

    On the basis of a combination of X-ray photoelectron spectroscopy and synchrotron-based X-ray emission spectroscopy, we present a detailed characterization of the chemical structure of CdS:O thin films that can be employed as a substitute for CdS layers in thin-film solar cells. It is possible to analyze the local chemical environment of the probed elements, in particular sulfur, hence allowing insights into the species-specific composition of the films and their surfaces. A detailed quantification of the observed sulfur environments (i.e., sulfide, sulfate, and an intermediate oxide) as a function of oxygen content is presented, allowing a deliberate optimization of CdS:O thin films for their use as alternative buffer layers in thin-film photovoltaic devices.

  16. Inorganic and Organic Solution-Processed Thin Film Devices

    Institute of Scientific and Technical Information of China (English)

    Morteza Eslamian

    2017-01-01

    Thin films and thin film devices have a ubiquitous presence in numerous conventional and emerging tech-nologies. This is because of the recent advances in nanotechnology, the development of functional and smart materials, conducting polymers, molecular semiconductors, carbon nanotubes, and graphene, and the employment of unique prop-erties of thin films and ultrathin films, such as high surface area, controlled nanostructure for effective charge transfer, and special physical and chemical properties, to develop new thin film devices. This paper is therefore intended to provide a concise critical review and research directions on most thin film devices, including thin film transistors, data storage memory, solar cells, organic light-emitting diodes, thermoelectric devices, smart materials, sensors, and actuators. The thin film devices may consist of organic, inorganic, and composite thin layers, and share similar functionality, properties, and fabrication routes. Therefore, due to the multidisciplinary nature of thin film devices, knowledge and advances already made in one area may be applicable to other similar areas. Owing to the importance of developing low-cost, scalable, and vacuum-free fabrication routes, this paper focuses on thin film devices that may be processed and deposited from solution.

  17. [Spectral analysis of effects of annealing on the characteristics of intrinsic SnO2 polycrystalline thin films].

    Science.gov (United States)

    Zeng, Guang-Gen; Zheng, Jia-Gui; Li, Bing; Chen, Qi; Wu, Li-Li; Li, Wei; Zhang, Jing-Quan; Lei, Zhi; Cai, Ya-Ping; Cai, Wei; Feng, Liang-Huan

    2008-02-01

    In order to improve the conversion efficiency of the CdTe solar cells, it is necessary to decrease the thickness of CdS layer. However, the decrease in CdS thickness may lead to adverse effects on the solar cells. Therefore, a high-resistance transparent layer (intrinsic SnO2) has been used as a buffer layer between the transparent conducting oxide (TCO) and CdS layer. In the present paper, SnO2 polycrystalline thin films were prepared by magnetic reactive sputtering. The properties of the films before and after annealing were studied by XRD and XPS. The results revealed that the films annealed at 550 degrees C for 30 minutesare polycrystalline SnO2 with a single phase of tetragonal structure and have orientation of (110) direction. XPS investigation shows that after annealing the oxygen content of the film increases, O1s peak shifts to lower energies, and SnO is oxidized into SnO2, After annealing the intrinsic SnO2 films of high-resistance as a buffer layer are very suitable for the CdTe solar cells.

  18. A New Method of Fabricating NASICON Thin Film

    Institute of Scientific and Technical Information of China (English)

    WNGLing; SUNJialin; 等

    1998-01-01

    Nasicon thin films of 15 μm thick on YSZ sub-strates were prepared by means of solid state reaction at 1230℃ for 10 hours,Stuctural characteriza-tion of the films were performed by XRD ,SEM and EDX,A new tyype of CO2 gas sensor with Nasicon thin film as solid electrolyte was developed.

  19. Bismuth thin films obtained by pulsed laser deposition

    Science.gov (United States)

    Flores, Teresa; Arronte, Miguel; Rodriguez, Eugenio; Ponce, Luis; Alonso, J. C.; Garcia, C.; Fernandez, M.; Haro, E.

    1999-07-01

    In the present work Bi thin films were obtained by Pulsed Laser Deposition, using Nd:YAG lasers. The films were characterized by optical microscopy. Raman spectroscopy and X-rays diffraction. It was accomplished the real time spectral emission characterization of the plasma generated during the laser evaporation process. Highly oriented thin films were obtained.

  20. Scanning tunneling spectroscopy of Pb thin films

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Michael

    2010-12-13

    The present thesis deals with the electronic structure, work function and single-atom contact conductance of Pb thin films, investigated with a low-temperature scanning tunneling microscope. The electronic structure of Pb(111) thin films on Ag(111) surfaces is investigated using scanning tunneling spectroscopy (STS). Quantum size effects, in particular, quantum well states (QWSs), play a crucial role in the electronic and physical properties of these films. Quantitative analysis of the spectra yields the QWS energies as a function of film thickness, the Pb bulk-band dispersion in {gamma}-L direction, scattering phase shifts at the Pb/Ag interface and vacuum barrier as well as the lifetime broadening at anti {gamma}. The work function {phi} is an important property of surfaces, which influences catalytic reactivity and charge injection at interfaces. It controls the availability of charge carriers in front of a surface. Modifying {phi} has been achieved by deposition of metals and molecules. For investigating {phi} at the atomic scale, scanning tunneling microscopy (STM) has become a widely used technique. STM measures an apparent barrier height {phi}{sub a}, which is commonly related to the sample work function {phi}{sub s} by: {phi}{sub a}=({phi}{sub s}+{phi}{sub t}- vertical stroke eV vertical stroke)/2, with {phi}{sub t} the work function of the tunneling tip, V the applied tunneling bias voltage, and -e the electron charge. Hence, the effect of the finite voltage in STM on {phi}{sub a} is assumed to be linear and the comparison of {phi}{sub a} measured at different surface sites is assumed to yield quantitative information about work function differences. Here, the dependence of {phi}{sub a} on the Pb film thickness and applied bias voltage V is investigated. {phi}{sub a} is found to vary significantly with V. This bias dependence leads to drastic changes and even inversion of contrast in spatial maps of {phi}{sub a}, which are related to the QWSs in the Pb

  1. Research and development of photovoltaic power system. Research on low temperature deposition of polycrystalline thin films; Taiyoko hatsuden system no kenkyu kaihatsu. Teion seimaku gijutsu no kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Sato, K. [Tokyo Univ. of Agriculture and Technology, Tokyo (Japan). Faculty of Technology

    1994-12-01

    This paper reports the result obtained during fiscal 1994 on research on a technology of low temperature deposition of polycrystalline thin films for solar cells. This research used ITO coated glass substrates, on which CdS was accumulated to a thickness of about 100 nm by using the CBD process, and over this deposition a CuInSe2 film was formed at 300{degree}C by using the ion cluster beam (ICB) process. The manufactured solar cells with a glass/ITO/CdS/CuInSe2/Au structure had an efficiency of 2%. In manufacturing a CuGaSe2 thin film by using the ICB process, effects of acceleration voltage relative to cluster beams and ionization current were investigated. It was found that the film morphology, the result of analysis by using X-ray diffraction, and the electric conductivity are sensitive to the ionization current. From these findings, an optimum film forming condition was derived. A CuGaSe2 thin film was manufactured by using the ICB process over a Cds thin film deposited by using the CDB process. Both of the surface morphology and X-ray diffraction patterns of the film did not show a large change, indicating a possibility of manufacturing cells with a reverse structure. Effects of heat treatment on CuInSe2 monocrystals were evaluated by using ESR and FTIR. 6 figs., 1 tab.

  2. Intrinsic instability of thin liquid films on nanostructured surfaces

    Science.gov (United States)

    Rokoni, Arif; Hu, Han; Sun, Liyong; Sun, Ying

    2016-11-01

    The instability of a thin liquid film on nanostructures is not well understood but is important in liquid-vapor two-phase heat transfer (e.g., thin film evaporation and boiling), lubrication, and nanomanufacturing. In thin film evaporation, the comparison between the non-evaporating film thickness and the critical film breakup thickness determines the stability of the film: the film becomes unstable when the critical film breakup thickness is larger than the non-evaporating film thickness. In this study, a closed-form model is developed to predict the critical breakup thickness of a thin liquid film on 2D periodic nanostructures based on minimization of system free energy in the limit of a liquid monolayer. Molecular dynamics simulations are performed for water thin films on square nanostructures of varying depth and wettability and the simulations agree with the model predictions. The results show that the critical film breakup thickness increases with the nanostructure depth and the surface wettability. The model developed here enables the prediction of the minimum film thickness for stable thin film evaporation on a given nanostructure.

  3. Size-dependent photodegradation of CdS particles deposited onto TiO{sub 2} mesoporous films by SILAR method

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Rasin; Will, Geoffrey; Bell, John; Wang Hongxia, E-mail: hx.wang@qut.edu.au [Queensland University of Technology, School of Chemistry, Physics and Mechanical Engineering (Australia)

    2012-09-15

    The particle size, size distribution and photostability of CdS nanoparticles incorporated onto mesoporous TiO{sub 2} films by a successive ionic layer adsorption and reaction (SILAR) method were investigated by Raman spectroscopy, UV-Visible spectroscopy, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). High-resolution TEM indicated that the synthesized CdS particles were hexagonal phase and the particle sizes were less than 5 nm for up to nine SILAR deposition cycles. Quantum size effect was found with the CdS-sensitized TiO{sub 2} films prepared with up to nine SILAR cycles. The band gap of CdS nanoparticles decreased from 2.65 to 2.37 eV with the increase of the SILAR cycles from 1 to 11. The investigation of the stability of the CdS/TiO{sub 2} films in air under illumination (440.6 {mu}W/cm{sup 2}) showed that the photodegradation rate was up to 85 % per day for the sample prepared with three SILAR cycles. XPS analysis indicated that the photodegradation was due to the oxidation of CdS, leading to the transformation from sulphide to sulphate (CdSO{sub 4}). Furthermore, the degradation rate was strongly dependent upon the particle size of CdS. Smaller particles showed faster degradation rate. The size-dependent photo-induced oxidization was rationalized with the variation of size-dependent distribution of surface atoms of CdS particles. Molecular dynamics-based theoretical calculation has indicated that the surface sulphide anion of a large CdS particle such as CdS made with 11 cycles (CdS Multiplication-Sign 11, average particle size = 5.6 nm) accounts for 9.6 % of the material whereas this value is increased to 19.2 % for (CdS Multiplication-Sign 3)-based smaller particles (average particle size = 2.7 nm). The photostability of CdS nanoparticles was significantly enhanced when coated with ZnS particles deposited with four SILAR cycles. The growth mechanism of ZnS upon CdS nanoparticles was discussed.

  4. Cerium Dioxide Thin Films Using Spin Coating

    Directory of Open Access Journals (Sweden)

    D. Channei

    2013-01-01

    Full Text Available Cerium dioxide (CeO2 thin films with varying Ce concentrations (0.1 to 0.9 M, metal basis were deposited on soda-lime-silica glass substrates using spin coating. It was found that all films exhibited the cubic fluorite structure after annealing at 500°C for 5 h. The laser Raman microspectroscopy and GAXRD analyses revealed that increasing concentrations of Ce resulted in an increase in the degree of crystallinity. FIB and FESEM images confirmed the laser Raman and GAXRD analyses results owing to the predicted increase in film thickness with increasing Ce concentration. However, porosity and shrinkage (drying cracking of the films also increased significantly with increasing Ce concentrations. UV-VIS spectrophotometry data showed that the transmission of the films decreased with increasing Ce concentrations due to the increasing crack formation. Furthermore, a red shift was observed with increasing Ce concentrations, which resulted in a decrease in the optical indirect band gap.

  5. Effects of Cd Interlayer on CdS/CdTe Thin Film Photovoltaics

    Science.gov (United States)

    Rivella, David; Cerqueira, Luis; Sahiner, M. Alper

    CdS/CdTe thin films are well known for their photovoltaic effects. However, it is also known that there are various factors that limit the output of the photovoltaic cells. In these particular thin films, a limiting factor is the interaction of CdS and the CdTe layers. By adding a Cd layer between CdS and CdTe, a buffer zone was created. Therefore, the interaction between the aforementioned layers was changed. In this study, the buffer zone was added to the photovoltaic cells, while the ratio of Cd to Te in the CdTe layer was varied, in order to observe the effects of the buffer in regards to the diffusion of Te in traditional CdTe/CdS photovoltaics. The samples were created on ITO coated glass using pulsed laser deposition. This created uniform samples with an approximate thickness of 0.75 microns. In order to test the effect of the Cd buffer layer, the CdTe layers were deposited with varying ratios of Cd to Te. XRD analysis confirmed that the deposited Cd and Te formed crystalline CdTe. The active carrier concentrations were then determined using Hall Effect measurements. The photovoltaic properties were measured using Keithley source meter set-up. The effect of structural modifications on the active carrier concentrations and photovoltaic properties will be discussed.

  6. Electroless plating of thin gold films directly onto silicon nitride thin films and into micropores.

    Science.gov (United States)

    Whelan, Julie C; Karawdeniya, Buddini Iroshika; Bandara, Y M Nuwan D Y; Velleco, Brian D; Masterson, Caitlin M; Dwyer, Jason R

    2014-07-23

    A method to directly electrolessly plate silicon-rich silicon nitride with thin gold films was developed and characterized. Films with thicknesses plating free-standing ultrathin silicon nitride membranes, and we successfully plated the interior walls of micropore arrays in 200 nm thick silicon nitride membranes. The method is thus amenable to coating planar, curved, and line-of-sight-obscured silicon nitride surfaces.

  7. Theoretical investigation of the thermodynamic properties of metallic thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Vu Van [Vietnam Education Publishing House, 81 Tran Hung Dao, Hanoi (Viet Nam); Phuong, Duong Dai [Hanoi National University of Education, 136 Xuan Thuy, Hanoi (Viet Nam); Hoa, Nguyen Thi [University of Transport and Communications, Lang Thuong, Dong Da, Hanoi (Viet Nam); Hieu, Ho Khac, E-mail: hieuhk@duytan.edu.vn [Institute of Research and Development, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam)

    2015-05-29

    The thermodynamic properties of metallic thin films with face-centered cubic structure at ambient conditions were investigated using the statistical moment method including the anharmonicity effects of thermal lattice vibrations. The analytical expressions of Helmholtz free energy, lattice parameter, linear thermal expansion coefficient, specific heats at the constant volume and constant pressure were derived in terms of the power moments of the atomic displacements. Numerical calculations of thermodynamic properties have been performed for Au and Al thin films and compared with those of bulk metals. This research proposes that thermodynamic quantities of thin films approach the values of bulk when the thickness of thin film is about 70 nm. - Highlights: • Thermodynamic properties of thin films were investigated using the moment method. • Expressions of Helmholtz energy, expansion coefficient, specific heats were derived. • Calculations for Au, Al thin films were performed and compared with those of bulks.

  8. Thin-liquid-film evaporation at contact line

    Institute of Scientific and Technical Information of China (English)

    Hao WANG; Zhenai PAN; Zhao CHEN

    2009-01-01

    When a liquid wets a solid wall, the extended meniscus near the contact line may be divided into three regions: a nonevaporating region, where the liquid is adsorbed on the wall; a transition region or thin-film region, where effects of long-range molecular forces (disjoining pressure) are felt; and an intrinsic meniscus region, where capillary forces dominate. The thin liquid film, with thickness from nanometers up to micrometers, covering the transition region and part of intrinsic meniscus, is gaining interest due to its high heat transfer rates. In this paper, a review was made of the researches on thin-liquid-film evaporation. The major characteristics of thin film, thin-film modeling based on continuum theory, simulations based on molecular dynamics, and thin-film profile and temperature measurements were summarized.

  9. Metallic Thin-Film Bonding and Alloy Generation

    Science.gov (United States)

    Fryer, Jack Merrill (Inventor); Campbell, Geoff (Inventor); Peotter, Brian S. (Inventor); Droppers, Lloyd (Inventor)

    2016-01-01

    Diffusion bonding a stack of aluminum thin films is particularly challenging due to a stable aluminum oxide coating that rapidly forms on the aluminum thin films when they are exposed to atmosphere and the relatively low meting temperature of aluminum. By plating the individual aluminum thin films with a metal that does not rapidly form a stable oxide coating, the individual aluminum thin films may be readily diffusion bonded together using heat and pressure. The resulting diffusion bonded structure can be an alloy of choice through the use of a carefully selected base and plating metals. The aluminum thin films may also be etched with distinct patterns that form a microfluidic fluid flow path through the stack of aluminum thin films when diffusion bonded together.

  10. [Preparation of large area Al-ZnO thin film by DC magnetron sputtering].

    Science.gov (United States)

    Jiao, Fei; Liao, Cheng; Han, Jun-Feng; Zhou, Zhen

    2009-03-01

    Solar cells of p-CIS/n-buffer/ZnO type, where CIS is (CuInS2, CuInSe2 or intermediates, are thin-film-based devices for the future high-efficiency and low-cost photovoltaic devices. As important thin film, the properties of Al-doped ZnO (AZO) directly affect the parameter of the cell, especially for large volume. In the present paper, AZO semiconductor transparent thin film on soda-lime glass was fabricated using cylindrical zinc-aluminum target, which can not only lower the cost of the target but also make the preparation of large area AZO thin film more easily. Using the DC magnet sputtering techniques and rolling target, high utilization efficiency of target was achieved and large area uniform and directional film was realized. An introduction to DC magnet sputtering techniques for large area film fabrication is given. With different measurement methods, such as X-ray diffraction (XRD) and scan electron microscope (SEM), we analyzed large size film's structure, appearance, and electrical and optical characteristics. The XRD spectrum indicated that the AZO film shows well zinc-blende structure with a preferred (002) growth and the c-axis is oriented normal to the substrate plane. The lattice constant is 5.603 9 nm and the mismatch with CdS thin film is only 2 percent. It absolutely satisfied the demand of the GIGS solar cell. The cross-section of the AZO thin film indicates the columnar structure and the surface morphology shows that the crystal size is about 50 nm that is consistent with the result of XRD spectrum. By the optical transmission curve, not only the high transmission rate over 85 percent in the visible spectrum between 400 nm and 700 nm was showed but also the band gap 3.1 eV was estimated. And all these parameters can meet the demand of the large area module of GIGS solar cell. The result is that using alloy target and Ar gas, and controlling the appropriate pressure of oxygen, we can get directional, condensed, uniform, high transmitting rate, low

  11. Stripe glasses in ferromagnetic thin films

    Science.gov (United States)

    Principi, Alessandro; Katsnelson, Mikhail I.

    2016-02-01

    Domain walls in magnetic multilayered systems can exhibit a very complex and fascinating behavior. For example, the magnetization of thin films of hard magnetic materials is in general perpendicular to the thin-film plane, thanks to the strong out-of-plane anisotropy, but its direction changes periodically, forming an alternating spin-up and spin-down stripe pattern. The latter is stabilized by the competition between the ferromagnetic coupling and dipole-dipole interactions, and disappears when a moderate in-plane magnetic field is applied. It has been suggested that such a behavior may be understood in terms of a self-induced stripe glassiness. In this paper we show that such a scenario is compatible with the experimental findings. The strong out-of-plane magnetic anisotropy of the film is found to be beneficial for the formation of both stripe-ordered and glassy phases. At zero magnetic field the system can form a glass only in a narrow interval of fairly large temperatures. An in-plane magnetic field, however, shifts the glass transition towards lower temperatures, therefore enabling it at or below room temperature. In good qualitative agreement with the experimental findings, we show that a moderate in-plane magnetic field of the order of 50 mT can lead to the formation of defects in the stripe pattern, which sets the onset of the glass transition.

  12. Orthogonal Thin Film Photovoltaics on Vertical Nanostructures.

    Science.gov (United States)

    Ahnood, Arman; Zhou, H; Suzuki, Y; Sliz, R; Fabritius, T; Nathan, Arokia; Amaratunga, G A J

    2015-12-01

    Decoupling paths of carrier collection and illumination within photovoltaic devices is one promising approach for improving their efficiency by simultaneously increasing light absorption and carrier collection efficiency. Orthogonal photovoltaic devices are core-shell type structures consisting of thin film photovoltaic stack on vertical nanopillar scaffolds. These types of devices allow charge collection to take place in the radial direction, perpendicular to the path of light in the vertical direction. This approach addresses the inherently high recombination rate of disordered thin films, by allowing semiconductor films with minimal thicknesses to be used in photovoltaic devices, without performance degradation associated with incomplete light absorption. This work considers effects which influence the performance of orthogonal photovoltaic devices. Illumination non-uniformity as light travels across the depth of the pillars, electric field enhancement due to the nanoscale size and shape of the pillars, and series resistance due to the additional surface structure created through the use of pillars are considered. All of these effects influence the operation of orthogonal solar cells and should be considered in the design of vertically nanostructured orthogonal photovoltaics.

  13. Nanomechanics of Ferroelectric Thin Films and Heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yulan; Hu, Shenyang Y.; Chen , L.Q.

    2016-08-31

    The focus of this chapter is to provide basic concepts of how external strains/stresses altering ferroelectric property of a material and how to evaluate quantitatively the effect of strains/stresses on phase stability, domain structure, and material ferroelectric properties using the phase-field method. The chapter starts from a brief introduction of ferroelectrics and the Landau-Devinshire description of ferroelectric transitions and ferroelectric phases in a homogeneous ferroelectric single crystal. Due to the fact that ferroelectric transitions involve crystal structure change and domain formation, strains and stresses can be produced inside of the material if a ferroelectric transition occurs and it is confined. These strains and stresses affect in turn the domain structure and material ferroelectric properties. Therefore, ferroelectrics and strains/stresses are coupled to each other. The ferroelectric-mechanical coupling can be used to engineer the material ferroelectric properties by designing the phase and structure. The followed section elucidates calculations of the strains/stresses and elastic energy in a thin film containing a single domain, twinned domains to complicated multidomains constrained by its underlying substrate. Furthermore, a phase field model for predicting ferroelectric stable phases and domain structure in a thin film is presented. Examples of using substrate constraint and temperature to obtain interested ferroelectric domain structures in BaTiO3 films are demonstrated b phase field simulations.

  14. Polarized Neutron Reflectivity Simulation of Ferromagnet/ Antiferromagnet Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Yeon; Lee, Jeong Soo

    2008-02-15

    This report investigates the current simulating and fitting programs capable of calculating the polarized neutron reflectivity of the exchange-biased ferromagnet/antiferromagnet magnetic thin films. The adequate programs are selected depending on whether nonspin flip and spin flip reflectivities of magnetic thin films and good user interface are available or not. The exchange-biased systems such as Fe/Cr, Co/CoO, CoFe/IrMn/Py thin films have been simulated successfully with selected programs.

  15. 3D Field Simulation of Magnetic Thin Film Inductor

    OpenAIRE

    FUJIWARA, Toshiyasu; CHOI, Kyung-Ku; SATO, SHIGEKI

    2006-01-01

    The 3D magnetic field simulations with FEM (finite element method) have been performed to predictand understand the performance of Magnetic Thin Film Inductor (MTFl). Inductor structures of planar electroplated Cu spiralcoil, which are sandwiched and underlaid with magnetic thin films, are considered as the simulation models. The inductance increment of 300% compared to air-core inductor was predicted when the sandwiched 5μm thickness magnetic thin film with relative permeability of 600 was a...

  16. Crystal structure of fiber structured pentacene thin films

    OpenAIRE

    2007-01-01

    This PhD thesis presents a technique based on the grazing incidence crystal truncation rod (GI-CTR) X-ray diffraction method used to solve the crystal structure of substrate induced fiber structured organic thin films. The crystal structures of pentacene thin films grown on technologically relevant gate dielectric substrates are reported. It is widely recognized, that the intrinsic charge transport properties in organic thin film transistors (OTFTs) depend strongly on the crystal structur...

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

    Science.gov (United States)

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

    2016-11-01

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

  18. Improved growth of solution-deposited thin films on polycrystalline Cu(In,Ga)Se{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Witte, Wolfram; Hariskos, Dimitrios [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), 70565, Stuttgart (Germany); Abou-Ras, Daniel [Helmholtz-Zentrum Berlin fuer Materialien und Energie, 14109, Berlin (Germany)

    2016-04-15

    CdS and Zn(O,S) grown by chemical bath deposition (CBD) are well established buffer materials for Cu(In,Ga)Se{sub 2} (CIGS) solar cells. As recently reported, a non-contiguous coverage of CBD buffers on CIGS grains with {112} surfaces can be detected, which was explained in terms of low surface energies of the {112} facets, leading to deteriorated wetting of the chemical solution on the CIGS surface. In the present contribution, we report on the effect of air annealing of CIGS thin films prior to the CBD of CdS and Zn(O,S) layers. In contrast to the growth on the as-grown CIGS layers, these buffer lay- ers grow densely on the annealed CIGS layer, even on grains with {112} surfaces. We explain the different growth behavior by increased surface energies of CIGS grains due to the annealing step, i.e., due to oxidation of the CIGS surface. Reference solar cells were processed and completed by i-ZnO/ZnO:Al layers for CdS and by (Zn,Mg)O/ZnO:Al for Zn(O,S) buffers. For solar cells with both, CdS and Zn(O,S) buffers, air-annealed CIGS films with improved buffer coverage resulted in higher power-conversion efficiencies, as compared with the devices containing as-grown CIGS layers. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Studies on Hall Effect and DC Conductivity Measurements of Semiconductor Thin films Prepared by Chemical Bath Deposition (CBD method

    Directory of Open Access Journals (Sweden)

    S. Thirumavalavana

    2015-12-01

    Full Text Available Semiconductors have various useful properties that can be exploited for the realization of a large number of high performance devices in fields such as electronics and optoelectronics. Many novel semiconductors, especially in the form of thin films, are continually being developed. Thin films have drawn the attention of many researchers because of their numerous applications. As the film becomes thinner, the properties acquire greater importance in the miniaturization of elements such as resistors, transistors, capacitors, and solar cells. In the present work, copper selenide (CuSe, cadmium selenide (CdSe, zinc selenide (ZnSe, lead sulphide (PbS, zinc sulphide (ZnS, and cadmium sulphide (CdS thin films were prepared by chemical bath deposition (CBD method. The prepared thin films were analyzed by using Hall measurements in Van Der Pauw configuration (ECOPIA HMS-3000 at room temperature. The Hall parameters such as Hall mobility of the material, resistivity, carrier concentration, Hall coefficient and conductivity were determined. The DC electrical conductivity measurements were also carried out for the thin films using the conventional two – probe technique. The activation energies were also calculated from DC conductivity studies.

  20. Effect of thermal annealing on structural and optical properties of In{sub 2}S{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Choudhary, Sonu, E-mail: sonuchoudhary1983@gmail.com [Department of Physics, Mohanlal Sukhadia University, Udaipur-313001 (India)

    2015-08-28

    There is a highly need of an alternate of toxic materials CdS for solar cell applications and indium sulfide is found the most suitable candidate to replace CdS due to its non-toxic and environmental friendly nature. In this paper, the effect of thermal annealing on the structural and optical properties of indium sulfide (In{sub 2}S{sub 3}) thin films is undertaken. The indium sulfide thin films of 121 nm were deposited on glass substrates employing thermal evaporation method. The films were subjected to the X-ray diffractometer and UV-Vis spectrophotometer respectively for structural and optical analysis. The XRD pattern show that the as-deposited thin film was amorphous in nature and crystallinity is found to be varied with annealing temperature. The optical analysis reveals that the optical band gap is varied with annealing. The optical parameters like absorption coefficient, extinction coefficient and refractive index were calculated. The results are in good agreement with available literature.

  1. Current-induced surface roughness reduction in conducting thin films

    Science.gov (United States)

    Du, Lin; Maroudas, Dimitrios

    2017-03-01

    Thin film surface roughness is responsible for various materials reliability problems in microelectronics and nanofabrication technologies, which requires the development of surface roughness reduction strategies. Toward this end, we report modeling results that establish the electrical surface treatment of conducting thin films as a physical processing strategy for surface roughness reduction. We develop a continuum model of surface morphological evolution that accounts for the residual stress in the film, surface diffusional anisotropy and film texture, film's wetting of the layer that is deposited on, and surface electromigration. Supported by linear stability theory, self-consistent dynamical simulations based on the model demonstrate that the action over several hours of a sufficiently strong and properly directed electric field on a conducting thin film can reduce its surface roughness and lead to a smooth planar film surface. The modeling predictions are in agreement with experimental measurements on copper thin films deposited on silicon nitride layers.

  2. Polycrystalline-thin-film thermophotovoltaic cells

    Science.gov (United States)

    Dhere, Neelkanth G.

    1996-02-01

    Thermophotovoltaic (TPV) cells convert thermal energy to electricity. Modularity, portability, silent operation, absence of moving parts, reduced air pollution, rapid start-up, high power densities, potentially high conversion efficiencies, choice of a wide range of heat sources employing fossil fuels, biomass, and even solar radiation are key advantages of TPV cells in comparison with fuel cells, thermionic and thermoelectric convertors, and heat engines. The potential applications of TPV systems include: remote electricity supplies, transportation, co-generation, electric-grid independent appliances, and space, aerospace, and military power applications. The range of bandgaps for achieving high conversion efficiencies using low temperature (1000-2000 K) black-body or selective radiators is in the 0.5-0.75 eV range. Present high efficiency convertors are based on single crystalline materials such as In1-xGaxAs, GaSb, and Ga1-xInxSb. Several polycrystalline thin films such as Hg1-xCdxTe, Sn1-xCd2xTe2, and Pb1-xCdxTe, etc., have great potential for economic large-scale applications. A small fraction of the high concentration of charge carriers generated at high fluences effectively saturates the large density of defects in polycrystalline thin films. Photovoltaic conversion efficiencies of polycrystalline thin films and PV solar cells are comparable to single crystalline Si solar cells, e.g., 17.1% for CuIn1-xGaxSe2 and 15.8% for CdTe. The best recombination-state density Nt is in the range of 10-15-10-16 cm-3 acceptable for TPV applications. Higher efficiencies may be achieved because of the higher fluences, possibility of bandgap tailoring, and use of selective emitters such as rare earth oxides (erbia, holmia, yttria) and rare earth-yttrium aluminium garnets. As compared to higher bandgap semiconductors such as CdTe, it is easier to dope the lower bandgap semiconductors. TPV cell development can benefit from the more mature PV solar cell and opto

  3. Design and Simulation of the Thin Film Pulse Transformer

    Institute of Scientific and Technical Information of China (English)

    LIU Bao-yuan; SHI Yu; WEN Qi-ye

    2005-01-01

    A new thin film pulse transformer for using in ISND and ADSL systems has been designed based on a domain wall pinning model, the parameters of nano-magnetic thin film such as permeability and coercivity can be calculated. The main properties of the thin film transformer including the size,parallel inductance, Q value and turn ratio have been simulated and optimized. Simulation results show that the thin film transformer can be fairly operated in a frequency range of 0. 001~20 MHz.

  4. Non-local thin films in Casimir force calculations

    CERN Document Server

    Esquivel, R

    2005-01-01

    he Casimir force is calculated between plates with thin metallic coating. Thin films are described with spatially dispersive (nonlocal) dielectric functions. For thin films the nonlocal effects are more relevant than for half-spaces. However, it is shown that even for film thickness smaller than the mean free path for electrons, the difference between local and nonlocal calculations of the Casimir force is of the order of a few tenths of a percent. Thus the local description of thin metallic films is adequate within the current experimental precision and range of separations.

  5. Characterizations of photoconductivity of graphene oxide thin films

    Directory of Open Access Journals (Sweden)

    Shiang-Kuo Chang-Jian

    2012-06-01

    Full Text Available Characterizations of photoresponse of a graphene oxide (GO thin film to a near infrared laser light were studied. Results showed the photocurrent in the GO thin film was cathodic, always flowing in an opposite direction to the initial current generated by the preset bias voltage that shows a fundamental discrepancy from the photocurrent in the reduced graphene oxide thin film. Light illumination on the GO thin film thus results in more free electrons that offset the initial current. By examining GO thin films reduced at different temperatures, the critical temperature for reversing the photocurrent from cathodic to anodic was found around 187°C. The dynamic photoresponse for the GO thin film was further characterized through the response time constants within the laser on and off durations, denoted as τon and τoff, respectively. τon for the GO thin film was comparable to the other carbon-based thin films such as carbon nanotubes and graphenes. τoff was, however, much larger than that of the other's. This discrepancy was attributable to the retardation of exciton recombination rate thanks to the existing oxygen functional groups and defects in the GO thin films.

  6. Sputtering materials for VLSI and thin film devices

    CERN Document Server

    Sarkar, Jaydeep

    2010-01-01

    An important resource for students, engineers and researchers working in the area of thin film deposition using physical vapor deposition (e.g. sputtering) for semiconductor, liquid crystal displays, high density recording media and photovoltaic device (e.g. thin film solar cell) manufacturing. This book also reviews microelectronics industry topics such as history of inventions and technology trends, recent developments in sputtering technologies, manufacturing steps that require sputtering of thin films, the properties of thin films and the role of sputtering target performance on overall p

  7. Physics of thin films advances in research and development

    CERN Document Server

    Hass, Georg; Vossen, John L

    2013-01-01

    Physics of Thin Films: Advances in Research and Development, Volume 12 reviews advances that have been made in research and development concerning the physics of thin films. This volume covers a wide range of preparative approaches, physics phenomena, and applications related to thin films. This book is comprised of four chapters and begins with a discussion on metal coatings and protective layers for front surface mirrors used at various angles of incidence from the ultraviolet to the far infrared. Thin-film materials and deposition conditions suitable for minimizing reflectance changes with

  8. Thin-Film Materials Synthesis and Processing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides a wide capability for deposition and processing of thin films, including sputter and ion-beam deposition, thermal evaporation, electro-deposition,...

  9. Atomic Structure Control of Silica Thin Films on Pt(111)

    KAUST Repository

    Crampton, Andrew S

    2015-05-27

    Metal oxide thin films grown on metal single crystals are commonly used to model heterogeneous catalyst supports. The structure and properties of thin silicon dioxide films grown on metal single crystals have only recently been thoroughly characterized and their spectral properties well established. We report the successful growth of a three- dimensional, vitreous silicon dioxide thin film on the Pt(111) surface and reproduce the closed bilayer structure previously reported. The confirmation of the three dimensional nature of the film is unequivocally shown by the infrared absorption band at 1252 cm−1. Temperature programmed desorption was used to show that this three-dimensional thin film covers the Pt(111) surface to such an extent that its application as a catalyst support for clusters/nanoparticles is possible. The growth of a three-dimensional film was seen to be directly correlated with the amount of oxygen present on the surface after the silicon evaporation process. This excess of oxygen is tentatively attributed to atomic oxygen being generated in the evaporator. The identification of atomic oxygen as a necessary building block for the formation of a three-dimensional thin film opens up new possibilities for thin film growth on metal supports, whereby simply changing the type of oxygen enables thin films with different atomic structures to be synthesized. This is a novel approach to tune the synthesis parameters of thin films to grow a specific structure and expands the options for modeling common amorphous silica supports under ultra high vacuum conditions.

  10. Dynamics of photoexcited carrier relaxation and recombination in CdTe/CdS thin films

    Energy Technology Data Exchange (ETDEWEB)

    Levi, D.H.; Fluegel, B.D.; Ahrenkiel, R.K. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-05-01

    Efficiency-limiting defects in photovoltaic devices are readily probed by time-resolved spectroscopy. This paper presents the first direct optical measurements of the relaxation and recombination pathways of photoexcited carriers in the CdS window layer of CdTe/CdS polycrystalline thin films. Femtosecond time-resolved pump/probe measurements indicate the possible existence of a two-phase CdS/CdSTe layer, rather than a continuously graded alloy layer at the CdTe/CdS interface. Complementary time-resolved photoluminescence (PL) measurements show that the photoexcited carriers are rapidly captured by deep-level defects. The temporal and density-dependent properties of the photoluminescence prove that the large Stokes shift of the PL relative to the band edge is due to strong phonon coupling to deep-level defects in CdS. The authors suggest that modifications in the CdS processing may enhance carrier collection efficiency in the blue spectral region.

  11. Dip coated nanocrystalline CdZnS thin films for solar cell application

    Energy Technology Data Exchange (ETDEWEB)

    Dongre, J. K., E-mail: jk-dongre@yahoo.com; Chaturvedi, Mahim; Patil, Yuvraj; Sharma, Sandhya; Jain, U. K. [Government Autonomous Post Graduate College Chhindwara, 480001 (India)

    2015-07-31

    Nanocrystalline cadmium sulfide (CdS) and zinc cadmium sulfide (ZnCdS) thin films have been grown via simple and low cost dip coating technique. The prepared films are characterized by X-ray diffraction (XRD), atomic force microscopic (AFM) and UV-VIS spectrophotometer techniques to reveal their structural, morphological and optical properties. XRD shows that both samples grown have zinc blende structure. The grain size is calculated as 6.2 and 8 nm using Scherrer’s formula. The band gap value of CdS and CdZnS film is estimated to be 2.58 and 2.69 eV respectively by UV-vis spectroscopy. Photoelectrochemical (PEC) investigations are carried out using cell configuration as n-CdZnS/(1M NaOH + 1M Na2S + 1M S)/C. The photovoltaic output characteristic is used to calculate fill-factor (FF) and solar conversion efficiency (η)

  12. Performance Comparison of Thin and Thick Film Microstrip Rejection Filters

    OpenAIRE

    Mandhare, M. M.; S.A. Gangal; M. S. Setty; Karekar, R. N.

    1988-01-01

    A performance comparison of microstripline circuits using thin and thick film techniques has been studied, in which a Microstrip rejection filter, in the X-band of microwaves, is used as test circuit. A thick film technique is capable of giving good adhesive films with comparable d.c. sheet resistivity, but other parameters such as open area (porosity), particle size, and edge definition are inferior to thin-film microstrip filters. Despite this drawback, the average value of transmission, tr...

  13. Electrical Resistance Tomography of Conductive Thin Films

    CERN Document Server

    Cultrera, Alessandro

    2016-01-01

    The Electrical Resistance Tomography (ERT) technique is applied to the measurement of sheet conductance maps of both uniform and patterned conductive thin films. Images of the sheet conductance spatial distribution, and local conductivity values are obtained. Test samples are tin oxide films on glass substrates, with electrical contacts on the sample boundary, some samples are deliberately patterned in order to induce null conductivity zones of known geometry while others contain higher conductivity inclusions. Four-terminal resistance measurements among the contacts are performed with a scanning setup. The ERT reconstruction is performed by a numerical algorithm based on the total variation regularization and the L-curve method. ERT correctly images the sheet conductance spatial distribution of the samples. The reconstructed conductance values are in good quantitative agreement with independent measurements performed with the van der Pauw and the four-point probe methods.

  14. Electron impinging on metallic thin film targets

    Energy Technology Data Exchange (ETDEWEB)

    Rouabah, Z. [Laboratoire de Physique Moleculaire et des Collisions, ICPMB (FR CNRS 2843), Institut de Physique, Universite Paul Verlaine-Metz, Metz Cedex 3 (France); Laboratoire Materiaux et Systemes Electroniques, Centre Universitaire de Bordj-Bou-Arreridj, El-Anasser, 34265 Bordj-Bou-Arreridj (Algeria); Bouarissa, N., E-mail: N_Bouarissa@yahoo.fr [Department of Physics, Faculty of Science, King Khalid University, Abha, P.O.Box 9004 (Saudi Arabia); Champion, C. [Laboratoire de Physique Moleculaire et des Collisions, ICPMB (FR CNRS 2843), Institut de Physique, Universite Paul Verlaine-Metz, Metz Cedex 3 (France)

    2010-03-15

    Based on the Vicanek and Urbassek theory [M. Vicanek, H.M. Urbassek, Phys. Rev. B 44 (1991) 7234] combined to a home-made Monte Carlo simulation, the present work deals with backscattering coefficients, mean penetration depths and stopping profiles for 1-4 keV electrons normally incident impinging on Al and Cu thin film targets. The cross-sections used to describe the electron transport are calculated via the appropriate analytical expression given by Jablonski [A. Jablonski, Phys. Rev. B 58 (1998) 16470] whose new improved version has been recently given [Z. Rouabah, N. Bouarissa, C. Champion, N. Bouaouadja, Appl. Surf. Sci. 255 (2009) 6217]. The behavior of the backscattering coefficient, mean penetration depth and stopping profiles versus the metallic film thickness at the nanometric scale and beyond is here analyzed and discussed.

  15. Analysis on mechanism of thin film lubrication

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chaohui; LUO Jianbin; HUANG Zhiqiang

    2005-01-01

    It is an important concern to explore the properties and principles of lubrication at nano or molecularscale. For a long time, measurement apparatus for filmthickness of thin film lubrication (TFL) at nano scale havebeen devised on the basis of superthin interferometry technique. Many experiments were carried out to study the lubrication principles of TFL by taking advantages of aforementioned techniques, in an attempt to unveil the mechanism of TFL. Comprehensive experiments were conducted to explore the distinctive characteristics of TFL. Results show that TFL is a distinctive lubrication state other than any known lubrication ones, and serves as a bridge between elastohydrodynamic lubrication (EHL) and boundary lubrication (BL). Two main influence factors of TFL are the solid surface effects and the molecular properties of the lubricant, whose combination effects result in alignment of liquid molecules near the solid surfaces and subsequently lubrication with ordered film emerged. Results of theoretical analysis considering microstructure are consistent with experimental outcomes, thus validating the proposed mechanism.

  16. Separation Efficiency of Thin-film Evaporators

    Institute of Scientific and Technical Information of China (English)

    R.Billet

    2004-01-01

    The recovery of contaminants and useful substances from liquid wastes, the purification of production effluents and the separation of thermally instable mixtures are some of the multivarious applications of thin-film distillors in many processes of the chemical and allied industries and of the food industries. In a study carried out in pilot plants with distillation test systems there was found a good agreement between the experimental separation results and those obtained by computing with a theorectical model; the latter is based on the assumption of phase equilibrium between the vapour formed on an infinitely small element of area in a liquid film of any given concentric periphery of the vertically arranged evaporator. These tests were perfomed under various phase loads.

  17. Birefringent thin films and polarizing elements

    CERN Document Server

    Hodgkinson, Ian J

    1997-01-01

    This book describes the propagation of light in biaxial media, the properties of biaxial thin films, and applications such as birefringent filters for tuning the wavelength of dye lasers.A novel feature of the first part is the parallel treatment of Stokes, Jones, and Berreman matrix formalisms in a chapter-by-chapter development of wave equations, basis vectors, transfer matrices, reflection and transmission equations, and guided waves. Computational tools for MATLAB are included.The second part focuses on an emerging planar technology in which anisotropic microstructures are formed by obliqu

  18. Synthesis and Characterization of Thin Films.

    Science.gov (United States)

    1987-07-10

    j,k tinteger; freq comp % array CO..203 of integer; A, phase ~carg : array CC. .2CJ of realI begin woriteln(’enter numfourierpts’);N readln(num fourier...Thesis DTIG SELECTfE: rmas do~amaat hau s appvildlttb tol a.l e... . . .o fix paut reloc~e and 9010) Is . < " ,,.’. 5’ , , "" "’’"°"" % Is ViifmyI lr...URIP) grants. 2. THIN FILM FACILITY A 1983 DoD University Research Instrumentation Program Grant to ISU was used for construction of the first phase

  19. Infrared control coating of thin film devices

    Energy Technology Data Exchange (ETDEWEB)

    Berland, Brian Spencer; Stowell, Jr., Michael Wayne; Hollingsworth, Russell

    2017-02-28

    Systems and methods for creating an infrared-control coated thin film device with certain visible light transmittance and infrared reflectance properties are disclosed. The device may be made using various techniques including physical vapor deposition, chemical vapor deposition, thermal evaporation, pulsed laser deposition, sputter deposition, and sol-gel processes. In particular, a pulsed energy microwave plasma enhanced chemical vapor deposition process may be used. Production of the device may occur at speeds greater than 50 Angstroms/second and temperatures lower than 200.degree. C.

  20. Robust, Thin Optical Films for Extreme Environments

    Science.gov (United States)

    2006-01-01

    The environment of space presents scientists and engineers with the challenges of a harsh, unforgiving laboratory in which to conduct their scientific research. Solar astronomy and X-ray astronomy are two of the more challenging areas into which NASA scientists delve, as the optics for this high-tech work must be extremely sensitive and accurate, yet also be able to withstand the battering dished out by radiation, extreme temperature swings, and flying debris. Recent NASA work on this rugged equipment has led to the development of a strong, thin film for both space and laboratory use.

  1. Thin-film optical shutter. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Matlow, S.L.

    1981-02-01

    A specific embodiment of macroconjugated macromolecules, the poly (p-phenylene)'s, has been chosen as the one most likely to meet all of the requirements of the Thin Film Optical Shutter project (TFOS). The reason for this choice is included. In order to be able to make meaningful calculations of the thermodynamic and optical properties of the poly (p-phenylene)'s a new quantum mechanical method was developed - Equilibrium Bond Length (EBL) Theory. Some results of EBL Theory are included.

  2. Vortex motion in YBCO thin films

    Science.gov (United States)

    Shapiro, V.; Verdyan, A.; Lapsker, I.; Azoulay, J.

    1999-09-01

    Hall resistivity measurements as function of temperature in the vicinity of Tc were carried out on a thin films YBCO superconductors. A sign reversal of Hall voltage with external magnetic field applied along c axis have been observed upon crossing Tc. Hall voltage in the mixed state was found to be insensitive to the external magnetic field inversion. These effects are discussed and explained in terms of vortex motion under the influence of Magnus force balanced by large damping force. It is argued that in this model the flux-line velocity has component opposite to the superfluid current direction thus yielding a negative Hall voltage.

  3. Nitrogen incorporation in sputter deposited molybdenum nitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Stöber, Laura, E-mail: laura.stoeber@tuwien.ac.at; Patocka, Florian, E-mail: florian.patocka@tuwien.ac.at; Schneider, Michael, E-mail: michael.schneider@tuwien.ac.at; Schmid, Ulrich, E-mail: ulrich.e366.schmid@tuwien.ac.at [Institute of Sensor and Actuator Systems, TU Wien, Gußhausstraße 27-29, A-1040 Vienna (Austria); Konrath, Jens Peter, E-mail: jenspeter.konrath@infineon.com; Haberl, Verena, E-mail: verena.haberl@infineon.com [Infineon Technologies Austria AG, Siemensstraße 2, 9500 Villach (Austria)

    2016-03-15

    In this paper, the authors report on the high temperature performance of sputter deposited molybdenum (Mo) and molybdenum nitride (Mo{sub 2}N) thin films. Various argon and nitrogen gas compositions are applied for thin film synthetization, and the amount of nitrogen incorporation is determined by Auger measurements. Furthermore, effusion measurements identifying the binding conditions of the nitrogen in the thin film are performed up to 1000 °C. These results are in excellent agreement with film stress and scanning electron microscope analyses, both indicating stable film properties up to annealing temperatures of 500 °C.

  4. Phase transitions in pure and dilute thin ferromagnetic films

    Science.gov (United States)

    Korneta, W.; Pytel, Z.

    1983-10-01

    The mean-field model of a thin ferromagnetic film where the nearest-neighbor exchange coupling in surface layers can be different from that inside the film is considered. The phase diagram, equations for the second-order phase-transition lines, and the spontaneous magnetization profiles near the phase transitions are given. It is shown that there is no extra-ordinary transition in a thin film. If the thickness of the film tends to infinity the well-known results for the mean-field model of a semi-infinite ferromagnet are obtained. The generalization for disordered dilute thin ferromagnetic films and semi-infinite ferromagnets is also given.

  5. Capillary instabilities in thin films. II. Kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Srolovitz, D.J.; Safran, S.A.

    1986-07-01

    We consider the kinetic evolution of perturbations to thin films. Since all small (nonsubstrate intersecting) perturbations to the film surface decay, we consider the evolution of large perturbations, in the form of a single hole which exposes the substrate. For large holes, the hole radius increases at a constant rate under the assumption of evaporation/condensation kinetics. When the dominant transport mode is surface diffusion, large holes grow with a rate proportional to t/sup -3/4/ (log/sup 3/(t/ rho/sup 4//sub c/)). Small holes with a radii less than rho/sub c/ shrink, where rho/sub c/ is the film thickness divided by the tangent of the equilibrium wetting angle. The growth of these holes eventually leads to hole impingement which ruptures the film, creating a set of disconnected islands. The relaxation time for these islands to go to their equilibrium shape and size (rho/sub eq/) scales as rho/sup 2//sub eq/ or rho/sup 4//sub eq/ for evaporation/condensation or surface diffusion kinetics, respectively.

  6. Growth and Characterization of CdS Polycrystalline Films by Electron Beam Evaporation%电子束蒸发制备CdS多晶薄膜及性质研究

    Institute of Scientific and Technical Information of China (English)

    杨定宇; 郑家贵; 朱兴华; 魏昭荣; 杨军; 高秀英

    2009-01-01

    The CdS thin films were grown by electron beam evaporation on glass substrates elevated at different temperatures.The impacts of the film growth conditions on its properties were studied.The microstructures and properties of the CdS film were characterized with X-ray diffraction(XRD),scanning electron microscopy(SEM)and conventional optical probes.The results show that the substrate temperature significantly affects the films growth and its properties.For instance,as substrate temperature rises up,the hexagonal grains with 〈002〉preferential orientation get bigger;the〈103〉,〈004〉and〈105〉orientations in the increasingly compact films gradually show up;and the wide absorption edge of the polycrystalline CdS films become steeper.The averaged transmittance of visible light after 550nm in CdS films was found to be 70%,good enough for the window material of CdTe solar cells.%采用电子束蒸发工艺在普通玻璃衬底上制备了硫化镉(CdS)多晶薄膜,研究了不同衬底温度对薄膜结构、表面形貌及光透过率的影响.测试结果显示:(1)不同衬底温度下沉积的CdS薄膜均呈现了〈002〉晶向的高度优势生长,属于六方相结构.随着衬底温度的升高,还逐渐出现了〈103〉、〈004〉、〈105〉等六方晶向;(2)CdS多晶薄膜表面连续,致密性好,且晶粒大小随着衬底温度的升高而增大;(3)低温下制备CdS薄膜吸收谱有较宽的吸收边,随着衬底温度的升高,吸收曲线趋于陡直.制备样品在550nm波段后的平均透过率都超过70%,符合作为CdTe太阳电池的窗口层.

  7. Calculation of Specific Heat for Aluminium Thin Films

    Institute of Scientific and Technical Information of China (English)

    LU Yao; SONG Qing-Lin; XIA Shan-Hong

    2005-01-01

    @@ We employ Prasher's non-dimensional form to analyse the size effects on specific heat of Al thin films. Compared the calculation results of pure aluminium film with the experimental data, it is found that the reduction of phonon states is not the main reason of the size effect on the specific heat Al thin films with thickness from 10hm to 370nm. However, the Al thin film in air usually has an oxidation layer and the specific heat of the layer is smaller than Al. By including the contribution of the oxidation layer to the thin-film specific heat, the calculation results are much closer to the experimental data. This may be a possible reason of the size effects on specific heat of Al thin films.

  8. Visible light photocatalysis via 3D-ordered macroporous TiO2 films sensitized with CdS quantum dots.

    Science.gov (United States)

    Xie, Hao; Zeng, Tao; Jin, Shaofen; Li, Yuanzhi; Wang, Xuelai; Sui, Xiaotao; Zhao, Xiujian

    2013-02-01

    CdS quantum dots (QDs)-sensitized TiO2 film with three-dimensionally (3D) ordered macropores was synthesized via a two-step method on ITO glass substrate. 3D-ordered macroporous TiO2 film was firstly fabricated on an ITO glass via layer-by-layer deposition and hydrolysis of tetrabutyl titanate using 3D-ordered latex film as organic template, followed by calcination at 450 degrees C for 2 h to remove the template. Then, the CdS QDs were deposited on the 3D-ordered macroporous TiO2 film by successive ionic layer adsorption and reaction technique. The as-prepared CdS-sensitized TiO2 film was characterized with X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, diffusive reflectance UV-visible absorption spectra, and photoelectrochemical measurements. Its photocatalytic activity was evaluated by the photocatalytic degradation of crystal violet aqueous solution at ambient temperature. It was revealed in our results that the CdS QDs-sensitized 3D-ordered macroporous TiO2 film exhibits enhanced photocatalytic activity for the photodegradation of crystal violet than that of the CdS-free 3D-ordered macroporous TiO2 film and that of CdS QD-sensitized TiO2 film without 3D-ordered macropores under the irradiation of visible light due to the co-existence of 3D-ordered interconnected macropores and the sensitization of CdS QDs.

  9. Antimony selenide thin-film solar cells

    Science.gov (United States)

    Zeng, Kai; Xue, Ding-Jiang; Tang, Jiang

    2016-06-01

    Due to their promising applications in low-cost, flexible and high-efficiency photovoltaics, there has been a booming exploration of thin-film solar cells using new absorber materials such as Sb2Se3, SnS, FeS2, CuSbS2 and CuSbSe2. Among them, Sb2Se3-based solar cells are a viable prospect because of their suitable band gap, high absorption coefficient, excellent electronic properties, non-toxicity, low cost, earth-abundant constituents, and intrinsically benign grain boundaries, if suitably oriented. This review surveys the recent development of Sb2Se3-based solar cells with special emphasis on the material and optoelectronic properties of Sb2Se3, the solution-based and vacuum-based fabrication process and the recent progress of Sb2Se3-sensitized and Sb2Se3 thin-film solar cells. A brief overview further addresses some of the future challenges to achieve low-cost, environmentally-friendly and high-efficiency Sb2Se3 solar cells.

  10. Rechargeable thin-film lithium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Bates, J.B.; Gruzalski, G.R.; Dudney, N.J.; Luck, C.F.; Yu, X.

    1993-09-01

    Rechargeable thin-film batteries consisting of lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have been fabricated and characterized. These include Li-TiS{sub 2}, Li-V{sub 2}O{sub 5}, and Li-Li{sub x}Mn{sub 2}O{sub 4} cells with open circuit voltages at full charge of about 2.5 V, 3.7 V, and 4.2 V, respectively. The realization of these robust cells, which can be cycled thousands of times, was possible because of the stability of the amorphous lithium electrolyte, lithium phosphorus oxynitride. This material has a typical composition of Li{sub 2.9}PO{sub 3.3}N{sub 0.46}and a conductivity at 25 C of 2 {mu}S/cm. The thin-film cells have been cycled at 100% depth of discharge using current densities of 5 to 100 {mu}A/cm{sup 2}. Over most of the charge-discharge range, the internal resistance appears to be dominated by the cathode, and the major source of the resistance is the diffusion of Li{sup +} ions from the electrolyte into the cathode. Chemical diffusion coefficients were determined from ac impedance measurements.

  11. Thin-film cadmium telluride photovoltaic cells. Final subcontract report, 1 November 1992--1 January 1994

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, A.D.; Bohn, R.G. [Toledo Univ., OH (United States)

    1994-09-01

    This report describes work to develop and optimize radio-frequency (rf) sputtering for the deposition of thin films of cadmium telluride (CdTe) and related semiconductors for thin-film solar cells. Pulsed laser physical vapor deposition was also used for exploratory work on these materials, especially where alloying or doping are involved, and for the deposition of cadmium chloride layers. The sputtering work utilized a 2-in diameter planar magnetron sputter gun. The film growth rate by rf sputtering was studied as a function of substrate temperature, gas pressure, and rf power. Complete solar cells were fabricated on tin-oxide-coated soda-lime glass substrates. Currently, work is being done to improve the open-circuit voltage by varying the CdTe-based absorber layer, and to improve the short-circuit current by modifying the CdS window layer.

  12. Polycystalline silicon thin films for electronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, Christian Claus

    2012-01-15

    For the thin polycrystalline Si films fabricated with the aluminium-induced-layer-exchange (ALILE) process a good structural quality up to a layer-thickness value of 10 nm was determined. For 5 nm thick layers however after the layer exchange no closes poly-silicon film was present. In this case the substrate was covered with spherically arranged semiconductor material. Furthermore amorphous contributions in the layer could be determined. The electrical characterization of the samples at room temperature proved a high hole concentration in the range 10{sup 18} cm{sup -3} up to 9.10{sup 19} cm{sup -3}, which is influenced by the process temperature and the layer thickness. Hereby higher hole concentrations at higher process temperatures and thinner films were observed. Furthermore above 150-200 K a thermically activated behaviour of the electrical conductivity was observed. At lower temperatures a deviation of the measured characteristic from the exponential Arrhenius behaviour was determined. For low temperatures (below 20 K) the conductivity follows the behaviour {sigma}{proportional_to}[-(T{sub 0}/T){sup 1/4}]. The hole mobility in the layers was lowered by a passivation step, which can be explained by defect states at the grain boundaries. The for these very thin layers present situation was simulated in the framework of the model of Seto, whereby both the defect states at the grain boundaries (with an area density Q{sub t}) and the defect states at the interfaces (with an area density Q{sub it}) were regarded. By this the values Q{sub t}{approx}(3-4).10{sup 12} cm{sup -2} and Q{sub it}{approx}(2-5).10{sup 12} cm{sup -2} could be determined for these thin ALILE layers on quartz substrates. Additionally th R-ALILE process was studied, which uses the reverse precursor-layer sequence substrate/amorphous silicon/oxide/aluminium. Hereby two steps in the crystallization process of the R-ALILE process were found. First a substrate/Al-Si mixture/poly-Si layer structure

  13. Theory and practical considerations of multilayer dielectric thin-film stacks in Ag-coated hollow waveguides.

    Science.gov (United States)

    Bledt, Carlos M; Melzer, Jeffrey E; Harrington, James A

    2014-02-01

    This analysis explores the theory and design of dielectric multilayer reflection-enhancing thin film stacks based on high and low refractive index alternating layers of cadmium sulfide (CdS) and lead sulfide (PbS) on silver (Ag)-coated hollow glass waveguides (HGWs) for low loss transmission at midinfrared wavelengths. The fundamentals for determining propagation losses in such multilayer thin-film-coated Ag hollow waveguides is thoroughly discussed, and forms the basis for further theoretical analysis presented in this study. The effects on propagation loss resulting from several key parameters of these multilayer thin film stacks is further explored in order to bridge the gap between results predicted through calculation under ideal conditions and deviations from such ideal models that often arise in practice. In particular, the effects on loss due to the number of dielectric thin film layers deposited, deviation from ideal individual layer thicknesses, and surface roughness related scattering losses are presented and thoroughly investigated. Through such extensive theoretical analysis the level of understanding of the underlying loss mechanisms of multilayer thin-film Ag-coated HGWs is greatly advanced, considerably increasing the potential practical development of next-generation ultralow-loss mid-IR Ag/multilayer dielectric-coated HGWs.

  14. Analysis and optimization of thin film photovoltaic materials and device fabrication by real time spectroscopic ellipsometry

    Science.gov (United States)

    Li, Jian; Stoke, Jason A.; Podraza, Nikolas J.; Sainju, Deepak; Parikh, Anuja; Cao, Xinmin; Khatri, Himal; Barreau, Nicolas; Marsillac, Sylvain; Deng, Xunming; Collins, Robert W.

    2007-09-01

    Methods of spectroscopic ellipsometry (SE) have been applied to investigate the growth and properties of the material components used in the three major thin film photovoltaics technologies: (1) hydrogenated silicon (Si:H); (2) cadmium telluride (CdTe); and (3) copper indium-gallium diselenide (CuIn 1-xGa xSe2 or CIGS). In Si:H technology, real time SE (RTSE) has been applied to establish deposition phase diagrams that describe very high frequency (vhf) plasmaenhanced chemical vapor deposition (PECVD) processes for hydrogenated silicon (Si:H) and silicon-germanium alloy (Si 1-xGe x:H) thin films. This study has reaffirmed that the highest efficiencies for a-Si:H and a-Si 1-xGe x:H component solar cells of multijunction devices are obtained when the i-layers are prepared under maximal H II dilution conditions. In CdTe technology, the magnetron sputter deposition of polycrystalline CdTe, CdS, and CdTe 1-xS x thin films as well as the formation of CdS/CdTe and CdTe/CdS heterojunctions has been studied. The nucleation and growth behaviors of CdTe and CdS show strong variations with deposition temperature, and this influences the ultimate grain size. The dielectric functions ɛ of the CdTe 1-xS x alloys have been deduced in order to set up a database for real time investigation of inter-diffusion at the CdS/CdTe and CdTe/CdS interfaces. In CIGS technology, strong variations in ɛ of the Mo back contact during sputter deposition have been observed, and these results have been understood applying a Drude relaxation time that varies with the Mo film thickness. Ex-situ SE measurements of a novel In IIS 3 window layer have shown critical point structures at 2.77+/-0.08 eV, 4.92+/-0.005 eV, and 5.64+/-0.005 eV, as well as an absorption tail with an onset near 1.9 eV. Simulations of solar cell performance comparing In IIS 3 and the conventional CdS have revealed similar quantum efficiencies, suggesting the possibility of a Cd-free window layer in CIGS technology.

  15. Exploring Cd-Zn-O-S alloys for optimal buffer layers in thin-film photovoltaics

    Science.gov (United States)

    Varley, J.; He, X.; Mackie, N.; Rockett, A.; Lordi, V.

    2015-03-01

    The development of thin-film photovoltaics has largely focused on alternative absorber materials, while the choices for other layers in the solar cell stack have remained somewhat limited. In particular, cadmium sulfide (CdS) is widely used as the buffer layer in typical record devices utilizing absorbers like Cu(In,Ga)Se2 (CIGSe) or Cu2ZnSnS4 (CZTS) despite leading to a loss of solar photocurrent due to its band gap of 2.4 eV. While different buffers such as Zn(S,O,OH) are beginning to become competitive with CdS, the identification of additional wider-band gap alternatives with electrical properties comparable to or better than CdS is highly desirable. Here we use hybrid functional calculations to characterize CdxZn1-xOyS1-y candidate buffer layers in the quaternary phase space composed by Cd, Zn, O, and S. We focus on the band gaps and band offsets of the alloys to assess strategies for improving absorption losses from conventional CdS buffers while maintaining similar conduction band offsets known to facilitate good device performance. We also consider additional criteria such as lattice matching to identify regions in the composition space that may provide improved epitaxy to CIGSe and CZTS absorbers. Lastly, we incorporate our calculated alloy properties into simulations of typical CIGSe devices to identify the CdxZn1-xOyS1-y buffer compositions that lead to the best performance. This work performed under the auspices of the USDoE by LLNL under Contract DE-AC52-07NA27344 and funded by the DoE EERE through the SunShot BRIDGE program.

  16. Microstructural and mechanical characteristics of Ni–Cr thin films

    Energy Technology Data Exchange (ETDEWEB)

    Petley, Vijay [Gas Turbine Research Establishment, DRDO, Bangalore 93 (India); Sathishkumar, S.; Thulasi Raman, K.H.; Rao, G.Mohan [Department of Instrumentation and Applied Physics, IISc, Bangalore 12 (India); Chandrasekhar, U. [Gas Turbine Research Establishment, DRDO, Bangalore 93 (India)

    2015-06-15

    Highlights: • Ni–Cr thin films of varied composition deposited by DC magnetron co-sputtering. • Thin film with Ni–Cr: 80–20 at% composition exhibits most distinct behavior. • The films were tensile tested and exhibited no cracking till the substrate yielding. - Abstract: Ni–Cr alloy thin films have been deposited using magnetron co-sputtering technique at room temperature. Crystal structure was evaluated using GIXRD. Ni–Cr solid solution upto 40 at% of Cr exhibited fcc solid solution of Cr in Ni and beyond that it exhibited bcc solid solution of Ni in Cr. X-ray diffraction analysis shows formation of (1 1 1) fiber texture in fcc and (2 2 0) fiber texture in bcc Ni–Cr thin films. Electron microscopy in both in-plane and transverse direction of the film surface revealed the presence of columnar microstructure for films having Cr upto 40 at%. Mechanical properties of the films are evaluated using nanoindentation. The modulus values increased with increase of Cr at% till the film is fcc. With further increase in Cr at% the modulus values decreased. Ni–Cr film with 20 at% Ni exhibits reduction in modulus and is correlated to the poor crystallization of the film as reflected in XRD analysis. The Ni–Cr thin film with 80 at% Ni and 20 at% Cr exhibited the most distinct columnar structure with highest electrical resistivity, indentation hardness and elastic modulus.

  17. Use of thin films in high-temperature superconducting bearings.

    Energy Technology Data Exchange (ETDEWEB)

    Hull, J. R.; Cansiz, A.

    1999-09-30

    In a PM/HTS bearing, locating a thin-film HTS above a bulk HTS was expected to maintain the large levitation force provided by the bulk with a lower rotational drag provided by the very high current density of the film. For low drag to be achieved, the thin film must shield the bulk from inhomogeneous magnetic fields. Measurement of rotational drag of a PM/HTS bearing that used a combination of bulk and film HTS showed that the thin film is not effective in reducing the rotational drag. Subsequent experiments, in which an AC coil was placed above the thin-film HTS and the magnetic field on the other side of the film was measured, showed that the thin film provides good shielding when the coil axis is perpendicular to the film surface but poor shielding when the coil axis is parallel to the surface. This is consistent with the lack of reduction in rotational drag being due to a horizontal magnetic moment of the permanent magnet. The poor shielding with the coil axis parallel to the film surface is attributed to the aspect ratio of the film and the three-dimensional nature of the current flow in the film for this coil orientation.

  18. Structural and Optical Properties of Nanoscale Galinobisuitite Thin Films

    Directory of Open Access Journals (Sweden)

    Omar H. Abd-Elkader

    2014-01-01

    Full Text Available Galinobisuitite thin films of (Bi2S3(PbS were prepared using the chemical bath deposition technique (CBD. Thin films were prepared by a modified chemical deposition process by allowing the triethanolamine (TEA complex of Bi3+ and Pb2+ to react with S2− ions, which are released slowly by the dissociation of the thiourea (TU solution. The films are polycrystalline and the average crystallite size is 35 nm. The composition of the films was measured using the atomic absorption spectroscopy (AAS technique. The films are very adherent to the substrates. The crystal structure of Galinobisuitite thin films was calculated by using the X-ray diffraction (XRD technique. The surface morphology and roughness of the films were studied using scanning electron microscopes (SEM, transmission electron microscopes (TEM and stylus profilers respectively. The optical band gaps of the films were estimated from optical measurements.

  19. High temperature superconducting thin films for microwave filters

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Xinjie(赵新杰); LI; Lin(李林); LEI; Chong(雷冲); TIAN; Ybngjun(田永军)

    2002-01-01

    YBa2Cu3O7-δ and Tl2Ba2CaCu2O8 thin films for microwave filters were synthesized by pulsed laser deposition and the two-step thalliation process. Substrate quality requirements and the relation of thin film morphology, microstructure with microwave surface resistance were discussed.

  20. Optimized grid design for thin film solar panels

    NARCIS (Netherlands)

    Deelen, J. van; Klerk, L.; Barink, M.

    2014-01-01

    There is a gap in efficiency between record thin film cells and mass produced thin film solar panels. In this paper we quantify the effect of monolithic integration on power output for various configurations by modeling and present metallization as a way to improve efficiency of solar panels. Grid d

  1. Thermochemical Analysis of Molybdenum Thin Films on Porous Alumina.

    Science.gov (United States)

    Lee, Kyoungjin; de Lannoy, Charles-François; Liguori, Simona; Wilcox, Jennifer

    2017-01-12

    Molybdenum (Mo) thin films (thickness thin-film composites were stable below 300 °C but had no reactivity toward gases. Mo thin films showed nitrogen incorporation on the surface as well as in the subsurface at 450 °C, as confirmed by X-ray photoelectron spectroscopy. The reactivity toward nitrogen was diminished in the presence of CO2, although no carbon species were detected either on the surface or in the subsurface. The Mo thin films have a very stable native oxide layer, which may further oxidize to higher oxidation states above 500 °C due to the reaction with the porous anodized alumina substrate. The oxidation of Mo thin films was accelerated in the presence of oxidizing gases. At 600 °C in N2, the Mo thin film on anodized alumina was completely oxidized and may also have been volatilized. The results imply that choosing thermally stable and inactive porous supports and operating in nonoxidizing conditions below 500 °C will likely maintain the stability of the Mo composite. This study provides key information about the chemical and structural stability of a Mo thin film on a porous substrate for future membrane applications and offers further insights into the integrity of thin-film composites when exposed to harsh conditions.

  2. Tools to Synthesize the Learning of Thin Films

    Science.gov (United States)

    Rojas, Roberto; Fuster, Gonzalo; Slusarenko, Viktor

    2011-01-01

    After a review of textbooks written for undergraduate courses in physics, we have found that discussions on thin films are mostly incomplete. They consider the reflected and not the transmitted light for two instead of the four types of thin films. In this work, we complement the discussion in elementary textbooks, by analysing the phase…

  3. Stretchable, adhesive and ultra-conformable elastomer thin films.

    Science.gov (United States)

    Sato, Nobutaka; Murata, Atsushi; Fujie, Toshinori; Takeoka, Shinji

    2016-11-16

    Thermoplastic elastomers are attractive materials because of the drastic changes in their physical properties above and below the glass transition temperature (Tg). In this paper, we report that free-standing polystyrene (PS, Tg: 100 °C) and polystyrene-polybutadiene-polystyrene triblock copolymer (SBS, Tg: -70 °C) thin films with a thickness of hundreds of nanometers were prepared by a gravure coating method. Among the mechanical properties of these thin films determined by bulge testing and tensile testing, the SBS thin films exhibited a much lower elastic modulus (ca. 0.045 GPa, 212 nm thickness) in comparison with the PS thin films (ca. 1.19 GPa, 217 nm thickness). The lower elastic modulus and lower thickness of the SBS thin films resulted in higher conformability and thus higher strength of adhesion to an uneven surface such as an artificial skin model with roughness (Ra = 10.6 μm), even though they both have similar surface energies. By analyzing the mechanical properties of the SBS thin films, the elastic modulus and thickness of the thin films were strongly correlated with their conformability to a rough surface, which thus led to a high adhesive strength. Therefore, the SBS thin films will be useful as coating layers for a variety of materials.

  4. Controlled nanostructuration of polycrystalline tungsten thin films

    Energy Technology Data Exchange (ETDEWEB)

    Girault, B. [Institut P' (UPR 3346 CNRS), Universite de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Institut de Recherche en Genie Civil et Mecanique (UMR CNRS 6183), LUNAM Universite, Universite de Nantes, Centrale Nantes, CRTT, 37 Bd de l' Universite, BP 406, 44602 Saint-Nazaire Cedex (France); Eyidi, D.; Goudeau, P.; Guerin, P.; Bourhis, E. Le; Renault, P.-O. [Institut P' (UPR 3346 CNRS), Universite de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Sauvage, T. [CEMHTI/CNRS (UPR 3079 CNRS), Universite d' Orleans, 3A rue de la Ferollerie, 45071 Orleans Cedex 2 (France)

    2013-05-07

    Nanostructured tungsten thin films have been obtained by ion beam sputtering technique stopping periodically the growing. The total thickness was maintained constant while nanostructure control was obtained using different stopping periods in order to induce film stratification. The effect of tungsten sublayers' thicknesses on film composition, residual stresses, and crystalline texture evolution has been established. Our study reveals that tungsten crystallizes in both stable {alpha}- and metastable {beta}-phases and that volume proportions evolve with deposited sublayers' thicknesses. {alpha}-W phase shows original fiber texture development with two major preferential crystallographic orientations, namely, {alpha}-W<110> and unexpectedly {alpha}-W<111> texture components. The partial pressure of oxygen and presence of carbon have been identified as critical parameters for the growth of metastable {beta}-W phase. Moreover, the texture development of {alpha}-W phase with two texture components is shown to be the result of a competition between crystallographic planes energy minimization and crystallographic orientation channeling effect maximization. Controlled grain size can be achieved for the {alpha}-W phase structure over 3 nm stratification step. Below, the {beta}-W phase structure becomes predominant.

  5. Vertically aligned biaxially textured molybdenum thin films

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Rahul [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Riley, Michael [Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Lee, Sabrina [US Army Armament Research, Development and Engineering Center, Benet Labs, Watervliet, New York 12189 (United States); Lu, Toh-Ming [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

    2011-09-15

    Vertically aligned, biaxially textured molybdenum nanorods were deposited using dc magnetron sputtering with glancing flux incidence (alpha = 85 degrees with respect to the substrate normal) and a two-step substrate-rotation mode. These nanorods were identified with a body-centered cubic crystal structure. The formation of a vertically aligned biaxial texture with a [110] out-of-plane orientation was combined with a [-110] in-plane orientation. The kinetics of the growth process was found to be highly sensitive to an optimum rest time of 35 seconds for the two-step substrate rotation mode. At all other rest times, the nanorods possessed two separate biaxial textures each tilted toward one flux direction. While the in-plane texture for the vertical nanorods maintains maximum flux capture area, inclined Mo nanorods deposited at alpha = 85 degrees without substrate rotation display a [-1-1-4] in-plane texture that does not comply with the maximum flux capture area argument. Finally, an in situ capping film was deposited with normal flux incidence over the biaxially textured vertical nanorods resulting in a thin film over the porous nanorods. This capping film possessed the same biaxial texture as the nanorods and could serve as an effective substrate for the epitaxial growth of other functional materials.

  6. Oxynitride Thin Film Barriers for PV Packaging

    Energy Technology Data Exchange (ETDEWEB)

    Glick, S. H.; delCueto, J. A.; Terwilliger, K. M.; Jorgensen, G. J.; Pankow, J. W.; Keyes, B. M.; Gedvilas, L. M.; Pern, F. J.

    2005-11-01

    Dielectric thin-film barrier and adhesion-promoting layers consisting of silicon oxynitride materials (SiOxNy, with various stoichiometry) were investigated. For process development, films were applied to glass (TCO, conductive SnO2:F; or soda-lime), polymer (PET, polyethylene terephthalate), aluminized soda-lime glass, or PV cell (a-Si, CIGS) substrates. Design strategy employed de-minimus hazard criteria to facilitate industrial adoption and reduce implementation costs for PV manufacturers or suppliers. A restricted process window was explored using dilute compressed gases (3% silane, 14% nitrous oxide, 23% oxygen) in nitrogen (or former mixtures, and 11.45% oxygen mix in helium and/or 99.999% helium dilution) with a worst-case flammable and non-corrosive hazard classification. Method employed low radio frequency (RF) power, less than or equal to 3 milliwatts per cm2, and low substrate temperatures, less than or equal to 100 deg C, over deposition areas less than or equal to 1000 cm2. Select material properties for barrier film thickness (profilometer), composition (XPS/FTIR), optical (refractive index, %T and %R), mechanical peel strength and WVTR barrier performance are presented.

  7. Amorphous molybdenum silicon superconducting thin films

    Directory of Open Access Journals (Sweden)

    D. Bosworth

    2015-08-01

    Full Text Available Amorphous superconductors have become attractive candidate materials for superconducting nanowire single-photon detectors due to their ease of growth, homogeneity and competitive superconducting properties. To date the majority of devices have been fabricated using WxSi1−x, though other amorphous superconductors such as molybdenum silicide (MoxSi1−x offer increased transition temperature. This study focuses on the properties of MoSi thin films grown by magnetron sputtering. We examine how the composition and growth conditions affect film properties. For 100 nm film thickness, we report that the superconducting transition temperature (Tc reaches a maximum of 7.6 K at a composition of Mo83Si17. The transition temperature and amorphous character can be improved by cooling of the substrate during growth which inhibits formation of a crystalline phase. X-ray diffraction and transmission electron microscopy studies confirm the absence of long range order. We observe that for a range of 6 common substrates (silicon, thermally oxidized silicon, R- and C-plane sapphire, x-plane lithium niobate and quartz, there is no variation in superconducting transition temperature, making MoSi an excellent candidate material for SNSPDs.

  8. Zinc sulfide thin films deposited by RF reactive sputtering for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Shao Lexi; Chang, K.-H.; Hwang, H.-L

    2003-05-15

    Zinc sulfide (ZnS) thin films with nano-scale grains of about 50 nm were deposited on glass substrates at a substrate temperature of 200 deg. C via RF reactive sputtering by using zinc plate target and hydrogen sulfide gas. The structure, compositions, electrical and optical characteristics of the deposited films were investigated for the photovoltaic device applications. All films showed a near stoichiometric composition as indicated in their AES data. Distinct single crystalline phase with preferential orientation along the (0 0 0 1) plane of wurtzite or the (1 1 1) plane of zinc blende (ZB) was revealed in their X-ray diffraction (XRD) patterns, and the spacing of the planes are well matched to those of (1 1 2) plane of the chalcopyrite CuInS{sub 2} (CIS). UV-Vis measurement showed that the films had more than 65% transmittance in the wavelength larger than 350 nm, and the fundamental absorption edge shifted to shorter wavelength with the increase of sulfur incorporated in the films, which corresponds to an increase in the energy band gap ranging from 3.59 to 3.72 eV. It was found that ZnS films are suitable for use as the buffer layer of the CIS solar cells, and it is the viable alternative for replacing CdS in the photovoltaic cell structure.

  9. Nanocoatings and ultra-thin films technologies and applications

    CERN Document Server

    Tiginyanu, Ion

    2011-01-01

    Gives a comprehensive account of the developments of nanocoatings and ultra-thin films. This book covers the fundamentals, processes of deposition and characterisation of nanocoatings, as well as the applications. It is suitable for the glass and glazing, automotive, electronics, aerospace, construction and biomedical industries in particular.$bCoatings are used for a wide range of applications, from anti-fogging coatings for glass through to corrosion control in the aerospace and automotive industries. Nanocoatings and ultra-thin films provides an up-to-date review of the fundamentals, processes of deposition, characterisation and applications of nanocoatings. Part one covers technologies used in the creation and analysis of thin films, including chapters on current and advanced coating technologies in industry, nanostructured thin films from amphiphilic molecules, chemical and physical vapour deposition methods and methods for analysing nanocoatings and ultra-thin films. Part two focuses on the applications...

  10. Infrared analysis of thin films amorphous, hydrogenated carbon on silicon

    CERN Document Server

    Jacob, W; Schwarz-Selinger, T

    2000-01-01

    The infrared analysis of thin films on a thick substrate is discussed using the example of plasma-deposited, amorphous, hydrogenated carbon layers (a-C:H) on silicon substrates. The framework for the optical analysis of thin films is presented. The main characteristic of thin film optics is the occurrence of interference effects due to the coherent superposition of light multiply reflected at the various internal and external interfaces of the optical system. These interference effects lead to a sinusoidal variation of the transmitted and reflected intensity. As a consequence, the Lambert-Beer law is not applicable for the determination of the absorption coefficient of thin films. Furthermore, observable changes of the transmission and reflection spectra occur in the vicinity of strong absorption bands due to the Kramers-Kronig relation. For a sound data evaluation these effects have to be included in the analysis. To be able to extract the full information contained in a measured optical thin film spectrum, ...

  11. Nanotwin hardening in a cubic chromium oxide thin film

    Directory of Open Access Journals (Sweden)

    Kazuma Suzuki

    2015-09-01

    Full Text Available NaCl-type (B1 chromium oxide (CrO has been expected to have a high hardness value and does not exist as an equilibrium phase. We report a B1-based Cr0.67O thin film with a thickness of 144 nm prepared by pulsed laser deposition as an epitaxial thin film on a MgO single crystal. The thin film contained a number of stacking faults and had a nanotwinned structure composed of B1 with disordered vacancies and corundum structures. The Cr0.67O thin film had a high indentation hardness value of 44 GPa, making it the hardest oxide thin film reported to date.

  12. Thin films and coatings toughening and toughness characterization

    CERN Document Server

    Zhang, Sam

    2015-01-01

    Thin Films and Coatings: Toughening and Toughness Characterization captures the latest developments in the toughening of hard coatings and in the measurement of the toughness of thin films and coatings. Featuring chapters contributed by experts from Australia, China, Czech Republic, Poland, Singapore, Spain, and the United Kingdom, this first-of-its-kind book:Presents the current status of hard-yet-tough ceramic coatingsReviews various toughness evaluation methods for films and hard coatingsExplores the toughness and toughening mechanisms of porous thin films and laser-treated surfacesExamines

  13. Peculiarities of spin reorientation in a thin YIG film.

    Energy Technology Data Exchange (ETDEWEB)

    Bazaliy, Ya. B.; Tsymbal, L. T.; Linnik, A. I.; Dan' shin, N. K.; Izotov, A. I.; Wigen, P. E.

    2002-06-28

    The issue of magnetic orientation transitions in thin films combines interesting physics and importance for applications. We study the magnetic transition and phase diagram of a 0.1{micro}m thick (YLaGd){sub 3}(FeGa){sub 5}O{sub 12} films grown on GGG substrate by liquid phase epitaxy. Observed transitions are compared with those in BiGa:TmIG thin films, studied in previous work by one of the authors. A general picture of orientation transitions in thin films of substituted YIG is discussed.

  14. Peculiarities of spin reorientation in a thin YIG film

    Energy Technology Data Exchange (ETDEWEB)

    Bazaliy, Ya.B.; Tsymbal, L.T.; Linnik, A.I.; Dan' shin, N.K.; Izotov, A.I.; Wigen, P.E

    2003-05-01

    The issue of magnetic orientation transitions in thin films combines interesting physics and importance for applications. We study the magnetic transition and phase diagram of a 0.1 {mu}m thick (YLaGd){sub 3}(FeGa){sub 5}O{sub 12} films grown on GGG substrate by liquid phase epitaxy. Observed transitions are compared with those in BiGa:TmIG thin films, studied in previous work by one of the authors. A general picture of orientation transitions in thin films of substituted YIG is discussed.

  15. Preface: Advanced Thin Film Developments and Nano Structures

    Institute of Scientific and Technical Information of China (English)

    Ray Y.Lin

    2005-01-01

    @@ In this special issue, we invited a few leading materials researchers to present topics in thin films, coatings, and nano structures. Readers will find most recent developments in topics, including recent advances in hard, tough, and low friction nanocomposite coatings; thin films for coating nanomaterials; electroless plating of silver thin films on porous Al2O3 substrate; CrN/Nano Cr interlayer coatings; nano-structured carbide derived carbon (CDC) films and their tribology; predicting interdiffusion in high-temperature coatings; gallium-catalyzed silica nanowire growth; and corrosion protection properties of organofunctional silanes. Authors are from both national laboratories and academia.

  16. Electrochemical Intercalation of Sodium into Silicon Thin Film

    Institute of Scientific and Technical Information of China (English)

    Dong-Yeon Kim; Hyo-Jun Ahn; Gyu-Bong Cho; Jong-Seon Kim; Ho-Suk Ryu; Ki-Won Kim; Jou-Hyeon Ahn; Won-Cheol Shin

    2008-01-01

    In order to investigate the possibility of Si thin film as an anode for Na battery, we studied the electrochemical intercalation of sodium into the Si film. Amorphous Si thin film electrode was prepared using DC magnetron sputtering. Sodium ion could intercalate into Si thin film upto Na0.52Si, i.e. 530mAh · g-1-Si. The first discharge capacity was 80mAh.·g-1-Si, which meant reversible amount of sodium intercalation. The discharge capacity slightly decreased to 70mAh · g-1-Si after 10 cycles.

  17. 12% efficient CdTe/CdS thin film solar cells deposited by low-temperature close space sublimation

    Science.gov (United States)

    Schaffner, Judith; Motzko, Markus; Tueschen, Alexander; Swirschuk, Andreas; Schimper, Hermann-Josef; Klein, Andreas; Modes, Thomas; Zywitzki, Olaf; Jaegermann, Wolfram

    2011-09-01

    We report 12% efficient CdS/CdTe thin film solar cells prepared by low temperature close space sublimation (CSS). Both semiconductor films, CdS and CdTe, were deposited by high vacuum CSS in superstrate configuration on glass substrates with fluorine doped tin oxide (FTO) front contact. The CdTe deposition was carried out at a substrate temperature (Tsub) of ≤340 ∘C, which is much lower than that used in conventional processes (>500 ∘C). The CdTe films were treated with the usual CdCl2 activation process. Different optimal annealing times and temperatures were found for low-temperature cells (Tsub≤ 340 ∘C) compared to high-temperature cells (Tsub = 520 ∘C). The influence of the activation step on the morphology of high-temperature and low-temperature CdTe is determined by XRD, AFM, SEM top views, and SEM cross-sections. Grain growth, strong recrystallization, and a reduction of planar defects during the activation step are observed, especially for low-temperature CdTe. Further, the influence of CdS deposition parameters on the solar cell performance is investigated by using three different sets of parameters with different deposition rates and substrate temperatures for the CdS preparation. Efficiencies about 10.9% with a copper-free back contact and 12.0% with a copper-containing back contact were achieved using the low temperature CdTe process.

  18. Thin film cadmium telluride photovoltaic cells. Annual subcontract report, 23 July 1990--31 October 1991

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, A.; Bohn, R. [Toledo Univ., OH (United States)

    1992-04-01

    This report describes research to develop to vacuum-based growth techniques for CdTe thin-film solar cells: (1) laser-driven physical vapor deposition (LDPVD) and (2) radio-frequency (rf) sputtering. The LDPVD process was successfully used to deposit thin films of CdS, CdTe, and CdCl{sub 2}, as well as related alloys and doped semiconductor materials. The laser-driven deposition process readily permits the use of several target materials in the same vacuum chamber and, thus, complete solar cell structures were fabricated on SnO{sub 2}-coated glass using LDPVD. The rf sputtering process for film growth became operational, and progress was made in implementing it. Time was also devoted to enhancing or implementing a variety of film characterization systems and device testing facilities. A new system for transient spectroscopy on the ablation plume provided important new information on the physical mechanisms of LDPVD. The measurements show that, e.g., Cd is predominantly in the neutral atomic state in the plume but with a fraction that is highly excited internally ({ge} 6 eV), and that the typical neutral Cd translational kinetic energies perpendicular to the target are 20 eV and greater. 19 refs.

  19. Evaluation of residual stress in sputtered tantalum thin-film

    Energy Technology Data Exchange (ETDEWEB)

    Al-masha’al, Asa’ad, E-mail: asaad.al@ed.ac.uk; Bunting, Andrew; Cheung, Rebecca

    2016-05-15

    Highlights: • Tantalum thin-films have been deposited by DC magnetron sputtering system. • Thin-film stress is observed to be strongly influenced by sputtering pressure. • Transition towards the compressive stress is ascribed to the annealing at 300 °C. • Expose thin-film to air ambient or ion bombardment lead to a noticeable change in the residual stress. - Abstract: The influence of deposition conditions on the residual stress of sputtered tantalum thin-film has been evaluated in the present study. Films have been deposited by DC magnetron sputtering and curvature measurement method has been employed to calculate the residual stress of the films. Transitions of tantalum film stress from compressive to tensile state have been observed as the sputtering pressure increases. Also, the effect of annealing process at temperature range of 90–300 °C in oxygen ambient on the residual stress of the films has been studied. The results demonstrate that the residual stress of the films that have been deposited at lower sputtering pressure has become more compressive when annealed at 300 °C. Furthermore, the impact of exposure to atmospheric ambient on the tantalum film stress has been investigated by monitoring the variation of the residual stress of both annealed and unannealed films over time. The as-deposited films have been exposed to pure Argon energy bombardment and as result, a high compressive stress has been developed in the films.

  20. Characterization of thin film semiconductors by scanning probe microscopy and tunneling spectroscopy

    Science.gov (United States)

    Gichuhi, Anthony

    We have used scanning tunneling microscopy, atomic force microscopy, tunneling spectroscopy, resonance Raman spectroscopy and electrochemistry to study the electrosynthesis of II-VI compound semiconductors with special emphasis on ZnS, CdS, and HgS. This dissertation will focus mainly on the electrochemical and scanning probe (STM and AFM) applications to these compounds, in addition to novel materials such as CoSb. We hope to understand the structural, as well optical properties of these materials. Finally, we hope to develop a recipe for the electrosynthesis of high quality semiconductor films. In Chapter 2, we report an electrochemical, scanning probe microscopic and Raman spectroscopic investigation of thin US films grown by electrochemical atomic layer epitaxy (EC-ALE) aimed at understanding the role played by the order of deposition on film quality. In Chapter 3, we report a study of electrosynthesized CdS-HgS heterojunctions using scanning tunneling microscopy (STM), photoluminescence spectroscopy (PL), and electrochemistry. US thin films were grown by electrochemical atomic layer epitaxy onto Au(111) substrates and were terminated with a single HgS monolayer. In Chapter 4, the structure and chemical composition of electrosynthesized ZnS thin films on Au(111) substrates grown by alternating underpotential deposition and oxidative adsorption cycles of S and Zn from solution precursors was studied by scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). In Chapter 5, conditions for the growth of. stable mercury sulfide (HgS) monolayers on Au(111) surfaces using electrochemical atomic layer epitaxy have been investigated. HgS thin films were characterized by X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM). Chapter 6: This chapter describes the use of resonance Raman spectroscopy to characterize thin films of the II-VI compound semiconductors electrosynthesized on metal surfaces. We describe how resonance

  1. The Structure and Stability of Molybdenum Ditelluride Thin Films

    Directory of Open Access Journals (Sweden)

    Zhouling Wang

    2014-01-01

    Full Text Available Molybdenum-tellurium alloy thin films were fabricated by electron beam evaporation and the films were annealed in different conditions in N2 ambient. The hexagonal molybdenum ditelluride thin films with well crystallization annealed at 470°C or higher were obtained by solid state reactions. Thermal stability measurements indicate the formation of MoTe2 took place at about 350°C, and a subtle weight-loss was in the range between 30°C and 500°C. The evolution of the chemistry for Mo-Te thin films was performed to investigate the growth of the MoTe2 thin films free of any secondary phase. And the effect of other postdeposition treatments on the film characteristics was also investigated.

  2. Density of organic thin films in organic photovoltaics

    Science.gov (United States)

    Zhao, Cindy X.; Xiao, Steven; Xu, Gu

    2015-07-01

    A practical parameter, the volume density of organic thin films, found to affect the electronic properties and in turn the performance of organic photovoltaics (OPVs), is investigated in order to benefit the polymer synthesis and thin film preparation in OPVs. To establish the correlation between film density and device performance, the density of organic thin films with various treatments was obtained, by two-dimensional X-ray diffraction measurement using the density mapping with respect to the crystallinity of thin films. Our results suggest that the OPV of higher performance has a denser photoactive layer, which may hopefully provide a solution to the question of whether the film density matters in organic electronics, and help to benefit the OPV industry in terms of better polymer design, standardized production, and quality control with less expenditure.

  3. A versatile platform for magnetostriction measurements in thin films

    Science.gov (United States)

    Pernpeintner, M.; Holländer, R. B.; Seitner, M. J.; Weig, E. M.; Gross, R.; Goennenwein, S. T. B.; Huebl, H.

    2016-03-01

    We present a versatile nanomechanical sensing platform for the investigation of magnetostriction in thin films. It is based on a doubly clamped silicon nitride nanobeam resonator covered with a thin magnetostrictive film. Changing the magnetization direction within the film plane by an applied magnetic field generates a magnetoelastic stress and thus changes the resonance frequency of the nanobeam. A measurement of the resulting resonance frequency shift, e.g., by optical interferometry, allows to quantitatively determine the magnetostriction constants of the thin film. In a proof-of-principle experiment, we determine the magnetostriction constants of a 10 nm thick polycrystalline cobalt film, showing very good agreement with literature values. The presented technique aims, in particular, for the precise measurement of magnetostriction in a variety of (conducting and insulating) thin films, which can be deposited by, e.g., electron beam deposition, thermal evaporation, or sputtering.

  4. Mechanism and characters of thin film lubrication at nanometer scale

    Institute of Scientific and Technical Information of China (English)

    雒建斌; 温诗铸

    1996-01-01

    Thin film lubrication is a transition region between elastohydrodynamic lubrication and boundary lubrication, A technique of relative optical interference intensity with the resolution of 0.5 nm in the vertical direction and 1.5 nm in the horizontal direction is used in a pure rolling process to measure the film thickness with different lubricants, speeds, loads and substrate surface energy. Experimental data show that the characteristics of thin film lubrication are different from those of elastohydrodynamic lubrication and boundary lubrication. As the rolling speed decreases, a critical film thickness can be found to distinguish thin film lubrication from elastohydrodynamic lubrication. Such thickness is related to the substrate surface energy, atmospheric viscosity of lubricant, etc. A physical model of thin film lubrication with the fluid layer, the ordered liquid layer and the adsorbed layer is proposed and the functions of these different layers are discussed.

  5. Thin Films for Advanced Glazing Applications

    Directory of Open Access Journals (Sweden)

    Ann-Louise Anderson

    2016-09-01

    Full Text Available Functional thin films provide many opportunities for advanced glazing systems. This can be achieved by adding additional functionalities such as self-cleaning or power generation, or alternately by providing energy demand reduction through the management or modulation of solar heat gain or blackbody radiation using spectrally selective films or chromogenic materials. Self-cleaning materials have been generating increasing interest for the past two decades. They may be based on hydrophobic or hydrophilic systems and are often inspired by nature, for example hydrophobic systems based on mimicking the lotus leaf. These materials help to maintain the aesthetic properties of the building, help to maintain a comfortable working environment and in the case of photocatalytic materials, may provide external pollutant remediation. Power generation through window coatings is a relatively new idea and is based around the use of semi-transparent solar cells as windows. In this fashion, energy can be generated whilst also absorbing some solar heat. There is also the possibility, in the case of dye sensitized solar cells, to tune the coloration of the window that provides unheralded external aesthetic possibilities. Materials and coatings for energy demand reduction is highly desirable in an increasingly energy intensive world. We discuss new developments with low emissivity coatings as the need to replace scarce indium becomes more apparent. We go on to discuss thermochromic systems based on vanadium dioxide films. Such systems are dynamic in nature and present a more sophisticated and potentially more beneficial approach to reducing energy demand than static systems such as low emissivity and solar control coatings. The ability to be able to tune some of the material parameters in order to optimize the film performance for a given climate provides exciting opportunities for future technologies. In this article, we review recent progress and challenges in

  6. An overview of thin film nitinol endovascular devices.

    Science.gov (United States)

    Shayan, Mahdis; Chun, Youngjae

    2015-07-01

    Thin film nitinol has unique mechanical properties (e.g., superelasticity), excellent biocompatibility, and ultra-smooth surface, as well as shape memory behavior. All these features along with its low-profile physical dimension (i.e., a few micrometers thick) make this material an ideal candidate in developing low-profile medical devices (e.g., endovascular devices). Thin film nitinol-based devices can be collapsed and inserted in remarkably smaller diameter catheters for a wide range of catheter-based procedures; therefore, it can be easily delivered through highly tortuous or narrow vascular system. A high-quality thin film nitinol can be fabricated by vacuum sputter deposition technique. Micromachining techniques were used to create micro patterns on the thin film nitinol to provide fenestrations for nutrition and oxygen transport and to increase the device's flexibility for the devices used as thin film nitinol covered stent. In addition, a new surface treatment method has been developed for improving the hemocompatibility of thin film nitinol when it is used as a graft material in endovascular devices. Both in vitro and in vivo test data demonstrated a superior hemocompatibility of the thin film nitinol when compared with commercially available endovascular graft materials such as ePTFE or Dacron polyester. Promising features like these have motivated the development of thin film nitinol as a novel biomaterial for creating endovascular devices such as stent grafts, neurovascular flow diverters, and heart valves. This review focuses on thin film nitinol fabrication processes, mechanical and biological properties of the material, as well as current and potential thin film nitinol medical applications.

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

    Science.gov (United States)

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

    2013-11-01

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

  8. Altering properties of cerium oxide thin films by Rh doping

    Energy Technology Data Exchange (ETDEWEB)

    Ševčíková, Klára, E-mail: klarak.sevcikova@seznam.cz [Faculty of Mathematics and Physics, Department of Surface and Plasma Science, Charles University in Prague, V Holešovičkách 2, 180 00 Prague 8 (Czech Republic); NIMS Beamline Station at SPring-8, National Institute for Materials Science, Sayo, Hyogo 679-5148 (Japan); Nehasil, Václav, E-mail: nehasil@mbox.troja.mff.cuni.cz [Faculty of Mathematics and Physics, Department of Surface and Plasma Science, Charles University in Prague, V Holešovičkách 2, 180 00 Prague 8 (Czech Republic); Vorokhta, Mykhailo, E-mail: vorohtam@gmail.com [Faculty of Mathematics and Physics, Department of Surface and Plasma Science, Charles University in Prague, V Holešovičkách 2, 180 00 Prague 8 (Czech Republic); Haviar, Stanislav, E-mail: stanislav.haviar@gmail.com [Faculty of Mathematics and Physics, Department of Surface and Plasma Science, Charles University in Prague, V Holešovičkách 2, 180 00 Prague 8 (Czech Republic); Matolín, Vladimír, E-mail: matolin@mbox.troja.mff.cuni.cz [Faculty of Mathematics and Physics, Department of Surface and Plasma Science, Charles University in Prague, V Holešovičkách 2, 180 00 Prague 8 (Czech Republic); and others

    2015-07-15

    Highlights: • Thin films of ceria doped by rhodium deposited by RF magnetron sputtering. • Concentration of rhodium has great impact on properties of Rh–CeO{sub x} thin films. • Intensive oxygen migration in films with low concentration of rhodium. • Oxygen migration suppressed in films with high amount of Rh dopants. - Abstract: Ceria containing highly dispersed ions of rhodium is a promising material for catalytic applications. The Rh–CeO{sub x} thin films with different concentrations of rhodium were deposited by RF magnetron sputtering and were studied by soft and hard X-ray photoelectron spectroscopies, Temperature programmed reaction and X-ray powder diffraction techniques. The sputtered films consist of rhodium–cerium mixed oxide where cerium exhibits a mixed valency of Ce{sup 4+} and Ce{sup 3+} and rhodium occurs in two oxidation states, Rh{sup 3+} and Rh{sup n+}. We show that the concentration of rhodium has a great influence on the chemical composition, structure and reducibility of the Rh–CeO{sub x} thin films. The films with low concentrations of rhodium are polycrystalline, while the films with higher amount of Rh dopants are amorphous. The morphology of the films strongly influences the mobility of oxygen in the material. Therefore, varying the concentration of rhodium in Rh–CeO{sub x} thin films leads to preparing materials with different properties.

  9. Novel photon management for thin-film photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Menon, Rajesh [Univ. of Utah, Salt Lake City, UT (United States)

    2016-11-11

    The objective of this project is to enable commercially viable thin-film photovoltaics whose efficiencies are increased by over 10% using a novel optical spectral-separation technique. A thin planar diffractive optic is proposed that efficiently separates the solar spectrum and assigns these bands to optimal thin-film sub-cells. An integrated device that is comprised of the optical element, an array of sub-cells and associated packaging is proposed.

  10. Self-Organization of CdS Nanoparticles in Polystyrene Film

    Institute of Scientific and Technical Information of China (English)

    梁海春; 向红; 容敏智; 章明秋; 曾汉民; 王树峰; 龚旗煌

    2002-01-01

    Self-organization of nano-CdS particles in polystyrene can be observed by encapsulating the particles with ndodecyl mercaptan owing to a strong electron transfer interaction between the modified CdS nanoparticles and aliphatic carbons in polystyrene. Consequently, ultraviolet/visible absorption edge of the treated nanoCdS/polystyrene composites is further blueshifted in addition to the shift caused by the quantum size effect, and the fluorescence emission peak of the composite becomes redshifted and narrow.

  11. Thin-film CdTe photovoltaic cells by laser deposition and rf sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, A.; Bohn, R.G.; Bhat, A.; Tabory, C.; Shao, M.; Li, Y.; Savage, M.E.; Tsien, L. (Department of Physics and Astronomy, The University of Toledo, Toledo, Ohio 43606 (United States))

    1992-12-01

    Laser-driven physical vapor deposition (LDPVD) and radio-frequency (rf) sputtering have been used to fabricate thin-film solar cells on SnO[sub 2]-coated glass substrates. The laser-ablation process readily permits the use of several target materials in the same vacuum chamber and complete solar cell structures have been fabricated on SnO[sub 2]-coated glass using LDPVD for the CdS, CdTe, and CdCl[sub 2]. To date the best devices ([similar to]9% AM1.5) have been obtained after a post-deposition anneal at 400 [degree]C. In addition, cells have been fabricated with the combination of LDPVD CdS, rf-sputtered CdTe, and LDPVD CdCl[sub 2]. The performance of these cells indicates considerable promise for the potential of rf sputtering for CdTe photovoltaic devices. The physical mechanisms of LDPVD have been studied by transient optical spectroscopy on the laser ablation plume. These measurements have shown that, e.g., Cd is predominantly in the neutral atomic state in the plume but with a large fraction which is highly excited internally ([ge]6 eV) and that the typical neutral Cd translational kinetic energies perpendicular to the target are 20 eV and greater. Quality of as-grown and annealed films has been analyzed by optical absorption. Raman scattering, photoluminescence, electrical conductivity, Hall effect, x-ray diffraction, and SEM/EDS.

  12. Thin film adhesion by nanoindentation-induced superlayers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gerberich, William W.; Volinsky, A.A.

    2001-06-01

    This work has analyzed the key variables of indentation tip radius, contact radius, delamination radius, residual stress and superlayer/film/interlayer properties on nanoindentation measurements of adhesion. The goal to connect practical works of adhesion for very thin films to true works of adhesion has been achieved. A review of this work titled ''Interfacial toughness measurements of thin metal films,'' which has been submitted to Acta Materialia, is included.

  13. On Ginzburg-Landau Vortices of Superconducting Thin Films

    Institute of Scientific and Technical Information of China (English)

    Shi Jin DING; Qiang DU

    2006-01-01

    In this paper, we discuss the vortex structure of the superconducting thin films placed in a magnetic field. We show that the global minimizer of the functional modelling the superconducting thin films has a bounded number of vortices when the applied magnetic field hex < Hc1 + K log |log ε|where Hc1 is the lower critical field of the film obtained by Ding and Du in SIAM J. Math. Anal.,2002. The locations of the vortices are also given.

  14. The Potentiostatic Electrodeposition of Indium doped Aluminium Selenide Thin Films

    Directory of Open Access Journals (Sweden)

    R.K. Pathak and Sipi Mohan

    2013-12-01

    Full Text Available The In containing AlSe thin films were electrosynthesized by electrochemical co-deposition technique. The morphological properties of thin films were studied through the Scanning Electron Micrograph (SEM while the structural features through X-Ray Diffraction technique (XRD. The deposition current along with the film thickness values, the charge carrier density, flat band potential, corrosion characteristics i.e., corrosion current, corrosion potential and corrosion rate were calculated.

  15. Pulsed laser deposition and characterisation of thin superconducting films

    Energy Technology Data Exchange (ETDEWEB)

    Morone, A. [CNR, zona industriale di Tito Scalo, Potenza (Italy). Istituto per i Materiali Speciali

    1996-09-01

    Same concepts on pulsed laser deposition of thin films will be discussed and same examples of high transition temperature (HTc) BiSrCaCuO (BISCO) and low transition temperature NbN/MgO/NbN multilayers will be presented. X-ray and others characterizations of these films will be reported and discussed. Electrical properties of superconducting thin films will be realized as a function of structural and morphological aspect.

  16. CdS and ZnS quantum dots embedded in hyaluronic acid films

    Energy Technology Data Exchange (ETDEWEB)

    Khachatryan, G.; Khachatryan, K. [Department of Chemistry, Agricultural University, Balicka 122, 30-149 Krakow (Poland); Stobinski, L. [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 48/52, 01-224 Warsaw (Poland); Faculty of Materials Science and Engineering, Warsaw University of Technology, Woloska 141, 02-507 Warszawa (Poland)], E-mail: lstob@ichf.edu.pl; Tomasik, P.; Fiedorowicz, M. [Department of Chemistry, Agricultural University, Balicka 122, 30-149 Krakow (Poland); Lin, H.M. [Department of Materials Engineering, Tatung University, Taipei 104, Taiwan, ROC (China)

    2009-07-29

    An in situ synthesis of ZnS and CdS quantum dots (QDs) in an aqueous solution of sodium hyaluronate (Hyal) produced foils emitting light on excitation with a UV light. The wavelength of emission was only slightly QDs size and more QDs concentration dependent and reached up to {approx}320 nm in the case of ZnS and {approx}400-450 nm in the case of CdS. Nanoparticles remained as non-agglomerated 10-20 nm nanoclusters. CdS/Hyal and ZnS/Hyal-QDs biocomposites were characterized using photoluminescence (PL), IR spectrometric techniques, and Transmission Electron Microscopy (TEM). The absolute molecular weights, radii of gyration, R{sub g}, and thermodynamic properties of the obtained foils are given. Electric resistivity studies performed for the hyaluronic foil in the 100-1000 V range have revealed that the hyaluronate foil has very weak conducting properties and QDs only insignificantly affect those properties as QDs practically did not interact with the foil. Size exclusion chromatography showed a decrease in the molecular weight of the hyaluronate after generation of QDs in its solution, particularly in the lower molecular fraction of the hyaluronate. The generation of CdS QDs was more destructive for the polysaccharide matrix.

  17. The corrosion behavior of nanocrystalline nickel based thin films

    Energy Technology Data Exchange (ETDEWEB)

    Danışman, Murat, E-mail: muratdan@gmail.com

    2016-03-01

    In this study, the effect of Cr addition on corrosion behavior of Ni thin films were investigated. Ni thin films and Ni films with three different Cr content were deposited on glass substrates by magnetron sputtering. After deposition process, thin films with different Cr content were thermally treated in a rapid thermal process system. Phase analysis and grain size calculations of the samples were carried out by X-ray diffraction analysis. In order to reveal corrosion properties, potentiodynamic tests were conducted on samples. Analysis revealed that, although Cr addition to pure-Ni thin films improved their corrosion resistance, occurrence of σ-Cr{sub 3}Ni{sub 2} phase at higher Cr contents increased corrosion rate. The corrosion properties of the samples were also investigated by electrochemical impedance spectroscopy and surface related parameters caused by corrosion reactions were calculated. The analysis revealed that at 55% wt. Cr, rapid ion exchange occurred and highest corrosion current, 23.4 nA cm{sup −2} was observed. - Highlights: • Thin film Ni–Cr samples were deposited on glass substrate. • Effect of Cr addition on corrosion behavior of Ni thin films were investigated. • Potentiodynamic tests and electrochemical impedance spectroscopy methods were used. • Cr content in Ni thin films plays and important role on corrosion. • Up to a certain Cr content, Cr addition reduces corrosion rate.

  18. Patterns and conformations in molecularly thin films

    Science.gov (United States)

    Basnet, Prem B.

    Molecularly thin films have been a subject of great interest for the last several years because of their large variety of industrial applications ranging from micro-electronics to bio-medicine. Additionally, molecularly thin films can be used as good models for biomembrane and other systems where surfaces are critical. Many different kinds of molecules can make stable films. My research has considered three such molecules: a polymerizable phospholipid, a bent-core molecules, and a polymer. One common theme of these three molecules is chirality. The phospolipid molecules studied here are strongly chiral, which can be due to intrinsically chiral centers on the molecules and also due to chiral conformations. We find that these molecules give rise to chiral patterns. Bent-core molecules are not intrinsically chiral, but individual molecules and groups of molecules can show chiral structures, which can be changed by surface interactions. One major, unconfirmed hypothesis for the polymer conformation at surface is that it forms helices, which would be chiral. Most experiments were carried out at the air/water interface, in what are called Langmuir films. Our major tools for studying these films are Brewster Angle Microscopy (BAM) coupled with the thermodynamic information that can be deduced from surface pressure isotherms. Phospholipids are one of the important constituents of liposomes -- a spherical vesicle com-posed of a bilayer membrane, typically composed of a phospholipid and cholesterol bilayer. The application of liposomes in drug delivery is well-known. Crumpling of vesicles of polymerizable phospholipids has been observed. With BAM, on Langmuir films of such phospholipids, we see novel spiral/target patterns during compression. We have found that both the patterns and the critical pressure at which they formed depend on temperature (below the transition to a i¬‘uid layer). Bent-core liquid crystals, sometimes knows as banana liquid crystals, have drawn

  19. Determination of magnetic properties of multilayer metallic thin films

    CERN Document Server

    Birlikseven, C

    2000-01-01

    and magnetization measurements were taken. In recent year, Giant Magnetoresistance Effect has been attracting an increasingly high interest. High sensitivity magnetic field detectors and high sensitivity read heads of magnetic media can be named as important applications of these films. In this work, magnetic and electrical properties of single layer and thin films were investigated. Multilayer thin films were supplied by Prof. Dr. A. Riza Koeymen from Texas University. Multilayer magnetic thin films are used especially for magnetic reading and magnetic writing. storing of large amount of information into small areas become possible with this technology. Single layer films were prepared using the electron beam evaporation technique. For the exact determination of film thicknesses, a careful calibration of the thicknesses was made. Magnetic properties of the multilayer films were studied using the magnetization, magnetoresistance measurements and ferromagnetic resonance technique. Besides, by fitting the exper...

  20. Sensing of volatile organic compounds by copper phthalocyanine thin films

    Science.gov (United States)

    Ridhi, R.; Saini, G. S. S.; Tripathi, S. K.

    2017-02-01

    Thin films of copper phthalocyanine have been deposited by thermal evaporation technique. We have subsequently exposed these films to the vapours of methanol, ethanol and propanol. Optical absorption, infrared spectra and electrical conductivities of these films before and after exposure to chemical vapours have been recorded in order to study their sensing mechanisms towards organic vapours. These films exhibit maximum sensing response to methanol while low sensitivities of the films towards ethanol and propanol have been observed. The changes in sensitivities have been correlated with presence of carbon groups in the chemical vapours. The effect of different types of electrodes on response-recovery times of the thin film with organic vapours has been studied and compared. The electrodes gap distance affects the sensitivity as well as response-recovery time values of the thin films.

  1. Glass transition and thermal expansivity of polystyrene thin films

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, R. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan); Kanaya, T. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan)]. E-mail: kanaya@scl.kyoto-u.ac.jp; Miyazaki, T. [Nitto Denko Corporation, 1-1-2 Shimohozumi, Ibaraki, Osaka-fu 567-8680 (Japan); Nishida, K. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan); Tsukushi, I. [Chiba Institute of Technology, Narashino, Chiba-ken 275-0023 (Japan); Shibata, K. [Japan Atomic Energy Research Institute, Tokai, Ibaraki-ken 319-1195 (Japan)

    2006-12-20

    We have studied glass transition temperature and thermal expansivity of polystyrene thin films supported on silicon substrate using X-ray reflectivity and inelastic neutron scattering techniques. In annealing experiments, we have found that the reported apparent negative expansivity of polymer thin films is caused by unrelaxed structure due to insufficient annealing. Using well-annealed films, we have evaluated glass transition temperature T {sub g} and thermal expansivity as a function of film thickness. The glass transition temperature decreases with film thickness and is constant below about 10 nm, suggesting the surface glass transition temperature of 355 K, which is lower than that in bulk. We have also found that the thermal expansivity in the glassy state decreases with film thickness even after annealing. The decrease has been attributed to hardening of harmonic force constant arising from chain confinement in a thin film. This idea has been confirmed in the inelastic neutron scattering measurements.

  2. Characterization of lithium phosphorous oxynitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiaohua; Bates, J.B.; Jellison, G.E. Jr.

    1996-01-01

    Electrical and electrochemical properties of an amorphous thin-film lithium electrolyte, lithium phosphorous oxynitride (Lipon), have been studied with emphasis on the stability window vs Li metal and the behavior of the Li/Lipon interface. Ion conductivity of Lipon exhibits Arrhenius behavior at {minus}26 to +140 C, with a conductivity of 1.7 {times} 10{sup {minus}6}S/cm at 25 C and an activity energy of 0.50 {plus_minus} 0.01 eV. A stability window of 5.5 V was observed with respect to a Li{sup +}/Li reference, and no detectable reaction or degradation was evident at the Li/Lipon interface upon lithium cycling.

  3. Nonlinear optics of astaxanthin thin films

    Science.gov (United States)

    Esser, A.; Fisch, Herbert; Haas, Karl-Heinz; Haedicke, E.; Paust, J.; Schrof, Wolfgang; Ticktin, Anton

    1993-02-01

    Carotinoids exhibit large nonlinear optical properties due to their extended (pi) -electron system. Compared to other polyenes which show a broad distribution of conjugation lengths, carotinoids exhibit a well defined molecular structure, i.e. a well defined conjugation length. Therefore the carotinoid molecules can serve as model compounds to study the relationship between structure and nonlinear optical properties. In this paper the synthesis of four astaxanthins with C-numbers ranging from 30 to 60, their preparation into thin films, wavelength dispersive Third Harmonic Generation (THG) measurements and some molecular modelling calculations will be presented. Resonant (chi) (3) values reach 1.2(DOT)10-10 esu for C60 astaxanthin. In the nonresonant regime a figure of merit (chi) (3)/(alpha) of several 10-13 esu-cm is demonstrated.

  4. Photoluminescence studies in epitaxial CZTSe thin films

    Science.gov (United States)

    Sendler, Jan; Thevenin, Maxime; Werner, Florian; Redinger, Alex; Li, Shuyi; Hägglund, Carl; Platzer-Björkman, Charlotte; Siebentritt, Susanne

    2016-09-01

    Epitaxial Cu 2 ZnSnSe 4 (CZTSe) thin films were grown by molecular beam epitaxy on GaAs(001) using two different growth processes, one containing an in-situ annealing stage as used for solar cell absorbers and one for which this step was omitted. Photoluminescences (PL) measurements carried out on these samples show no dependence of the emission shape on the excitation intensity at different temperatures ranging from 4 K to 300 K . To describe the PL measurements, we employ a model with fluctuating band edges in which the density of states of the resulting tail states does not seem to depend on the excited charge carrier density. In this interpretation, the PL measurements show that the annealing stage removes a defect level, which is present in the samples without this annealing.

  5. Photodesorption from copper, beryllium, and thin films

    Science.gov (United States)

    Foerster, C. L.; Halama, H. J.; Korn, G.

    Ever increasing circulating currents in electron-positron colliders and light sources demand lower and lower photodesportion (PSD) from the surfaces of their vacuum chambers and their photon absorbers. This is particularly important in compact electron storage rings and B meson factories where photon power of several kw cm(exp -1) is deposited on the surfaces. Given the above factors, we have measured PSD from 1 m long bars of solid copper and solid beryllium, and TiN, Au and C thin films deposited on solid copper bars. Each sample was exposed to about 10(exp 23) photons/m with a critical energy of 500 eV at the VUV ring of the NSLS. PSD was recorded for two conditions: after a 200 C bake-out and after an Ar glow discharge cleaning. In addition, we also measured reflected photons, photoelectrons and desorption as functions of normal, 75 mrad, 100 mrad, and 125 mrad incident photons.

  6. Plasma synthesis of photocatalytic TiO x thin films

    Science.gov (United States)

    Sirghi, L.

    2016-06-01

    The development of efficient photocatalytic materials is promising technology for sustainable and green energy production, fabrication of self-cleaning, bactericidal, and super hydrophilic surfaces, CO2 photoreduction, and decomposition of toxic pollutants in air and water. Semiconductors with good photocatalytic activity have been known for four decades and they are regarded as promising candidates for these new technologies. Low-pressure discharge plasma is one of the most versatile technologies being used for the deposition of photocatalytic semiconductor thin films. This article reviews the main results obtained by the author in using low-pressure plasma for synthesis of TiO x thin films with applications in photocatalysis. Titanium dioxide thin films were obtained by radio frequency magnetron sputtering deposition, plasma enhanced chemical vapour deposition, and high power impulse magnetron sputtering deposition. The effects of the plasma deposition method, plasma parameters, film thickness and substrate on the film structure, chemical composition and photocatalytic activity are investigated. The photocatalytic activity of plasma synthesised TiO x thin films was estimated by UV light induced hydrophilicity. Measurements of photocurrent decay in TiO x thin films in vacuum and air showed that the photocatalytic activity is closely connected to the production, recombination and availability for surface reactions of photo-generated charge carriers. The photocatalytic activity of TiO x thin films was investigated at nanoscale by atomic force microscopy. Microscopic regions of different hydrophilicity on UV light irradiated films are discriminated by AFM atomic force microscopy measurements of adhesion and friction force.

  7. Thin film characterization by resonantly excited internal standing waves

    Energy Technology Data Exchange (ETDEWEB)

    Di Fonzio, S. [SINCROTRONE TRIESTE, Trieste (Italy)

    1996-09-01

    This contribution describes how a standing wave excited in a thin film can be used for the characterization of the properties of the film. By means of grazing incidence X-ray reflectometry one can deduce the total film thickness. On the other hand in making use of a strong resonance effect in the electric field intensity distribution inside a thin film on a bulk substrate one can learn more about the internal structure of the film. The profile of the internal standing wave is proven by diffraction experiments. The most appropriate non-destructive technique for the subsequent thin film characterization is angularly dependent X-ray fluorescence analysis. The existence of the resonance makes it a powerful tool for the detection of impurities and of ultra-thin maker layers, for which the position can be determined with very high precision (about 1% of the total film thickness). This latter aspect will be discussed here on samples which had a thin Ti marker layer at different positions in a carbon film. Due to the resonance enhancement it was still possible to perform these experiments with a standard laboratory x-ray tube and with standard laboratory tool for marker or impurity detection in thin films.

  8. Growth of epitaxial CdTe/CdS heterostructures for single crystal thin film solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, K.; Tiwari, A.N.; Blunier, S.; Zogg, H. [Swiss Federal Inst. of Tech., Zuerich (Switzerland). Arbeitsgemeinschaft fuer Industrielle Forschung

    1994-12-31

    Epitaxial CdTe/CdS heterostructures have been grown by molecular beam epitaxy onto BaF{sub 2} covered Si (111) substrates. An epitaxial BaF{sub 2} buffer is used for compatibility reasons, and because of easier dissolution during the lift-off processing. Epitaxy of cubic CdS (111) layers on BaF{sub 2}/Si (111) is achieved; electron channeling patterns exhibit a three-fold symmetry which is a characteristic for cubic crystal structures. The growth kinetics and structural properties of epitaxial CdS and CdTe/CdS have been studied with reflection high energy electron diffraction, Rutherford backscattering spectrometry and X-ray diffraction rocking curve measurements.the full width at half maximum of the (222) CdS and (333) CdTe X-ray peaks are {approximately} 1,150 arc sec for 2.7 and 3.4 {micro}m thick CdS and CdTe layers, respectively. To fabricate CdTe/CdS single crystal thin film solar cells, a lift-off process has been developed to remove the epitaxial layers from the Si substrates.

  9. Orthogonal thin film magnetometer using the anisotropic magnetoresistance effect

    NARCIS (Netherlands)

    Ridder, de René M.; Fluitman, Jan H.

    1984-01-01

    In an orthogonal thin film magnetometer a driving field oriented in the plane of a permalloy film along its hard-axis, saturates this film periodically in positive and negative direction. On return from saturation and in absence of a magnetic field component along the easy-axis, the magnetization in

  10. Reorientation of magnetic anisotropy in obliquely sputtered metallic thin films

    NARCIS (Netherlands)

    Lisfi, A.; Lodder, J.C.; Wormeester, H.; Poelsema, B.

    2002-01-01

    Reorientation in the magnetic anisotropy as a function of film thickness has been observed in Co-Ni and Co thin films, obliquely sputtered on a polyethylene terephthalate substrate at a large incidence angle (70°). This effect is a consequence of the low magnetocrystalline anisotropy of the films (f

  11. Wettability and photochromic behaviour of Molybdenum oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Allogho, Guy-Germain, E-mail: guy-germain.allogho@umoncton.ca; Ashrit, P.V., E-mail: pandurang.ashrit@umoncton.ca

    2012-01-01

    The temporal wettability (hydrophobic-hydrophilic) behaviour of thermally evaporated Molybdenum oxide thin films is examined via water droplet contact angle and water droplet lifetime measurements. Super-hydrophilic state is quickly achieved in these films and the rapidity of this conversion depends strongly on the film preparation conditions. It is found that film microstructure, humidity content and UV irradiation have a profound influence on the wettability behaviour of these films. The ensuing photochromic effect under UV irradiation is also followed through the optical changes occurring in the film. Films deposited at higher chamber pressure have a generally smaller initial contact angle and lifetime.

  12. Cadmium sulfide nanowires for the window semiconductor layer in thin film CdS-CdTe solar cells.

    Science.gov (United States)

    Liu, Piao; Singh, Vijay P; Jarro, Carlos A; Rajaputra, Suresh

    2011-04-08

    Thin film CdS/CdTe heterojunction device is a leading technology for the solar cells of the next generation. We report on two novel device configurations for these cells where the traditional CdS window layer is replaced by nanowires (NW) of CdS, embedded in an aluminum oxide matrix or free-standing. An estimated 26.8% improvement in power conversion efficiency over the traditional device structure is expected, primarily because of the enhanced spectral transmission of sunlight through the NW-CdS layer and a reduction in the junction area/optical area ratio. In initial experiments, nanostructured devices of the two designs were fabricated and a power conversion efficiency value of 6.5% was achieved.

  13. Effects of Controlling the AZO Thin Film's Optical Band Gap on AZO/MEH-PPV Devices with Buffer Layer

    Directory of Open Access Journals (Sweden)

    Jaehyoung Park

    2012-01-01

    Full Text Available Organic/inorganic hybrid solar cells were fabricated incorporating aluminum-doped zinc oxide (AZO thin films of varying optical band gap in AZO/poly(2-methoxy-5-(2′-ethyl-hexyloxy-p-phenylene vinylene structures. The band gaps were controlled by varying the flow rates of Ar and O2 used to deposit the AZO. Devices with CdS buffer layer were also fabricated for improved efficiency. The effects of AZO optical band gap were assessed by testing the I–V characteristics of devices with structures of glass/ITO/AZO/MEH-PPV/Ag under AM1.5 illumination (100 mW/cm2. Efficiency was improved about 30 times by decreasing the AZO optical band gap, except in devices deposited without oxygen. A power conversion efficiency of 0.102% was obtained with the incorporation of a CdS buffer layer.

  14. Combinatorial Chemical Bath Deposition of CdS Contacts for Chalcogenide Photovoltaics.

    Science.gov (United States)

    Mokurala, Krishnaiah; Baranowski, Lauryn L; de Souza Lucas, Francisco W; Siol, Sebastian; van Hest, Maikel F A M; Mallick, Sudhanshu; Bhargava, Parag; Zakutayev, Andriy

    2016-09-12

    Contact layers play an important role in thin film solar cells, but new material development and optimization of its thickness is usually a long and tedious process. A high-throughput experimental approach has been used to accelerate the rate of research in photovoltaic (PV) light absorbers and transparent conductive electrodes, however the combinatorial research on contact layers is less common. Here, we report on the chemical bath deposition (CBD) of CdS thin films by combinatorial dip coating technique and apply these contact layers to Cu(In,Ga)Se2 (CIGSe) and Cu2ZnSnSe4 (CZTSe) light absorbers in PV devices. Combinatorial thickness steps of CdS thin films were achieved by removal of the substrate from the chemical bath, at regular intervals of time, and in equal distance increments. The trends in the photoconversion efficiency and in the spectral response of the PV devices as a function of thickness of CdS contacts were explained with the help of optical and morphological characterization of the CdS thin films. The maximum PV efficiency achieved for the combinatorial dip-coating CBD was similar to that for the PV devices processed using conventional CBD. The results of this study lead to the conclusion that combinatorial dip-coating can be used to accelerate the optimization of PV device performance of CdS and other candidate contact layers for a wide range of emerging absorbers.

  15. Combinatorial Chemical Bath Deposition of CdS Contacts for Chalcogenide Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Mokurala, Krishnaiah; Baranowski, Lauryn L.; de Souza Lucas, Francisco W.; Siol, Sebastian; van Hest, Maikel F. A. M.; Mallick, Sudhanshu; Bhargava, Parag; Zakutayev, Andriy

    2016-09-12

    Contact layers play an important role in thin film solar cells, but new material development and optimization of its thickness is usually a long and tedious process. A high-throughput experimental approach has been used to accelerate the rate of research in photovoltaic (PV) light absorbers and transparent conductive electrodes, however the combinatorial research on contact layers is less common. Here, we report on the chemical bath deposition (CBD) of CdS thin films by combinatorial dip coating technique and apply these contact layers to Cu(In,Ga)Se2 (CIGSe) and Cu2ZnSnSe4 (CZTSe) light absorbers in PV devices. Combinatorial thickness steps of CdS thin films were achieved by removal of the substrate from the chemical bath, at regular intervals of time, and in equal distance increments. The trends in the photoconversion efficiency and in the spectral response of the PV devices as a function of thickness of CdS contacts were explained with the help of optical and morphological characterization of the CdS thin films. The maximum PV efficiency achieved for the combinatorial dip-coating CBD was similar to that for the PV devices processed using conventional CBD. The results of this study lead to the conclusion that combinatorial dip-coating can be used to accelerate the optimization of PV device performance of CdS and other candidate contact layers for a wide range of emerging absorbers.

  16. Two approaches for enhancing the hydrogenation properties of palladium: Metal nanoparticle and thin film over layers

    Indian Academy of Sciences (India)

    Manika Khanuja; B R Mehta; S M Shivaprasad

    2008-11-01

    In the present study, two approaches have been used for enhancing the hydrogenation properties of Pd. In the first approach, metal thin film (Cu, Ag) has been deposited over Pd and hydrogenation properties of bimetal layer Cu (thin film)/Pd(thin film) and Ag(thin film)/Pd(thin film) have been studied. In the second approach, Ag metal nanoparticles have been deposited over Pd and hydrogenation properties of Ag (nanoparticle)/Pd (thin film) have been studied and compared with Ag(thin film)/Pd(thin film) bimetal layer system. The observed hydrogen sensing response is stable and reversible over a number of hydrogen loading and deloading cycles in both bimetallic systems. Alloying between Ag and Pd is suppressed in case of Ag(nanoparticle)/Pd(thin film) bimetallic layer on annealing as compared to Ag (thin film)/Pd(thin film).

  17. Eddy current analysis of thin film recording heads

    Science.gov (United States)

    Shenton, D.; Cendes, Z. J.

    1984-03-01

    Due to inherently thin pole tips which enhance the sharpness of read/write pulses, thin-film magnetic recording heads provide a unique potential for increasing disk file capacity. However, the very feature of these heads which makes them attractive in the recording process, namely, their small size, also makes thin-film heads difficult to study experimentally. For this reason, a finite element simulation of the thin-film head has been developed to provide the magnetic field distribution and the resistance/inductance characteristics of these heads under a variety of conditions. A study based on a one-step multipath eddy current procedure is reported. This procedure may be used in thin film heads to compute the variation of magnetic field with respect to frequency. Computations with the IBM 3370 head show that a large phase shift occurs due to eddy currents in the frequency range 1-10 MHz.

  18. Plasma polymerised thin films for flexible electronic applications

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, Mohan V., E-mail: mohan.jacob@jcu.edu.au [Electronic Materials Research Lab, School of Engineering and Physical Sciences, James Cook University, Townsville 4811 (Australia); Olsen, Natalie S.; Anderson, Liam J.; Bazaka, Kateryna [Electronic Materials Research Lab, School of Engineering and Physical Sciences, James Cook University, Townsville 4811 (Australia); Shanks, Robert A. [Applied Sciences, RMIT University, GPO Box 2476V, Melbourne 3001 (Australia)

    2013-11-01

    The significant advancement and growth of organic and flexible electronic applications demand materials with enhanced properties. This paper reports the fabrication of a nonsynthetic polymer thin film using radio frequency plasma polymerisation of 3,7-dimethyl-1,6-octadien-3-ol. The fabricated optically transparent thin film exhibited refractive index of approximately 1.55 at 500 nm and rate of deposition was estimated to be 40 nm/min. The surface morphology and chemical properties of the thin films were also reported in this paper. The optical band gap of the material is around 2.8 eV. The force of adhesion and Young's modulus of the linalool polymer thin films were measured using force-displacement curves obtained from a scanning probe microscope. The friction coefficient of linalool polymer thin films was measured using the nanoscratch test. The calculated Young's modulus increased linearly with increase in input power while the friction coefficient decreased. - Highlights: • Fabrication of a novel polymer thin film from non-synthetic source • The surface, optical and chemical properties are reported. • The fabricated thin film is transparent and smooth. • An environmentally friendly material • Candidate for flexible electronics as dielectric layer or as an encapsulation layer.

  19. Organic photo detectors for an integrated thin-film spectrometer

    Science.gov (United States)

    Peters, Sabine; Sui, Yunwu; Glöckler, Felix; Lemmer, Uli; Gerken, Martina

    2007-09-01

    We introduce a thin-film spectrometer that is based on the superprism effect in photonic crystals. While the reliable fabrication of two and three dimensional photonic crystals is still a challenge, the realization of one-dimensional photonic crystals as thin-film stacks is a relatively easy and inexpensive approach. Additionally, dispersive thin-film stacks offer the possibility to custom-design the dispersion profile according to the application. The thin-film stack is designed such that light incident at an angle experiences a wavelength-dependent spatial beam shift at the output surface. We propose the monolithic integration of organic photo detectors to register the spatial beam position and thus determine the beam wavelength. This thin-film spectrometer has a size of approximately 5 mm2. We demonstrate that the output position of a laser beam is determined with a resolution of at least 20 μm by the fabricated organic photo detectors. Depending on the design of the thin-film filter the wavelength resolution of the proposed spectrometer is at least 1 nm. Possible applications for the proposed thin-film spectrometer are in the field of absorption spectroscopy, e.g., for gas analysis or biomedical applications.

  20. Polyelectrolyte Coacervates Deposited as High Gas Barrier Thin Films.

    Science.gov (United States)

    Haile, Merid; Sarwar, Owais; Henderson, Robert; Smith, Ryan; Grunlan, Jaime C

    2017-01-01

    Multilayer coatings consisting of oppositely charged polyelectrolytes have proven to be extraordinarily effective oxygen barriers but require many processing steps to fabricate. In an effort to prepare high oxygen barrier thin films more quickly, a polyelectrolyte complex coacervate composed of polyethylenimine and polyacrylic acid is prepared. The coacervate fluid is applied as a thin film using a rod coating process. With humidity and thermal post-treatment, a 2 µm thin film reduces the oxygen transmission rate of 0.127 mm poly(ethylene terephthalate) by two orders of magnitude, rivalling conventional oxygen barrier technologies. These films are fabricated in ambient conditions using low-cost, water-based solutions, providing a tremendous opportunity for single-step deposition of polymeric high barrier thin films.