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Sample records for cdte films electrodeposited

  1. Synthesis of CdTe thin films on flexible metal foil by electrodeposition

    Science.gov (United States)

    Luo, H.; Ma, L. G.; Xie, W. M.; Wei, Z. L.; Gao, K. G.; Zhang, F. M.; Wu, X. S.

    2016-04-01

    CdTe thin films have been deposited onto the Mo foil from aqueous acidic bath via electrodeposition method with water-soluble Na2TeO3 instead of the usually used TeO2. X-ray diffraction studies indicate that the CdTe thin films are crystallized in zinc-blende symmetry. The effect of tellurite concentration on the morphology of the deposited thin film is investigated. In such case, the Cd:Te molar ratios in the films are both stoichiometric at different tellurite concentrations. In addition, the reduction in tellurite concentration leads to the porous thin film and weakens the crystallinity of thin film. The island growth model is used to interpret the growth mechanism of CdTe. The bandgap of the CdTe thin films is assigned to be 1.49 eV from the UV-Vis spectroscopy measurement, which is considered to serve as a promising candidate for the heterojunction solar cells.

  2. Preparation and characterization of thin films of electrodeposited CdTe semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, M.; Elgamal, M. [Alexandria University (Egypt). Institute of Graduate Studies and Research; Kashyout, A.B. [Mubarak City for Scientific Research and Technological Applications, Alexandria (Egypt); Shabana, M. [Alexandria University (Egypt). Faculty of Engineering

    2001-07-01

    Thin films of CdTe semiconductors were prepared by electrodeposition technique in aqueous solutions. The deposition mechanism was investigated by cyclic voltammetry. The potential regions for the formation of the n-CdTe and p-CdTe films were determined. The structure, composition and morphology characteristics of as-deposited thin films of CdTe grown on SnO{sub 2}/glass and CdS/SnO{sub 2}/glass were investigated by XRD, EDAX and SEM techniques. The optical properties were measured to determine the absorption coefficient and band gap values. The as-deposited CdTe films grown on SnO{sub 2}/glass contained free Te while those grown on CdS/SnO{sub 2}/glass did not contain this phase. The CdTe has the cubic structure with strong (111) orientation. The EDAX analysis showed a nearly stoichiometric Cd:Te ratio. The band gap has a value of 1.48 eV, which is in a good accordance with those reported in the literature. The effect of annealing at 350 and 400{sup o}C after, CdCI{sub 2} treatment on the structure and morphology was also examined. (author)

  3. Electronic structure of electrodeposited thin film CdTe solar cells

    Science.gov (United States)

    Ullal, H. S.

    1988-05-01

    Independent experimental verification done at four research laboratories, namely, Ametek, Colorado State University (CSU), Institute of Energy Conversion (IEC), and Solar Energy Research Institute (SERI) confirm the n-i-p model proposed by Ametek. The experiments done for the verification of the n-i-p structure are the high frequency capacitance-voltage, light and voltage bias quantum efficiency, and EBIC measurements. All experimental evidence suggests that the n-i-p model is appropriate for the existing n-CdS/i-CdTe/p-ZnTe cell structure. From the C-V measurements, the depletion width has been estimated at 1.7 to 2.0 microns and corresponds to the thickness of the CdTe film. This unique thin films device design has resulted in improved stability and a SERI-verified world record single-junction total area AM1.5 global efficiency of 11 percent. Further refinements in device design and cell processing should result in 12 to 13 percent efficiencies for thin-film CdTe solar cells in the not-too-distant future.

  4. Electronic structure of electrodeposited thin film CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ullal, H.S.

    1988-05-01

    Independent experimental verification done at four research laboratories, namely, Ametek, Colorado State University (CSU), Institute of Energy Conversion (IEC), and Solar Energy Research Institute (SERI) confirm the n-i-p model proposed by Ametek. The experiments done for the verification of the n-i-p structure are the high frequency capacitance-voltage, light and voltage bias quantum efficiency, and EBIC measurements. All experimental evidence suggests that the n-i-p model is appropriate for the existing n-CdS/i-CdTe/p-ZnTe cell structure. From the C-V measurements, the depletion width has been estimated at 1.7-2.0 ..mu..m and corresponds to the thickness of the CdTe film. This unique thin films device design has resulted in improved stability and a SERI-verified world record single-junction total area AM1.5 global efficiency of 11%. Further refinements in device design and cell processing should result in 12-13% efficiencies for thin-film CdTe solar cells in the not-too-distant future.

  5. Preparation and characterisation of nearly stoichiometric CdTe films from a non-aqueous electrodeposition bath

    Science.gov (United States)

    Gore, R. B.; Pandey, Rajendra Kumar; Kumar, S. R.

    1991-06-01

    The cathodic polarisation characteristics and the growth behaviour of CdTe films in an ethylene-glycol-based bath have been studied. Conditions favouring stoichiometric deposition have been examined. The influence of the processing variables on the film properties has also been discussed with the help of the XRD, SEM and XPS studies. It has been shown that the films deposited potentiostatically at -0.8 V are stoichiometric and single phase.

  6. 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.

  7. Electrodeposited CdTe and HgCdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Basol, B.M.

    1988-01-15

    The processing steps necessary for producing high efficiency electrodeposited CdTe and HgCdTe solar cells are described. The key step in obtaining solar cell grade p-type CdTe and HgCdTe is the 'type conversion-junction formation' (TCJF) process. The TCJF process involves the heat treatment of the as-deposited n-type CdTe and HgCdTe layers at around 400 /sup 0/C. This procedure converts these n-type films into high resistivity p type and forms a rectifying junction between them and the underlying n-type window layers. Possible effects of oxygen on the TCJF process are discussed. The results of studies made on the structural, electrical and optical properties of the electrodeposited CdS, CdTe and HgCdTe films are presented. The resistivity of the electrodeposited HgCdTe can be made lower than that of CdTe. Consequently, solar cells made using the HgCdTe films have, on the average, better fill factors than those made using the CdTe layers, HgCdTe is also attractive for tandem-cell applications because of its variable band gap which can be easily tuned to the desired value. CdS/CdTe and CdS/HgCdTe heterojunction solar cells with 10.3% and 10.6% efficiency have been demonstrated using electrodeposition techniques and the TCJF process.

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

    OpenAIRE

    Obi K. Echendu; Imyhamy M. Dharmadasa

    2015-01-01

    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 impro...

  9. Electrodeposition of CdTe by potentiostatic and periodic pulse techniques

    Energy Technology Data Exchange (ETDEWEB)

    Moorthy Babu, S.; Dhanasekaran, R.; Ramasamy, P. (Crystal Growth Centre, Anna Univ., Madras (India))

    1991-07-15

    Cadmium telluride was electrodeposited from an aqueous solution containing the species CdCl{sub 2} and TeO{sub 2} by potentiostatic and periodic pulse techniques. The effect of different parameters such as concentration of the individual species, hydrogen ion concentration, applied potential and temperature are analysed to obtain optimum conditions for codeposition. X-ray diffractograms, X-ray microprobe analysis, scanning electron microscopy and voltammetry were employed to understand the crystalline nature, elemental composition and surface properties of the deposited films. A theoretical model has been developed for the electrodeposition of CdTe to understand the mechanism involved in the process. The results are discussed. (orig.).

  10. 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.

  11. Electrodeposited FePt films

    OpenAIRE

    Rhen, Fernando M. F.; Hinds, Gareth; O'Reilly, Cora; Coey, John Michael David

    2003-01-01

    A novel bath for electrodepositing FePt films was developed and films were electrodeposited on copper substrates with thickness up to 0.45 m. The magnetic and structural properties of the films were measured. The films developed 0.3-T coercivity after annealing at 400 C and formed the 10 FePt phase. Films are shiny and smooth. Morphology was found to be affected by the annealing process.

  12. Electrochemical deposition and characterization of CdTe polycrystalline thin films

    Energy Technology Data Exchange (ETDEWEB)

    Bonilla, S.; Dalchiele, E.A. (Inst. de Fisica, Facultad de Ingenieria, Montevideo (Uruguay))

    1991-10-10

    CdTe thin films have been prepared by potentiostatic electrodeposition from acidic solutions containing CdSO{sub 4} and TeO{sub 2}, or CdCl{sub 2} and TeO{sub 2}. The films were characterized by X-ray diffraction and scanning electron microscopy. The influence of the deposition potential and bath temperature on the presence of tellurium and crystallite size was studied. The effect of annealing treatment on the increase in grain size of the electrochemically deposited CdTe films has been investigated. (orig.).

  13. Resistivity and activation energy of CdTe electrodeposited at various Cd(II) concentrations

    Energy Technology Data Exchange (ETDEWEB)

    von Windheim, J.A.; Cocivera, M. (Guelph-Waterloo Centre for Graduate Work in Chemistry, Univ. of Guelph, Guelph, Ontario N1G 2WI (CA))

    1991-01-01

    This paper reports on two methods investigated for incorporating excess cadmium into CdTe electrodeposited from tri-n-butyl-phosphine telluride. These were: (i) variation of the Cd(II):Te concentration ratio in situ from 0.009 to 0.30 and (ii) the diffusion of metallic cadmium at high temperature. Resistivity and light response of various samples were studied after they had been removed from their substrates. Scanning electron microscopy was used to examine the morphology of some of the samples. For the series of films in which the Cd(II):Te concentration ratio was varied in situ the resistivity was found to increase moderately with increasing Cd(II) concentration. However, the activation energy was found to increase significantly only at the highest Cd(II):Te ratio, otherwise it remained more or less constant. The light response was similarly unaffected. When cadmium was diffused into the film, the light response was increased markedly and the resistivity generally decreased while the activation energy remained more or less the same.

  14. Resistivity and activation energy of CdTe electrodeposited at various Cd(II) concentrations

    International Nuclear Information System (INIS)

    This paper reports on two methods investigated for incorporating excess cadmium into CdTe electrodeposited from tri-n-butyl-phosphine telluride. These were: (i) variation of the Cd(II):Te concentration ratio in situ from 0.009 to 0.30 and (ii) the diffusion of metallic cadmium at high temperature. Resistivity and light response of various samples were studied after they had been removed from their substrates. Scanning electron microscopy was used to examine the morphology of some of the samples. For the series of films in which the Cd(II):Te concentration ratio was varied in situ the resistivity was found to increase moderately with increasing Cd(II) concentration. However, the activation energy was found to increase significantly only at the highest Cd(II):Te ratio, otherwise it remained more or less constant. The light response was similarly unaffected. When cadmium was diffused into the film, the light response was increased markedly and the resistivity generally decreased while the activation energy remained more or less the same

  15. CdTe Films Deposited by Closed-space Sublimation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    CdTe films are prepared by closed-space sublimation technology. Dependence of film crystalline on substrate materials and substrate temperature is investigated. It is found that films exhibit higher crystallinity at substrate temperature higher than 400℃. And the CdTe films deposited on CdS films with higher crystallinity have bigger crystallite and higher uniformity. Treatment with CdCl2 methanol solution promotes the crystallite growth of CdTe films during annealing.

  16. Growth of CdTe: Al films

    International Nuclear Information System (INIS)

    CdTe: AI films were grown by the close space vapor transport technique combined with free evaporation (CSVT-FE). The Aluminum (Al) evaporation was made by two kinds of sources: one made of graphite and the other of tantalum. The films were deposited on glass substrates. The Al source temperature was varied maintaining the CdTe source temperature fixed as well as the substrate temperature. The films were characterized by x-ray energy dispersive analysis (EDAX), x-ray diffraction and optical transmission. The results showed for the films grown with the graphite source for Al evaporation, the Al did not incorporate in the CdTe matrix, at least to the level of EDAX sensitivity; they maintained the same crystal structure and band gap. For the samples grown with the tantalum source, we were able to incorporate the Al. The x-ray diffraction patterns show that the films have a crystal structure that depends on Al concentration. They were cubic up to 2.16 at. % Al concentration; for 19.65 at. % we found a mixed phase; for Al concentration higher than 21 at. % the films were amorphous. For samples with cubic structure it was found that the lattice parameter decreases and the band gap increases with Al concentration. (Author)

  17. Electrodeposition of Oriented Cerium Oxide Films

    OpenAIRE

    Golden, Teresa D.; Adele Qi Wang

    2013-01-01

    Cerium oxide films of preferred orientation are electrodeposited under anodic conditions. A complexing ligand, acetate, was used to stabilize the cerium (III) ion in solution for deposition of the thin films. Fourier transform infrared spectroscopy showed that the ligand and metal tended to bind as a weakly bidentate complex. The crystallite size of the films was in the nanometer range as shown by Raman spectroscopy and was calculated from X-ray diffraction data. Crystallite sizes from 6 to 2...

  18. Patterned self-assembled film guided electrodeposition

    Institute of Scientific and Technical Information of China (English)

    ZHOU; Feng; LI; Bin; XU; Tao; CHEN; Miao; HAO; Jingcheng; LI

    2004-01-01

    The paper describes the fabrication of polypyrrole (PPy) microstructures through patterned self-assembled film guided electrodeposition. Thus the patterned self-assembled monolayer is prepared by microcontact printing (μCP) and used as the template in the electrodeposition of PPy. It has been found that the self-assembled monolayer plays completely different roles on different substrates in directing the deposition of the PPy. Namely, the electrodeposition mainly occurs on the exposed area of the gold substrates patterned with dodecanethiol (DDT) and octadecanelthiol (ODT) and on the indium tin oxide (ITO) substrate patterned with octadecyltrichlorosilane (OTS), while PPy nucleates on the OTS covered area and no deposition is found on the exposed area of a semiconductor substrate (silicon). This is attributed to the cooperative effect between the substrate conductivity and the compatibility of the PPy oligomer with the covered or exposed area of the substrate surface.

  19. Electro-Plating and Characterisation of CdTe Thin Films Using CdCl2 as the Cadmium Source

    Directory of Open Access Journals (Sweden)

    Nor A. Abdul-Manaf

    2015-09-01

    Full Text Available Cadmium telluride (CdTe thin films have been successfully prepared from an aqueous electrolyte bath containing cadmium chloride (CdCl2·H2O and tellurium dioxide (TeO2 using an electrodeposition technique. The structural, electrical, morphological and optical properties of these thin films have been characterised using X-ray diffraction (XRD, Raman spectroscopy, optical profilometry, DC current-voltage (I-V measurements, photoelectrochemical (PEC cell measurement, scanning electron microscopy (SEM, atomic force microscopy (AFM and UV-Vis spectrophotometry. It is observed that the best cathodic potential is 698 mV with respect to standard calomel electrode (SCE in a three electrode system. Structural analysis using XRD shows polycrystalline crystal structure in the as-deposited CdTe thin films and the peaks intensity increase after CdCl2 treatment. PEC cell measurements show the possibility of growing p-, i- and n-type CdTe layers by varying the growth potential during electrodeposition. The electrical resistivity of the as-deposited layers are in the order of 104 Ω·cm. SEM and AFM show that the CdCl2 treated samples are more roughness and have larger grain size when compared to CdTe grown by CdSO4 precursor. Results obtained from the optical absorption reveal that the bandgap of as-deposited CdTe (1.48–1.52 eV reduce to (1.45–1.49 eV after CdCl2 treatment. Full characterisation of this material is providing new information on crucial CdCl2 treatment of CdTe thin films due to its built-in CdCl2 treatment during the material growth. The work is progressing to fabricate solar cells with this material and compare with CdTe thin films grown by conventional sulphate precursors.

  20. Study of CdTe and HgCdTe thin films obtained by electrochemical methods

    International Nuclear Information System (INIS)

    Cadmium telluride polycrystalline thin films were fabricated on SnO2-coated glass substrates by potentiostatic electrodeposition and characterized by X-ray diffraction, energy dispersive X-ray analyses (EDAX), optical and electrical measurements. The films dseposited at potentials more positive than -0.65 V vs.SCE were p-type but those deposited at more negative potentials were n-type. All CdTe thin films showed a band-gap energy about 1.45 eV and a large absorption coeffici-ent (a=105 cm-1) above de band edge. The addition of even small amounts of mercury to the CdTe produces higuer conductivity values and lower band-gap energies. We have prepared HgCdTe thin films where the band-gap energies ranged between 0.93 and 0.88 eV depending on the ratio of mercury to cadmium. Heat treatment at 3000C increases the crystalline diameter and alter the composition of the electrodeposited films, a decrease of the resistivity values was also observed. (Author)

  1. Growth and Characterization of CdTe Thin Films on CdS/TCO/glass superstrate

    Science.gov (United States)

    Oladeji, Isaiah O.; Chow, Lee; Zhou, Dan; Stevie, Fred

    1998-11-01

    The performance of CdTe/CdS/TCO/glass structure which is generally used as a solar cell depends on the impurities incorporated in the system before and after electrodeposition of CdTe thin films. In this report we present a detailed investigation of this structure using secondary ion mass spectrometry(SIMS), x-ray microanalysis, x-ray diffraction(XRD), and scanning electron microscopy(SEM) to identify those impurities. We also discuss possible ways of minimizing or eliminating some of these impurities in order to improve the cell efficiency.

  2. Polycrystalline thin film cadmium telluride solar cells fabricated by electrodeposition. Annual technical report, 20 March 1995--19 March 1996

    Energy Technology Data Exchange (ETDEWEB)

    Trefny, J U; Mao, D [Colorado School of Mines, Golden, CO (United States)

    1997-04-01

    The objective of this project is to develop improved processes for fabricating CdTe/CdS polycrystalline thin-film solar cells. Researchers used electrodeposition to form CdTe; electrodeposition is a non-vacuum, low-cost technique that is attractive for economic, large-scale production. During the past year, research and development efforts focused on several steps that are most critical to the fabricating high-efficiency CdTe solar cells. These include the optimization of the CdTe electrodeposition process, the effect of pretreatment of CdS substrates, the post-deposition annealing of CdTe, and back-contact formation using Cu-doped ZnTe. Systematic investigations of these processing steps have led to a better understanding and improved performance of the CdTe-based cells. Researchers studied the structural properties of chemical-bath-deposited CdS thin films and their growth mechanisms by investigating CdS samples prepared at different deposition times; investigated the effect of CdCl{sub 2} treatment of CdS films on the photovoltaic performance of CdTe solar cells; studied Cu-doped ZnTe as a promising material for forming stable, low-resistance contacts to the p-type CdTe; and investigated the effect of CdTe and CdS thickness on the photovoltaic performance of the resulting cells. As a result of their systematic investigation and optimization of the processing conditions, researchers improved the efficiency of CdTe/CdS cells using ZnTe back-contact and electrodeposited CdTe. The best CdTe/CdS cell exhibited a V{sub oc} of 0.778 V, a J{sub sc} of 22.4 mA/cm{sup 2}, a FF of 74%, and an efficiency of 12.9% (verified at NREL). In terms of individual parameters, researchers obtained a V{sub oc} over 0.8 V and a FF of 76% on other cells.

  3. High-quality CdTe films from nanoparticle precursors

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, D.L.; Pehnt, M.; Urgiles, E. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1996-05-01

    In this paper the authors demonstrate that nanoparticulate precursors coupled with spray deposition offers an attractive route into electronic materials with improved smoothness, density, and lower processing temperatures. Employing a metathesis approach, cadmium iodide was reacted with sodium telluride in methanol solvent, resulting in the formation of soluble NaI and insoluble CdTe nanoparticles. After appropriate chemical workup, methanol-capped CdTe colloids were isolated. CdTe thin film formation was achieved by spray depositing the nanoparticle colloids (25-75 {Angstrom} diameter) onto substrates at elevated temperatures (T = 280-440{degrees}C) with no further thermal treatment. These films were characterized by x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Cubic CdTe phase formation was observed by XRD, with a contaminant oxide phase also detected. XPS analysis showed that CdTe films produced by this one-step method contained no Na or C and substantial O. AFM gave CdTe grain sizes of {approx}0.1-0.3 {mu}m for film sprayed at 400{degrees}C. A layer-by-layer film growth mechanism proposed for the one-step spray deposition of nanoparticle precursors will be discussed.

  4. High short-circuit current density CdTe solar cells using all-electrodeposited semiconductors

    International Nuclear Information System (INIS)

    CdS/CdTe and ZnS/CdTe n–n heterojunction solar cells have been fabricated using all-electrodeposited semiconductors. The best devices show remarkable high short-circuit current densities of 38.5 mAcm−2 and 47.8 mAcm−2, open-circuit voltages of 630 mV and 646 mV and conversion efficiencies of 8.0% and 12.0% respectively. The major strength of these device structures lies in the combination of n–n heterojunction with a large Schottky barrier at the n-CdTe/metal back contact which provides the required band bending for the separation of photo-generated charge carriers. This is in addition to the use of a high quality n-type CdTe absorber layer with high electron mobility. The potential barrier heights estimated for these devices from the current–voltage characteristics exceed 1.09 eV and 1.13 eV for CdS/CdTe and ZnS/CdTe cells respectively. The diode rectification factors of both devices are in excess of four orders of magnitude with reverse saturation current densities of 1.0 × 10−7 Acm−2 and 4.0 × 10−7 Acm−2 respectively. These all-electrodeposited solar cell device structures are currently being studied and developed as an alternative to the well-known p–n junction structures which utilise chemical bath-deposited CdS. The preliminary material growth, device fabrication and assessment results are presented in this paper. - Highlights: • Two-electrode deposition. • High Jsc Schottky barrier solar cells. • CdCl2 + CdF2 treatment

  5. Electrodeposition of Sr-Ti alloy films from DMSO bath

    International Nuclear Information System (INIS)

    Electrodeposition of Sr-Ti alloy films from non aqueous dimethyl sulphoxide (DMSO) bath has been carried out onto stainless steel and fluorine doped tin oxide (FTO) coated glass substrate. The preparative parameters were studied and optimised. Alloy films with thickness 2 to 3 microns were obtained for 30 minutes of deposition. The films were uniform, dense and adhesive to the substrate. The electrodeposited Sr-Ti alloy films were oxidised at higher temperature in order to obtain SrTiO3 films. Electrical and microstructural properties were carried out. (author). 6 refs., 6 figs

  6. Magnetoresistance Measurements on Electrodeposited Cox Cu1-x Alloy Films

    OpenAIRE

    BAKKALOŽLU, Ömer F.

    2001-01-01

    Cox Cu1-x alloy films were prepared by using electrodeposition technique. The variations of Co and Cu contents of the films were investigated as functions of bath pH and Co content. The compositions of the alloy films were determined using an atomic absorption spectrophotometer. The crystal structures of the alloy films were analyzed using a Cu (K a )-X-ray diffractometer. The diffraction lines observed were only those of copper component in the alloy films. All three films showed...

  7. Thin-film CdTe cells: Reducing the CdTe

    International Nuclear Information System (INIS)

    Polycrystalline thin-film CdTe is currently the dominant thin-film technology in world-wide PV manufacturing. With finite Te resources world-wide, it is appropriate to consider the limits to reducing the thickness of the CdTe layer in these devices. In our laboratory we have emphasized the use of magnetron sputtering for both CdS and CdTe achieving AM1.5 efficiency over 13% on 3 mm soda-lime glass with commercial TCO and 14% on 1 mm aluminosilicate glass. This deposition technique is well suited to good control of very thin layers and yields relatively small grain size which also facilitates high performance with ultra-thin layers. This paper describes our magnetron sputtering studies for fabrication of very thin CdTe cells. Our thinnest cells had CdTe thicknesses of 1 μm, 0.5 μm and 0.3 μm and yielded efficiencies of 12%, 9.7% and 6.8% respectively. With thinner cells Voc, FF and Jsc are reduced. Current-voltage (J-V), temperature dependent J-V (J-V-T) and apparent quantum efficiency (AQE) measurements provide valuable information for understanding and optimizing cell performance. We find that the stability under light soak appears not to depend on CdTe thickness from 2.5 to 0.5 μm. The use of semitransparent back contacts allows the study of bifacial response which is particularly useful in understanding carrier collection in the very thin devices.

  8. Design of a thin film CdTe solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, P.V.

    1988-01-15

    Cadmium telluride was originally considered for thin film solar cells because of its optimum band gap, high optical absorption coefficient and ability to be doped. Furthermore, it is a stable compound which can be produced by a wide variety of methods from stable raw materials. As thin film photovoltaics mature, however, it is clear that several more subtle attributes have a significant impact on the viability of commercialization. We discuss the observations which have provided insight and direction to Ametek's CdTe solar cell program. Rather than try to modify the inherent material properties of CdTe, advances have been made by designing a solar cell that exploits existing properties. Specifically, the tendency to self-compensate, which makes low resistance contacting difficult, is turned into an advantage in the n-i-p configuration; the CdTe provides an intrinsic layer with good carrier collection efficiency.

  9. Electron transient transport in CdTe polycrystalline films

    Science.gov (United States)

    Ramírez-Bon, R.; Sánchez-Sinencio, F.; González de la Cruz, G.; Zelaya, O.

    1991-11-01

    Electron transient currents between coplanar electrodes have been measured in intrinsic polycrystalline films of CdTe, by means of the time of flight technique. The experimental results: electron transient current vs time, transit time vs voltage and the temperature dependence of the electron drift mobility, show features characteristics of dispersive electrical transport similar to that observed in disordered solids.

  10. Characterization of CdTe Films Deposited at Various Bath Temperatures and Concentrations Using Electrophoretic Deposition

    Directory of Open Access Journals (Sweden)

    Zulkarnain Zainal

    2012-05-01

    Full Text Available CdTe film was deposited using the electrophoretic deposition technique onto an ITO glass at various bath temperatures. Four batch film compositions were used by mixing 1 to 4 wt% concentration of CdTe powder with 10 mL of a solution of methanol and toluene. X-ray Diffraction analysis showed that the films exhibited polycrystalline nature of zinc-blende structure with the (111 orientation as the most prominent peak. From the Atomic Force Microscopy, the thickness and surface roughness of the CdTe film increased with the increase of CdTe concentration. The optical energy band gap of film decreased with the increase of CdTe concentration, and with the increase of isothermal bath temperature. The film thickness increased with respect to the increase of CdTe concentration and bath temperature, and following, the numerical expression for the film thickness with respect to these two variables has been established.

  11. Fabrication of mesoporous cerium dioxide films by cathodic electrodeposition.

    Science.gov (United States)

    Kim, Young-Soo; Lee, Jin-Kyu; Ahn, Jae-Hoon; Park, Eun-Kyung; Kim, Gil-Pyo; Baeck, Sung-Hyeon

    2007-11-01

    Mesoporous cerium dioxide (Ceria, CeO2) thin films have been successfully electrodeposited onto ITO-coated glass substrates from an aqueous solution of cerium nitrate using CTAB (Cetyltrimethylammonium Bromide) as a templating agent. The synthesized films underwent detailed characterizations. The crystallinity of synthesized CeO2 film was confirmed by XRD analysis and HR-TEM analysis, and surface morphology was investigated by SEM analysis. The presence of mesoporosity in fabricated films was confirmed by TEM and small angle X-ray analysis. As-synthesized film was observed from XRD analysis and HR-TEM image to have well-crystallized structure of cubic phase CeO2. Transmission electron microscopy and small angle X-ray analysis revealed the presence of uniform mesoporosity with a well-ordered lamellar phase in the CeO2 films electrodeposited with CTAB templating. PMID:18047150

  12. Growth of CdTe films on GaAs by ionized cluster beam epitaxy

    Science.gov (United States)

    Tang, H. P.; Feng, J. Y.; Fan, Y. D.; Li, H. D.

    1991-06-01

    Stoichiometric epitaxial films of CdTe were grown on (100)GaAs substrates by ionized cluster beam (ICB) epitaxy. Streaky RHEED patterns indicated good crystallinity and surface flatness of the epitaxial CdTe films. CdTe(100) orientation was obtained when the substrate preheating temperature was 480°C, while CdTe growth inboth (100) and (111) orientations occured when the substrate preheating temperature was above 550°C. The characteristics of the ICB growth process were investigated and the cluster-involving growth behavior has been evidenced. When sufficient clusters were generated in the deposition beam under adequate source vapor pressures, the crystalline quality of the resulting CdTe epilayers improved significantly with the increase of kinetic energy of the CdTe clusters. The best CdTe epilayer obtained exhibited a CdTe(400) double crystal rocking curve (DCRC) having a FWHM of 630 arc sec.

  13. Growth of CdTe films on GaAs by ionized cluster beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Tang, H.P.; Feng, J.Y.; Fan, Y.D.; Li, H.D. (Dept. of Materials Science and Engineering, Tsinghua Univ., Beijing (China))

    1991-06-01

    Stoichiometric epitaxial films of CdTe were grown on (100)GaAs substrates by ionized cluster beam (ICB) epitaxy. Streaky RHEED patterns indicated good crystallinity and surface flatness of the epitaxial CdTe films. CdTe(100) orientation was obtained when the substrate preheating temperature was 480degC, while CdTe growth in both (100) and (111) orientations occurred when the substrate preheating temperature was above 550degC. The characteristics of the ICB growth process were investigated and the cluster-involving growth behavior has been evidenced. When sufficient clusters were generated in the deposition beam under adequate source vapor pressures, the crystalline quality of the resulting CdTe epilayers improved significantly with the increase of kinetic energy of the CdTe clusters. The best CdTe epilayer obtained exhibited a CdTe(400) double crystal rocking curve (DCRC) having a FWHM of 630 arc sec. (orig.).

  14. Synthesis and luminescence properties of electrodeposited ZnO films

    OpenAIRE

    Manzano, Cristina V.; Alegre, Daniel; Caballero-Calero, Olga; Alén, Benito; Martín-González, Marisol S.

    2011-01-01

    Zinc oxide (ZnO) films have been grown on gold (111) by electrodeposition using two different OH− sources, nitrate and peroxide, in order to obtain a comparative study between them. The morphology, structural and optical characterization of the films were investigated depending on the solution used (nitrate and peroxide) and the applied potential. Scanning electron microscopy pictures show different morphologies in each case. X-ray diffraction confirms that the films are pure ZnO oriented alo...

  15. Electrodeposition of magnesium film from BMIMBF4 ionic liquid

    International Nuclear Information System (INIS)

    In this paper, we reported for the first time magnesium electrodeposition and dissolution processes in the ionic liquid of BMIMBF4 with 1 M Mg(CF3SO3)2 at room temperature. Our study found that complete electrochemical reoxidation of the electrodeposited magnesium film was feasible only on Ag substrate, comparing with the Pt, Ni, and stainless-steel. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) results showed that magnesium was found in the deposited film and the deposits were dense. The electrodeposition of magnesium on Ag substrate in the ionic liquid was considered to be a reversible process by cyclic voltammetry. Plots of peak current versus the square root of the scan rate were found to be linear, which indicates that the mass-transport process of electroactive species was mainly diffusion controlled. The diffusion coefficient D values of electroactive species were calculated from cyclic voltammetry and chronoamperometry, respectively

  16. CdTe polycrystalline films on Ni foil substrates by screen printing and their photoelectric performance

    International Nuclear Information System (INIS)

    Highlights: • The sintered CdTe polycrystalline films by a simple screen printing. • The flexible Ni foil was chose as substrates to reduce the weight of the electrode. • The compact CdTe film was obtained at 550 °C sintering temperature. • The photoelectric activity of the CdTe polycrystalline films was excellent. - Abstract: CdTe polycrystalline films were prepared on flexible Ni foil substrates by sequential screen printing and sintering in a nitrogen atmosphere for the first time. The effect of temperature on the quality of the screen-printed film was investigated in our work. The high-quality CdTe films were obtained after sintering at 550 °C for 2 h. The properties of the sintered CdTe films were characterized by scanning electron microscopy, X-ray diffraction pattern and UV–visible spectroscopy. The high-quality CdTe films have the photocurrent was 2.04 mA/cm2, which is higher than that of samples prepared at other temperatures. Furthermore, CdCl2 treatment reduced the band gap of the CdTe film due to the larger grain size. The photocurrent of photoelectrode based on high crystalline CdTe polycrystalline films after CdCl2 treatment improved to 2.97 mA/cm2, indicating a potential application in photovoltaic devices

  17. Poly CdTe thin films solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Marfaing, Y.

    1982-01-01

    CdTe is potentially one of the most interesting materials for the photovoltaic conversion of solar energy. The width of its forbidden band of 1.5 eV puts it to the maximum of the theoretical yield curve (24%). Its high coefficient of optical absorption in the main band allows the use of thin films (2 to 3 microns). It is appropriate for production of thin polycristalline films with good optical and photoelectrical properties, which is probably due to its ionic character. The goal of the research performed as part of this contract is to determine the optimum conditions for the use of CdTe as photovoltaic converter. The authors think that the virtual efficiency of this material calls for confirmation and evidence provided by a systematic and profound investigation.

  18. Methods and electrolytes for electrodeposition of smooth films

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiguang; Xu, Wu; Graff, Gordon L; Chen, Xilin; Ding, Fei; Shao, Yuyan

    2015-03-17

    Electrodeposition involving an electrolyte having a surface-smoothing additive can result in self-healing, instead of self-amplification, of initial protuberant tips that give rise to roughness and/or dendrite formation on the substrate and/or film surface. For electrodeposition of a first conductive material (C1) on a substrate from one or more reactants in an electrolyte solution, the electrolyte solution is characterized by a surface-smoothing additive containing cations of a second conductive material (C2), wherein cations of C2 have an effective electrochemical reduction potential in the solution lower than that of the reactants.

  19. Piezoelectric film electro-deposition for optical fiber sensor with ZnO coating

    Institute of Scientific and Technical Information of China (English)

    Li Zhou; Ping Gu; Ya Zhou

    2008-01-01

    The piezoelectric film electro-deposition for optical fiber sensor with ZnO coating is studied. The zinc oxide plating film is made on the copper surface directly by cathodic electro-deposition in the Zn(NO3)2 single salt aqueous solution systems. The influences of main experimental conditions on the properties of ZnO thin film in the electro-deposition processes are analyzed and a stable, practical and economic technique is obtained.

  20. Stable, high efficiency thin film solar cells produced by electrodeposition of cadmium telluride

    Energy Technology Data Exchange (ETDEWEB)

    Turner, A.K.; Woodcock, J.M.; Ozsan, M.E.; Summers, J.G.; Barker, J.; Binns, S.; Buchanan, K.; Chai, C.; Dennison, S.; Hart, R.; Johnson, D.; Marshall, R.; Oktik, S.; Patterson, M.; Perks, R.; Roberts, S.; Sadeghi, M.; Sherborne, J.; Szubert, J.; Webster, S. (BP Solar, Solar House, Leatherhead (United Kingdom))

    1991-12-01

    The highest known efficiency of 9.5% for a 300x300 mm series interconnected cadmium telluride solar cell is reported. In addition, efficiencies of up to 13% have been measured for small cells based on electrodeposited CdTe. The stability of modules in outdoor tests is discussed and an outline is given of the device fabrication procedure. (orig.).

  1. Comparative study of CdTe sources used for deposition of CdTe thin films by close spaced sublimation technique

    OpenAIRE

    Wagner Anacleto Pinheiro; Vivienne Denise Falcão; Leila Rosa de Oliveira Cruz; Carlos Luiz Ferreira

    2006-01-01

    Unlike other thin film deposition techniques, close spaced sublimation (CSS) requires a short source-substrate distance. The kind of source used in this technique strongly affects the control of the deposition parameters, especially the deposition rate. When depositing CdTe thin films by CSS, the most common CdTe sources are: single-crystal or polycrystalline wafers, powders, pellets or pieces, a thick CdTe film deposited onto glass or molybdenum substrate (CdTe source-plate) and a sintered C...

  2. InSb thin films grown by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Joginder, E-mail: joginderchauhan82@gmail.com; Rajaram, P., E-mail: joginderchauhan82@gmail.com [School of Studies in Physics, Jiwaji University, Gwalior-474011 (India)

    2014-04-24

    We have grown InSb thin films on Cu substrates using the electrodeposition technique. The electrochemical bath from which the InSb thin films were grown was made up of a mixture of aqueous solutions of 0.05 M InCl{sub 3} and 0.03M SbCl{sub 3}, 0 .20M citric acid and 0.30M sodium citrate. Citric acid and sodium citrate were used as complexing agents to bring the reduction potential of In and Sb closer to maintain binary growth. The electrodeposited films were characterized by structural, morphological and optical studies. X-ray diffraction studies show that the films are polycrystalline InSb having the zinc blende structure. Scanning electron microscopy (SEM) studies reveal that the surface of the films is uniformly covered with submicron sized spherical particles. FTIR spectra of InSb thin films show a sharp absorption peak at wave number 1022 cm{sup −1} corresponding to the band gap. Hot probe analysis shows that the InSb thin films have p type conductivity.

  3. Comparative study of CdTe sources used for deposition of CdTe thin films by close spaced sublimation technique

    Directory of Open Access Journals (Sweden)

    Wagner Anacleto Pinheiro

    2006-03-01

    Full Text Available Unlike other thin film deposition techniques, close spaced sublimation (CSS requires a short source-substrate distance. The kind of source used in this technique strongly affects the control of the deposition parameters, especially the deposition rate. When depositing CdTe thin films by CSS, the most common CdTe sources are: single-crystal or polycrystalline wafers, powders, pellets or pieces, a thick CdTe film deposited onto glass or molybdenum substrate (CdTe source-plate and a sintered CdTe powder. In this work, CdTe thin films were deposited by CSS technique from different CdTe sources: particles, powder, compact powder, a paste made of CdTe and propylene glycol and source-plates (CdTe/Mo and CdTe/glass. The largest deposition rate was achieved when a paste made of CdTe and propylene glycol was used as the source. CdTe source-plates led to lower rates, probably due to the poor heat transmission, caused by the introduction of the plate substrate. The results also showed that compacting the powder the deposition rate increases due to the better thermal contact between powder particles.

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

    Science.gov (United States)

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

    2012-02-01

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

  5. Electrodeposition of Vanadium Oxide/Manganese Oxide Hybrid Thin Films on Nanostructured Aluminum Substrates

    OpenAIRE

    Rehnlund, David; Valvo, Mario; Edström, Kristina; Nyholm, Leif

    2014-01-01

    Electrodeposition of functional coatings on aluminum electrodes in aqueous solutions often is impeded by the corrosion of aluminum. In the present work it is demonstrated that electrodeposition of vanadium, oxide films on nanostructured aluminum substrates can be achieved in acidic electrolytes employing a novel strategy in which a thin interspacing layer of manganese oxide is first electrodeposited on aluminum microrod substrates. Such deposited films, which were studied using SEM, XPS, XRD,...

  6. Flexible CdTe solar cells on polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, A.N.; Romeo, A.; Baetzner, D.; Zogg, H. [ETH Swiss Federal Inst. of Technology, Thin Film Physics Group, Zurich (Switzerland)

    2001-07-01

    Lightweight and flexible CdTe/CdS solar cells on polyimide films have been developed in a 'superstrate configuration' where the light is absorbed in CdTe after passing through the polyimide substrate. The average optical transmission of the approximately 10-{mu}m-thin spin-coated polyimide substrate layer is more than {approx}75% for wavelengths above 550 nm. RF magnetron sputtering was used to grow transparent conducting ZnO:Al layers on polyimide films. CdTe/CdS layers were grown by evaporation of compounds, and a CdCl{sub 2} annealing treatment was applied for the recrystallisation and junction activation. Solar cells of 8.6% efficiency with V{sub oc} = 763 mV, I{sub sc} = 20.3 mA/cm{sup 2} and FF = 55.7% were obtained. (Author)

  7. Aluminum doping of CdTe polycrystalline films starting from the heterostructure CdTe/Al

    OpenAIRE

    Becerril, M.; O. Vigil-Galán; G. Contreras-Puente; O. Zelaya-Angel

    2011-01-01

    Aluminum doped CdTe polycrystalline films were obtained from the heterostructure CdTe/Al/Corning glass. The aluminum was deposited by thermal vacuum evaporation and the CdTe by sputtering of a CdTe target. The aluminum was introduced into the lattice of the CdTe from a thermal annealed to the CdTe/Al/Corning glas heterostructure. The electrical, structural, nd optical properties were analyzed as a function of the Al concentrations. It found that when Al is incorporated, the electrical resisti...

  8. PENINGKATAN KUALITAS FILM TIPIS CdTe SEBAGAI ABSORBER SEL SURYA DENGAN MENGGUNAKAN DOPING TEMBAGA (Cu)

    OpenAIRE

    P. Marwoto; N.M. Darmaputra; Sugianto -; Othaman, Z.; E. Wibowo; S.Y. Astuti

    2012-01-01

    Film tipis CdTe dengan doping tembaga (Cu) berkonsenterasi 2% telah berhasil ditumbuhkan di atas substrat Indium Tin Oxide (ITO) dengan metode dc magnetron sputtering. Penelitian ini dilakukan untuk mengetahui pengaruh doping Cu(2%) terhadap struktur morfologi, struktur kristal, fotoluminisensi dan resistivitas listrik film CdTe. Citra morfologi Scanning Electron Microscopy (SEM) dan hasil analisis struktur dengan X-Ray Diffraction (XRD) menunjukkan bahwa film CdTe:Cu(2%) mempunyai citra perm...

  9. Study of trapping density in electrical characteristics of CdTe thin films

    International Nuclear Information System (INIS)

    CdTe thin films were deposited on glass at various substrate temperatures using vacuum evaporated technique. The X-ray diffraction analysis of vacuum evaporated cadmium telluride (CdTe) films reveals was polycrystalline in nature for the samples prepared at higher temperatures. Micro structural feature associated with the as deposited CdTe thin films were studied by Transmission Electron Microscopy (TEM). A high density of trapping centers, responsible for grain boundary space-charge potential barriers, which oppose the passage of carriers from a grain to the neighbouring ones, was explained from this analysis. (author)

  10. Cathodic electrodeposition of cobalt oxide films using polyelectrolytes

    International Nuclear Information System (INIS)

    Composite films consisting of cobalt hydroxide and polyelectrolytes, such as poly(diallyldimethylammonium chloride) (PDDA) and polyethylenimine (PEI), were obtained by electrodeposition. In the proposed method, electrophoretic deposition of PDDA macromolecules or PEI-Co2+ complexes has been combined with cathodic electrosynthesis of cobalt hydroxide. By varying the concentration of the polyelectrolytes in solutions, the deposition time and the current density, the amount of deposited material and its composition can be varied. The composite deposits have been studied by scanning, transmission and atomic force microscopy, X-ray diffraction and thermogravimetric analysis. The obtained results have been compared with the results of investigation of pure cobalt hydroxide films. Heat treatment of the deposits resulted in decomposition of the hydroxide precursor and burning out of polymer to form cobalt oxide films. This method enables the formation of thick nanostructured oxide films

  11. Electrodeposition and growth mechanism of SnSe thin films

    Science.gov (United States)

    Biçer, Mustafa; Şişman, İlkay

    2011-01-01

    Tin selenide (SnSe) thin films were electrochemically deposited onto Au(1 1 1) substrates from an aqueous solution containing SnCl2, Na2SeO3, and EDTA at room temperature (25 °C). The electrochemical behaviors and the codeposition potentials of Sn and Se were explored by cyclic voltammetry. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and UV-vis absorption spectroscopy were employed to characterize the thin films. When the electrodeposition potential increased, the Se content in the films decreased. It was found that the stoichiometric SnSe thin films could be obtained at -0.50 V. The as-deposited films were crystallized in the preferential orientation along the (1 1 1) plane. The morphologies of SnSe films could be changed from spherical grains to platelet-like particles as the deposition potential increases. The SEM investigations show that the film growth proceeds via nucleation, growth of film layer and formation of needle-like particles on the overlayer of the film. The optical absorption study showed the film has direct transition with band gap energy of 1.3 eV.

  12. Properties of CdTe nanocrystalline thin films grown on different substrates by low temperature sputtering

    Institute of Scientific and Technical Information of China (English)

    Chen Huimin; Guo Fuqiang; Zhang Baohua

    2009-01-01

    CdTe nanocrystalline thin films have been prepared on glass, Si and Al2O3 substrates by radio-frequency magnetron sputtering at liquid nitrogen temperature. The crystal structure and morphology of the films were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). The XRD examinations revealed that CdTe films on glass and Si had a better crystal quality and higher preferential orientation along the (111) plane than the Al2O3. FESEM observations revealed a continuous and dense morphology of CdTe films on glass and Si substrates. Optical properties of nanocrystalline CdTe films deposited on glass substrates for different deposited times were studied.

  13. Structural and optical characterization of CdTe quantum dots thin films

    International Nuclear Information System (INIS)

    Highlights: • CdTe QDs are prepared by hot injection method. • Thermally evaporated CdTeQDs thin films were prepared. • Structural characterization and analysis were done. • Optical parameters were studied. - Abstract: Cadmium telluride quantum dots (CdTe QDs) have been synthesized using hot-injection chemical technique. The CdTe QDs thin films were deposited onto optical flat fused quartz substrates using thermal evaporation technique. The CdTe QDs powder and the as deposited films were characterized using X-ray diffraction and high resolution transmission electron microscope (HRTEM). The X-ray analysis shows that both CdTe QDs powder and the as deposited films crystallize in cubic zinc-blende type structure with lattice parameter 6.46 Å and 6.45 Å, respectively. The X-ray calculation shows that the average crystallite size of the as deposited CdTe QDs films varied from 1.1 nm for the powder to 2.3 nm for the thin film. The HRTEM examination of the as deposited films shows that the average particle size vary from 2.5 nm for the powder to 2.7 nm for the thin film. For the as deposited films, the dependence of (αhν)2 on the incident photon energy indicates that the optical transitions within the film are allowed direct with energies observed at Eg1≅2eV and Eg2≅2.3eV which attributed to quantum confinement effect. The optical band gap increases from 1.5 eV for microstructure CdTe to 2 eV for nanostructure quantum dots which corresponding to wavelength(620 nm) so it is a great benefit to use CdTe quantum dots as solar harvesting devices application in solar spectrum region (400–800 nm). Urbach energy is calculated and found to be 360 meV which is higher than microstructure CdTe. The refractive index and refractive index dispersion of the as deposited CdTe QDs film has been calculated from transmission and reflection spectra. It has been found that the refractive index is reduced from (2.66) for microstructure CdTe to be (1.7) for CdTe quantum dots

  14. Electrodeposition of hybrid ZnO/organic dye films

    Energy Technology Data Exchange (ETDEWEB)

    Moya, Monica; Mari, Bernabe; Mollar, Miquel [Department de Fisica Aplicada-IDF, Universitat Politecnica de Valencia, Cami de Vera s/n, 46022 Valencia (Spain)

    2011-06-15

    The viability of the electrodeposition as a suitable technique for preparing new porous hybrid materials has been tested in this paper. Hybrid ZnO films with two different organic dyes: Eosin-Y and Tetrasulphonated-Cu-phtalocyanine were prepared. Their physical and chemical properties as well as their dependence on the growth conditions were investigated. It is found that the type of dye has a big influence on the morphology and porosity of hybrid films. Open and connected pores are created in hybrid ZnO/Eosin-Y films while both open and closed pores coexist in hybrid ZnO/Tetrasulfonated-Cu-phthalocyanine. As one of the promising applications of hybrid materials is photovoltaic conversion of sunlight, photoelectrochemical characterization of hybrid films is also reported. Photocurrent generation owing to both contributions ZnO and Eosin-Y is observed in ZnO/Eosin-Y films but no photocurrent has been observed in ZnO/Tetrasulfonated-Cu-phthalocyanine films. SEM micrographs of hybrid ZnO films grown in aqueous bath; (Left) ZnO/Eosin-Y films grown at 70 C, -0.9 V (Right) ZnO/Ts-CuPc films grown at 70 C, -0.9 V. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Efficient electrochromic nickel oxide thin films by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Sonavane, A.C. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur - 416 004, Maharashtra (India); Inamdar, A.I. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur - 416 004, Maharashtra (India); Department of Semiconductor Science, Dongguk University, Seoul - 100-715 (Korea, Republic of); Shinde, P.S. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur - 416 004, Maharashtra (India); Deshmukh, H.P. [Department of Physics, Y. M. College, Bharati Vidyapeeth, Erandwane, Pune (India); Patil, R.S. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur - 416 004, Maharashtra (India); Patil, P.S., E-mail: psp_phy@unishivaji.ac.i [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur - 416 004, Maharashtra (India)

    2010-01-21

    Nickel oxide (NiO) thin films were prepared by electrodeposition technique onto the fluorine doped tin oxide (FTO) coated glass substrates in one step deposition at 20, 30, 40 and 50 min deposition times respectively. The effect of film thickness (thereby microstructural changes) on their structural, morphological, optical and electrochromic properties was investigated. The mass change with potential and cyclic voltammogram was recorded in the range from +0.3 to -0.8 V versus Ag/AgCl. One step deposition of polycrystalline cubic phase NiO was confirmed from X-ray diffraction study. Optical absorption study revealed direct band gap energy of 3.2 eV. The optical transmittance of the film decreased with increase in film thickness. A uniform granular and porous morphology of the films deposited for 20 min was observed. The film becomes more compact and devoid of pores when deposition time was increased to 30 min. Thereafter severe cracks are observed. All the films exhibit anodic electrochromism in OH{sup -} containing electrolyte (0.1 M KOH). The maximum coloration efficiency of 107 cm{sup 2}/C and electrochemical stability of up to 10{sup 4} colour/bleach cycles were observed for the films deposited for 20 min (film thickness of 104 nm).

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

    Science.gov (United States)

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

    2016-04-01

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

  17. Growth of CdTe thin films on graphene by close-spaced sublimation method

    International Nuclear Information System (INIS)

    CdTe thin films grown on bi-layer graphene were demonstrated by using the close-spaced sublimation method, where CdTe was selectively grown on the graphene. The density of the CdTe domains was increased with increasing the number of the defective sites in the graphene, which was controlled by the duration of UV exposure. The CdTe growth rate on the bi-layer graphene electrodes was 400 nm/min with a bandgap energy of 1.45–1.49 eV. Scanning electron microscopy, micro-Raman spectroscopy, micro-photoluminescence, and X-ray diffraction technique were used to confirm the high quality of the CdTe thin films grown on the graphene electrodes

  18. Electrochemical Deposition of CdTe Semiconductor Thin Films for Solar Cell Application Using Two-Electrode and Three-Electrode Configurations: A Comparative Study

    Directory of Open Access Journals (Sweden)

    O. K. Echendu

    2016-01-01

    Full Text Available Thin films of CdTe semiconductor were electrochemically deposited using two-electrode and three-electrode configurations in potentiostatic mode for comparison. Cadmium sulphate and tellurium dioxide were used as cadmium and tellurium sources, respectively. The layers obtained using both configurations exhibit similar structural, optical, and electrical properties with no specific dependence on any particular electrode configuration used. These results indicate that electrochemical deposition (electrodeposition of CdTe and semiconductors in general can equally be carried out using two-electrode system as well as the conventional three-electrode system without compromising the essential qualities of the materials produced. The results also highlight the advantages of the two-electrode configuration in process simplification, cost reduction, and removal of a possible impurity source in the growth system, especially as the reference electrode ages.

  19. Electrodeposition of magnetic thin films of cobalt on silicon

    International Nuclear Information System (INIS)

    To understand the electrodeposition of Co on Si, sulphate electrolytes containing two different Co ion concentrations were tested. Thin films with uniform thickness, ranging from 10 to 700 nm, low surface roughness, compact and metallic appearance were obtained for Co concentrations of 26 and 104 mM, respectively. Transverse MOKE measurements showed in-plane magnetization with the magnitude of the coercive field being dependent on the thickness of the deposited layers. VSM measurements with the applied field perpendicular to the surface allowed the observation of an out-of-plane remanent magnetization. These properties are of considerable interest for technological applications

  20. Enhanced electrochromic coloration of poly(3-hexylthiophene) films by electrodeposited Au nanoparticles.

    Science.gov (United States)

    Nah, Yoon-Chae

    2013-05-01

    Au nanoparticles and poly(3-hexylthiophene) (P3HT) composite films were prepared by electrodeposition of Au nanoparticles using pulse-current electrodeposition followed by the spin coating of P3HT and their enhanced electrochromic coloration was investigated. A relatively uniformed Au nanoparticle was obtained by the controlled electrodeposition on indium tin oxide (ITO) substrate and plasmon absorption band of Au nanoparticles were observed. Optical and electrochemical properties of Au/P3HT composite films were compared with the pure P3HT films. The enhanced electrochromic absorption of the composite films was observed due to the surface plasmon resonance of the Au nanoparticles. PMID:23858881

  1. Electrodeposition of Ni-SiC nanocomposite film

    Institute of Scientific and Technical Information of China (English)

    NIU Zhao-xia; CAO Fa-he; WANG Wei; ZHANG Zhao; ZHANG Jian-qing; CAO Chu-nan

    2007-01-01

    The point of zero charge(PZC) of SiC nanoparticles was determined by means of standard potentiometric titration method, while the influences of the main technological parameters on the microstructure of electrodeposited Ni-SiC composite film were studied and optimized. The results show that high bath pH value favors SiC nanoparticles negatively charged and high bath temperature promotes them positively charged. Under the experimental conditions, sodium dodecyl-glycol is proven to be an effective surface modification anionic surfactant for SiC nanoparticles. The results also show that the optimized Ni-SiC composite film is composed of the nanoparticles with the average grain size in the nanometer range (100 nm), and SiC nanoparticles disperse into the nickel matrix uniformly.

  2. The Role of Dopant Concentration on Conductivity and Mobility of CdTe Thin Films

    Directory of Open Access Journals (Sweden)

    Ala J. Al-Douri

    2011-01-01

    Full Text Available Films of CdTe pure and doped with various atomic percentages of Al and Sb (0.5, 1.5 & 2.5 were prepared, and their electrical properties were investigated. The films were prepared by thermal evaporation on glass substrates at two substrate temperatures (Ts=RT & 423 K. The results showed that the conduction phenomena of all the investigated CdTe thin films on glass substrates are caused by two distinct mechanisms. Room temperature DC conductivity increases by a factor of four for undoped CdTe thin films as Ts increases and by 1-2 orders of magnitude with increasing dopant percentage of Al and Sb. In general, films doped with Sb are more efficient than Al-doped films. The activation energy (Ea2 decreases with increasing Ts and dopant percentage for both Al and Sb. Undoped CdTe films deposited at RT are p-type convert to n-type with increasing Ts and upon doping with Al at more than 0.5%. The carrier concentration decreases as Ts increases while it increases with increasing dopant percentage. Hall mobility decreases more than three times as Al increases whereas it increases about one order of magnitude with increasing Sb percentage in CdTe thin films deposited at 423 K and RT, respectively.

  3. Orientational domains in metalorganic chemical vapor deposited CdTe(111) film on cube-textured Ni

    International Nuclear Information System (INIS)

    CdTe thin film was grown by metal organic chemical vapor deposition on cube-textured Ni substrate. The microstructures of the CdTe film and Ni substrate were studied using transmission electron microscopy (TEM) lattice imaging in cross sectional. The orientational relationships of multiple hetereoepitaxial domains in the CdTe film were examined by TEM diffraction. The observed epitaxy is [111]CdTe//[001]Ni. The adjacent domains in CdTe film have a 30° rotation with respect to each other as inferred by the observed different diffraction patterns obtained from different zone axes. The high resolution lattice imaging shows that lamellar twins dominate within each domain. Our results are compared with CdTe(111) film epitaxially grown on Si(001) substrate by molecular beam epitaxy reported in the literature. - Highlights: ► Epitaxial CdTe film grew on textured Ni at 350 °C despite of a large lattice mismatch. ► Epitaxial relationship is CdTe(111) parallel to Ni(001). ► 30° CdTe orientation domains inferred from transmission electron microscopy patterns ► Local inclined angle between CdTe and Ni at the interface is due to vertical mismatch. ► Single crystal-like epitaxial semiconductors can be grown on low cost metal sheet

  4. Effects of ultrasonic field in pulse electrodeposition of NiFe film on Cu substrate

    International Nuclear Information System (INIS)

    NiFe film was pulse electrodeposited on conductive Cu substrate under galvanostatic mode in the presence of an ultrasonic field. The NiFe film electrodeposited was subjected to structural and surface analyses by X-ray diffraction, energy dispersive X-ray spectroscopy, surface profiling and scanning electron microscopy, respectively. The results show that the ultrasonic field has significantly improved the surface roughness, reduced the spherical grain size in the range from 490-575 nm to 90-150 nm, and increased the Ni content from 76.08% to 79.74% in the NiFe film electrodeposited.

  5. Electrodeposited oxotungstate films: Towards the molecular nature of recharging processes

    International Nuclear Information System (INIS)

    In situ Raman spectroscopy is applied to supplement voltammetric, spectroelectrochemical, and XRD data on redox transformations of electrodeposited oxotungstate films. These films undergo electrochromic transition at rather positive potentials, as compared to usual sputtered tungsten oxides. The depth of electroreduction for the films conditioned in acidic solutions under open circuit is about 0.11 e- per W atom. Coloration of the films correlates with the decrease of Raman band, corresponding to the terminal W(VI)=O vibration in the hydrated phase of highly defective tungstic acid (hydrated tungsten oxide). Our data allow to state the absence of oxotungstate octahedra rearrangement in the course of reduction at positive RHE potentials, and to assume that slightly deeper reduction up to 0.15 W(V)/[W(V) + W(VI)] ratio is possible at more negative potentials. We also demonstrate that the gas phase reduction is less reversible as compared to electrochemical reduction in solution. The most possible nature of films degradation in the gas phase is their partial dehydration in the course of reduction.

  6. Electrodeposited cerium film as chromate replacement for tinplate

    International Nuclear Information System (INIS)

    The cerium film was prepared on tinplate by electrodeposition method. Sulfide-stain resistance of the Ce-passivated, unpassivated and Cr-passivated tinplates was evaluated using a cysteine tarnish test. Corrosion behavior of these tinplates in contact with 3.5% NaCl solution and 0.1 M citric-citrate buffer solution was investigated using Tafel measurement and electrochemical impedance spectroscopy measurement, respectively. The adhesion of epoxyphenolic lacquer to the Ce-passivated tinplate was checked using a cross hatch cutter. The morphology, composition and thickness of the cerium film were studied by atomic force microscopy, X-ray photoelectron spectroscopy and X-ray fluorescence spectrometry. According to the results, the Ce-passivated tinplate shows the best sulfide-stain resistance and the best corrosion protection property compared with the unpassivated and Cr-passivated tinplates. The adhesion of epoxyphenolic lacquer to the Ce-passivated tinplate is good. The cerium film is composed of the closely packed particles of about 50-200 nm in diameter. The film mainly consists of cerium and oxygen, which mainly exist as CeO2, Ce2O3 and their hydrates such as Ce(OH)4, Ce(OH)3. The total cerium amount of the film is about 0.110 g/m2

  7. PENINGKATAN KUALITAS FILM TIPIS CdTe SEBAGAI ABSORBER SEL SURYA DENGAN MENGGUNAKAN DOPING TEMBAGA (Cu

    Directory of Open Access Journals (Sweden)

    P. Marwoto

    2012-12-01

    Full Text Available Film tipis CdTe dengan doping tembaga (Cu berkonsenterasi 2% telah berhasil ditumbuhkan di atas substrat Indium Tin Oxide (ITO dengan metode dc magnetron sputtering. Penelitian ini dilakukan untuk mengetahui pengaruh doping Cu(2% terhadap struktur morfologi, struktur kristal, fotoluminisensi dan resistivitas listrik film CdTe. Citra morfologi Scanning Electron Microscopy (SEM dan hasil analisis struktur dengan X-Ray Diffraction (XRD menunjukkan bahwa film CdTe:Cu(2% mempunyai citra permukaan dan struktur kristal yang lebih sempurna dibandingkan film CdTe tanpa doping. Hasil analisis spektrometer fotoluminisensi menunjukkan bahwa film CdTe dan CdTe(2% mempunyai puncak fotoluminisensi pada tiga panjang gelombang yang identik yaitu 685 nm (1,81 eV, 725 nm (1,71 eV dan 740 nm (1,67 eV. Film CdTe dengan doping Cu(2% memiliki intensitas puncak fotoluminisensi yang lebih tajam pada pita energi 1,81 eV dibandingkan dengan film CdTe tanpa doping. Pengukuran arus dan tegangan (I-V menunjukkan bahwa pemberian doping Cu(2% dapat menurunkan resistivitas film dari 8,40x109 Ωcm menjadi 6,92x105 Ωcm. Sebagai absorber sel surya, kualitas film tipis CdTe telah berhasil ditingkatkan dengan pemberian doping Cu(2%.CdTe:Cu(2% thin film has been successfully grown on Indium Tin Oxide (ITO substrates by using dc magnetron sputtering. This study was carried out in order to investigate the effect of Cu(2% doping on the morphologycal structure, crystal structure, photoluminesence, and resistivity of CdTe thin film. Scanning Electron Microscopy (SEM  images and X-Ray Diffraction (XRD results showed that CdTe:Cu(2% thin film has morphologycal and crystal structures more perfect than undoped CdTe film. Photoluminesence spectroscopy results showed that CdTe and CdTe:Cu(2% thin films have luminesence peak at three identical wevelength regions i.e. 685 nm (1.81 eV, 725 nm (1.71 eV and 740 nm (1.67 eV however CdTe:Cu(2% film shows sharper photoluminescence peak at band

  8. On the doping problem of CdTe films: The bismuth case

    International Nuclear Information System (INIS)

    The controlled increase of hole concentration is an important issue and still an unsolved problem for polycrystalline CdTe-based solar cells. The typical hole concentration of as-grown CdTe thin-films goes up to 1013 cm-3, depending on the specific growth technique. The highest electron concentration obtained for CdS, the suitable window partner material of CdTe, is around 1015 cm-3. Thus, the PV-performance of a CdS/CdTe device can be optimized if the hole concentration in CdTe is increased. We have faced up this problem by studying the electrical properties of two types of CdTe films: CdTe films grown by Close Space Vapor Transport using a CdTe:Bi powder as the starting material and CdTe sputtered films doped by implantation with different Bi-doses. Temperature-dependent resistivity and Hall effect measurements and a discussion on the efficiency of both doping processes are presented

  9. On the doping problem of CdTe films: The bismuth case

    Energy Technology Data Exchange (ETDEWEB)

    Vigil-Galan, O. [Escuela Superior de Fisica y Matematicas del IPN, Edif. 9, UPALM, 07738 Mexico, D. F. (Mexico); Brown, M. [Department of Physics and Astronomy, The University of Toledo, 43606 Toledo, OH (United States); Ruiz, C.M. [Depto. Fisica de Materiales, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Vidal-Borbolla, M.A. [Instituto de Investigacion en Comunicacion Optica, Av. Karakorum 1470, Lomas 4a. Secc., 78210 San Luis Potosi, SLP (Mexico); Ramirez-Bon, R. [CINVESTAV-IPN, U. Queretaro, Libramiento Norponiente No. 2000, Fracc. Real de Juriquilla, 76230 Santiago de Queretaro, Qro. (Mexico); Sanchez-Meza, E. [Escuela Superior de Fisica y Matematicas del IPN, Edif. 9, UPALM, 07738 Mexico, D. F. (Mexico); Tufino-Velazquez, M. [Escuela Superior de Fisica y Matematicas del IPN, Edif. 9, UPALM, 07738 Mexico, D. F. (Mexico)], E-mail: mtufinovel@yahoo.com.mx; Calixto, M. Estela [Escuela Superior de Fisica y Matematicas del IPN, Edif. 9, UPALM, 07738 Mexico, D. F. (Mexico); Compaan, A.D. [Department of Physics and Astronomy, The University of Toledo, 43606 Toledo, OH (United States); Contreras-Puente, G. [Escuela Superior de Fisica y Matematicas del IPN, Edif. 9, UPALM, 07738 Mexico, D. F. (Mexico)

    2008-08-30

    The controlled increase of hole concentration is an important issue and still an unsolved problem for polycrystalline CdTe-based solar cells. The typical hole concentration of as-grown CdTe thin-films goes up to 10{sup 13} cm{sup -3}, depending on the specific growth technique. The highest electron concentration obtained for CdS, the suitable window partner material of CdTe, is around 10{sup 15} cm{sup -3}. Thus, the PV-performance of a CdS/CdTe device can be optimized if the hole concentration in CdTe is increased. We have faced up this problem by studying the electrical properties of two types of CdTe films: CdTe films grown by Close Space Vapor Transport using a CdTe:Bi powder as the starting material and CdTe sputtered films doped by implantation with different Bi-doses. Temperature-dependent resistivity and Hall effect measurements and a discussion on the efficiency of both doping processes are presented.

  10. Preparation and multicolored fluorescent properties of CdTe quantum dots/polymethylmethacrylate composite films

    International Nuclear Information System (INIS)

    A new simple route was presented for the preparation of stable fluorescent CdTe/polymethylmethacrylate (CdTe/PMMA) composite films by using hydrophilic thioglycolic acid capped CdTe quantum dots (TGA-CdTe QDs) and polymethylmethacrylate (PMMA) as raw materials. The TGA-CdTe QDs were firstly exchanged with n-dodecanethiol (DDT) to become hydrophobic DDT-CdTe QDs via a ligand exchange strategy, and then incorporated into PMMA matrix to obtain fluorescent CdTe/PMMA composite films. The structure and optical properties of DDT-CdTe QDs and CdTe/PMMA composite films were investigated by XRD, IR, UV and PL techniques. The results indicated that the obtained DDT-CdTe QDs well preserved the intrinsic structure and the maximum emission wavelength of the initial water-soluble QDs and the resulting 6.10 wt% CdTe/PMMA composite film exhibited significantly enhanced PL intensity. Furthermore, the multicolored composite films with green, yellow-green, yellow and orange light emissions were well tuned by incorporating the CdTe QDs of various maximum emission wavelengths. The TEM image demonstrated that the CdTe QDs were well-dispersed in the PMMA matrix without aggregation. Superior photostability of QDs in the composite film was confirmed by fluorescence lifetime measurement. Thermo-gravimetric analysis of CdTe/PMMA composite films showed no obvious enhancement of thermal stability compared with pure PMMA. - Highlights: • Ligand-exchange strategy was used to render CdTe QDs oil-soluble. • CdTe QDs were incorporated into PMMA matrix to fabricate fluorescent films. • The resulting 6.10 wt% CdTe/PMMA film exhibited significantly enhanced PL intensity. • Fluorescent colors of films were tuned by varying the λem of incorporated CdTe QDs

  11. Preparation and multicolored fluorescent properties of CdTe quantum dots/polymethylmethacrylate composite films

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanni; Liu, Jianjun, E-mail: jjliu717@aliyun.com; Yu, Yingchun; Zuo, Shengli

    2015-10-25

    A new simple route was presented for the preparation of stable fluorescent CdTe/polymethylmethacrylate (CdTe/PMMA) composite films by using hydrophilic thioglycolic acid capped CdTe quantum dots (TGA-CdTe QDs) and polymethylmethacrylate (PMMA) as raw materials. The TGA-CdTe QDs were firstly exchanged with n-dodecanethiol (DDT) to become hydrophobic DDT-CdTe QDs via a ligand exchange strategy, and then incorporated into PMMA matrix to obtain fluorescent CdTe/PMMA composite films. The structure and optical properties of DDT-CdTe QDs and CdTe/PMMA composite films were investigated by XRD, IR, UV and PL techniques. The results indicated that the obtained DDT-CdTe QDs well preserved the intrinsic structure and the maximum emission wavelength of the initial water-soluble QDs and the resulting 6.10 wt% CdTe/PMMA composite film exhibited significantly enhanced PL intensity. Furthermore, the multicolored composite films with green, yellow-green, yellow and orange light emissions were well tuned by incorporating the CdTe QDs of various maximum emission wavelengths. The TEM image demonstrated that the CdTe QDs were well-dispersed in the PMMA matrix without aggregation. Superior photostability of QDs in the composite film was confirmed by fluorescence lifetime measurement. Thermo-gravimetric analysis of CdTe/PMMA composite films showed no obvious enhancement of thermal stability compared with pure PMMA. - Highlights: • Ligand-exchange strategy was used to render CdTe QDs oil-soluble. • CdTe QDs were incorporated into PMMA matrix to fabricate fluorescent films. • The resulting 6.10 wt% CdTe/PMMA film exhibited significantly enhanced PL intensity. • Fluorescent colors of films were tuned by varying the λ{sub em} of incorporated CdTe QDs.

  12. Deposition of Cl-doped CdTe polycrystalline films by close-spaced sublimation

    International Nuclear Information System (INIS)

    The effects of Cl-doping on the CdTe layers by the close-spaced sublimation (CSS) deposition were investigated. Cl-doped CdTe polycrystalline films were deposited on graphite substrates by CSS method using a mixture of CdTe and CdCl2 powder as a source. In X-ray diffraction (XRD) patterns of the obtained films with various deposition times, many diffraction peaks other than CdTe peaks were observed in the deposition times lower than 10 min. These diffraction peaks were probably due to the formation of chlorides of Cd, Te and C, such as CdCl2, TeCl4, Te3Cl2 and C10Cl8. X-ray fluorescence (XRF) and secondary ion mass spectrometry (SIMS) analyses revealed that a large amount of chlorine was contained in the films with the deposition times lower than 10 min, and that Cl concentration decreased with increasing the deposition time above 3 min. These results indicate that the films containing the chlorides of Cd, Te and C in addition to CdTe are formed in the initial stage of the CSS deposition using a mixture of CdTe and CdCl2 powder as a source. Cross-sectional images revealed that the grain size was decreased by the effect of Cl-doping. Furthermore, current-voltage (I -V) characteristics of the CdTe/graphite structures were measured, and it was found that the resistivity of the Cl-doped CdTe layer was much higher than that of the undoped CdTe layer. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Electrodeposition of Zn based nanostructure thin films for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Al-Bat’hi, S. A. M. [Department of Manufacturing and Materials Engineering, Faculty of Engineering, International Islamic University Malaysia IIUM, P.O. Box 10, 50728 Kuala Lumpur, Malaysia su3ad@iium.edu.my (Malaysia)

    2015-03-30

    We present here a systematic study on the synthesis thin films of various ZnO, CdO, Zn{sub x}Cd{sub 1-x} (O) and ZnTe nanostructures by electrodeposition technique with ZnCl{sub 2,} CdCl{sub 2} and ZnSO{sub 4} solution as starting reactant. Several reaction parameters were examined to develop an optimal procedure for controlling the size, shape, and surface morphology of the nanostructure. The results showed that the morphology of the products can be carefully controlled through adjusting the concentration of the electrolyte. The products present well shaped Nanorods arrays at specific concentration and temperature. UV-VIS spectroscopy and X-ray diffraction results show that the product presents good crystallinity. A possible formation process has been proposed.

  14. The prospects of CdTe thin films as solar control coatings

    Energy Technology Data Exchange (ETDEWEB)

    Sebastian, P.J.; Sivaramakrishnan, V. (Thin Film Lab., Dept. of Physics, Indian Inst. of Tech., Madras (India))

    1991-07-15

    Solar control coating refers to solar radiation filters applied on glazings of buildings in tropical countries. CdTe thin films were studied in this regard for use as an effective solar control coating. The films were characterized with respect to the film parameters such as film thickness, substrate temperature and deposition rate. On calculating the solar control parameters of various films, it was observed that the solar control parameters of the films depend on the above film parameters. CdTe films were found to be a better solar control coating than the commercial metallic coatings and exhibit comparable characteristics with Cu{sub x}S and PbS films. (orig.).

  15. First principles study of Bi dopen CdTe thin film solar cells: electronic and optical properties

    OpenAIRE

    Seminóvski Pérez, Yohanna; Palacios Clemente, Pablo; Wahnón Benarroch, Perla

    2011-01-01

    Nowadays, efficiency improvement of solar cells is one of the most important issues in photovoltaic systems and CdTe is one of the most promising thin film photovoltaic materials we can found. CdTe reported efficiencies in solar energy conversion have been as good as that found in polycrystalline Si thin film cell [1], besides CdTe can be easily produced at industrial scale.

  16. Physical vapor deposition of CdTe thin films at low temperature for solar cell applications

    International Nuclear Information System (INIS)

    Cadmium telluride is successfully utilized as an absorber material for thin film solar cells. Industrial production makes use of high substrate temperatures for the deposition of CdTe absorber layers. However, in order to exploit flexible substrates and to simplify the manufacturing process, lower deposition temperatures are beneficial. Based on the phase diagram of CdTe, predictions on the stoichiometry of CdTe thin films grown at low substrate temperatures are made in this work. These predictions were verified experimentally using additional sources of Cd and Te during the deposition of the CdTe thin films at different substrate temperatures. The deposited layers were analyzed with energy-dispersive X-ray spectroscopy. In case of CdTe layers which were deposited at substrate temperatures lower than 200 C without usage of additional sources we found a non-stoichiometric growth of the CdTe layers. The application of the additional sources leads to a stoichiometric growth for substrate temperatures down to 100 C which is a significant reduction of the substrate temperature during deposition.

  17. CdTe thin film solar cells with reduced CdS film thickness

    International Nuclear Information System (INIS)

    A study was performed to reduce the CdS film thickness in CdTe thin film solar cells to minimize losses in quantum efficiency. Using close space sublimation deposition for CdS and CdTe a maximum efficiency of ∼ 9.5% was obtained with the standard CdS film thickness of ∼ 160 nm. Reduction of the film CdS thickness to less than 100 nm leads to poor cell performance with ∼ 5% efficiency, mainly due to a lower open circuit voltage. An alternative approach has been tested to reduce the CdS film thickness (∼ 80 nm) by depositing a CdS double layer. The first CdS layer was deposited at high substrate temperature in the range of 520-540 deg. C and the second CdS layer was deposited at low substrate temperature of ∼ 250 deg. C. The cell prepared using a CdS double layer show better performance with cell efficiency over 10%. Quantum efficiency measurement confirmed that the improvement in the device performance is due to the reduction in CdS film thickness. The effect of double layer structure on cell performance is also observed with chemical bath deposited CdS using fluorine doped SnO2 as substrate.

  18. Research on oxidation resistance of Al2O3 thin film prepared by electrodeposition-pyrolysis

    Directory of Open Access Journals (Sweden)

    Jing MA

    2015-08-01

    Full Text Available Al2O3 thin films are deposited on the surface of 304 stainless steel by electrodeposition-pyrolysis, and the effects of electrolyte concentration and electro-deposition voltage on the oxidation behavior of Al2O3 thin film at 900 ℃ are investigated. Macroscopic surface morphologies, XRD analysis and oxidation kinetics curves show that the electrodeposition-Al2O3 thin films reduce the partial pressure of oxygen at the initial oxidation stage on the substrate surface, promoting the selective oxidation, thus the oxidation resistance of 304 stainless steel is significantly improved. The high temperature oxidation resistance of Al2O3 film prepared under voltage of 25 V and aluminum nitrate alcohol solution of 0.10 mol/L is the best.

  19. Characterization of CdTe Films Deposited at Various Bath Temperatures and Concentrations Using Electrophoretic Deposition

    OpenAIRE

    Zulkarnain Zainal; Mohd Norizam Md Daud; Azmi Zakaria; Mohd Sabri Mohd Ghazali; Atefeh Jafari; Wan Rafizah Wan Abdullah

    2012-01-01

    CdTe film was deposited using the electrophoretic deposition technique onto an ITO glass at various bath temperatures. Four batch film compositions were used by mixing 1 to 4 wt% concentration of CdTe powder with 10 mL of a solution of methanol and toluene. X-ray Diffraction analysis showed that the films exhibited polycrystalline nature of zinc-blende structure with the (111) orientation as the most prominent peak. From the Atomic Force Microscopy, the thickness and surface roughness of the ...

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

    Science.gov (United States)

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

    2016-05-01

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

  1. Electrodeposited nanoporous ZnO films exhibiting enhanced performance in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Electrodeposition of nanoporous ZnO films and their applications to dye-sensitized solar cells (DSSCs) were investigated in the aim of developing cost-effective alternative synthetic methods and improving the ZnO-based DSSCs performance. ZnO films were grown by cathodic electrodeposition from an aqueous zinc nitrate solution containing polyvinylpyrrolidone (PVP) surfactant. PVP concentration had strong effects on the grain sizes and surface morphologies of ZnO films. Nanoporous ZnO film with grain size of 20-40 nm was obtained in the electrolyte containing 4 g/L PVP. The X-ray diffraction pattern showed that nanoporous ZnO films had a hexagonal wurtzite structure. Optical properties of such films were studied and the results indicated that the films had a band gap of 3.3 eV. DSSCs were fabricated from nanoporous ZnO films and the cell performance could be greatly improved with the increase of ZnO film thickness. The highest solar-to-electric energy conversion efficiency of 5.08% was obtained by using the electrodeposited double-layer ZnO films (8 μm thick nanoporous ZnO films on a 200 nm thick compact nanocrystalline ZnO film). The performance of such cell surpassed levels attained in previous studies on ZnO film-based DSSCs and was among the highest for DSSCs containing electrodeposited film components

  2. Optical Polarization Properties of Metal Nanowire Array Film Synthesized by Electrodeposition Technology

    Institute of Scientific and Technical Information of China (English)

    梁燕萍; 史启祯; 吴振森; 王尧宇; 高胜利

    2005-01-01

    Metal nanowire array films were prepared by electrodepositing Cu, Ag, Ni, Co and Cu-Ag on porous anodic alumina film. Optical transmittance of both the porous anodic alumina film and metal nanowire array film was measured in the wavelength range of 400---2600 nm under an obliquely incident light. The experimental results show that metal nanowire array films exhibit a prominent polarization function. It was found that optical polarization properties can be improved by choosing suitable kinds of electrodepositing metal, controlling the shape and length of nanowire, and changing the incident angle.

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

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • CdS nanostructure is directly fabricated on CdTe film only by heating treatment under H2S/N2 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 H2S/N2 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 H2S/N2 mixed gas, fabricating CdS nanostructure on CdTe film can open up the new possibility for obtaining high efficient CdTe solar cell

  4. 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.

  5. Formation and Properties of Polycrystalline p-Type High-Conductivity CdTe Films by Coevaporation of CdTe and Te

    Science.gov (United States)

    Hayashi, Toshiya; Hayashi, Hiroaki; Fukaya, Mitsuru; Ema, Yoshinori

    1991-10-01

    Polycrystalline p-type high-dark-conductivity CdTe films have been prepared by coevaporation of CdTe and Te. The structural and electrical properties were investigated. The dark conductivity of the films at 300 K ranged from 6.32× 10-8 to 3.41 S cm-1. The film structure was of the zincblende type with a preferential orientation of the (111) planes parallel to the substrate. The crystallinity was rather good. From the measurements of the carrier concentration versus ambient temperature characteristics, it was found that the high-conductivity p-type conduction of the films was due to the formation of Cd vacancies, acceptors resulting from the coevaporation of CdTe and Te. It is shown that the high-conductivity films obtained are suitable for p-CdTe/n-CdS solar cells.

  6. Soft magnetic CoNiFe films electrodeposited under centrifugal forces

    International Nuclear Information System (INIS)

    Physical and magnetic properties of soft magnetic CoNiFe films electrodeposited under centrifugal forces were investigated. It was demonstrated that employing an external centrifugal force during the deposition process provides stronger magnetic properties of the soft magnet electrodeposited. Based on the approach proposed, preparation of soft magnetic CoNiFe film with Bs higher than 2.1 T and Hc lower than 1.1 Ωe is possible. For a conventional CoNiFe film with Bs of 1.96 T (electrodeposited under Earth's gravity), the saturation induction can be increased to 2.14 T by applying a 290g centrifugal force during the electrodeposition process, while the Hc approximately remained the same. It is thought that this enhancement provided by an applied centrifugal force is due to the increase of bcc/fcc ratio, where this increase is not associated with a significant crystallite growth in this case

  7. Performance of supercapacitor with electrodeposited ruthenium oxide film electrodes—effect of film thickness

    Science.gov (United States)

    Park, Bong-Ok; Lokhande, C. D.; Park, Hyung-Sang; Jung, Kwang-Deog; Joo, Oh-Shim

    Thin-film ruthenium oxide electrodes are prepared by cathodic electrodeposition on a titanium substrate. Different deposition periods are used to obtain different film thicknesses. The electrodes are used to form a supercapacitor with a 0.5 M H 2SO 4 electrolyte. The specific capacitance and charge-discharge periods are found to be dependent on the electrode thickness. A maximum specific capacitance of 788 F g -1 is achieved with an electrode thickness of 0.0014 g cm -2. These results are explained by considering the morphological changes that take place with increasing film thickness.

  8. Glow discharge optical emission spectroscopy: a complementary technique to analyze thin electrodeposited polyaniline films

    International Nuclear Information System (INIS)

    Glow Discharge Optical Emission Spectroscopy (GDOES) has been developed to perform depth profiles of thick metallic films, in tens of microns range. GDOES spectroscopy can also be used to analyze thin organic polymer films since this technique has a great potential thanks to its high depth resolution, multi-element capability, sensitivity, and adaptability to solids or films and to conducting or non-conducting samples. In particular thin electrodeposited conducting polymer films remain an unexplored field of investigation for GDOES technique. However GDOES was used in this work to analyze electrodeposited polyaniline films, in addition to other techniques such as profilometry, electron microscopy and X-ray diffraction (XRD). More precisely polyaniline thin films were electrodeposited from HCl solutions and the presence of an anilinium chloride excess at the top surface of the polymer film was demonstrated using GDOES and XRD. Rinsing of these films with water led to the removal of this excess and to the partial dedoping of the polymer film due to the porous structure of polymer films. Polyaniline thin films were also electrodeposited from H2SO4 solutions and an anilinium hydrogen sulfate was similarly observed at the top surface of the polymer. This excess was removed by rinsing, contrary to hydrogen sulfate anions incorporated into the polymer film during the electrochemical polymerization that were not completely expulsed from the polyaniline films as proved using GDOES. - Highlights: • Polyaniline films were electrodeposited from HCl and H2SO4 solutions • Polymer films were analyzed by Glow Discharge Optical Emission Spectroscopy (GDOES) • The incorporation of anions in the films was proved using GDOES depth profiles • The crystalline structure of polyaniline films was modified by water rinsing

  9. Structural, optical, photoluminescence, dielectric and electrical studies of vacuum-evaporated CdTe thin films

    Indian Academy of Sciences (India)

    Ziaul Raza Khan; M Zulfequar; Mohd Shahid Khan

    2012-04-01

    Highly-oriented CdTe thin films were fabricated on quartz and glass substrates by thermal evaporation technique in the vacuum of about 2 × 10-5 torr. The CdTe thin films were characterized by X-ray diffraction (XRD), UV–VIS–NIR, photoluminescence spectroscopy and scanning electron microscopy (SEM). X-ray diffraction results showed that the films were polycrystalline with cubic structure and had preferred growth of grains along the (111) crystallographic direction. Scanning electron micrographs showed that the growth of crystallites of comparable size on both the substrates. At the room temperature, photoluminescence spectra of the films on both the substrates showed sharp peaks with a maximum at 805 nm. This band showed significant narrowing suggesting that it originates from the transitions involving grain boundary defects. The refractive index of CdTe thin films was calculated using interference pattern of transmission spectra. The optical band gap of thin films was found to allow direct transition with energy gap of 1.47–1.50 eV. a.c. conductivity of CdTe thin films was found to increase with the increase in frequency whereas dielectric constant was observed to decrease with the increase in frequency.

  10. Studies on optoelectronic properties of DC reactive magnetron sputtered CdTe thin films

    International Nuclear Information System (INIS)

    Cadmium telluride continues to be a leading candidate for the development of cost effective photovoltaics for terrestrial applications. In the present work two individual metallic targets of Cd and Te were used for the deposition of CdTe thin films on mica substrates from room temperature to 300 °C by DC reactive magnetron sputtering method. XRD patterns of CdTe thin films deposited on mica substrates exhibit peaks at 2θ = 27.7°, 46.1° and 54.6°, which corresponds to reflection on (1 1 1), (2 2 0) and (3 1 1) planes of CdTe cubic structure. The intensities of XRD patterns increases with the increase of substrate temperature upto 150 °C and then it decreases at higher substrate temperatures. The conductivity of CdTe thin films measured from four probe method increases with the increase of substrate temperature. The activation energies (ΔE) are found to be decrease with the increase of substrate temperature. The optical transmittance spectra of CdTe thin films deposited on mica have a clear interference pattern in the longer wavelength region. The films have good transparency (T > 85 %) exhibiting interference pattern in the spectral region between 1200 – 2500 nm. The optical band gap of CdTe thin films are found to be in the range of 1.48 – 1.57. The refractive index, n decreases with the increase of wavelength, λ. The value of n and k increases with the increase of substrate temperature

  11. Electrodeposited nanostructured WO3 thin films for photoelectrochemical applications

    International Nuclear Information System (INIS)

    Thin films of WO3 were deposited on FTO-coated glass substrates by electrodeposition using aqueous solutions of peroxotungstic acid. The effects of varying the tungsten concentration of peroxotungstic acid and deposition time on the mineralogical, microstructural, morphological, optical, and photoelectrochemical properties were determined using X-ray diffraction, scanning electron microscopy, focused ion beam milling, UV–vis spectrophotometry, and linear potentiodynamic voltammetry, respectively. The films consisted of monoclinic WO3 of grain sizes in the range 77–122 nm and thicknesses in the range 258–1394 nm; the true porosities were <5%. These microstructural and morphological parameters depended largely upon the tungsten concentration and deposition time. Some preferred orientation was observed and this was considered to result from crystallographic and microstructural factors. The optical transmission data revealed significant decreases in the optical indirect band gap, from 3.05 eV to 2.60 eV, as a function of increasing film thickness. This was considered to result from differential contributions from the surface and bulk band gap components as well as compressive stress. The voltammetry data and associated Butler plot revealed the establishment of a Schottky depletion layer and a flat-band potential of +0.2 V to +0.3 V versus Ag/AgCl. Although the calculated photoconversion efficiencies were in the range 0.02–0.14%, which is commensurate with the use of a tungsten–halogen light rather than xenon, there was a trend of increasing efficiency as a function of increasing film thickness. This was attributed to decreasing band gap and increasing light absorption. The shape of the curve of the preceding data supports the conclusion of differential contributions from the surface and bulk band gap components. Finally, evidence of photolysis in the absence of an external applied potential suggests the importance of the effect of grain size on the pH and its

  12. Preparation and properties of evaporated CdTe films compared with single crystal CdTe

    Science.gov (United States)

    Bube, R. H.

    The hot wall vacuum deposition system is discussed and is is good temperature tracking between the furnace core and the CdTe source itself are indicated. Homojunction cells prepared by HWVE deposition of n-CdTe on p-CdTe substrates show no significant change in dark or light properties after open circuit storage for the next 9 months. CdTe single crystal boules were grown with P, As and Cs impurity. For P impurity it appears that the segregation coefficient is close to unity, that the value of hole density is controlled by the P, and that growth with excess Cd gives slightly higher values of hole density than growth with excess Te. CdTe:As crystals appear similar to CdTe:P crystals.

  13. Preparation of vanadium diselenide thin films and their application in CdTe solar cells

    International Nuclear Information System (INIS)

    Vanadium diselenide thin films were prepared by electron beam evaporation. The properties of vanadium diselenide thin films were investigated using X-ray diffraction, scanning electron microscope, transmission spectra, electrical and Hall measurements. To further investigate the application of vanadium diselenide thin films, device performance in CdTe solar cells with a vanadium diselenide layer was also studied. The results indicate that vanadium diselenide thin films had a stable hexagonal structure after annealing. The thin films were p-type semiconductor materials with the high work function and high carrier concentration. Vanadium diselenide thin films could form a good ohmic contact to CdTe solar cells. Thus, cell performance was greatly improved when introduced a vanadium diselenide buffer layer. - Highlights: • VSe2 was prepared by electron beam evaporation. • VSe2 was a p-type material with the high work function and high carrier concentration. • VSe2 was used as a Cu-free buffer layer in CdTe solar cells. • Performance of CdTe solar cells was improved

  14. Enhanced magnetic moment of ultrathin Co films measured by in situ electrodeposition in a SQUID

    Science.gov (United States)

    Topolovec, Stefan; Krenn, Heinz; Würschum, Roland

    2016-01-01

    A special electrochemical cell enabling in situ electrodeposition in a SQUID magnetometer is applied to study the magnetic moment of ultrathin Co films during growth on an Au(111) substrate. The in situ electrodeposition approach allows a total elimination of the magnetic background signal of the substrate, thus the magnetic moment which arises exclusively from the deposited Co film could be measured with monolayer sensitivity. The average thickness of the deposited Co films dav as determined from the transferred charge can be adjusted easily by varying the parameters of the electrodeposition. Hence, the magnetic moment of Co thin films could be determined in absolute terms as a function of the film thickness dav. For the first few atomic layers an enhancement of the magnetic moment per Co atom compared to the bulk could be observed, which increases steadily with lowering dav, reaching up to 40%.

  15. Electrodeposition of Manganese-Nickel Oxide Films on a Graphite Sheet for Electrochemical Capacitor Applications

    Directory of Open Access Journals (Sweden)

    Hae-Min Lee

    2014-01-01

    Full Text Available Manganese-nickel (Mn-Ni oxide films were electrodeposited on a graphite sheet in a bath consisting of manganese acetate and nickel chloride, and the structural, morphological, and electrochemical properties of these films were investigated. The electrodeposited Mn-Ni oxide films had porous structures covered with nanofibers. The X-ray diffractometer pattern revealed the presence of separate manganese oxide (g-MnO2 and nickel oxide (NiO in the films. The electrodeposited Mn-Ni oxide electrode exhibited a specific capacitance of 424 F/g in Na2SO4 electrolyte. This electrode maintained 86% of its initial specific capacitance over 2000 cycles of the charge-discharge operation, showing good cycling stability.

  16. Radiative recombination mechanisms in CdTe thin films deposited by elemental vapor transport

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Shamara [Department of Electrical Engineering, University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620 (United States); Vatavu, Sergiu, E-mail: svatavu@usm.md [Department of Electrical Engineering, University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620 (United States); Faculty of Physics and Engineering, Moldova State University, 60 A. Mateevici str., Chisinau, MD-2009, Republic of Moldova (Moldova, Republic of); Evani, Vamsi; Khan, Md; Bakhshi, Sara; Palekis, Vasilios [Department of Electrical Engineering, University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620 (United States); Rotaru, Corneliu [Faculty of Physics and Engineering, Moldova State University, 60 A. Mateevici str., Chisinau, MD-2009, Republic of Moldova (Moldova, Republic of); Ferekides, Chris [Department of Electrical Engineering, University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620 (United States)

    2015-05-01

    A photoluminesence (PL) study of the radiative recombination mechanisms for CdTe films deposited under different Cd and Te overpressure by elemental vapor transport is presented. The experiment and analysis have been carried out in the temperature range of 12-130 K. The intensity of the PL laser excitation beam was varied by two orders of magnitude. It has been established that the bands in the 1.47-1.50 eV are determined by transitions involving shallow D and A states and the 1.36x-1.37x eV band is due to band to level transitions. Deep transitions at 1.042 eV and 1.129 eV are due to radiative transitions to levels determined by CdTe native defects. - Highlights: • Photoluminescense (PL) of CdTe thin films is present in the 0.8-1.6 eV spectral region. • High intensity excitonic peaks are among the main radiative paths. • Radiative transitions at 1.36x eV are assisted by dislocations caused levels. • Extremal Cd/Te overpressure ratios enhance PL for 1.497 eV, 1.486 eV, 1.474 eV bands. • PL intensity reaches its max value for the 0.45 and 1.25 Cd/Te overpressure ratios.

  17. Radiative recombination mechanisms in CdTe thin films deposited by elemental vapor transport

    International Nuclear Information System (INIS)

    A photoluminesence (PL) study of the radiative recombination mechanisms for CdTe films deposited under different Cd and Te overpressure by elemental vapor transport is presented. The experiment and analysis have been carried out in the temperature range of 12-130 K. The intensity of the PL laser excitation beam was varied by two orders of magnitude. It has been established that the bands in the 1.47-1.50 eV are determined by transitions involving shallow D and A states and the 1.36x-1.37x eV band is due to band to level transitions. Deep transitions at 1.042 eV and 1.129 eV are due to radiative transitions to levels determined by CdTe native defects. - Highlights: • Photoluminescense (PL) of CdTe thin films is present in the 0.8-1.6 eV spectral region. • High intensity excitonic peaks are among the main radiative paths. • Radiative transitions at 1.36x eV are assisted by dislocations caused levels. • Extremal Cd/Te overpressure ratios enhance PL for 1.497 eV, 1.486 eV, 1.474 eV bands. • PL intensity reaches its max value for the 0.45 and 1.25 Cd/Te overpressure ratios

  18. Characteristics of CdTe films and CdTe/CdS solar cells fabricated by photostimulated sublimation

    International Nuclear Information System (INIS)

    Full text : The effect of illumination during the close-spaced sublimation (CSS) growth on composition, structural, electrical, optical and photovoltaic properties of CdTe films and CdTe/CdS solar cells was investigated. Data on comparative study by using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), absorption spectra and conductivity-temperature measurements of CdTe films prepared by CSS method in a dark (CSSD) and under illumination (CSSI) were presented. It is shown that the growth rate of CdTe films under illumination is higher than that for films prepared without illumination. Moreover, the polycrystalline CdTe films of the cubic structure grown by CSSI technology were characterized with larger the grain size as compared to that for films prepared by CSSD

  19. Thin Film CIGS and CdTe Photovoltaic Technologies: Commercialization, Critical Issues, and Applications; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Ullal, H. S.; von Roedern, B.

    2007-09-01

    We report here on the major commercialization aspects of thin-film photovoltaic (PV) technologies based on CIGS and CdTe (a-Si and thin-Si are also reported for completeness on the status of thin-film PV). Worldwide silicon (Si) based PV technologies continues to dominate at more than 94% of the market share, with the share of thin-film PV at less than 6%. However, the market share for thin-film PV in the United States continues to grow rapidly over the past several years and in CY 2006, they had a substantial contribution of about 44%, compared to less than 10% in CY 2003. In CY 2007, thin-film PV market share is expected to surpass that of Si technology in the United States. Worldwide estimated projections for CY 2010 are that thin-film PV production capacity will be more than 3700 MW. A 40-MW thin-film CdTe solar field is currently being installed in Saxony, Germany, and will be completed in early CY 2009. The total project cost is Euro 130 million, which equates to an installed PV system price of Euro 3.25/-watt averaged over the entire solar project. This is the lowest price for any installed PV system in the world today. Critical research, development, and technology issues for thin-film CIGS and CdTe are also elucidated in this paper.

  20. Investigation of deep level defects in CdTe thin films

    Energy Technology Data Exchange (ETDEWEB)

    Shankar, H.; Castaldini, A. [Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Dieguez, E.; Rubio, S. [Crystal Growth Lab, Department of Materials Physics, Faculty of Science, University Autonoma of Madrid, Ciudad Universitaria de Cantoblanco, 28049, Madrid (Spain); Dauksta, E.; Medvid, A. [Institute of Technical Physics, Riga Technical University, 14 Azenes Str, Riga, Latvia, Department of Materials (Latvia); Cavallini, A. [Department of Physics and Astronomy,University of Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy)

    2014-02-21

    In the past few years, a large body of work has been dedicated to CdTe thin film semiconductors, as the electronic and optical properties of CdTe nanostructures make them desirable for photovoltaic applications. The performance of semiconductor devices is greatly influenced by the deep levels. Knowledge of parameters of deep levels present in as-grown materials and the identification of their origin is the key factor in the development of photovoltaic device performance. Photo Induced Current Transient Spectroscopy technique (PICTS) has proven to be a very powerful method for the study of deep levels enabling us to identify the type of traps, their activation energy and apparent capture cross section. In the present work, we report the effect of growth parameters and LASER irradiation intensity on the photo-electric and transport properties of CdTe thin films prepared by Close-Space Sublimation method using SiC electrical heating element. CdTe thin films were grown at three different source temperatures (630, 650 and 700 °C). The grown films were irradiated with Nd:YAG LASER and characterized by Photo-Induced Current Transient Spectroscopy, Photocurrent measurementand Current Voltage measurements. The defect levels are found to be significantly influenced by the growth temperature.

  1. Metal-insulator transition in nanocomposite VOx films formed by anodic electrodeposition

    OpenAIRE

    Tsui, Lok-kun; Hildebrand, Helga; Lu, Jiwei; Schmuki, Patrik; Zangari, Giovanni

    2014-01-01

    The ability to grow VO2 films by electrochemical methods would open a low-cost, easily scalable production route to a number of electronic devices. We have synthesized VOx films by anodic electrodeposition of V2O5, followed by partial reduction by annealing in Ar. The resulting films are heterogeneous, consisting of various metallic/oxide phases and including regions with VO2 stoichiometry. A gradual metal insulator transition with a nearly two order of magnitude change in film resistance is ...

  2. Effects of various deposition times and RF powers on CdTe thin film growth using magnetron sputtering

    Science.gov (United States)

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

    2016-04-01

    Cadmium telluride (CdTe) is a p-type II-VI compound semiconductor, which is an active component for producing photovoltaic solar cells in the form of thin films, due to its desirable physical properties. In this study, CdTe film was deposited using the radio frequency (RF) magnetron sputtering system onto a glass substrate. To improve the properties of the CdTe film, effects of two experimental parameters of deposition time and RF power were investigated on the physical properties of the CdTe films. X-ray Diffraction (XRD), atomic force microscopy (AFM) and spectrophotometer were used to study the structural, morphological and optical properties of the CdTe samples grown at different experimental conditions, respectively. Our results suggest that film properties strongly depend on the experimental parameters and by optimizing these parameters, it is possible to tune the desired structural, morphological and optical properties. From XRD data, it is found that increasing the deposition time and RF power leads to increasing the crystallinity as well as the crystal sizes of the grown film, and all the films represent zinc blende cubic structure. Roughness values given from AFM images suggest increasing the roughness of the CdTe films by increasing the RF power and deposition times. Finally, optical investigations reveal increasing the film band gaps by increasing the RF power and the deposition time.

  3. Effects of various deposition times and RF powers on CdTe thin film growth using magnetron sputtering

    Science.gov (United States)

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

    2016-09-01

    Cadmium telluride (CdTe) is a p-type II-VI compound semiconductor, which is an active component for producing photovoltaic solar cells in the form of thin films, due to its desirable physical properties. In this study, CdTe film was deposited using the radio frequency (RF) magnetron sputtering system onto a glass substrate. To improve the properties of the CdTe film, effects of two experimental parameters of deposition time and RF power were investigated on the physical properties of the CdTe films. X-ray Diffraction (XRD), atomic force microscopy (AFM) and spectrophotometer were used to study the structural, morphological and optical properties of the CdTe samples grown at different experimental conditions, respectively. Our results suggest that film properties strongly depend on the experimental parameters and by optimizing these parameters, it is possible to tune the desired structural, morphological and optical properties. From XRD data, it is found that increasing the deposition time and RF power leads to increasing the crystallinity as well as the crystal sizes of the grown film, and all the films represent zinc blende cubic structure. Roughness values given from AFM images suggest increasing the roughness of the CdTe films by increasing the RF power and deposition times. Finally, optical investigations reveal increasing the film band gaps by increasing the RF power and the deposition time.

  4. Preliminary study of CdTe and CdTe:Cu thin films nanostructures deposited by using DC magnetron sputtering

    International Nuclear Information System (INIS)

    Growth and properties of CdTe and CdTe:Cu thin films nanostrucures deposited by using dc magnetron sputtering are reported. Scanning electron microscope (SEM) was used to observe the surface morphologies of the thin films. At growth conditions of 250 °C and 14 W, CdTe films did not yet evenly deposited. However, at growth temperature and plasma power of 325 °C and 43 W, both CdTe and CdTe:Cu(2%) have deposited on the substrates. In this condition, the morphology of the films indicate that the films have a grain-like nanostructures. Grain size diameter of about 200 nm begin to appear on top of the films. Energy Dispersive X-rays spectroscopy (EDX) was used to investigate chemical elements of the Cu doped CdTe film deposited. It was found that the film deposited consist of Cd, Te and Cu elements. XRD was used to investigate the full width at half maximum (FWHM) values of the thin films deposited. The results show that CdTe:Cu(2%) thin film has better crystallographic properties than CdTe thin film. The UV-Vis spectrometer was used to investigate the optical properties of thin films deposited. The transmittance spectra showed that transmittance of CdTe:Cu(2%) film is lower than CdTe film. It was found that the bandgap energy of CdTe and CdTe:Cu(2%) thin films of about 1.48 eV

  5. Characterization of CuInSe2 thin films grown by photo-assisted electrodeposition

    International Nuclear Information System (INIS)

    A photo-assisted one-step electrodeposition has been applied to help in forming smooth and dense CuInSe2 (CIS) films. The difference in surface morphology and crystalline quality between CIS films with and without photo-assistance has been investigated. In the photo-assisted electrodeposition process, a halogen lamp providing maximum light intensity at about 0.6 μm–1.0 μm was used as light source to be irradiated onto the surface of Mo-coated soda lime glass substrates. Electrodeposited CIS thin films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM) and Raman spectroscopy. SEM and AFM results show a smoother film with lower roughness by photo-assisted electrodeposition at lower deposition potential. From the XRD patterns, it was found that photo-assistance enhanced the crystalline quality, and the enhancement remained after annealing at 500 °C for 120 s. The analysis of Raman spectra indicated a reduction in secondary phases after applying photo-assistance. These results suggested effects of photo-assistance including activating surface diffusion and growing high-crystalline quality films with reduced defects during electrodeposition. - Highlights: ► A photo-assisted electrodeposition process is proposed. ► Dense CuInSe2 films with lower roughness are achieved by photo-assistance. ► Better crystallinity is achieved by photo-assistance. ► Secondary phases in CuInSe2 thin films are reduced by photo-assistance

  6. Effect of film thickness on microstructure parameters and optical constants of CdTe thin films

    Energy Technology Data Exchange (ETDEWEB)

    Shaaban, E.R., E-mail: esam_ramadan2008@yahoo.co [Physics Department, Faculty of Science, Qassim University, Buridah 51452 (Saudi Arabia); Physics Department, Faculty of Science, Al-Azhar University, Assiut, P.O. 71452 (Egypt); Afify, N. [Physics Department, Assiut University, Assiut (Egypt); El-Taher, A. [Physics Department, Faculty of Science, Qassim University, Buridah 51452 (Saudi Arabia); Physics Department, Faculty of Science, Al-Azhar University, Assiut, P.O. 71452 (Egypt)

    2009-08-12

    Different thickness of cadmium telluride (CdTe) thin films was deposited onto glass substrates by the thermal evaporation technique. Their structural characteristics were studied by X-ray diffraction (XRD). The XRD experiments showed that the films are polycrystalline and have a zinc-blende (cubic) structure. The microstructure parameters, crystallite size and microstrain were calculated. It is observed that the crystallite size increases and microstrain decreases with the increase in the film thickness. The fundamental optical parameters like band gap and extinction coefficient are calculated in the strong absorption region of transmittance and reflectance spectrum. The possible optical transition in these films is found to be allowed direct transition with energy gap increase from 1.481 to 1.533 eV with the increase in the film thickness. It was found that the optical band gap increases with the increase in thickness. The refractive indices have been evaluated in transparent region in terms of envelope method, which has been suggested by Swanepoul in the transparent region. The refractive index can be extrapolated by Cauchy dispersion relationship over the whole spectral range, which extended from 400 to 2500 nm. It is observed that the refractive index, n increases on increasing the film thickness up to 671 nm and then the variation of n with higher thickness lie within the experimental errors.

  7. Cu containing CdTe thin films deposited by two sources technique

    International Nuclear Information System (INIS)

    Cadmium Telluride (CdTe) thin films were deposited onto glass substrates by the two-source evaporation technique. Films were heated under vacuum at 500 degree C for 1 hour and dipped in Cu(No/sub 3/)/sub 2/-H/sub 2/O solution at room temperature These films were again heated under vacuum for 1 hour at 500 degree C to obtain maximum Cu diffusion. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), optically by Lambda 900 UV/VIS/NIR spectrophotometer and electrically, i.e. DC electrical resistivity, by the Van der Pauw method at room temperature. The EDX results showed an increase of Cu content in the samples by increasing the immersion time of the CdTe films in the solution. (author)

  8. Magnetic vortex state and multi-domain pattern in electrodeposited hemispherical nanogranular nickel films

    International Nuclear Information System (INIS)

    Magnetic states of nickel nanogranular films were studied in two distinct structures of individual and agglomerated granules electrodeposited on n-type Si(1 1 1) surface from a modified Watts bath at a low pH of 2. Magnetic force microscopy and micromagnetic simulations revealed three-dimensional out-of-plane magnetic vortex states in stand-alone hemispherical granules and their arrays, and multi-domain patterns in large agglomerates and integrated films. Once the granules coalesce into small chains or clusters, the coercivity values increased due to the reduction of inter-granular spacing and strengthening of the magnetostatic interaction. Further growth leads to the formation of a continuous granulated film which strongly affected the coercivity and remanence. This was characterized by the domain wall nucleation and propagation leading to a stripe domain pattern. Magnetoresistance measurements as a function of external magnetic field are indicative of anisotropic magnetoresistance (AMR) for the continuous films electrodeposited on Si substrate. - Highlights: • Magnetic states of electrodeposited nickel in isolated spherical and agglomerated nanogranules, and a continuous film. • Preferential magnetization reversal mechanism in isolated granules is vortex state. • Micromagnetic simulations confirm the three-dimensional vortex. • Transition between the vortex state and multi-domain magnetic pattern causes a significant decrease in the coercive force. • Continuous nickel films electrodeposited on silicon substrate exhibit AMR whose magnitude increases with the film thickness

  9. Magnetic vortex state and multi-domain pattern in electrodeposited hemispherical nanogranular nickel films

    Energy Technology Data Exchange (ETDEWEB)

    Samardak, Alexander; Sukovatitsina, Ekaterina; Ognev, Alexey; Stebliy, Maksim; Davydenko, Alexander; Chebotkevich, Ludmila [Laboratory of Thin Film Technologies, School of Natural Sciences, Far Eastern Federal University, Vladivostok (Russian Federation); Keun Kim, Young [Department of Materials Science and Engineering, Korea University, Seoul (Korea, Republic of); Nasirpouri, Forough [Department of Physics, University of Tabriz, Tabriz (Iran, Islamic Republic of); Janjan, Seyed-Mehdi [Faculty of Materials Engineering, Sahand University of Technology, Tabriz 51335-1996 (Iran, Islamic Republic of); Nasirpouri, Farzad, E-mail: nasirpouri@sut.ac.ir [Faculty of Materials Engineering, Sahand University of Technology, Tabriz 51335-1996 (Iran, Islamic Republic of)

    2014-12-15

    Magnetic states of nickel nanogranular films were studied in two distinct structures of individual and agglomerated granules electrodeposited on n-type Si(1 1 1) surface from a modified Watts bath at a low pH of 2. Magnetic force microscopy and micromagnetic simulations revealed three-dimensional out-of-plane magnetic vortex states in stand-alone hemispherical granules and their arrays, and multi-domain patterns in large agglomerates and integrated films. Once the granules coalesce into small chains or clusters, the coercivity values increased due to the reduction of inter-granular spacing and strengthening of the magnetostatic interaction. Further growth leads to the formation of a continuous granulated film which strongly affected the coercivity and remanence. This was characterized by the domain wall nucleation and propagation leading to a stripe domain pattern. Magnetoresistance measurements as a function of external magnetic field are indicative of anisotropic magnetoresistance (AMR) for the continuous films electrodeposited on Si substrate. - Highlights: • Magnetic states of electrodeposited nickel in isolated spherical and agglomerated nanogranules, and a continuous film. • Preferential magnetization reversal mechanism in isolated granules is vortex state. • Micromagnetic simulations confirm the three-dimensional vortex. • Transition between the vortex state and multi-domain magnetic pattern causes a significant decrease in the coercive force. • Continuous nickel films electrodeposited on silicon substrate exhibit AMR whose magnitude increases with the film thickness.

  10. Native Defect Control of CdTe Thin Film Solar Cells by Close-Spaced Sublimation

    Science.gov (United States)

    Okamoto, Tamotsu; Kitamoto, Shinji; Yamada, Akira; Konagai, Makoto

    2001-05-01

    The control of native defects in the CdTe thin film solar cells was investigated using a novel source for close-spaced sublimation (CSS) process which was prepared by vacuum evaporation with elemental Cd and Te (evaporated source). The evaporated sources were prepared on glass substrates at room temperature, and the Cd/Te ratio was controlled by varying the Cd and Te beam equivalent pressures. In the cells using the Te-rich source, the conversion efficiency was less than 0.2% because of the extremely low shunt resistance. On the other hand, a conversion efficiency above 15% was obtained by using the Cd-rich source. Capacitance-voltage (C-V) characteristics revealed that the acceptor concentration in the CdTe layer increased with increasing Cd/Te ratio of the evaporated source. Furthermore, photoluminescence spectra implied that the formation of the Cd vacancies in the CdTe layer was suppressed using the Cd-rich source.

  11. FeS2(pyrite)electrodeposition thin films and study of growth mechanism

    Institute of Scientific and Technical Information of China (English)

    DONG; Youzhong; ZHENG; Yufeng; ZHANG; Xiaogang; DUAN; He

    2005-01-01

    Ferrous sulfide (FeS) thin films were initially electrodeposited on indium-tin oxide (ITO) substrates in the aqueous solution containing iron, sulfur elements and then annealed in the sulfur atmosphere. Thereby, we successfully obtained the single-phased iron pyrite (FeS2) thin films with good quality. The experimental parameters for electrodeposition and the post-growth thermal-dynamical conditions have been calculated so that more details about the effect of thermal-dynamical conditions on the micromechanism concerned with the iron pyrite crystal growth as well as the properties of the samples have been discussed.

  12. Electrodeposition of zinc-doped silane films for corrosion protection of mild steels

    International Nuclear Information System (INIS)

    Highlights: ► Metallic zinc is doped into organosilane films by one-step electrodeposition. ► The composite films exhibit the improved corrosion resistance of mild steels. ► Zinc-doping provides additional cathodic protection to the mild steels. - Abstract: Organosilane/zinc composite films are prepared by one-step electrodeposition onto cold-rolled steels for corrosion protection. Electrochemical impedance spectroscopy measurement, bulk solution immersion and wet heat tests all show that the composite films have improved corrosion performance. X-ray photoelectron spectroscopy measurement suggests the successful encapsulation of metallic zinc. The embedding of metallic zinc results in negative shift in open-circuit potential of the film-covered electrodes. Such cathodic protection effect given by the metallic zinc provides the improved corrosion resistance of the composite films.

  13. Structural and optical properties of electrodeposited culnSe2 thin films for photovoltaic solar cells

    International Nuclear Information System (INIS)

    Optical an structural properties of electrodeposited copper indium diselenide, CulnSe2, thin films were studied for its application in photovoltaic devices. X-ray diffraction patterns showed that thin films were grown in chalcopyrite phase after suitable treatments. Values of Eg for the CulnSe2 thin films showed a dependence on the deposition potential as determined by optical measurements. (Author) 47 refs

  14. Atomic layer deposition of copper nitride film and its application to copper seed layer for electrodeposition

    International Nuclear Information System (INIS)

    We report the formation of smooth and conformal copper seed layer for electrodeposition by atomic layer deposition (ALD) and reducing anneal of a copper nitride film. The ALD copper nitride film was prepared at 100–140 °C using bis(1-dimethylamino-2-methyl-2-butoxy)copper(II) and NH3, and reduced to metallic copper film by annealing at 200 °C or higher temperatures. The growth rate of ALD copper nitride was 0.1 nm/cycle at 120–140 °C on both ruthenium and silicon oxide substrates, and the thickness of film was reduced approximately 20% by annealing. The resistivity of the 4.2 nm-thick copper film was 30 μΩ·cm. Both the ALD copper nitride and the reduced copper films exhibited extremely smooth surface and excellent step coverage, whereas the copper film deposited using alternating exposures to the copper precursor and H2 showed a rough surface. The copper film electrodeposited on the copper seed of this study exhibited lower resistivity and smoother surface as compared to the copper film electrodeposited on the ALD ruthenium seed. - Highlights: • Copper nitride thin film was grown by atomic layer deposition (ALD) at 100–140 °C. • Copper nitride was reduced to metallic copper by annealing in H2 at ≥ 200 °C. • Copper nitride and copper films showed smooth surface and excellent step coverage. • The copper film was better than ALD Ru as the seed layer for electrodeposition

  15. Optical Properties of Al- and Sb-Doped CdTe Thin Films

    Directory of Open Access Journals (Sweden)

    A. A. J. Al-Douri

    2010-01-01

    Full Text Available Nondoped and (Al, Sb-doped CdTe thin films with 0.5, 1.5, and 2.5  wt.%, respectively, were deposited by thermal evaporation technique under vacuum onto Corning 7059 glass at substrate temperatures ( of room temperature (RT and 423 K. The optical properties of deposited CdTe films such as band gap, refractive index (n, extinction coefficient (, and dielectric coefficients were investigated as function of Al and Sb wt.% doping, respectively. The results showed that films have direct optical transition. Increasing and the wt.% of both types of dopant, the band gap decrease but the optical is constant as n, and real and imaginary parts of the dielectric coefficient increase.

  16. Electrodeposition and characterization of nano-crystalline antimony telluride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Lensch-Falk, J.L.; Banga, D. [Sandia National Laboratories, Livermore, CA 94550 (United States); Hopkins, P.E. [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA 22904 (United States); Robinson, D.B.; Stavila, V. [Sandia National Laboratories, Livermore, CA 94550 (United States); Sharma, P.A. [Sandia National Laboratories, Albuquerque, NM 87185 (United States); Medlin, D.L., E-mail: dlmedli@sandia.gov [Sandia National Laboratories, Livermore, CA 94550 (United States)

    2012-07-31

    Electrodeposition is a promising low-cost method to fabricate nanostructured thermoelectric thin films such as Sb{sub 2}Te{sub 3}. However, electrodeposition of crystalline Sb{sub 2}Te{sub 3} without the need for additional processing and with good compositional control has presented a challenge. Here we report on the electrodeposition of crystalline Sb{sub 2}Te{sub 3} thin films at room temperature from a tartaric-nitric acid electrolyte using a pulsed, potentiostatic process. The effects of synthesis conditions on the resulting microstructure and compositional homogeneity are investigated using x-ray diffraction, electron diffraction, electron microscopy, and energy dispersive x-ray spectroscopy. The composition of the Sb-Te films was found to be dependent on the interval between pulses, a result that is likely due to the slow kinetics associated with Sb{sub 2}Te{sub 3} formation at the surface. We also observed a change in texture and microstructure with varied applied pulse duration: for short pulse durations a lamellar microstructure with a {l_brace}000 Script-Small-L {r_brace} texture forms, whereas for longer pulse durations a more equiaxed and randomly oriented microstructure forms. The thermal conductivities of the pulsed electrodeposited films are surprisingly low at less than 2 W/K{center_dot}m and are found to systematically decrease with reduced pulse time. - Highlights: Black-Right-Pointing-Pointer We investigate the growth, microstructure, and thermal conductivity of Sb{sub 2}Te{sub 3} films. Black-Right-Pointing-Pointer Pulsed electrodeposition is used to grow crystalline Sb{sub 2}Te{sub 3} films. Black-Right-Pointing-Pointer Film composition and microstructure depend on the growth conditions. Black-Right-Pointing-Pointer Kinetics and thermodynamics are used to explain these observations. Black-Right-Pointing-Pointer The low thermal conductivities observed are correlated to microstructure and texture.

  17. Preparation of Bi2-xSbxTe3 thermoelectric films by electrodeposition

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Bi2-xSbxTe3 thermoelectric films were electrochemically deposited from the solution containing Bi3+, HTeO2+and SbO+.ESEM (environmental scanning electron microscope) investigations indicated that the crystalline state of Bi2-xSbxTe3 films transformed from equiaxed crystal to dendritic crystal with the negative shift of deposition potential. XRD and EDS were used to characterize the structure and composition of the electrodeposited films. The Seebeck coefficient and the temperature dependence of the resistance of Bi2-xSbxTe3 films were measured. The results showed that the composition of the film electrodeposited at -0.5 V is Bi0.5Sb1.5Te3 with the largest Seebeck coefficient of 213 μV·K-1.

  18. Pulsed electrodeposition of Cu2ZnSnS4 thin films: Effect of pulse potentials

    Science.gov (United States)

    Gurav, K. V.; Kim, Y. K.; Shin, S. W.; Suryawanshi, M. P.; Tarwal, N. L.; Ghorpade, U. V.; Pawar, S. M.; Vanalakar, S. A.; Kim, I. Y.; Yun, J. H.; Patil, P. S.; Kim, J. H.

    2015-04-01

    Cu2ZnSnS4 (CZTS) thin films are electrodeposited on Mo substrate using pulsed electrodeposition (PED) at different pulse potentials. The pulse potential (V1) is varied from 0 V/SCE to -0.9 V/SCE and V2 fixed at -1.1 V/SCE. The effects of pulse potentials on the properties of CZTS thin films are investigated. Formation of secondary phases along with CZTS phase is evident for films deposited at low pulse potentials. The secondary phases seem to be reduced with increase in pulse potentials. The morphology of CZTS films is systematically evolved from agglomerated grains to compact one with increase in pulse potentials. The film deposited using optimized pulse potentials (V1 - -0.9 V/SCE and V2 - -1.1 V/SCE) exhibit prominent CZTS phase with nearly stoichiometric composition and has compact morphology with optical band gap energy of 1.46 eV.

  19. Effect of different surfactants and thicknesses on electrodeposited films of bismuth telluride and its thermoelectric performance

    Science.gov (United States)

    Kulsi, Chiranjit; Mitra, Mousumi; Kargupta, Kajari; Ganguly, Saibal; Banerjee, Dipali; Goswami, Shyamaprosad

    2015-10-01

    Thin films of bismuth telluride using various surfactants such as sodium dodecyl sulfate (SDS) and polyvinylpyrrolidone (PVP) have been electrochemically deposited. The influence of different surfactants on crystal orientation and morphology was investigated and correlated with the thermoelectric performance of the electrodeposited films. Since thickness affects the thermoelectric performance compared to the surfactant, thickness- dependent thermoelectric performance has also been investigated. The carrier mobilities of the films obtained are significantly enhanced due to improved surface morphology using different surfactants. Between the two surfactants, films with SDS exhibited the higher value of thermoelectric power, power factor, and figure of merit, which is due to the effect of micelle formation. The XRD pattern of all the films, which are electrodeposited without surfactant or using SDS and PVP, showed preferred crystal orientation along the (018) direction. The roles of organic molecules in the development of nanoparticles with improved thermoelectric properties have been investigated.

  20. CdTe detector use for PIXE characterization of TbCoFe thin films

    International Nuclear Information System (INIS)

    Peltier cooled CdTe detectors have good efficiency beyond the range of energies normally covered by Si(Li) detectors, the most common detectors in PIXE applications. An important advantage of CdTe detectors is the possibility of studying K X-rays lines instead the L X-rays lines in various cases since CdTe detectors present an energy efficiency plateau reaching 70 keV or more. The ITN CdTe useful energy range starts at K-Kα (3.312 keV) and goes up to 120 keV, just above the energy of the lowest γ-ray of the 19F(p, p'γ)19F reaction. In the new ITN HRHE-PIXE line, a CdTe detector is associated to a POLARIS microcalorimeter X-ray detector built by Vericold Technologies GmbH (an Oxford Instruments Group Company). The ITN POLARIS has a resolution of 15 eV at 1.486 keV (Al-Kα) and 24 eV at 10.550 keV (Pb-Lα1). In the present work, a TbCoFe thin film deposited on a Si substrate was analysed at the HRHE-PIXE system. The good efficiency of the CdTe detector at 45 keV (Tb-Kα), and the excellent resolution of POLARIS microcalorimeter at 6.403 keV (Fe-Kα), are presented and the new possibilities open to the IBA analysis of systems with traditionally overlapping X-rays and near mass elements are discussed.

  1. Electrodeposition of bismuth telluride thermoelectric films from a nonaqueous electrolyte using ethylene glycol

    NARCIS (Netherlands)

    Nguyen, H.P.; Wu, M.; Su, J.; Vullers, R.J.M.; Vereecken, P.M.; Fransaer, J.

    2012-01-01

    Ethylene glycol was studied as an electrolyte for the electrodeposition of thermoelectric bismuth telluride films by cyclic voltammetry, rotating ring disk electrode and electrochemical quartz crystal microbalance (EQCM). The reduction of both Bi3+ and Te4+ ions proceeds in one step without the form

  2. Electrodeposition of enzymes-integrated mesoporous composite films by interfacial templating: A paradigm for electrochemical biosensors

    International Nuclear Information System (INIS)

    The development of nanostructured electrodes for electrochemical biosensors is of significant interest for modern detection, portable devices, and enhanced performance. However, development of such sensors still remains challenging due to the time-consuming, detriment-to-nature, and costly modifications of both electrodes and enzymes. In this work, we report a simple one-step approach to fabricating high-performance, direct electron transfer (DET) based nanoporous enzyme-embedded electrodes by electrodeposition coupled with recent progress in potential-controlled interfacial surfactant assemblies. In contrast to those previously electrodeposited mesoporous materials that are not bioactive, we imparted the biofunctionality to electrodeposited mesoporous thin films by means of the amphiphilic phospholipid templates strongly interacting with enzymes. Thus, phospholipid-templated mesoporous ZnO films covalently inlaid with the pristine enzymes were prepared by simple one-step electrodeposition. We further demonstrate two examples of such hybrid film electrodes embedded with alcohol dehydrogenase (ADH) and glucose oxidase (GOx), which are effectively employed as electrochemical biosensors for amperometric sensing of ethanol and glucose without using any electron relays. The favorable mass transport and large contact surface area provided by nanopores play an important role in improving the performance of these two biosensors, such as excellent sensitivities, low detection limits, and fast response. The matrix mesoporous films acting as effective electronic bridges are responsible for DET between enzyme molecules and metal electrode

  3. Admittance spectroscopy characterize graphite paste for back contact of CdTe thin film solar cells

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    CdTe thin film solar cells with a doped-graphite paste back contact layer were studied using admittance spectroscopy technology.The positions and the capture cross sections of energy level in the forbidden band were calculated,which are the important parameters to affect solar cell performance.The results showed that there were three defects in the CdTe thin films solar cells with the doped-graphite paste back contact layer,whose positions in the forbidden band were close to 0.34,0.46 and 0.51 eV,respectively above the valence band,and capture cross sections were 2.23×10-16,2.41×10-14,4.38×10-13 cm2,respectively.

  4. Identification of critical stacking faults in thin-film CdTe solar cells

    International Nuclear Information System (INIS)

    Cadmium telluride (CdTe) is a p-type semiconductor used in thin-film solar cells. To achieve high light-to-electricity conversion, annealing in the presence of CdCl2 is essential, but the underlying mechanism is still under debate. Recent evidence suggests that a reduction in the high density of stacking faults in the CdTe grains is a key process that occurs during the chemical treatment. A range of stacking faults, including intrinsic, extrinsic, and twin boundary, are computationally investigated to identify the extended defects that limit performance. The low-energy faults are found to be electrically benign, while a number of higher energy faults, consistent with atomic-resolution micrographs, are predicted to be hole traps with fluctuations in the local electrostatic potential. It is expected that stacking faults will also be important for other thin-film photovoltaic technologies

  5. Thermoelectric power and Hall effect measurements in polycrystalline CdTe thin films

    Energy Technology Data Exchange (ETDEWEB)

    Paez, B.A. [Pontificia Univ. Javeriana, Santafe de Bogota (Colombia). Thin Films Group

    2000-07-01

    Polycrystalline CdTe thin films deposited by close space sublimation (CSS), were characterized through thermoelectric power, {alpha}, Hall coefficient, and resistivity, {rho}, measurements in the range of 90 to 400 K. This was in order to determine the scattering mechanisms which mainly affect the electrical transport properties in CdTe thin films. The results were analyzed based on theoretical calculations of {alpha} against temperature. This model includes scattering processes within the grains and at the grain boundaries. Some of the parameters used in this calculation were determined experimentally: grain size, crystal structure, activation energy and effective mass. It is important to state that the main approximations were justified according to experimental measurements. (orig.)

  6. Effect of samarium doping on electrodeposited CeO2 thin film

    International Nuclear Information System (INIS)

    Samarium-doped cerium oxide (CeO2:Sm) and undoped cerium oxide (CeO2) thin films were fabricated by electrodeposition on biaxially textured Ni-3% W substrates. The electrodeposited layers were annealed for several hours at temperatures ranging from 910 to 980 C. The resulting crystalline films were investigated by XRD and SEM. The CeO2 crystallite size was correlated to the formation of microcrack in CeO2 and CeO2:Sm using the Scherrer equation of XRD analysis. Crack-free films with an average grain size of about 28 nm were obtained for both Ce0.92Sm0.08O2-δ and Ce0.8Sm0.2O2-δ films. Sm doping strongly affects the crystallite size, crystal structure, texture, and crack formation in ceria films. The lattice parameter a increases and crystallite size is reduced with increased Sm doping. All electrodeposited films are highly biaxially textured. When compared to Ni-based substrates, improvements in the out-of-plane and in-plane texture in ceria- and Sm-doped ceria films were achieved. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Sputtered CdTe thin film solar cells with Cu2Te/Au back contact

    International Nuclear Information System (INIS)

    In this work, Cu2Te/Au back contact for CdTe thin film solar cells were prepared by vacuum evaporation. Influence of annealing temperature on the structure and electrical properties of Cu2Te films were investigated by field emission scanning electron microscope, X-ray diffraction, and Hall effect measurement. Also, CdS/CdTe thin film solar cells were fabricated by magnetron sputtering process, which is favorable for large area deposition and mass production, and the photovoltaic characteristics were studied. As the annealing temperature was increased, the crystal structure transformed from Cu2Te for as-deposited film to Cu2−xTe hexagonal phase, and the grains in the film became bigger. The electrical resistivity was slightly higher by the annealing. The cell efficiency was significantly improved by the heat treatment, and showed a maximum value of 9.14% at 180 °C. From these results, Cu2Te/Au contact acts as the proper pseudo-ohmic contact onto CdTe film. However, further increase of annealing temperature caused the deterioration of cell performance. - Highlights: • Annealing effects of the vacuum evaporated Cu2Te films were investigated. • The transformation from Cu2Te to Cu2−xTe hexagonal phase occurred by annealing. • The performance of the solar cell was highly increased by annealing at 180 °C. • Cu2Te/Au contact acts as the proper pseudo-ohmic contact onto CdTe film

  8. Physical properties of electron beam evaporated CdTe and CdTe:Cu thin films

    International Nuclear Information System (INIS)

    In this paper, we report on physical properties of pure and Cu doped cadmium telluride (CdTe) films deposited onto corning 7059 microscopic glass substrates by electron beam evaporation technique. X-ray diffraction study showed that all the deposited films belong to amorphous nature. The average transmittance of the films is varied between 77% and 90%. The optical energy band gap of pure CdTe film is 1.57 eV and it decreased to 1.47 eV upon 4 wt. % of Cu addition, which may be due to the extension of localized states in the band structure. The refractive index of the films was calculated using Swanepoel method. It was observed that the dispersion data obeyed the single oscillator of the Wemple-Didomenico model, from which the dispersion energy (Ed) parameters, dielectric constants, plasma frequency, and oscillator energy (Eo) of CdTe and CdTe:Cu films were calculated and discussed in detail with the light of possible mechanisms underlying the phenomena. The variation in intensity of photoluminescence band edge emission peak observed at 820 nm with Cu dopant is due to the change in surface state density. The observed trigonal lattice of Te peaks in the micro-Raman spectra confirms the p-type conductive nature of films, which was further corroborated by the Hall effect measurement. The lowest resistivity of 6.61 × 104 Ω cm was obtained for the CdTe:Cu (3 wt. %) film

  9. Structurally and mechanically tunable molybdenum oxide films and patterned submicrometer structures by electrodeposition

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted -- Abstract: 1.5 μm-thick molybdenum oxide films have been electrodeposited potentiostatically from 0.2 M Na2MoO4 electrolyte onto indium tin oxide (ITO)/glass substrates at pH = 1, 6 and 9. The influence of cetyltrimethylammonium bromide (CTAB) surfactant on films' adhesion, morphology, degree of porosity, molybdenum speciation, and crystallographic structure has been systematically investigated. The addition of CTAB (0.01 M) to the bath clearly improves film adherence to the substrate, reduces cracking, and increases crystallinity. This has an impact on the physical properties of the films. In particular, both hardness (H) and Young's modulus (E) increase, as determined from nanoindentation tests. The growth of ordered arrays of molybdenum oxide submicrometer structures, including pillars and stripes, by electrodeposition onto e-beam lithographed Au/Ti/Si substrates is also reported

  10. Structural and compositional properties of CZTS thin films formed by rapid thermal annealing of electrodeposited layers

    Science.gov (United States)

    Lehner, J.; Ganchev, M.; Loorits, M.; Revathi, N.; Raadik, T.; Raudoja, J.; Grossberg, M.; Mellikov, E.; Volobujeva, O.

    2013-10-01

    In this work Cu2ZnSnS4 (CZTS) thin films were formed by rapid thermal annealing (RTA) of sequentially electrodeposited Cu-Zn and Sn films in 5% H2S containing atmosphere. Six different thermal profiles were used in the experiments. In three of these, the temperature ramping up was varied, while the variable in the other three profiles was the cooling down rate. The optimising parameters for RTA of electrodeposited films were found and annealed films were characterised by X-ray diffraction (XRD), micro-Raman spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM+EDS). The material parameters such as lattice strain and crystallite size were also determined and the influence of annealing temperature and heating rate on these parameters was discussed.The pathway of MoS2 formation was investigated.

  11. Ion channeling studies of CdTe films on GaAs

    International Nuclear Information System (INIS)

    Thin films of [111] oriented CdTe have been MOCVD grown onto [111] GaAs substrates. When thickness exceed 1000 Angstrom the epitaxy is quite good (backscattering minimum yield of approximately 15%) in spite of a 14% lattice mismatch. A narrowing of the Cd angular scan suggests a displacement of some of the Cd atoms in the lattice. A model based on a Te vacancy is presented to describe the data

  12. Structural and optical properties of ZnS thin film grown by pulsed electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Hennayaka, H.M.M.N.; Lee, Ho Seong, E-mail: hs.lee@knu.ac.kr

    2013-12-02

    ZnS thin films were grown on indium–tin-oxide coated glass substrates using pulsed electrodeposition and the effect of the deposition temperature on the structural and optical properties of the ZnS films was investigated. Polycrystalline cubic ZnS films were obtained at all the deposition temperatures. At temperatures below 70 °C, less dense films were obtained and particle agglomeration was visible. On the other hand, at temperatures above 70 °C, more dense films with well-defined grains were obtained. With increasing deposition temperatures, the optical transmittance and bandgap of the ZnS films decreased. These results are attributed to the increase in the thickness of ZnS films and their particle size. The ZnS films grown at 90 °C exhibited the highly (200) preferred orientation and n-type conductivity with a wide bandgap of 3.75 eV. - Highlights: • This study describes the effect of the deposition temperature on the growth of the ZnS thin films. • ZnS thin films were grown using pulsed electrodeposition. • ZnS thin films exhibited the good crystal quality and chemical composition. • ZnS thin films exhibited n-type conductivity with a wide bandgap of 3.75 eV.

  13. Thin film CdTe solar cells by close spaced sublimation: Recent results from pilot line

    International Nuclear Information System (INIS)

    CdTe is an attractive material to produce high efficient and low cost thin film solar cells. The semiconducting layers of this kind of solar cell can be deposited by the Close Spaced Sublimation (CSS) process. The advantages of this technique are high deposition rates and an excellent utilization of the raw material, leading to low production costs and competitive module prices. CTF Solar GmbH is offering equipment and process knowhow for the production of CdTe solar modules. For further improvement of the technology, research is done at a pilot line, which covers all relevant process steps for manufacture of CdTe solar cells. Herein, we present the latest results from the process development and our research activities on single functional layers as well as for complete solar cell devices. Efficiencies above 13% have already been obtained with Cu-free back contacts. An additional focus is set on different transparent conducting oxide materials for the front contact and a Sb2Te3 based back contact. - Highlights: ► Laboratory established on industrial level for CdTe solar cell research ► 13.0% cell efficiency with our standard front contact and Cu-free back contact ► Research on ZnO-based transparent conducting oxide and Sb2Te3 back contacts ► High resolution scanning electron microscopy analysis of ion polished cross section

  14. Characterization of Highly Efficient CdTe Thin Film Solar Cells by Low-Temperature Photoluminescence

    Science.gov (United States)

    Okamoto, Tamotsu; Matsuzaki, Yuichi; Amin, Nowshad; Yamada, Akira; Konagai, Makoto

    1998-07-01

    Highly efficient CdTe thin film solar cells prepared by close-spaced sublimation (CSS) method with a glass/ITO/CdS/CdTe/Cu-doped carbon/Ag structure were characterized by low-temperature photoluminescence (PL) measurement. A broad 1.42 eV band probably due to VCd Cl defect complexes appeared as a result of CdCl2 treatment. CdS/CdTe junction PL revealed that a CdSxTe1-x mixed crystal layer was formed at the CdS/CdTe interface region during the deposition of CdTe by CSS and that CdCl2 treatment promoted the formation of the mixed crystal layer. Furthermore, in the PL spectra of the heat-treated CdTe after screen printing of the Cu-doped carbon electrode, a neutral-acceptor bound exciton (ACu0, X) line at 1.590 eV was observed, suggesting that Cu atoms were incorporated into CdTe as effective acceptors after the heat treatment.

  15. Effect of active treatments on photovoltaic characteristics of structures based on CdTe films

    International Nuclear Information System (INIS)

    Photoelectric characteristics of ITO/CdTe structures fabricated by the thermal evaporation in vacuum followed by their deposition in a quasi closed volume have been studied before and after treatments of various kinds. Some specimens were subjected to a 'chloride' treatment, the others were annealed in air. Afterward, the specimens were treated in hydrogen plasma, and they were covered with a thin diamond-like carbon film. The 'chloride' treatment of ITO/CdTe structures is shown to result in an increase of the diffusion length of charge carriers in the CdTe layer. The thermal annealing did not affect this parameter, but significantly enhanced the photosensitivity, which means a reduction of the surface recombination rate in the surface CdTe layer. For all considered ITO/CdTe structures obtained by the thermal evaporation in vacuum, the following treatment in hydrogen plasma and the deposition of thin diamondlike films brought about a substantial increase in the diffusion length of charge carriers in the CdTe layer. The ITO/CdTe structures obtained by the thermal vacuum evaporation and treated with hydrogen plasma demonstrated a significant enhancement of their spectral sensitivity in a wavelength range of 400-800 nm, whereas the same effect for structures subjected to the 'chloride' treatment was obtained after the sequential hydrogen plasma treatment and the diamond-like carbon film deposition.

  16. Preparation and Properties of CdTe Polycrystalline Films for Solar Cells

    Institute of Scientific and Technical Information of China (English)

    ZHENG Huajing; ZHANG Jingquan; FENG Lianghuan; ZHENG Jiagui; CAI Wei; LI Bing; CAI Yaping

    2006-01-01

    The structure and characteristics of CdTe thin films are closely dependent on the whole deposition process in close-space sublimation (CSS). The physical mechanism of CSS was analyzed and the temperature distribution in CSS system was measured, and the influences of the increasing-temperature process and pressure on the preliminary nucleus creation were studied. The results indicate: the samples deposited at different pressures have a cubical structure of CdTe and the diffraction peaks of CdS and SnO2∶F. As the atmosphere pressure increases, the crystal size of CdTe decreases, the rate of the transparency of the thin film decreases and the absorption side moves towards the short-wave direction. After a 4-minute depositing process with a substrate temperature of 500 ℃ and a source temperature of 620 ℃, the polycrystalline thin films can be made, so the production of high-quality integrated cell with SnO2:F/CdS/CdTe/Au structure is hopeful.

  17. Fabrication of nanostructured CuO films by electrodeposition and their photocatalytic properties

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • The plausible growth mechanism for the formation of CuO film with star-like structure is proposed for the first time. • In the process of electrodeposition, the electrodepisition voltage is the key factor to control the surface morphology of CuO films. • Cu2O works as hard template to control the surface morphologies of CuO. • As-prepared CuO films whose photo-degradation rate of methylene blue can reach 95% own the best photocatalytic activity compared to CuO powder with nanoscale or general size. - Abstract: Monoclinic nanostructured CuO films with star-like morphology on indium tin oxide (ITO)-coated glass substrates were successfully synthesized by electrodeposition method in acidic solution with the pH of 5.7. The as-synthesized films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV–vis. The influence of different electrodeposition parameters and annealing temperature on the growth of CuO films were investigated. The results showed that the nanostructured CuO film was well-crystallized and electrodeposition voltage is the main factor to control its morphology. Moreover, good photocatalytic activity was exhibited and photo-degradation rate to methylene blue can reach 95%. Its optical energy band gap is 3.3 eV. The plausible growth mechanism for the formation of CuO film with star-like structure is also proposed for the first time

  18. Electrodeposition of black chromium thin films from trivalent chromium-ionic liquid solution

    OpenAIRE

    Eugénio, S.; Vilar, Rui; C. M. Rangel; Baskaran, I.

    2009-01-01

    In the present study, black chromium thin films were electrodeposited from a solution of 1-butyl-3- methylimidazolium tetrafluoroborate ([BMIm][BF4] ionic liquid containing trivalent chromium (Cr(III)). Homogeneous and well adherent coatings have been obtained on nickel, copper and stainless steel substrates. The nucleation and growth of the films were investigated by cyclic voltammetry and current-density/time transient techniques. SEM/EDS, XPS and XRD were used to study the morphology, chem...

  19. Frictional and wear properties of cobalt/multiwalled carbon nanotube composite films formed by electrodeposition

    OpenAIRE

    Arai, Susumu; Miyagawa, Kazuaki

    2013-01-01

    Carbon nanotubes (CNTs) have solid lubricity due to their unique structure, and as such, CNT composites are also expected to exhibit superior tribological properties. In this study, Co/CNT composite films were fabricated using a composite electrodeposition technique, and their tribological properties were investigated. Three different sizes of multiwalled carbon nanotubes (MWCNTs) were used as the CNTs in this study. The microstructures of the composite films were examined using scanning elec...

  20. Surface plasmon effect in nanocrystalline copper/DLC composite films by electrodeposition technique

    Indian Academy of Sciences (India)

    S Hussain; A K Pal

    2006-11-01

    Composite films of nanocrystalline copper embedded in DLC matrix prepared by electrodeposition technique were studied for their optical properties. Particle size and metal volume fractions were tailored by varying the amount of copper containing salt in the electrolyte. Blue-shift of the surface plasmon resonance peak in the absorbance spectra of the films was observed with the reduction in size and volume fraction of metal particles. Mie theory was found to describe the experimental spectra quite well.

  1. Structural and optical properties of Cu-doped CdTe films with hexagonal phase grown by pulsed laser deposition

    OpenAIRE

    F. de Moure-Flores; J. G. Quiñones-Galván; A. Guillén-Cervantes; Santoyo-Salazar, J.; A. Hernández-Hernández; Olvera, M. de la L.; M. Zapata-Torres; Meléndez-Lira, M.

    2012-01-01

    Cu-doped CdTe thin films were prepared by pulsed laser deposition on Corning glass substrates using powders as target. Films were deposited at substrate temperatures ranging from 100 to 300 °C. The X-ray diffraction shows that both the Cu-doping and the increase in the substrate temperature promote the presence of the hexagonal CdTe phase. For a substrate temperature of 300 °C a CdTe:Cu film with hexagonal phase was obtained. Raman and EDS analysis indicate that the films grew with an excess ...

  2. Influence of CuxS back contact on CdTe thin film solar cells

    Institute of Scientific and Technical Information of China (English)

    Lei Zhi; Feng Lianghuan; Zeng Guanggen; Li Wei; Zhang Jingquan; Wu Lili; Wang Wenwu

    2013-01-01

    We present a detailed study on CuxS polycrystalline thin films prepared by chemical bath method and utilized as back contact material for CdTe solar cells.The characteristics of the films deposited on Si-substrate are studied by XRD.The results show that as-deposited CuxS thin film is in an amorphous phase while after annealing,samples are in polycrystalline phases with increasing temperature.The thickness of CuxS thin films has great impact on the performance of CdS/CdTe solar cells.When the thickness of the film is about 75 nm the performance of CdS/CdTe thin film solar cells is found to be the best.The energy conversion efficiency can be higher than 12.19%,the filling factor is higher than 68.82% and the open-circuit voltage is more than 820 mV.

  3. Adsorption of organic layers over electrodeposited magnetite (Fe3O4) thin films

    International Nuclear Information System (INIS)

    Research highlights: → Adherent low roughness magnetite films ranging from 80 nm to 3.75 μm-thick were electrodeposited on Au/glass substrates under galvanostatic control. → X-ray diffraction and magnetic measurements corroborates the purity of the electrodeposited magnetite. → Both dodecanethiol and oleic acid are shown to adsorb on the magnetite prepared at low temperature, significantly inducing the hydrophobicity of the surface. → Contact angle and voltammetric measurements, as well as XPS confirm the monolayers formation. - Abstract: The formation of monolayers of two organic compounds (oleic acid and dodecanethiol) over magnetite films was studied. Magnetite films ranging from 80 nm to 3.75 μm-thick were electrodeposited on Au on glass substrates under galvanostatic control, with deposition parameters optimized for minimum surface roughness. Films were characterised by SEM and AFM, showing granular deposits with a low rms roughness of 5-40 nm measured over an area of 1 μm2. The growth rate was estimated by measuring cross-sections of the thin films. Pure magnetite with an fcc structure is observed in XRD diffractograms. The adsorption of both oleic acid and dodecanethiol on the magnetite films was tested by immersing them in ethanol solutions containing the organic molecules, for different deposition time, temperature and cleaning procedure. Monolayer formation in both cases was studied by contact angle and voltammetric measurements, as well as XPS.

  4. Electrodeposition of nanocrystalline silver films and nanowires from the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethylsulfonate

    International Nuclear Information System (INIS)

    We report in this paper on the electrodeposition of nanocrystalline silver films and nanowires in the air and water stable ionic liquid 1-ethyl-3-methylimidazolium trifluoromethylsulfonate [EMIm]TfO containing Ag(TfO) as a source of silver. The study was performed by means of cyclic voltammetry and chronoamperometry, and the electrodeposits were characterized by SEM-EDX and XRD. The cyclic voltammetry behaviour showed typical reduction and oxidation peaks corresponding to the deposition and stripping of silver in the employed electrolyte. XRD patterns of the electrodeposited silver layers revealed the characteristic peaks of crystalline silver with crystallites in the nanosize regime. Silver nanowires with average diameters and lengths of about 200 nm and 3 μm, respectively, were prepared by potentiostatic deposition within a commercial nuclear track-etched polycarbonate template.

  5. Electronic structure, structural and optical properties of thermally evaporated CdTe thin films

    International Nuclear Information System (INIS)

    Thin films of CdTe were deposited on glass substrates by thermal evaporation. From the XRD measurements it is found that the films are of zinc-blende-type structure. The lattice parameter was determined as a=6.529A, which is larger than 6.48A of the powder sample, because the recrystallized lattice of the grown films is subjected to a compressive stress aroused as a result of the lattice mismatch and/or differences in thermal expansion coefficient between the CdTe and the underlying substrate. Transmittance, absorption, extinction and refractive coefficients are measured. Electronic structure, band parameters and optical spectra of CdTe were calculated from ab initio studies within the LDA and LDA+U approximations. It is shown that LDA underestimates the band gap, energy levels of the Cd-4d states, s-d coupling and band dispersion. However, it calculates the spin-orbit coupling correctly. LDA+U did not increase much the band gap value, but it corrected the s-d coupling by shifting the Cd-4d levels towards the experimentally determined location and by splitting the LDA-derived single s peak into two peaks, which originates from admixture of s and d states. It is shown that the s-d coupling plays an important role in absorption and reflectivity constants. The calculated optical spectra fairly agree with experimental data. Independent of wave vector scissors operator is found to be a good first approximation to shift rigidly the band gap of CdTe underestimated by LDA

  6. Effect of electric field on spray deposited CdTe thin films

    International Nuclear Information System (INIS)

    CdTe thin films have been deposited using spray pyrolysis with and without electric field. The improvement in the film properties with the electric field is observed which is mainly due to the reduction of droplet size. The presence of CdTeO3 peaks in the X-ray diffraction pattern for films deposited without electric field at 350 deg. C is attributed to the slow dissociation of complexes containing Cd and Te ions on the substrate. The reduction in the droplet size under the influence of electric field and faster dissociation of droplets at high temperature leads to complete pyrolytic reaction for a nearly oxide free CdTe film formation. Energy dispersive X-ray analysis indicates stoichiometric Cd and Te atomic concentrations, with oxygen and chlorine impurities in varying amount for different substrate temperatures, with and without electric field. The presence of chlorine gives rise to an intense photoluminescence peak at 1.40 eV along with a weak peak at 0.84 eV. The intensities of both peaks diminish when the films are prepared with the electric field, due to reduction of chlorine concentration and morphological changes in the films

  7. Processing and characterization of large-grain thin-film CdTe

    International Nuclear Information System (INIS)

    Basic material studies addressing the growth and processing of CdTe have resulted in dense, defect-free as-grown CdTe films on 7059 glass with initial grain sizes of ∼0.2 μm. Innovations in postdeposition processing (no CdCl2) have resulted in films with >50 μm grain sizes. Scanning electron microscopy analyses confirm film density while concurrent cathodluminescence reveals a change in the recombination efficiency. Transmission electron microscopy analyses reveal that films grown below 300 degree C are defect-free, while films grown above 300 degree C contain defects. Photoluminescence lifetime measurements reveal a fivefold increase in lifetime following postdeposition processing of these films. These results were correlated with x-ray photoemission measurements of the Te 4d, Cd 4d, and valence band. This indicates that grain boundaries are the main factor limiting lifetimes. Based on these results, we have developed an understanding of the effects of oxygen and grain boundary oxides on postdeposition processing and enhanced grain growth

  8. Hydrogen-induced superabundant vacancies in electrodeposited Fe–C alloy films

    Energy Technology Data Exchange (ETDEWEB)

    Fukumuro, Naoki; Kojima, Saeka; Fujino, Moeko; Mizuta, Yasunori; Maruo, Toshiaki; Yae, Shinji [Department of Materials Science and Chemistry, Graduate School of Engineering, University of Hyogo, Himeji, Hyogo (Japan); Fukai, Yuh [Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo (Japan)

    2015-10-05

    Highlights: • The hydrogen behavior in electrodeposited Fe–C films was investigated. • The H content in Fe–C films increased with increasing of C content. • The changes in lattice parameters of Fe–C films were observed. • Both the contraction and expansion of lattice were reduced by heat treatments. • The limiting composition of VacCH{sub 5} clusters was estimated from the results. - Abstract: Fe–C alloy films containing supersaturated C and H were prepared by electrodeposition, and investigated for the hydrogen behavior in annealing processes utilizing X-ray diffraction and thermal desorption spectroscopy. The H content x{sub H} (x{sub H} = H/Fe) in the films increased from about 0.031 in pure Fe to about 0.36 in Fe–C alloy (x{sub C} = C/Fe = 0.073) in proportion to the C content. The lattice contraction of about 0.2% was observed in pure Fe films, whereas the lattice expansion increasing with C content was observed in Fe–C alloy films. Both the lattice contraction of the Fe films and the lattice expansion of the Fe–C alloy films were decreased as H was desorbed during heat treatments. The atomistic structure of vacancy–hydrogen and vacancy–carbon–hydrogen clusters in Fe–C alloy films is discussed, based on these experimental results.

  9. Electrochemical cell for in situ electrodeposition of magnetic thin films in a superconducting quantum interference device magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Topolovec, Stefan, E-mail: stefan.topolovec@tugraz.at; Würschum, Roland, E-mail: wuerschum@tugraz.at [Institute of Materials Physics, Graz University of Technology, Petersgasse 16, 8010 Graz (Austria); Krenn, Heinz [Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz (Austria)

    2015-06-15

    An electrochemical cell is designed and applied for in situ electrodeposition of magnetic thin films in a commercial SQUID magnetometer system. The cell is constructed in such a way that any parasitic contribution of the cell and of the substrate for electrodeposition to the magnetic moment of the deposited film is reduced to a minimum. A remanent minor contribution is readily taken into account by a proper analysis of the detected signal. Thus, a precise determination of the absolute magnetic moment of the electrodeposited magnetic film during its growth and dissolution is achieved. The feasibility of the cell design is demonstrated by performing Co electrodeposition using cyclic voltammetry. For an average Co film thickness of (35.6 ± 3.0) atomic layers, a magnetic moment per Co atom of (1.75 ± 0.11) μ{sub B} was estimated, in good agreement with the literature bulk value.

  10. Electrochemical cell for in situ electrodeposition of magnetic thin films in a superconducting quantum interference device magnetometer

    International Nuclear Information System (INIS)

    An electrochemical cell is designed and applied for in situ electrodeposition of magnetic thin films in a commercial SQUID magnetometer system. The cell is constructed in such a way that any parasitic contribution of the cell and of the substrate for electrodeposition to the magnetic moment of the deposited film is reduced to a minimum. A remanent minor contribution is readily taken into account by a proper analysis of the detected signal. Thus, a precise determination of the absolute magnetic moment of the electrodeposited magnetic film during its growth and dissolution is achieved. The feasibility of the cell design is demonstrated by performing Co electrodeposition using cyclic voltammetry. For an average Co film thickness of (35.6 ± 3.0) atomic layers, a magnetic moment per Co atom of (1.75 ± 0.11) μB was estimated, in good agreement with the literature bulk value

  11. Deposition of CdTe films under microgravity: Foton M3 mission

    Energy Technology Data Exchange (ETDEWEB)

    Benz, K.W.; Croell, A. [Freiburger Materialforschungszentrum FMF, Albert-Ludwigs-Universitaet Freiburg (Germany); Zappettini, A.; Calestani, D. [CNR Parma, Instituto Materiali Speciali per Elettronica e Magnetismo IMEM, Fontani Parma (Italy); Dieguez, E. [Universidad Autonoma de Madrid (Spain). Departamento de Fisica de Materiales; Carotenuto, L.; Bassano, E. [Telespazio Napoli, Via Gianturco 31, 80146 Napoli (Italy); Fiederle, M.

    2009-10-15

    Experiments of deposition of CdTe films have been carried out under microgravity in the Russian Foton M3 mission. The influence of gravity has been studied with these experiments and compared to the results of simulations. The measured deposition rate could be confirmed by the theoretical results for lower temperatures. For higher temperatures the measured thickness of the deposited films was larger compared to the theoretical data. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Effect of substrate temperature on photoconductivity in CdTe thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sarmah, K.C.; Das, H.L. (Dept. of Physics, Gauhati Univ., Assam (India))

    1991-03-20

    Thin films of highly pure (99.999%) CdTe grown by vacuum evaporation on glass substrates held at elevated temperatures have been found to be polycrystalline. Within the range from liquid nitrogen temperature to 425 K two distinct conductivity regions both in the dark and under illumination have been observed in all the films having different grain sizes. From lower temperatures to 285 K the conductivity is essentially temperature independent and above 285 K the potential barriers localized at grain boundaries limit the conductivity. (orig.).

  13. Electrodeposition and Thermoelectric Properties of Cu-Se Binary Compound Films

    Science.gov (United States)

    Yang, Mengqian; Shen, Zhengwu; Liu, Xiaoqing; Wang, Wei

    2016-03-01

    Cu-Se binary compound films have been prepared by electrodeposition from solutions containing CuSO4, H2SeO3, and H2SO4 and their composition, structure, and thermoelectric performance analyzed. Moving the depositing potential negatively increased the Cu content in the film, remarkably so for relatively low Cu2+ concentration in the solution. X-ray diffraction analysis showed that the phase composition of the films varied with their Cu content. Cu-Se binary compound films electrodeposited from solutions with different concentration ratios of CuSO4 to H2SeO3 showed two different phases: α-Cu2- x Se (monoclinic) with Se content in the range of 33.3 at.% to 33.8 at.%, and β-Cu2Se (cubic) with Se content in the range of 35.3 at.% to 36.0 at.%. The highest power factor for electrodeposited Cu2- x Se film was 0.13 mW/(K2 m) with Seebeck coefficient of 56.0 μV/K.

  14. Electrochromic Properties of Iridium Oxide Films Prepared by Pulsed Anodic Electrodeposition

    Science.gov (United States)

    Jung, Youngwoo; Tak, Yongsug; Lee, Jaeyoung

    2002-12-01

    Thin films of iridium oxide to be used as an electrochromic material were prepared by pulsed anodic current electrodeposition onto indium tin oxide (ITO) coated glass substrates. Before the pulsed electrodeposition, iridium oxide films formed by cyclic voltammetry (CV) played an important role in good adhesion as a seed layer. Iridium oxide films with light-blue color (100 mC/cm2) were deposited when anodic current of 0.07 mA/cm2 for 0.5 sec was superimposed on off-time of 0.5 sec (i.e., zero current) in each cycle. During CV experiment in phosphate buffered saline solution, electrodeposited iridium oxide films exhibited anodic electrochromism of blue and black color at two oxidation potentials (i.e., the ejection of H+) of +0.5 V and +0.9 V (vs. SCE), respectively, while on the cathodic scan, black thin film became colorless due to the injection of H+. When +0.9 V and -0.7 V were applied for coloring and bleaching observation in different pulse voltammetry, minimal times needed for each process are 9 sec and 5 sec, respectively.

  15. Photoluminescence waveguiding in CdSe and CdTe QDs-PMMA nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, I; Gordillo, H; Abargues, R; Albert, S; Martinez-Pastor, J, E-mail: isaac.suarez@uv.es [UMDO - Unidad Asociada al CSIC-IMM, Instituto de Ciencia de los Materiales, Universidad de Valencia, PO Box 22085, 46071 Valencia (Spain)

    2011-10-28

    In this paper, active planar waveguides based on the incorporation of CdSe and CdTe nanocrystal quantum dots in a polymer matrix are demonstrated. In the case of doping the polymer with both types of quantum dots, the nanocomposite film guides both emitted colors, green (550 nm, CdTe) and orange (600 nm, CdSe). The optical pumping laser can be coupled not only with a standard end-fire coupling system, but also directing the beam to the surface of the sample, indicating a good absorption cross-section and waveguide properties. To achieve these results, a study of the nanocomposite optical properties as a function of the nanocrystal concentration is presented and the optimum conditions are found for waveguiding.

  16. High efficiency thin film CdTe solar cells. Second quarterly progress report, June 19-September 18, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Serreze, H.B.; Entine, G.; Goldner, R.B.

    1979-10-01

    During the second quarter of this program primary emphasis was put into depositing and evaluating both n and p-type CdTe films on a variety of conducting and non-conducting substrates. Improvements in the deposition apparatus permitted preparation of a large number of CdTe films and numerous analytic techniques available at Tufts University were utilized to examine these films. It was found that the introduction of a thin (100 A). In layer between the ITO and the CdTe significantly reduced the previously observed barrier present at the ITO/n-CdTe interface without adversely reducing optical transmission. While the resistivity of the films is still rather high, very recent results show that proper changes in procedure are capable of markedly lowering the resistivity. Preliminary Schottky barrier devices have been made which show promising photovoltaic characteristics.

  17. Effect of ZnO films on CdTe solar cells

    Institute of Scientific and Technical Information of China (English)

    Liu Tingliang; He Xulin; Zhang Jingquan; Feng Lianghuan; Wu Lili; Li Wei; Zeng Guanggen; Li Bing

    2012-01-01

    The ZnO high resistivity transparent (HRT) layers were prepared by DC magnetron sputtering on the 1mm borosilicate glass with 150 nm 1TO coating.The structural,optical and electrical properties of the as-deposited films were investigated by XRD,UV/Vis spectroscopy and four-probe technology.The interface characters of the ITO/ZnO and ZnO/CdS systems were studied by ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS) depth profiling tests.The results show that ZnO has good optical and electrical properties.The insertion of the ZnO films decreases the energy barrier between ITO and CdS films.The energy conversion efficiency and quantum efficiency were found to be 12.77% (8.9%) and > 90% (79%) with or (without)ZnO films of CdTe solar cells.Furthermore,the effect of thickness,mobility and carrier density of ZnO films on CdTe solar cells was analyzed by AMPD-1D.

  18. Effect of ZnO films on CdTe solar cells

    International Nuclear Information System (INIS)

    The ZnO high resistivity transparent (HRT) layers were prepared by DC magnetron sputtering on the 1 mm borosilicate glass with 150 nm ITO coating. The structural, optical and electrical properties of the as-deposited films were investigated by XRD, UV/Vis spectroscopy and four-probe technology. The interface characters of the ITO/ZnO and ZnO/CdS systems were studied by ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS) depth profiling tests. The results show that ZnO has good optical and electrical properties. The insertion of the ZnO films decreases the energy barrier between ITO and CdS films. The energy conversion efficiency and quantum efficiency were found to be 12.77% (8.9%) and > 90% (79%) with or (without) ZnO films of CdTe solar cells. Furthermore, the effect of thickness, mobility and carrier density of ZnO films on CdTe solar cells was analyzed by AMPD-1D. (semiconductor materials)

  19. Epitaxial growth of CdTe oriented thin films, infrared characterization and possible applications to photo-voltaic cells

    OpenAIRE

    Gerbaux, X.; Pianelli, A.; Hadni, A.; Jeanniard, C.; Strimer, P.

    1980-01-01

    The growth of CdTe oriented thin films by the ENSH method - i.e. Epitaxial Nucleation in Sub-microscopic Holes of an intermediate layer closely applied on a bulk single crystal — has been recently described. The CdTe films are generally difficult to detach from the bulk crystal. However free films are needed to study the infrared transmission in the spectral region of high absorption. To get them, the vitreous or amorphous thin intermediate layers are substituted by quite soluble an oriented ...

  20. Nanocrystalline CdTe thin films by electrochemical synthesis

    Directory of Open Access Journals (Sweden)

    Ramesh S. Kapadnis

    2013-03-01

    Full Text Available Cadmium telluride thin films were deposited onto different substrates as copper, Fluorine-doped tin oxide (FTO, Indium tin oxide (ITO, Aluminum and zinc at room temperature via electrochemical route. The morphology of the film shows the nanostructures on the deposited surface of the films and their growth in vertical direction. Different nanostructures developed on different substrates. The X-ray diffraction study reveals that the deposited films are nanocrystalline in nature. UV-Visible absorption spectrum shows the wide range of absorption in the visible region. Energy-dispersive spectroscopy confirms the formation of cadmium telluride.

  1. Photo-responsivity characterizations of CdTe films for direct-conversion X-ray detectors

    International Nuclear Information System (INIS)

    We have fabricated and investigated thin, polycrystalline, cadmium-telluride (CdTe) films in order to utilize them for optical switching readout layers in direct-conversion X-ray detectors. The polycrystalline CdTe films are fabricated on ITO glasses by using the physical vapor deposition (PVD) method at a slow deposition rate and a pressure of 10-6 torr. CdTe films with thicknesses of 5 and 20 μm are grown. The electrical and the optical characteristics of the CdTe films are investigated by measuring the dark-current and the photo-current as functions of the applied field under different wavelengths of light. Higher photo-currents are generated at the longer wavelengths of light for the same applied voltage. When a higher electrical field is applied to the 20 μm-thick CdTe film, a higher dark-current, a higher photo-current, a larger number of charges, and a higher quantum efficiency are generated.

  2. Optical and electrical characterizations of highly efficient CdTe thin film solar cells prepared by close-spaced sublimation

    Science.gov (United States)

    Okamoto, T.; Yamada, A.; Konagai, M.

    2000-06-01

    The effects of the Cu diffusion on the optical and electrical properties of CdTe thin film solar cells prepared by close-spaced sublimation (CSS) were investigated by capacitance-voltage ( C- V) measurement and low-temperature photoluminescence (PL) measurement. C- V measurement revealed that the net acceptor concentration in the CdTe layer was independent of the heat treatment after screen printing of the Cu-doped graphite electrode for Cu diffusion into the CdTe layer, although it greatly affected the solar cell performance. Furthermore, the depth profile of PL spectrum of CdTe layer implies that the heat treatment for Cu diffusion facilitates the formation of low-resistance contact to CdTe through the formation of a heavily doped (p +) region in the CdTe adjacent to the back electrode, but Cu atoms do not act as effective acceptors in the CdTe layer except the region near the back electrode.

  3. Photoelectrochemical properties of WO3 nanoparticulate thin films prepared by carboxylic acid-assisted electrodeposition

    International Nuclear Information System (INIS)

    Optimisation of particle sizes of WO3 films is important for photoelectrochemical applications. However, most of the developed size-controlled synthesis techniques involve complicated instruments or vacuum systems. The present work presents an alternative method using carboxylic acid-assisted electrodeposition where WO3 thin films were deposited from peroxotungstic acid (PTA) solution containing different carboxylic acids (formic, oxalic, citric). The effects of carboxylic acids on the electrodeposition and the resultant morphological, mineralogical, optical, and photoelectrochemical properties of the WO3 films were investigated. The analysis showed that the films consisted of equiaxed nanoparticulate monoclinic WO3. The deposition thicknesses and the average grain (individual particle and agglomerate) sizes of the films were dependent on the amount of hydronium ions and the molecular weight and associated sizes of the conjugate bases released upon the dissociation of carboxylic acids in the PTA solutions, which result in hydrogen bond formation and molecular dispersion. The photocurrent densities of the films deposited with carboxylic acids were greater than that of the film deposited from pure PTA. These differences were attributed to improvements in (1) grain size, which controls photogenerated electron-hole transport, and (2) effective grain boundary area, which controls the numbers of active reaction sites and electron-hole recombination sites. - Highlights: • Carboxylic acid-assisted electrodeposition of WO3 films from peroxotungstic acid. • The types of carboxylic acids control the deposition rates and microstructure. • WO3 grain sizes and effective grain boundary areas determine the photocurrents. • Maximal photocurrent measured in the smallest-aggregate films (∼ 83 nm)

  4. Preparation and characterization of Cu-In-S thin films by electrodeposition

    International Nuclear Information System (INIS)

    In this paper, we report the preparation and characterization of Cu-In-S thin films on stainless steel prepared by electrodeposition technique. The electrolytic bath used for preparation of the thin films consists of metal salts dissolved in a buffer solution. This buffer solution can control the formation and composition of thin films. In order to get adequate crystalline of CuInS2 thin films, the as deposited films were annealed in N2-atmosphere. Samples were characterized using X-ray diffraction (XRD), electron probe micro-analysis (EPMA), and scanning electron microscopy (SEM). The band-gap value of the material was estimated using optical transmittance and reflectance data on thin films deposited on commercial glass/indium tin oxide (ITO) substrates. It was found that the band-gap of the films is close to 1.5 eV

  5. Anomalous scaling in surface roughness evaluation of electrodeposited nanocrystalline Pt thin films

    Energy Technology Data Exchange (ETDEWEB)

    Nabiyouni, G., E-mail: g-nabiyouni@araku.ac.ir [Department of Physics, University of Arak, Beheshti Avenue, Arak 38156 (Iran, Islamic Republic of); Farahani, B. Jalali [Electrical Engineering Department, Arizona State University, Goldwater Building 340, Tempe, AZ (United States)

    2009-11-15

    Atomic force microscopy (AFM) is used to measure the surface roughness of crystalline Pt thin films as a function of film thickness and growth rate. Our films were electrodeposited on Au/Cr/glass substrates, under galvanostatic control (constant current density), from a single electrolyte containing Pt{sup 4+} ions. Crystalline structure of the films was confirmed by X-ray diffraction (XRD) technique. The effect of growth rate (deposition current density) and film thickness (deposition time) on the kinetic roughening of the films were studied using AFM and roughness calculation. The data is consistent with a rather complex behaviour known as 'anomalous scaling' where both local and large scale roughnesses show power law dependence on the film thickness.

  6. Nanostructured ZnO Films Electrodeposited on Hydrophilic Substrate Utilizing Cooperative Surface Assembly

    Institute of Scientific and Technical Information of China (English)

    YANG Lirong; JIN Zhengguo; WU Weibing; BU Shaojing

    2006-01-01

    Nanoporous amorphous ZnO films with lamellar structure were electrodeposited on the hydrophilic substrate by utilizing cooperative surface assembly of anionic sodium dodecyl sulfonate (SDS) at a very low concentration and inorganic species Zn(NO3)2 under the influence of an electrostatic potential. The deposited films were characterized by X-ray diffraction (XRD) in the range of low-angle and wide-angle, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and UV-Vis light absorption spectroscopy. The formation mechanism of the films was elementarily discussed.

  7. Thin film growth of epitaxial gadolinium oxide, gadolinium yttrium oxide, and gadolinium cerium oxide by electrodeposition

    International Nuclear Information System (INIS)

    Thin films of gadolinium oxide, gadolinium yttrium oxide, and gadolinium cerium oxide were electrodeposited from non-aqueous baths. The films were on the order of 15 nm thick, and were grown epitaxially on textured nickel-tungsten substrates. The effect of deposition rate, annealing temperature and secondary metals on crystallinity and crystal orientation was investigated by X-ray diffraction and transmission electron microscopy. Slower rates, higher temperatures and low concentrations of yttrium improve the crystallinity of gadolinium oxide films, whereas the introduction of cerium induced polycrystallinity.

  8. Thin film growth of epitaxial gadolinium oxide, gadolinium yttrium oxide, and gadolinium cerium oxide by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Jonathan R., E-mail: jonathan.mann@nrel.gov; Bhattacharya, Raghu N.

    2010-10-29

    Thin films of gadolinium oxide, gadolinium yttrium oxide, and gadolinium cerium oxide were electrodeposited from non-aqueous baths. The films were on the order of 15 nm thick, and were grown epitaxially on textured nickel-tungsten substrates. The effect of deposition rate, annealing temperature and secondary metals on crystallinity and crystal orientation was investigated by X-ray diffraction and transmission electron microscopy. Slower rates, higher temperatures and low concentrations of yttrium improve the crystallinity of gadolinium oxide films, whereas the introduction of cerium induced polycrystallinity.

  9. Hydrogen sensing characteristics of an electrodeposited WO3 thin film gasochromic sensor activated by Pt catalyst

    International Nuclear Information System (INIS)

    The hydrogen gas sensing performance of platinum (Pt) catalyst activated tungsten trioxide (WO3) thin films were investigated in the present study. The WO3 thin films exhibited a gasochromic effect; i.e., a reversible change in color from transparent when in air to blue when in hydrogen (H2). All processes proceeded rapidly at room temperature. The films were prepared by the electrodeposition method under ambient conditions. A layer of Pt was then sputtered onto the surface of WO3 film. The cycling of the coloration was obtained from UV-Vis spectra. The Pt catalyst dissociated H2 into H atoms, which then diffused into the WO3 thin film, which transformed from WO3 to HxW1-xVIWxVO3 and changed the color of the WO3 thin film. Therefore, we could detect the existence of H2 by the coloration of the WO3 thin film. Sensor properties of WO3/Pt films were investigated at room temperature in H2-N2 gas mixtures containing 0-50 mol% of H2. The results show that the transmittance change (ΔT) of the electrodeposited WO3 hydrogen sensor was ∼ 2% when the concentration of H2 was 5 mol%, and ∼ 20% when the concentration of H2 was 50 mol%. Coloration and bleaching had good response and recovery times in the range of 5-60 s, respectively

  10. CdTe film structure formation in layerwise component sorption

    Energy Technology Data Exchange (ETDEWEB)

    Murashev, S.V.; Denisova, A.T.; Ezhovskii, Yu.K.

    1988-04-10

    Aleskovskii's insular hypothesis has been used in a new approach to film synthesis, where irreversible reactions occur at surfaces on sequential component treatment, where the components contain the compound units. One can synthesize a film of a strictly defined composition on the basis of the critical condensation temperatures T/sub A/ and T/sub B/ together with the compound decomposition temperature T/sub AB/, i.e., it is necessary to have T/sub A/, T/sub B/ < T/sub s/ < T/sub AB/, where T/sub s/ is substrate temperature. The authors used AGChT-23-17 single-crystal gallium arsenide substrates having (100) orientation. Films up to 15 nm thick were measured by ellipsometry, while thicker films were assessed with an interferometer. The cadmium telluride films were made by alternating treatment in cadmium and tellurium beams made by evaporation from Knudsen cells. The lower limit to monolayer growth is set by the onset of tellurium condensation, and the upper by the transition from irreversible chemisorption to reversible. The growth constant and the diffraction data indicate the mode of film formation, the growth direction, and the relationship to the structure, which is related to the temperature. Films with the best structure are made at substrate temperatures of 498-535 K.

  11. Dual-bath electrodeposition of n-type Bi–Te/Bi–Se multilayer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Ken; Okuhata, Mitsuaki; Takashiri, Masayuki, E-mail: takashiri@tokai-u.jp

    2015-11-15

    N-type Bi–Te/Bi–Se multilayer thin films were prepared by dual-bath electrodeposition. We varied the number of layers from 2 to 10 while the total film thickness was maintained at approximately 1 μm. All the multilayer films displayed the X-ray diffraction peaks normally observed from individual Bi{sub 2}Te{sub 3} and Bi{sub 2}Se{sub 3} crystal structures, indicating that both phases coexist in the multilayer. The cross-section of the 10-layer Bi–Te/Bi–Se film was composed of stacked layers with nano-sized grains but the boundaries between the layers were not planar. The Seebeck coefficient was almost constant throughout the entire range of our experiment, but the electrical conductivity of the multilayer thin films increased significantly as the number of layers was increased. This may be because the electron mobility increases as the thickness of each layer is decreased. As a result of the increased electrical conductivity, the power factor also increased with the number of layers. The maximum power factor was 1.44 μW/(cm K{sup 2}) for the 10-layer Bi–Te/Bi–Se film, this was approximately 3 times higher than that of the 2-layer sample. - Highlights: • N-type Bi–Te/Bi–Se multilayer thin films were deposited by electrodeposition. • We employed a dual-bath electrodeposition process for preparing the multilayers. • The Bi–Te/Bi–Se film was composed of stacked layers with nano-sized grains. • The electrical conductivity increased as the number of layers was increased. • The power factor improved by 3 times as the number of layers was increased.

  12. Dual-bath electrodeposition of n-type Bi–Te/Bi–Se multilayer thin films

    International Nuclear Information System (INIS)

    N-type Bi–Te/Bi–Se multilayer thin films were prepared by dual-bath electrodeposition. We varied the number of layers from 2 to 10 while the total film thickness was maintained at approximately 1 μm. All the multilayer films displayed the X-ray diffraction peaks normally observed from individual Bi2Te3 and Bi2Se3 crystal structures, indicating that both phases coexist in the multilayer. The cross-section of the 10-layer Bi–Te/Bi–Se film was composed of stacked layers with nano-sized grains but the boundaries between the layers were not planar. The Seebeck coefficient was almost constant throughout the entire range of our experiment, but the electrical conductivity of the multilayer thin films increased significantly as the number of layers was increased. This may be because the electron mobility increases as the thickness of each layer is decreased. As a result of the increased electrical conductivity, the power factor also increased with the number of layers. The maximum power factor was 1.44 μW/(cm K2) for the 10-layer Bi–Te/Bi–Se film, this was approximately 3 times higher than that of the 2-layer sample. - Highlights: • N-type Bi–Te/Bi–Se multilayer thin films were deposited by electrodeposition. • We employed a dual-bath electrodeposition process for preparing the multilayers. • The Bi–Te/Bi–Se film was composed of stacked layers with nano-sized grains. • The electrical conductivity increased as the number of layers was increased. • The power factor improved by 3 times as the number of layers was increased

  13. Physical properties of spray deposited CdTe thin films: PEC performance

    Institute of Scientific and Technical Information of China (English)

    V. M. Nikale; S. S. Shinde; C. H. Bhosale; K.Y. Rajpure

    2011-01-01

    p-CdTe thin films were prepared by spray pyrolysis under different ambient conditions and characterized using photoelectrochemical (PEC),X-ray diffraction (XRD),scanning electron microscopy,energy-dispersive analysis by X-ray (EDAX),and optical transmission studies.The different preparative parameters viz solution pH,solution quantity,substrate temperature and solution concentration have been optimized by the PEC technique in order to get good-quality photosensitive material.XRD analysis shows the polycrystalline nature of the film,having cubic structure with strong (111) orientation.Micrographs reveal that grains are uniformly distributed over the surface of the substrate indicating the well-defined growth ofpolycrystalline CdTe thin film.The EDAX study for the sample deposited at optimized preparative parameters shows the nearly stoichiometric Cd:Te ratio.Optical absorption shows the presence of direct transition with band gap energy of 1.5 eV.Deposited films exhibit the highest photocurrent of 2.3 mA,a photovoltage of 462 mV,a 0.48 fill factor and 3.4% efficiency for the optimized preparative parameters.

  14. Effect of Substrate Temperature on Structural and Optical Properties of Nanocrystalline CdTe Thin Films Deposited by Electron Beam Evaporation

    Directory of Open Access Journals (Sweden)

    M. Rigana Begam

    2013-07-01

    Full Text Available Nanocrystalline Cadmium Telluride (CdTe thin films were deposited onto glass substrates using electron beam evaporation technique. The effect of substrate temperature on the structural, morphological and optical properties of CdTe thin films has been investigated. All the CdTe films exhibited zinc blende structure with (111 preferential orientation. The crystallite size of the films increased from 35 nm to 116 nm with the increase of substrate temperature and the band gap of the films decreased from 2.87 eV to 2.05 eV with the increase of the crystallite size.

  15. Electrical behaviour, characteristics and properties of anodic aluminium oxide films coloured by nickel electrodeposition

    OpenAIRE

    Arurault, Laurent; Zamora, Gaël; Vilar, Virginie; Winterton, Peter; Bes, René

    2010-01-01

    Porous anodic films on 1050 aluminium substrate were coloured by AC electrodeposition of nickel. Several experiments were performed at different deposition voltages and nickel concentrations in the electrolyte in order to correlate the applied electrical power to the electrical behaviour, as well as the characteristics and properties of the coatings. The content of nickel inside the coatings reached 1.67 g/m2, depending on the experimental conditions. According to the applied AC voltage in...

  16. The activation of thin film CdTe solar cells using alternative chlorine containing compounds

    Energy Technology Data Exchange (ETDEWEB)

    Maniscalco, B., E-mail: B.Maniscalco@lboro.ac.uk [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering (United Kingdom); Abbas, A.; Bowers, J.W.; Kaminski, P.M.; Bass, K. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering (United Kingdom); West, G. [Department of Materials, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Walls, J.M. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering (United Kingdom)

    2015-05-01

    The re-crystallisation of thin film cadmium telluride (CdTe) using cadmium chloride (CdCl{sub 2}) is a vital process for obtaining high efficiency photovoltaic devices. However, the precise micro-structural mechanisms involved are not well understood. In this study, we have used alternative chlorine-containing compounds to determine if these can also assist the re-crystallisation of the CdTe layer and to understand the separate roles of cadmium and chlorine during the activation. The compounds used were: tellurium tetrachloride (TeCl{sub 4}), cadmium acetate (Cd(CH{sub 3}CO{sub 2}){sub 2}), hydrochloric acid (HCl) and zinc chloride (ZnCl{sub 2}). TeCl{sub 4} was used to assess the role of Cl and the formation of a Te-rich outer layer which may assist the formation of the back contact. (Cd(CH{sub 3}CO{sub 2}){sub 2}) and HCl were used to distinguish between the roles of cadmium and chlorine in the process. Finally, ZnCl{sub 2} was employed as an alternative to CdCl{sub 2}. We report on the efficacy of using these alternative Cl-containing compounds to remove the high density of planar defects present in untreated CdTe. - Highlights: • Cadmium chloride (CdCl{sub 2}) activation treatment • Alternative chlorine containing compounds • Microstructure analysis and electrical performances.

  17. The activation of thin film CdTe solar cells using alternative chlorine containing compounds

    International Nuclear Information System (INIS)

    The re-crystallisation of thin film cadmium telluride (CdTe) using cadmium chloride (CdCl2) is a vital process for obtaining high efficiency photovoltaic devices. However, the precise micro-structural mechanisms involved are not well understood. In this study, we have used alternative chlorine-containing compounds to determine if these can also assist the re-crystallisation of the CdTe layer and to understand the separate roles of cadmium and chlorine during the activation. The compounds used were: tellurium tetrachloride (TeCl4), cadmium acetate (Cd(CH3CO2)2), hydrochloric acid (HCl) and zinc chloride (ZnCl2). TeCl4 was used to assess the role of Cl and the formation of a Te-rich outer layer which may assist the formation of the back contact. (Cd(CH3CO2)2) and HCl were used to distinguish between the roles of cadmium and chlorine in the process. Finally, ZnCl2 was employed as an alternative to CdCl2. We report on the efficacy of using these alternative Cl-containing compounds to remove the high density of planar defects present in untreated CdTe. - Highlights: • Cadmium chloride (CdCl2) activation treatment • Alternative chlorine containing compounds • Microstructure analysis and electrical performances

  18. Electrodeposited porous metal oxide films with interconnected nanoparticles applied as anode of lithium ion battery

    International Nuclear Information System (INIS)

    Highlights: • Highly porous NiO film is prepared by a co-electrodeposition method. • Porous NiO film is composed of interconnected nanoparticles. • Porous structure is favorable for fast ion/electron transfer. • Porous NiO film shows good lithium ion storage properties. - Abstract: Controllable synthesis of porous metal oxide films is highly desirable for high-performance electrochemical devices. In this work, a highly porous NiO film composed of interconnected nanoparticles is prepared by a simple co-electrodeposition method. The nanoparticles in the NiO film have a size ranging from 30 to 100 nm and construct large-quantity pores of 20–120 nm. As an anode material for lithium ion batteries, the highly porous NiO film electrode delivers a high discharge capacity of 700 mA h g−1 at 0.2 C, as well as good high-rate performance. After 100 cycles at 0.2 C, a specific capacitance of 517 mA h g−1 is attained. The good electrochemical performance is attributed to the interconnected porous structure, which facilitates the diffusion of ion and electron, and provides large reaction surface area leading to improved performance

  19. Effects of nitrogen atoms of benzotriazole and its derivatives on the properties of electrodeposited Cu films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hoe Chul; Kim, Myung Jun; Lim, Taeho; Park, Kyung Ju; Kim, Kwang Hwan; Choe, Seunghoe [School of Chemical and Biological Engineering, Institute of Chemical Process, Seoul National University, Gwanak 1, Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Kim, Soo-Kil, E-mail: sookilkim@cau.ac.kr [School of Integrative Engineering, Chung-Ang University, 221 Heukseok-dong, Dongjak-gu, Seoul 156-756 (Korea, Republic of); Kim, Jae Jeong, E-mail: jjkimm@snu.ac.kr [School of Chemical and Biological Engineering, Institute of Chemical Process, Seoul National University, Gwanak 1, Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of)

    2014-01-01

    Additives having azole groups with different numbers of nitrogen atoms, such as indole, benzimidazole, indazole, benzotriazole (BTA), and 1H-benzotriazole-methanol (BTA-MeOH) were adopted to improve the mechanical hardness of electrodeposited Cu films. The effects of these additives on the film properties were elucidated in relation to their number of nitrogen atoms. Electrochemical current–potential behaviors showed that the additives containing three nitrogen atoms (BTA and BTA-MeOH) more effectively inhibited Cu electrodeposition. The inhibition strongly affected the film properties, resulting in reduced grain size and surface roughness, and increased resistivity and hardness. Cu films deposited with BTA or BTA-MeOH also exhibited 35% reduced grain size and 1.5-time higher hardness than Cu films deposited in electrolyte containing other BTA-derivatives having fewer nitrogen atoms. This notable grain refining effect of BTA and BTA-MeOH can be evaluated with respect to the strong interaction of their nitrogen atoms with the substrate and the copper ions, as well. - Highlights: • Additives of similar structure containing 1, 2, and 3 nitrogen atoms were used. • Additives with 3 nitrogen atoms more strongly inhibited Cu deposition than others. • Additives containing 3 nitrogen atoms efficiently affected film properties. • Additives having 3 nitrogen atoms remarkably improved film hardness.

  20. Electrodeposited porous metal oxide films with interconnected nanoparticles applied as anode of lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Anguo, E-mail: hixiaoanguo@126.com; Zhou, Shibiao; Zuo, Chenggang; Zhuan, Yongbing; Ding, Xiang

    2014-12-15

    Highlights: • Highly porous NiO film is prepared by a co-electrodeposition method. • Porous NiO film is composed of interconnected nanoparticles. • Porous structure is favorable for fast ion/electron transfer. • Porous NiO film shows good lithium ion storage properties. - Abstract: Controllable synthesis of porous metal oxide films is highly desirable for high-performance electrochemical devices. In this work, a highly porous NiO film composed of interconnected nanoparticles is prepared by a simple co-electrodeposition method. The nanoparticles in the NiO film have a size ranging from 30 to 100 nm and construct large-quantity pores of 20–120 nm. As an anode material for lithium ion batteries, the highly porous NiO film electrode delivers a high discharge capacity of 700 mA h g{sup −1} at 0.2 C, as well as good high-rate performance. After 100 cycles at 0.2 C, a specific capacitance of 517 mA h g{sup −1} is attained. The good electrochemical performance is attributed to the interconnected porous structure, which facilitates the diffusion of ion and electron, and provides large reaction surface area leading to improved performance.

  1. Nanoindentation and micro-mechanical fracture toughness of electrodeposited nanocrystalline Ni–W alloy films

    International Nuclear Information System (INIS)

    Nanocrystalline nickel–tungsten alloys have great potential in the fabrication of components for microelectromechanical systems. Here the fracture toughness of Ni–12.7 at.%W alloy micro-cantilever beams was investigated. Micro-cantilevers were fabricated by UV lithography and electrodeposition and notched by focused ion beam machining. Load was applied using a nanoindenter and fracture toughness was calculated from the fracture load. Fracture toughness of the Ni–12.7 at.%W was in the range of 1.49–5.14 MPa √m. This is higher than the fracture toughness of Si (another important microelectromechanical systems material), but considerably lower than that of electrodeposited nickel and other nickel based alloys. - Highlights: ► Micro-scale cantilevers manufactured by electro-deposition and focused ion beam machining. ► Nanoindenter used to perform micro-scale fracture test on Ni-13at%W micro-cantilevers. ► Calculation of fracture toughness of electrodeposited Ni-13at%W thin films. ► Fracture toughness values lower than that of nanocrystalline nickel.

  2. Nanoindentation and micro-mechanical fracture toughness of electrodeposited nanocrystalline Ni-W alloy films

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, D.E.J., E-mail: david.armstrong@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH (United Kingdom); Haseeb, A.S.M.A. [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Roberts, S.G.; Wilkinson, A.J. [Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH (United Kingdom); Bade, K. [Institut fuer Mikrostrukturtechnik (IMT), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2012-04-30

    Nanocrystalline nickel-tungsten alloys have great potential in the fabrication of components for microelectromechanical systems. Here the fracture toughness of Ni-12.7 at.%W alloy micro-cantilever beams was investigated. Micro-cantilevers were fabricated by UV lithography and electrodeposition and notched by focused ion beam machining. Load was applied using a nanoindenter and fracture toughness was calculated from the fracture load. Fracture toughness of the Ni-12.7 at.%W was in the range of 1.49-5.14 MPa {radical}m. This is higher than the fracture toughness of Si (another important microelectromechanical systems material), but considerably lower than that of electrodeposited nickel and other nickel based alloys. - Highlights: Black-Right-Pointing-Pointer Micro-scale cantilevers manufactured by electro-deposition and focused ion beam machining. Black-Right-Pointing-Pointer Nanoindenter used to perform micro-scale fracture test on Ni-13at%W micro-cantilevers. Black-Right-Pointing-Pointer Calculation of fracture toughness of electrodeposited Ni-13at%W thin films. Black-Right-Pointing-Pointer Fracture toughness values lower than that of nanocrystalline nickel.

  3. A greener electrodeposition recipe for ZnO films in terawatt photovoltaics

    International Nuclear Information System (INIS)

    Electrodeposition of ZnO can be performed in an aqueous solution using a greener recipe, where the solution can be reused for multiple deposition runs. The solution in this greener recipe has only one function, i.e. to provide electrical conductivity for the deposition reactions. A Zn sheet serves as the anode, which dissolves during the deposition as the Zn source. O2 is bubbled into the solution and reduced to OH− ions as the O source. This recipe minimizes concentration changes in the solution as deposition proceeds, making the solution reusable. An initial Zn2+ concentration of a few mM in the solution is required, not to serve as a Zn source but to facilitate the deposition and prevent precipitation of ZnO in the solution. Multiple deposition runs for ZnO films in the same solution have been demonstrated. X-ray diffraction, optical transmittance and absorption spectra reveal that all the ZnO films have similar structural and optical properties. They all display high transmittance of ∼ 80% and low absorbance of ∼ 10%. - Highlights: ► A new ZnO electrodeposition recipe is developed where the solution is reusable. ► Waste solutions from ZnO electrodeposition are reduced by over four fold. ► ZnO films from the same solution show high transmittance and low absorbance.

  4. Giant magnetoresistance of electrodeposited Cu–Co–Ni alloy films

    Indian Academy of Sciences (India)

    İ H Karahan; Ö F Bakkaloğlu; M Bedir

    2007-01-01

    Electrodeposition of CuCoNi alloys was performed in an acid–citrate medium. Nickel density parameter was varied in order to analyse its influence on the magnetoresistance. The structure and giant magneto- resistance (GMR) effect of CuCoNi alloys have been investigated. The maximum value for GMR ratio, at room temperature is 1% at a field of 12 kOe, and at 20 K is 2.1% at a field of 8.5 kOe for 3.1 Ni. The MR ratio of Cu100−−CoNi alloys first increases and then decreases monotonically with increasing Ni content. The GMR and its dependence on magnetic field and temperature were discussed.

  5. Structural and optical properties of electrodeposited ZnO thin films

    International Nuclear Information System (INIS)

    Zinc oxide thin films were electrodeposited on different substrates. Electrodeposition was performed with hydrogen peroxide, as hydroxide ions source, at - 1.5 V versus mercurial sulfate electrode during one hour, and a temperature maintained at 70 deg. C . The resulting thin films have a good crystallinity and a high c-axis orientation, and the unit cell parameters determined by X-ray diffraction experiment are a = 0.326 nm and c = 0.523 nm, respectively. Microstructure studies using scanning electron microscopy and atomic force microscopy show a good homogeneity of the film and a roughness around 22 nm. Optical properties were studied with Raman spectroscopy and photoluminescence spectroscopy. Optical properties of the films revealed a low defect emission in photoluminescence spectra. The E2 vibration mode for ZnO was observed near 439 cm-1, indicating that the as-deposited films were under compressive stress. Oscillations were observed in the photoluminescence spectra, from which the refractive index of ZnO thin films was extracted, that is ∼ 1.90

  6. Synthesis and characterization of Cu2SnSe3 thin films by electrodeposition route

    Science.gov (United States)

    Chihi, Adel; Bessais, Brahim

    2016-09-01

    A single phase Cu2SnSe3 polycrystalline semiconductor compound has been easily synthesized through electrodeposition technique onto conductive glass ITO substrates from an acidic solution at room temperature for the first time. The electrodeposition of CTSe films was studied using cyclic voltammetry, structural, morphological, optical, and electrical measurements. The effects of the annealing temperature on the growth of CTSe films were studied. XRD and Raman studies showed that the annealed CTSe thin films have a polycrystalline nature with a cubic crystal structure with a preferential orientation (111), and the crystalline size of the CTSe thin films increases as the annealing temperature increases. The AFM investigations show that the deposited film layer widely varies on annealing temperature. The optical band gap of CTSe alloys is inversely related to the grain size and decreases from 1.08 to 0.96 eV. Finally, the Hall effect measurements reveal that the all CTSe films are p-type semiconductors in particular a sample annealed at 300 °C exhibit a high Hall mobility 5.27 cm2/V s and low electrical resistivity 0.91 Ω cm compared to other samples.

  7. Effect of NaCl concentration in electrodeposited Co-P alloy thin films

    International Nuclear Information System (INIS)

    Cobalt-Phosphorous (Co-P) alloy thin films were prepared by electrodeposition technique from an aqueous electrolytic bath at various sodium chloride (NaCl) concentrations. The effect of sodium chloride concentration on electrochemical, structural, morphological, compositional and magnetic properties of the films was investigated by cyclic voltammetry, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and vibrating sample magnetometer techniques, respectively. The mechanism of formation of Co-P alloy thin films was studied using cyclic voltammetry. The compositional analysis shows that the content of phosphorous (P) increases and the content of cobalt (Co) decreases by adding NaCl. X-ray diffraction studies revealed amorphous nature for films obtained at high concentration of NaCl and hexagonal closed packed (hcp) structure for films obtained at low NaCl concentration. Magnetic properties illustrate that high value of coercivity, saturation magnetization, remanence, and saturating field were obtained at high concentration of NaCl.

  8. Metal-insulator transition in nanocomposite VOx films formed by anodic electrodeposition

    Science.gov (United States)

    Tsui, Lok-kun; Hildebrand, Helga; Lu, Jiwei; Schmuki, Patrik; Zangari, Giovanni

    2013-11-01

    The ability to grow VO2 films by electrochemical methods would open a low-cost, easily scalable production route to a number of electronic devices. We have synthesized VOx films by anodic electrodeposition of V2O5, followed by partial reduction by annealing in Ar. The resulting films are heterogeneous, consisting of various metallic/oxide phases and including regions with VO2 stoichiometry. A gradual metal insulator transition with a nearly two order of magnitude change in film resistance is observed between room temperature and 140 °C. In addition, the films exhibit a temperature coefficient of resistance of ˜ -2.4%/ °C from 20 to 140 °C.

  9. Influence of thermal treatment temperatures on CdTe nanocrystal films and photoelectric properties of ITO/CdTe/Al

    Institute of Scientific and Technical Information of China (English)

    Xu Wenqing; Qu Shengchun; Wang Kefan; Bi Yu; Liu Kong; Wang Zhanguo

    2012-01-01

    The influence of sintering temperatures on solution-processed cadmium telluride (CdTe) nanocrystal films is studied in order to maximize the performance of CdTe/Al Schottky nanocrystal solar cells,The best overall performance of 2.67% efficiency at air mass 1.5 was achieved from devices with CdTe films sintered at 350 ℃ X-ray diffraction,scanning electron microscopy and UV-vis absorption measurements show that the CdTe nanocrystal grains began to grow remarkably well when sintering temperatures increased to 350 ℃.By analyzing the current-voltage characteristics,we find that the short-circuit current densities of devices increase with sintering temperatures ranging from 200 to 400 ℃,but,the over-sintered (450 ℃) treatment induces the shunting of devices.

  10. Impact of thermal annealing on physical properties of vacuum evaporated polycrystalline CdTe thin films for solar cell applications

    Science.gov (United States)

    Chander, Subhash; Dhaka, M. S.

    2016-06-01

    A study on impact of post-deposition thermal annealing on the physical properties of CdTe thin films is undertaken in this paper. The thin films of thickness 500 nm were grown on ITO and glass substrates employing thermal vacuum evaporation followed by post-deposition thermal annealing in air atmosphere within low temperature range 150-350 °C. These films were subjected to the XRD, UV-Vis NIR spectrophotometer, source meter, SEM coupled with EDS and AFM for structural, optical, electrical and surface topographical analysis respectively. The diffraction patterns reveal that the films are having zinc-blende cubic structure with preferred orientation along (111) and polycrystalline in nature. The crystallographic parameters are calculated and discussed in detail. The optical band gap is found in the range 1.48-1.64 eV and observed to decrease with thermal annealing. The current-voltage characteristics show that the CdTe films exhibit linear ohmic behavior. The SEM studies show that the as-grown films are homogeneous, uniform and free from defects. The AFM studies reveal that the surface roughness of films is observed to increase with annealing. The experimental results reveal that the thermal annealing has significant impact on the physical properties of CdTe thin films and may be used as absorber layer to the CdTe/CdS thin films solar cells.

  11. Magnetic properties and microstructure investigation of electrodeposited FeNi/ITO films with different thickness

    International Nuclear Information System (INIS)

    Highlights: •FeNi alloy thin films with different thickness deposited on Indium Tin Oxides (ITOs) conductive glass substrates by electrodeposition method. •A columnar crystalline microstructure and domain structure were obtained in FeNi thin films. •Particular FMR spectra of FeNi alloy with different thickness were studied. -- Abstract: FeNi alloy thin films with different thickness deposited on Indium Tin Oxides (ITOs) conductive glass substrates from the electrolytes by electrodeposition method have been studied by magnetic force microscopy (MFM), scanning electron microscopy (SEM) and ferromagnetic resonance (FMR) technique. For these films possessing an in-plane isotropy, the remanence decreases with the increasing of film thickness and the critical thickness that a stripe domain structure emerges is about 116 nm. Characteristic differences of the FMR spectra of different thickness are also observed. The results show that the resonance field at high measured angle increases firstly then decreases with increasing thickness, which may be related to the striped domain structure

  12. Rocking disc electro-deposition of copper films on Mo/MoSe{sub 2} substrates

    Energy Technology Data Exchange (ETDEWEB)

    Cummings, Charles Y.; Frith, Paul E. [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Zoppi, Guillaume; Forbes, Ian [Northumbria Photovoltaics Applications Centre, Northumbria University, NE1 8ST (United Kingdom); Rogers, Keith D. [Cranfield Health, Cranfield University, Shrivenham Campus, Swindon, SN6 8LA (United Kingdom); Lane, David W. [Department of Applied Science, Security and Resilience, Cranfield University, Shrivenham, Swindon, SN6 8LA (United Kingdom); Marken, Frank, E-mail: F.Marken@bath.ac.uk [Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)

    2011-08-31

    A novel electro-deposition method based on a rocking disc system with {pi}/3 amplitude and variable frequency is introduced. Uniform copper films were deposited from a 0.1 M CuSO{sub 4}/3.0 M NaOH/0.2 M sorbitol bath directly onto 12.1 cm{sup 2} Mo/MoSe{sub 2} substrates with X-ray diffraction showing a thickness variation of {+-}5% over this area. Investigation of the mass transport conditions suggests (i) uniform diffusion over the sample, (ii) a rate of mass transport proportional to the square root of the rocking rate, and (iii) turbulent conditions, which are able to dislodge gas bubbles during electro-deposition.

  13. Effect of Colloidal Silica and Pre-Coating of Cathode on Copper Electrodeposited Film

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S. B.; Kim, B. I. [Sunchon National University, Sunchon (Korea); Yoon, J. M. [Chonbuk National University, Chonju (Korea); Park, H. H.; Bae, I. S. [Korea Research Institute of Rare Metals, (Korea)

    2001-07-01

    The crystal structure, surface morphology and preferred orientation of the copper electrodeposit were investigated by the using sulfate bath with SiO{sub 2} suspensions and the cathode substrate Au sputtered. As by the addition of colloidal silica in copper electrolytic bath and Au pre-coating on substrate, the crystal particles of deposits was fined-down, made uniform and the account of particles were increased. Hardness of copper electrodeposits with colloidal silica increased about 15% in comparison with that of pure copper deposit film and (111), (200) and (311) plane of X-ray diffraction patterns were almost swept away, so preferred orientation of the copper deposits changed from (111) to (110) plane by codeposit SiO{sub 2} and precoating the substrate. (author). 5 refs., 9 figs., 2 tabs.

  14. Physical properties of vacuum evaporated CdTe thin films with post-deposition thermal annealing

    Science.gov (United States)

    Chander, Subhash; Dhaka, M. S.

    2015-09-01

    This paper presents the physical properties of vacuum evaporated CdTe thin films with post-deposition thermal annealing. The thin films of thickness 500 nm were grown on glass and indium tin oxide (ITO) coated glass substrates employing thermal vacuum evaporation technique followed by post-deposition thermal annealing at temperature 450 °C. These films were subjected to the X-ray diffraction (XRD),UV-Vis spectrophotometer, source meter and atomic force microscopy (AFM) for structural, optical, electrical and surface morphological analysis respectively. The X-ray diffraction patterns reveal that the films have zinc-blende structure of single cubic phase with preferred orientation (111) and polycrystalline in nature. The crystallographic and optical parameters are calculated and discussed in brief. The optical band gap is found to be 1.62 eV and 1.52 eV for as-grown and annealed films respectively. The I-V characteristics show that the conductivity is decreased for annealed thin films. The AFM studies reveal that the surface roughness is observed to be increased for thermally annealed films.

  15. Preparing Cu2ZnSnS4 films using the co-electrodeposition method with ionic liquids*

    Institute of Scientific and Technical Information of China (English)

    Chen Yong-Sheng; Wang Ying-Jun; Li Rui; Gu Jin-Hua; Lu Jing-Xiao; Yang Shi-E

    2012-01-01

    Cu2ZnSnS4(CZTS)films are successfully prepared by co-electrodeposition in aqueous ionic solution and sulfurized in elemental sulfur vapor ambient at 400℃ for 30 min using nitrogen as the protective gas.It is found that the CZTS film synthesized at Cu/(Zn+Sn)=0.71 has a kesterite structure,a bandgap of about 1.51 eV,and an absorption coefficient of the order of 104 cm-1.This indicates that the co-electrodeposition method with aqueous ionic solution is a viable process for the growth of CZTS films for application in photovoltaic devices.

  16. Analysis of Electrodeposited Nickel-Iron Alloy Film Composition Using Particle-Induced X-Ray Emission

    OpenAIRE

    Frey, Alyssa A.; Nicholas R. Wozniak; Nagi, Timothy B.; Keller, Matthew P.; J. Mark Lunderberg; Peaslee, Graham F.; Paul A. DeYoung; Hampton, Jennifer R.

    2011-01-01

    The elemental composition of electrodeposited NiFe thin films was analyzed with particle-induced X-ray emission (PIXE). The thin films were electrodeposited on polycrystalline Au substrates from a 100 mM NiSO4, 10 mM FeSO4, 0.5 M H3BO3, and 1 M Na2SO4 solution. PIXE spectra of these films were analyzed to obtain relative amounts of Ni and Fe as a function of deposition potential and deposition time. The results show that PIXE can measure the total deposited metal in a sample over at least fou...

  17. Characterization of thin film CdS-CdTe solar cells. [CDS-CDTE

    Energy Technology Data Exchange (ETDEWEB)

    Singh, V.P.; Brafman, H.; Makwana, J. (Texas Univ., El Paso (USA). Dept. of Electrical Engineering); McClure, J.C. (Texas Univ., El Paso, TX (USA). Metallurgical and Materials Engineering Dept.)

    1991-02-01

    Current-voltage, junction capacitance and optical characteristics of thin film CdS-CdTe cells on sprayed CdS films were measured. These characteristics have some interesting features such as reversal of the polarity of the a.c. short-circuit current and the a.c. open-circuit voltage when a large forward bias is applied across the cell. The reverse saturation current density j{sub 0} increases from 5.9x10{sup -9} A cm{sup -2} in the dark to 18.1x10{sup -6} A cm{sup -2} under '1 sun' illumination. Diode ideality factors are higher than 2.0 and the slope {alpha} of log I vs. V curve is almost temperature independent. The zero-bias depletion layer width is 1.9 {mu}m. The experimental results are interpreted by a model which proposes a highly compensated layer in CdTe and a high space charge layer in CdTe next to the CdS-CdTe interface. The origin of the high space charge layer is thought to be the ionization of a deep trap level at energy E{sub T} below the conduction band edge. For our calculations, we have used E{sub T}=0.45 eV. (orig.).

  18. Advances in CuInSe sub 2 and CdTe thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Shafarmann, W.N.; Birkmire, R.W.; Farding, D.A.; McCandless, B.E.; Mondal, A.; Phillips, J.E.; Varrin, R.D. Jr. (Delaware Univ., Newark (USA). Inst. of Energy Conversion)

    1991-05-01

    Research on CuInSe{sub 2} and CdTe thin film solar cells is discussed. CuInSe{sub 2} was deposited by selenization of Cu/In layers and was used to make a 10% efficient CuInSe{sub 2}/(CdZn)S cell. Characterization of the reaction mechanisms is described. The open-circuit voltage V{sub oc} of CuInSe{sub 2}/(CdZn)S cells is dominated by recombination in the space charge region, so increassing the band gap or decreasing the width of this region should increase V{sub oc}. Increasing the band gap with a thin Cu(InGa)Se{sub 2} layer at the CuInSe{sub 2} surface has demonstrated increased V{sub oc} with collection out to the CuInSe{sub 2} band gap. A post-deposition treatment and contacting process for evaporated CdS/CdTe cells was developed and high efficiency cells were made. Several steps in the process, including a CdCl{sub 2} coating, a 400deg C heat treatment, and a contact containing copper are critical. ZnTe films were deposited from an aqueous solution as a contact to CdTe. (orig.).

  19. SCAPS Modeling for Degradation of Ultrathin CdTe Films: Materials Interdiffusion

    Science.gov (United States)

    Houshmand, Mohammad; Zandi, M. Hossein; Gorji, Nima E.

    2015-09-01

    Ultrathin film solar cells based on CdS/CdTe ( d CdTe ≤ 1 µm) suffer from two main issues: incomplete photo absorption and high degradation rate. The former is cured by light-trapping techniques, whereas the latter is a matter of fabrication details. Interdiffusion of the material components and formation of subsequent interlayers at the front/back region can change the optical/electrical properties and performance/stability of the device. We model the degradation of the ultrathin CdTe film devices considering the material interdiffusion and interlayers formation: CdTeS, CdZnTe, Cu x Te (i.e., Te/Cu bilayer), and oxide interlayers (i.e., CdTeO3). The diffusion rate of the materials is considered separately and the reactions that change the interlayer's properties are studied. Additionally, a back contact of single-walled carbon nanotube showed a higher stability than the metallic contacts. A new time-dependent approach is applied to simulate the degradation rate due to formation of any interlayer. It is shown that the materials interdiffusion causes a defect increment under thermal stress and illumination. The metallic back contact accelerates the degradation, whereas single-walled carbon nanotubes show the highest stability. A SCAPS simulator was used because of its ability in defining the properties of the back contact and metastabilities at the interface layers. The properties of the layers were taken from the experimental data reported in the literature.

  20. Impact of thermal annealing on optical properties of vacuum evaporated CdTe thin films for solar cells

    Science.gov (United States)

    Chander, Subhash; Purohit, A.; Lal, C.; Nehra, S. P.; Dhaka, M. S.

    2016-05-01

    In this paper, the impact of thermal annealing on optical properties of cadmium telluride (CdTe) thin films is investigated. The films of thickness 650 nm were deposited on thoroughly cleaned glass substrate employing vacuum evaporation followed by thermal annealing in the temperature range 250-450 °C. The as-deposited and annealed films were characterized using UV-Vis spectrophotometer. The optical band gap is found to be decreased from 1.88 eV to 1.48 eV with thermal annealing. The refractive index is found to be in the range 2.73-2.92 and observed to increase with annealing treatment. The experimental results reveal that the thermal annealing plays an important role to enhance the optical properties of CdTe thin films and annealed films may be used as absorber layer in CdTe/CdS solar cells.

  1. Simple Formation of Nanostructured Molybdenum Disulfide Thin Films by Electrodeposition

    Directory of Open Access Journals (Sweden)

    S. K. Ghosh

    2013-01-01

    Full Text Available Nanostructured molybdenum disulfide thin films were deposited on various substrates by direct current (DC electrolysis form aqueous electrolyte containing molybdate and sulfide ions. Post deposition annealing at higher temperatures in the range 450–700°C transformed the as-deposited amorphous films to nanocrystalline structure. High temperature X-ray diffraction studies clearly recorded the crystal structure transformations associated with grain growth with increase in annealing temperature. Surface morphology investigations revealed featureless structure in case of as-deposited surface; upon annealing it converts into a surface with protruding nanotubes, nanorods, or dumbbell shape nanofeatures. UV-visible and FTIR spectra confirmed about the presence of Mo-S bonding in the deposited films. Transmission electron microscopic examination showed that the annealed MoS2 films consist of nanoballs, nanoribbons, and multiple wall nanotubes.

  2. The deposit stress behavior and magnetic properties of electrodeposited Ni-Co-Fe ternary alloy films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin-Soo; Kwak, Jun-Ho; Na, Seong-Hun; Lim, Seung-Kyu; Suh, Su-Jeong [Sungkyunkwan University, Suwon (Korea, Republic of)

    2012-08-15

    Ni-Co-Fe ternary alloy films were electrodeposited from a sulfate bath. The effects of the saccharin concentration on the deposit stress behavior of these films were investigated. When the saccharin concentration was 0.004 M, the deposit stress was the lowest (61 MPa, tensile stress mode). Then, the relation between the deposit stress and the magnetic properties was investigated. As the deposit stress of the Ni-Co-Fe thin films decreased from 307 to 61 MPa, the coercivity and the squareness decreased from 6.17 to 1.35 Oe and from 0.65 to 0.18, respectively. The dependence of the deposit stress on the temperature in the plating bath was investigated. As the temperature in the plating bath was increased from 25 to 50 .deg. C the deposit stress of the Ni-Co-Fe alloy films decreased from 61 to 32 MPa.

  3. Structural, optical and electrochromic properties of nickel oxide thin films grown from electrodeposited nickel sulphide

    International Nuclear Information System (INIS)

    Nickel oxide thin films were grown onto FTO-coated glass substrates by a two-step process: electrodeposition of nickel sulphide and their thermal oxidation at 425, 475 and 525 deg. C. The influence of thermal oxidation temperature on structural, optical, morphological and electrochromic properties was studied. The structural properties undoubtedly revealed NiO formation. The electrochromic properties were studied by means of cyclic voltammetry. The films exhibited anodic electrochromism, changing from a transparent state to a coloured state at +0.75 V versus SCE, i.e. by simultaneous ion and electron ejection. The transmittance in the coloured and bleached states was recorded to access electrochromic quality of the films. Colouration efficiency and electrochromic reversibility were found to be maximum (21 mC/cm2 and 89%, respectively) for the films oxidized at 425 deg. C. The optical band gap energy of nickel oxide slightly varies with increase in annealing temperature

  4. Structural, optical and electrochromic properties of nickel oxide thin films grown from electrodeposited nickel sulphide

    Energy Technology Data Exchange (ETDEWEB)

    Uplane, M.M.; Mujawar, S.H.; Inamdar, A.I.; Shinde, P.S.; Sonavane, A.C. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, Maharashtra (India); Patil, P.S. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur 416004, Maharashtra (India)], E-mail: psp_phy@unishivaji.ac.in

    2007-10-15

    Nickel oxide thin films were grown onto FTO-coated glass substrates by a two-step process: electrodeposition of nickel sulphide and their thermal oxidation at 425, 475 and 525 deg. C. The influence of thermal oxidation temperature on structural, optical, morphological and electrochromic properties was studied. The structural properties undoubtedly revealed NiO formation. The electrochromic properties were studied by means of cyclic voltammetry. The films exhibited anodic electrochromism, changing from a transparent state to a coloured state at +0.75 V versus SCE, i.e. by simultaneous ion and electron ejection. The transmittance in the coloured and bleached states was recorded to access electrochromic quality of the films. Colouration efficiency and electrochromic reversibility were found to be maximum (21 mC/cm{sup 2} and 89%, respectively) for the films oxidized at 425 deg. C. The optical band gap energy of nickel oxide slightly varies with increase in annealing temperature.

  5. Structural, optical and electrochromic properties of nickel oxide thin films grown from electrodeposited nickel sulphide

    Science.gov (United States)

    Uplane, M. M.; Mujawar, S. H.; Inamdar, A. I.; Shinde, P. S.; Sonavane, A. C.; Patil, P. S.

    2007-10-01

    Nickel oxide thin films were grown onto FTO-coated glass substrates by a two-step process: electrodeposition of nickel sulphide and their thermal oxidation at 425, 475 and 525 °C. The influence of thermal oxidation temperature on structural, optical, morphological and electrochromic properties was studied. The structural properties undoubtedly revealed NiO formation. The electrochromic properties were studied by means of cyclic voltammetry. The films exhibited anodic electrochromism, changing from a transparent state to a coloured state at +0.75 V versus SCE, i.e. by simultaneous ion and electron ejection. The transmittance in the coloured and bleached states was recorded to access electrochromic quality of the films. Colouration efficiency and electrochromic reversibility were found to be maximum (21 mC/cm 2 and 89%, respectively) for the films oxidized at 425 °C. The optical band gap energy of nickel oxide slightly varies with increase in annealing temperature.

  6. Super-hydrophobic nickel films with micro-nano hierarchical structure prepared by electrodeposition

    International Nuclear Information System (INIS)

    Super-hydrophobic nickel films were prepared by a simple and low cost electrodepositing method. The surface morphologies of the films characterized by scanning electronic microscope exhibit hierarchical structure with micro-nanocones array, which can be responsible for their super-hydrophobic characteristic (water contact angle over 150o) without chemical modification. The wettability of the film can be varied from super-hydrophobic (water contact angle 154o) to relatively hydrophilic (water contact angle 87o) by controlling the size of the micro-nanocones. The mechanism of the hydrophobic characteristic of nickel films with this unique structure was illustrated by several models. Such micro-nanostructure and its special wettability are expected to be applied in the practical industry.

  7. Band edges determination of CuInS2 thin films prepared by electrodeposition

    International Nuclear Information System (INIS)

    A CuInS2 (CIS) semiconductor thin film was growth by electrodeposition on a stainless steel substrate. In order to improve the polycrystallinity the samples were annealed in a N2 atmosphere. The films were characterized by electrochemical techniques and X ray diffraction and their band gaps were determined by photocurrent spectroscopy. When the electrolytic bath has the same concentration [Cu2+] = [In3+] the resulting film was of the n-type, while for different concentrations of Cu and In ions the film was of the p-type. A depletion zone during capacitance-voltage measurements at 10 kHz frequency was seen over the voltage range used. Using C-V plots in the depletion zone, flat-band potentials and the energetic position of band edges were calculated

  8. Inline atmospheric pressure metal-organic chemical vapour deposition for thin film CdTe solar cells

    International Nuclear Information System (INIS)

    A detailed study has been undertaken to assess the deposition of CdTe for thin film devices via an inline atmospheric pressure metal-organic chemical vapour deposition (AP-MOCVD) reactor. The precursors for CdTe synthesis were released from a showerhead assembly normal to a transparent conductive oxide (TCO)/glass substrate, previously coated with a CdZnS window layer using a conventional batch AP-MOCVD reactor with horizontal flow delivery. Under a simulated illumination with air mass coefficient 1.5 (AM1.5), the initial best cell conversion efficiency (11.2%) for such hybrid cells was comparable to a reference device efficiency (∼ 13%), grown entirely in the AP-MOCVD batch reactor. The performance and structure of the hybrid and conventional devices are compared for spectral response, CdTe grain morphology and crystal structure. These preliminary results reported on the transfer from a batch to an inline AP-MOCVD reactor which holds a good potential for the large-scale production of thin film photovoltaics devices and related materials. - Highlights: • Inline metal-organic chemical vapour deposition (MOCVD) used to grow CdTe films • Desired dopant profiles in CdTe:As achieved with inline MOCVD reactor • Initial conversion efficiency of 11.2% was comparable to batch devices (∼ 13%). • Inline MOCVD holds a good potential for large-scale thin film photovoltaics production

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

    International Nuclear Information System (INIS)

    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

  10. 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.

  11. 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.

  12. Thermoelectric power of CdTe thin films prepared by vacuum evaporation method

    International Nuclear Information System (INIS)

    Cadmium Telluride (CdTe) thin films of different thickness have been prepared by vacuum evaporation method on glass substrate at room temperature. X-ray diffraction and thermoelectric power (TEP) measurements were carried out on these films. The XRD pattern shows that as-deposited films are amorphous in character. Thermoelectric power (TEP) measured from room temperature to 450 K and it shows positive value at room temperature and decreases with the increase of temperature up to T approx. 314 K, above which it remains almost constant. At higher temperature, T > 410 K, TEP becomes negative. These experimental results reveal that there are two types of carriers present in as-deposited films. In low temperature region, dominant carriers are holes and at high temperature (T > 410 K) it is electron. The activation energy E0 and temperature coefficient of activation energy g have been calculated from TEP data. E0 and g varies with film thickness and their values range from 0.52 to 1.21 eV and 7.05x10-4 to 18.4x10-4 eV K-1 respectively. It is found that TEP does not vary systematically with film thickness, which is one of the characteristics of amorphous materials reported in the text. (author)

  13. Local structure of chromium incorporated into electrodeposited nickel hydroxide films

    International Nuclear Information System (INIS)

    We have utilized X-ray Absorption Fine Structure (XAFS) spectroscopy to investigate the local structure of Cr (III) and Cr (VI) ions incorporated into α-Ni(OH)2 films. The films were prepared by cathodic co-deposition of Cr and Ni at a constant current from aqueous solutions of nickel nitrate, chromium nitrate and potassium chromate. XAFS measurements show that in films formed from 0.1 M Ni(NO3)2 + 0.0005 M Cr(NO3)3, Cr (III) is incorporated into the Ni lattice sites of alpha-Ni(OH)2. In contrast, co-deposition from a 0.1 M Ni(NO3)2 + 0.001 M K2CrO4 solution results in Cr (VI) occupying the interlamellar sites of the brucite structure. (au)

  14. Growth and magnetic properties dependence of the Co–Cu/Cu films electrodeposited under high magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Franczak, Agnieszka, E-mail: agnieszka.franczak@mtm.kuleuven.be [Laboratoire d’Ingénierie et Sciences des Matériaux (LISM EA 4695), Université de Reims Champagne-Ardenne, UFR Sciences et Naturelles, Bat. 6, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2 (France); Department of Materials Science (MTM), KU Leuven, Kasteelpark Arenberg 44, 3001 Haverlee (Leuven) (Belgium); Levesque, Alexandra [Laboratoire d’Ingénierie et Sciences des Matériaux (LISM EA 4695), Université de Reims Champagne-Ardenne, UFR Sciences et Naturelles, Bat. 6, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2 (France); Zabinski, Piotr [Laboratory of Physical Chemistry and Electrochemistry, Faculty of Non-Ferrous Metals, AGH University of Science and Technology, al. A. Mickiewicza 30, 30059 Krakow (Poland); Li, Donggang [Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education), Northeastern University, 314 Box, 110004 Shenyang (China); Czapkiewicz, Maciej [Department of Electronics, AGH University of Science and Technology, al. A. Mickiewicza 30, 30059 Krakow (Poland); Kowalik, Remigiusz [Laboratory of Physical Chemistry and Electrochemistry, Faculty of Non-Ferrous Metals, AGH University of Science and Technology, al. A. Mickiewicza 30, 30059 Krakow (Poland); Bohr, Frédéric [Laboratoire d’Ingénierie et Sciences des Matériaux (LISM EA 4695), Université de Reims Champagne-Ardenne, UFR Sciences et Naturelles, Bat. 6, Moulin de la Housse, BP 1039, 51687 Reims Cedex 2 (France); and others

    2015-07-15

    The present work is focused on the investigations of magnetic properties dependence on microstructure of Co–Cu/Cu films electrodeposited under superimposed high magnetic field. The experimental results indicate a strong effect of an external magnetic field on the morphology of deposited films, more precisely on the Co:Cu ratio that determines the film growth. It is shown that the Co–Cu/Cu films electrodeposited without superimposed magnetic field consisted of two clearly visible features: compact film with incorporated granular particles. Under a superimposed external high magnetic field the privilege growth of the particles was induced. As a consequence, development of the well-defined branched structure of Co–Cu/Cu film was observed. In contrary, the phase compositional investigations do not reveal any changes in the phase formation during electrodeposition under magnetic field conditions. Thus, it is assumed that a strong growth of Co–Cu/Cu films in (111) direction under magnetic or non-magnetic electrodeposition conditions is related with the growth of Cu (111) plane and embedded into it some of the Co fcc atoms of same (111) orientation, as well as the Co hcp atoms that grows in the (002) direction. This non-equilibrium growth of Co–Cu/Cu films under magnetic deposition conditions affects strongly the magnetic properties of deposited films, revealing that films obtained under magnetic fields higher than 3 T were no more magnetic materials. - Highlights: • Co–Cu/Cu electrodeposits were obtained at elevated temperature under HMFs. • The effects of HMFs on microstructure and magnetic properties were investigated. • Interesting morphological changes due to HMFs has been observed. • Changes in Co:Cu ratio due to HMFs modified the magnetic properties of deposits.

  15. Growth and magnetic properties dependence of the Co–Cu/Cu films electrodeposited under high magnetic fields

    International Nuclear Information System (INIS)

    The present work is focused on the investigations of magnetic properties dependence on microstructure of Co–Cu/Cu films electrodeposited under superimposed high magnetic field. The experimental results indicate a strong effect of an external magnetic field on the morphology of deposited films, more precisely on the Co:Cu ratio that determines the film growth. It is shown that the Co–Cu/Cu films electrodeposited without superimposed magnetic field consisted of two clearly visible features: compact film with incorporated granular particles. Under a superimposed external high magnetic field the privilege growth of the particles was induced. As a consequence, development of the well-defined branched structure of Co–Cu/Cu film was observed. In contrary, the phase compositional investigations do not reveal any changes in the phase formation during electrodeposition under magnetic field conditions. Thus, it is assumed that a strong growth of Co–Cu/Cu films in (111) direction under magnetic or non-magnetic electrodeposition conditions is related with the growth of Cu (111) plane and embedded into it some of the Co fcc atoms of same (111) orientation, as well as the Co hcp atoms that grows in the (002) direction. This non-equilibrium growth of Co–Cu/Cu films under magnetic deposition conditions affects strongly the magnetic properties of deposited films, revealing that films obtained under magnetic fields higher than 3 T were no more magnetic materials. - Highlights: • Co–Cu/Cu electrodeposits were obtained at elevated temperature under HMFs. • The effects of HMFs on microstructure and magnetic properties were investigated. • Interesting morphological changes due to HMFs has been observed. • Changes in Co:Cu ratio due to HMFs modified the magnetic properties of deposits

  16. Chemical bath composition effect on the properties of electrodeposited CuInSe2 thin films

    International Nuclear Information System (INIS)

    Highlights: • CIS thin films were grown by electrodeposition technique. • For [Se]/[Cu + In] molar ratio less than 1.3 CIS films have single phase chalcopyrite structure. • For [Se]/[Cu + In] = 1.3 CuSe secondary phase is present. • The optical absorption is due to an allowed direct transition with band gap range between 1.04 and 1.2 eV. -- Abstract: Polycrystalline chalcopyrite CuInSe2 (CIS) thin films were deposited by electrodeposition technique onto ITO coated glass substrates. The used bath solution is formed by dissolution of CuCl2, InCl3, and SeO2 salts in de-ionized water, where the [Se]/[Cu + In] molar ratio is ranged from 0.4 to 1.3. The deposited films have been annealed at 300 °C for 30 min in argon atmosphere. The films structure and surface morphology characterizations were carried out respectively by means of X-ray diffraction method (XRD) and scanning electron microscope (SEM). XRD results indicate that CIS films having single phase chalcopyrite are obtained when the [Se]/[Cu + In] molar ratio is less than 1.3. While, for [Se]/[Cu + In] = 1.3, CuSe secondary phase is present together with CIS chalcopyrite phase. The crystallites were found to have a preferred orientation along (1 1 2) direction. The UV–visible optical transmittance measurements show that films absorption is due to allowed direct transition with a band gap ranged from 1.04 to 1.2 eV

  17. Synthesis and characterization of electrodeposited samaria and samaria-doped ceria thin films

    Energy Technology Data Exchange (ETDEWEB)

    Lair, V., E-mail: virginie-lair@ens.chimie-paristech.f [Laboratoire d' Electrochimie, Chimie des Interfaces et Modelisation pour l' Energie, LECIME, CNRS UMR 7575-ENSCP Chimie Paristech, 11rue Pierre et Marie Curie, 75231 Paris cedex 05 (France); Zivkovic, L.S. [Laboratoire d' Electrochimie, Chimie des Interfaces et Modelisation pour l' Energie, LECIME, CNRS UMR 7575-ENSCP Chimie Paristech, 11rue Pierre et Marie Curie, 75231 Paris cedex 05 (France); The Vinca Institute of Nuclear Sciences, University of Belgrade, PO Box 522, 11 001Belgrade (Serbia); Lupan, O. [Laboratoire d' Electrochimie, Chimie des Interfaces et Modelisation pour l' Energie, LECIME, CNRS UMR 7575-ENSCP Chimie Paristech, 11rue Pierre et Marie Curie, 75231 Paris cedex 05 (France); Department of Microelectronics and Semiconductor Devices, Technical University of Moldova, 168 Stefan cel Mare Blvd., Chisinau, MD-2004, Republic of Moldova (Moldova, Republic of); Ringuede, A. [Laboratoire d' Electrochimie, Chimie des Interfaces et Modelisation pour l' Energie, LECIME, CNRS UMR 7575-ENSCP Chimie Paristech, 11rue Pierre et Marie Curie, 75231 Paris cedex 05 (France)

    2011-04-30

    Graphical abstract: . Display Omitted Highlights: {yields} It reported hereby on the electrochemical deposition of pure Sm{sub 2}O{sub 3} and samaria-doped ceria SDC-films at low-temperature (30 {sup o}C). {yields} A detailed analysis of the composition, structural, morphological and vibrational properties of SDC electrodeposited films are presented. {yields} Effects of thermal annealing on the evolution of the material properties of Sm{sub 2}O{sub 3} and SDC by means of XRD and Raman spectroscopy were analyzed. {yields} Presented results indicate that electrochemical Sm{sub 2}O{sub 3} and SDC-films are good for further studies in applications as protective coatings against corrosion of different metallic surfaces and in solid oxide fuel cell. - Abstract: Samaria (Sm{sub 2}O{sub 3}) and samaria-doped ceria (SDC) films are electrochemically deposited on stainless steel in view of a potential use in solid oxide fuel cells. As it is possible to deposit separately pure ceria (CeO{sub 2}) and pure samaria (Sm{sub 2}O{sub 3}) in similar conditions, SDC films were successfully obtained in one electrochemical conditions set. Thin films have been fabricated at low-temperature (30 {sup o}C) by applying a cathodic potential of -0.8 V/SCE, for 2 h. Structural and morphological properties of electrodeposited films have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), techniques and Raman spectroscopy. Special attention has been focused on the Raman spectroscopy study to emphasize the effect of heat treatment and samarium doping. Despite cracks, single SDC phase was obtained crystallizing in a cubic symmetry.

  18. Electrodeposited NiCoFe films from electrolytes with different Fe ion concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Kockar, Hakan, E-mail: hkockar@balikesir.edu.tr [Balikesir Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, Cagıs Yerleskesi, 10145 Balikesir (Turkey); Demirbas, Ozen, E-mail: ozendemirbas@hotmail.com [Balikesir Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, Cagıs Yerleskesi, 10145 Balikesir (Turkey); Kuru, Hilal, E-mail: htopcu@balikesir.edu.tr [Balikesir Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, Cagıs Yerleskesi, 10145 Balikesir (Turkey); Alper, Mursel, E-mail: malper@uludag.edu.tr [Uludag Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, 16059 Gorukle, Bursa (Turkey); Karaagac, Oznur, E-mail: karaagac@balikesir.edu.tr [Balikesir Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, Cagıs Yerleskesi, 10145 Balikesir (Turkey); Haciismailoglu, Murside, E-mail: msafak@uludag.edu.tr [Uludag Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, 16059 Gorukle, Bursa (Turkey); Ozergin, Ercument, E-mail: ercumentz@yahoo.com [Balikesir Universitesi, Fen Edebiyat Fakultesi, Fizik Bolumu, Cagıs Yerleskesi, 10145 Balikesir (Turkey)

    2014-06-01

    Ternary NiCoFe films, relating their magnetic and magnetoresistance properties with film composition, and the corresponding crystal structure were investigated in terms of different Fe ion concentrations in the electrolyte. The current–time transients were recorded to control the growth of proper films. The film composition by energy dispersive X-ray spectroscopy revealed that as the Fe ion concentration in the electrolyte was increased, the Fe and Co contents in the films increased and Ni content decreased. From the structural analysis by X-ray diffraction, all films had a face-centred cubic structure and, no reflection from body-centred cubic (bcc) Fe was existed in all samples due to <12 at% Fe. The saturation magnetisation increased from 865 emu/cm{sup 3} to 1080 emu/cm{sup 3} and the coercivities decreased from 60 Oe to 13 Oe with increasing Fe and Co contents and decreasing Ni content in the films. All NiCoFe films showed anisotropic magnetoresistance. The longitudinal magnetoresistance magnitudes decreased from 6.3% to 2.2% with increasing Fe and Co contents and decreasing Ni in the films while the magnitudes of transverse magnetoresistance stayed almost constant at ∼5.0%. The variations in magnetic and magnetoresistive properties related to the crystal structure were attributed to the compositional changes caused by the variation of the Fe ion concentration in the electrolyte. - Highlights: • Structural and magnetic properties of electrodeposited NiCoFe films were studied. • The Fe and Co increased and Ni decreased with increasing Fe concentration. • All films had a face-centred cubic structure irrespective of the film content. • The M{sub s} increased and H{sub c} decreased with the change of film content. • All films showed AMR.

  19. Electrodeposited NiCoFe films from electrolytes with different Fe ion concentrations

    International Nuclear Information System (INIS)

    Ternary NiCoFe films, relating their magnetic and magnetoresistance properties with film composition, and the corresponding crystal structure were investigated in terms of different Fe ion concentrations in the electrolyte. The current–time transients were recorded to control the growth of proper films. The film composition by energy dispersive X-ray spectroscopy revealed that as the Fe ion concentration in the electrolyte was increased, the Fe and Co contents in the films increased and Ni content decreased. From the structural analysis by X-ray diffraction, all films had a face-centred cubic structure and, no reflection from body-centred cubic (bcc) Fe was existed in all samples due to 3 to 1080 emu/cm3 and the coercivities decreased from 60 Oe to 13 Oe with increasing Fe and Co contents and decreasing Ni content in the films. All NiCoFe films showed anisotropic magnetoresistance. The longitudinal magnetoresistance magnitudes decreased from 6.3% to 2.2% with increasing Fe and Co contents and decreasing Ni in the films while the magnitudes of transverse magnetoresistance stayed almost constant at ∼5.0%. The variations in magnetic and magnetoresistive properties related to the crystal structure were attributed to the compositional changes caused by the variation of the Fe ion concentration in the electrolyte. - Highlights: • Structural and magnetic properties of electrodeposited NiCoFe films were studied. • The Fe and Co increased and Ni decreased with increasing Fe concentration. • All films had a face-centred cubic structure irrespective of the film content. • The Ms increased and Hc decreased with the change of film content. • All films showed AMR

  20. Atmospheric Pressure Chemical Vapor Deposition of CdTe for High-Efficiency Thin-Film PV Devices; Annual Report, 26 January 1998-25 January 1999

    International Nuclear Information System (INIS)

    ITN's 3-year project, titled ''Atmospheric Pressure Chemical Vapor Deposition (APCVD) of CdTe for High-Efficiency Thin-Film Photovoltaic (PV) Devices,'' has the overall objectives of improving thin-film CdTe PV manufacturing technology and increasing CdTe PV device power conversion efficiency. CdTe deposition by APCVD employs the same reaction chemistry as has been used to deposit 16%-efficient CdTe PV films, i.e., close-spaced sublimation, but employs forced convection rather than diffusion as a mechanism of mass transport. Tasks of the APCVD program center on demonstrating APCVD of CdTe films, discovering fundamental mass-transport parameters, applying established engineering principles to the deposition of CdTe films, and verifying reactor design principles that could be used to design high-throughput, high-yield manufacturing equipment. Additional tasks relate to improved device measurement and characterization procedures that can lead to a more fundamental understanding of CdTe PV device operation, and ultimately, to higher device conversion efficiency and greater stability. Specifically, under the APCVD program, device analysis goes beyond conventional one-dimensional device characterization and analysis toward two-dimension measurements and modeling. Accomplishments of the first year of the APCVD subcontract include: selection of the Stagnant Flow Reactor design concept for the APCVD reactor, development of a detailed reactor design, performance of detailed numerical calculations simulating reactor performance, fabrication and installation of an APCVD reactor, performance of dry runs to verify reactor performance, performance of one-dimensional modeling of CdTe PV device performance, and development of a detailed plan for quantification of grain-boundary effects in polycrystalline CdTe devices

  1. CdTe Thin Film Solar Cells and Modules Tutorial; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Albin, David S.

    2015-06-13

    This is a tutorial presented at the 42nd IEEE Photovoltaics Specialists Conference to cover the introduction, background, and updates on CdTe cell and module technology, including CdTe cell and module structure and fabrication.

  2. The large-area CdTe thin film for CdS/CdTe solar cell prepared by physical vapor deposition in medium pressure

    Science.gov (United States)

    Luo, Run; Liu, Bo; Yang, Xiaoyan; Bao, Zheng; Li, Bing; Zhang, Jingquan; Li, Wei; Wu, Lili; Feng, Lianghuan

    2016-01-01

    The Cadmium telluride (CdTe) thin film has been prepared by physical vapor deposition (PVD), the Ar + O2 pressure is about 0.9 kPa. This method is a newer technique to deposit CdTe thin film in large area, and the size of the film is 30 × 40 cm2. This method is much different from the close-spaced sublimation (CSS), as the relevance between the source temperature and the substrate temperature is weak, and the gas phase of CdTe is transferred to the substrate by Ar + O2 flow. Through this method, the compact and uniform CdTe film (30 × 40 cm2) has been achieved, and the performances of the CdTe thin film have been determined by transmission spectrum, SEM and XRD. The film is observed to be compact with a good crystallinity, the CdTe is polycrystalline with a cubic structure and a strongly preferred (1 1 1) orientation. Using the CdTe thin film (3 × 5 cm2) which is taken from the deposited large-area film, the 14.6% efficiency CdS/CdTe thin film solar cell has been prepared successfully. The structure of the cell is glass/FTO/CdS/CdTe/graphite slurry/Au, short circuit current density (Jsc) of the cell is 26.9 mA/cm2, open circuit voltage (Voc) is 823 mV, and filling factor (FF) is 66.05%. This technique can be a quite promising method to apply in the industrial production, as it has great prospects in the fabricating of large-area CdTe film.

  3. Purified water etching of native oxides on heteroepitaxial CdTe thin films

    Science.gov (United States)

    Meinander, Kristoffer; Carvalho, Jessica L.; Miki, Carley; Rideout, Joshua; Jovanovic, Stephen M.; Devenyi, Gabriel A.; Preston, John S.

    2014-12-01

    The etching of native oxides on compound semiconductors is an important step in the production of electronic and optoelectronic devices. Although it is known that the native oxide on CdTe can be etched through a rinsing in purified water, a deeper investigation into this process has not been done. Here we present results on both surface morphology changes and reaction rates for purified water etching of the native oxide on heteroepitaxial CdTe thin films, as studied by atomic force microscopy and x-ray photoelectron spectroscopy. Together with a characterization of both the structure and stoichiometry of the initial native oxide, we show how an altering of the pH-level of the etchant will affect the etching rates. If oxide regrowth was allowed, constant etching rates could be observed for all etchants, while a logarithmic decrease in oxide thickness was observed if regrowth was inhibited. Both acidic and basic etchants proved to be more efficient than neutral water.

  4. Coating of hydroxyapatite films on titanium substrates by electrodeposition under pulse current

    OpenAIRE

    HAYAKAWA, Tomoyasu; Kawashita, Masakazu; TAKAOAKA, Gikan H.

    2008-01-01

    Titanium (Ti) metal substrates were etched in sulfuric acid (H2SO4) with concentrations of 25, 50, 75 and 97% at 60°C for 30 min. Hydroxyapatite (HA) films were deposited onto unetched and etched substrates by an electrodeposition method under a pulse current. The electrolyte was metastable calcium phosphate solution that had 1.5 times the ion concentrations of human body fluid, but did not contain magnesium ion at 36.5°C. Deposition times were 90 min. We used the average current density of 0...

  5. Growth and properties of electrodeposited cobalt films on Pt/Si(1 0 0) surface

    International Nuclear Information System (INIS)

    In this paper, the growth, structural and magnetic properties of cobalt (Co) films electrodeposited on a Pt/Si(1 0 0) substrate have been investigated. Co films with metallic appearance were obtained from aqueous solution of 0.1 M CoSO4, 10 mM CoCl2 as the source of metal ions and 1 M Na2SO4 as a supporting electrolyte with 0.5 M H3BO3 at pH 4.2. This electrochemical technique indicated a deposition peak signature of limited diffusion growth with the transition from progressive to instantaneous nucleation mechanism. The atomic force microscopy (AFM) images showed a granular structure of the electrodeposited layers. X-ray measurements (XRD) and nuclear magnetic resonance (NMR) indicate a small grain size with the presence of a mixture of Co hcp and fcc structures. The magnetic properties of the deposited films were investigated with a magnetic field in the parallel and perpendicular direction and showed that the easy magnetization axis is in the plane

  6. Electrodeposition and Characterization of CulnSe2 Thin Films for Solar Cells

    Institute of Scientific and Technical Information of China (English)

    LI Jianzhuang; ZHAO Xiujian; XIA Donglin

    2007-01-01

    CuInSe2 (CIS) thin films were prepared by electrodeposition from the de-ionized water solution consisting of CuCl2, InCl3, H2SeO3 and Na-citrate onto Mo/soda-lime glass (SLG) substrates. A thermal processing in Se atmosphere at 450 ℃ was carried out for the electrodepositied films to improve the stoichiometry. The composition and morphology of selenized CIS thin films were studied using energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM), respectively. X-ray diffraction(XRD) studies show that the annealing in Se atmosphere at 450 ℃ promotes the structural formation of CIS chalcopyrite structure.

  7. Electro-deposition of cerium thin film compound, elaboration and characterisation

    International Nuclear Information System (INIS)

    Cerium oxide films are widely studied as a promising alternative to the toxic hexavalent Chromium Cr(VI) based pre-treatments for the corrosion protection of different metals and alloys. Cathodic electro-deposition of Cerium compound thin films was realised on Ti alloy (TA6V) substrates from a Ce(NO3)3, 6H2O in water-ethyl alcohol solutions at 0.01 M. Experimental conditions to obtain homogeneous and crack free thin films were determined. The deposited cerium quantity, as expected, is proportional to the used electric charge, following the Faraday law. Subsequent thermal treatment led to a CeO2 coating, which is expected to increase the TA6V oxidation resistance at high temperatures. The deposits were characterized by Differential Scanning Calorimetry (DSC), optical and scanning electron microscopies.(author)

  8. A modified layer-removal method for residual stress measurement in electrodeposited nickel films

    International Nuclear Information System (INIS)

    Combining the traditional layer-removal method with a cantilever beam model, a modified layer-removal method is developed and used to measure residual stress in single and multi-layer electrodeposited nickel films with thickness of 2.5 μm. The out-of-plane displacement of the free tip of a cantilever beam is measured by the digital speckle correlation method. The results show that residual stress in a single semimat nickel film is compressive, while in a multi-layer system composed of dark, semimat and holophote nickel, residual stress in the surface layer is tensile. Residual stress decreases gradually with the increase of etching depths of single and multi-layer films. These findings are in qualitative agreement with nanoindentation tests, which confirms the reliability of the modified layer-removal method.

  9. New Method of Pulsed Electrodeposition of Nanostructure of ZnS Films

    Directory of Open Access Journals (Sweden)

    M.B. Dergacheva

    2016-03-01

    Full Text Available The voltammetry method of analysis is used to investigate the electrochemical behavior of zinc(II and thiosulfate (\\(\\text{S}_{2}\\text{O}_{3}^{2-}\\ ions in acidic solutions and their electrochemical deposition onto glass coated with a conductive layer of tin oxide. It is found that electrodeposition conducted according to the two-electrode scheme using the pulse current generated by the industrial alternating current produces sound zinc sulfide deposits. Physical and chemical properties of obtained zinc sulfide films have been characterized by using scanning electron microscope and UV spectroscopy. The "cross-section" method is used to determine the thickness of zinc sulfide film, which is equal to 140–160 nm. The obtained films have n-type conductivity.

  10. A Comparative Study on the Optical Properties of Multilayer CdSe / CdTe Thin Film with Single Layer CdTe and CdSe Films

    OpenAIRE

    M. Melvin David Kumar; Suganthi Devadason

    2013-01-01

    CdTe and CdSe single layer thin films and CdSe / CdTe multilayer (ML) thin film were prepared by using physical vapour deposition method. Optical properties of CdSe / CdTe multilayer thin film shows different behavior due to type II band structure alignment. Energy band gap value of CdSe / CdTe ML thin film is shifted to higher value than that of single layer CdTe film. This is due to decrease in crystallite size to dimension smaller than the Bohr exciton radius of CdTe (14 nm). Crystallite ...

  11. Effect of Annealing on the Properties of Antimony Telluride Thin Films and Their Applications in CdTe Solar Cells

    Directory of Open Access Journals (Sweden)

    Zhouling Wang

    2014-01-01

    Full Text Available Antimony telluride alloy thin films were deposited at room temperature by using the vacuum coevaporation method. The films were annealed at different temperatures in N2 ambient, and then the compositional, structural, and electrical properties of antimony telluride thin films were characterized by X-ray fluorescence, X-ray diffraction, differential thermal analysis, and Hall measurements. The results indicate that single phase antimony telluride existed when the annealing temperature was higher than 488 K. All thin films exhibited p-type conductivity with high carrier concentrations. Cell performance was greatly improved when the antimony telluride thin films were used as the back contact layer for CdTe thin film solar cells. The dark current voltage and capacitance voltage measurements were performed to investigate the formation of the back contacts for the cells with or without Sb2Te3 buffer layers. CdTe solar cells with the buffer layers can reduce the series resistance and eliminate the reverse junction between CdTe and metal electrodes.

  12. Electrodeposition of low residual stress CoNiMnP hard magnetic thin films for magnetic MEMS actuators

    International Nuclear Information System (INIS)

    A new technique for electrodeposition of CoNiMnP hard magnetic thin films is developed to provide thin films with low residual stress and magnetic properties useful for MEMS applications. Processing parameters including applied current density, film thickness, pH and temperature of the electrolyte are regulated in order to reduce residual stress of the film. In addition, a hybrid residual stress reliever composed of sodium saccharine and a rare-earth salts mixture of Ce2(SO4)3 and Nd2(SO4)3 is created to further reduce the residual stress, eliminate microcracks and improve surface morphology of the film. The effects of residual stress on the magnetic properties of electrodeposited CoNiMnP hard magnetic films such as coercivity, saturation and residual magnetization are reported in this paper

  13. Nanostructured superhydrophobic films synthesized by electrodeposition of fluorinated polyindoles

    OpenAIRE

    Gabriela Ramos Chagas; Thierry Darmanin; Frédéric Guittard

    2015-01-01

    Materials with bioinspired superhydrophobic properties are highly desirable for many potential applications. Here, nine novel monomers derived from indole are synthesized to obtain these properties by electropolymerization. These monomers differ by the length (C4F9, C6F13 and C8F17) and the position (4-, 5- and 6-position of indole) of the perfluorinated substituent. Polymeric films were obtained with C4F9 and C6F13 chains and differences in the surface morphology depend especially on the sub...

  14. An effective combination of electrodeposition and layer-by-layer assembly to construct composite films with luminescence switching behavior.

    Science.gov (United States)

    Gao, Wenmei; Ma, Hongwei; Zheng, Daming; Dong, Zhaojun; Wu, Lixin; Bi, Lihua

    2015-09-01

    This article presents a combination strategy of electrodeposition and a layer-by-layer assembly to fabricate functional composite films with luminescence switching behavior. Firstly, a novel green luminescence film consisting of 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HOPTS) was first obtained on ITO by a facile electrodeposition method. Then, the multilayer films containing different layers of tungstophosphate K12.5Na1.5[NaP5W30O110]·15H2O (P5W30) were further fabricated on the green luminescence film to form the composite films [(HOPTS)50/(PDDA/P5W30)n] (n = 10, film 1; n = 27, film 2; n = 57, film 3). Cyclic voltammetry and fluorescence spectroscopy were used to characterize the electrochemical activity of P5W30 and the luminescence property of HOPTS in the composite films, respectively. Lastly, in situ UV-Vis spectroelectrochemical and fluorescence spectroelectrochemical measurements were applied to investigate the luminescence switching behaviors of the composite films controlled by the electrochromism component of P5W30 upon electrochemical modulation. In summary, the investigation results revealed that the electrodeposition method is convenient and rapid, and thus-prepared composite films showed improved luminescence switching performance in terms of switching process, activation cycles, coloration efficiency, and bleached-state transparency as well as good stability, wide voltage range and good reversibility. Therefore, the present study offers a new fabrication route for the multifunctional composite films through an effective combination of electrodeposition and layer-by-layer assembly technique. PMID:26219637

  15. Wide bandgap thin film solar cells from CdTe alloys

    International Nuclear Information System (INIS)

    Ternary films of CdZnTe and CdMnTe were grown by molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD), respectively, on glass/SnO2/CdS substrates with target bandgap of 1.7 to 1.8 eV for solar cell applications. The authors describe x-ray diffraction, surface photovoltage spectroscopy, and Auger electron spectroscopy measurements performed to estimate bandgap, compositional uniformity, and interface quality of the films. Front-wall CdTe cell (glass/SnO2/CdS/CdTe/ZnTe/Metal) efficiencies were --9%, while CdZnTe and CdMnTe efficiencies were --3.6% and 6%, respectively. n-i-p cell efficiencies were consistently higher than n-p cells. Optimum cell processing temperature for CdZnTe films was found to be less than 4000C. Higher processing temperatures caused a shift in bandgap coupled with film quality degradation

  16. Co{sub 100−x}Fe{sub x} magnetic thick films prepared by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre, M. del C., E-mail: carmenaguirre@famaf.unc.edu.ar [Instituto de Física Enrique Gaviola-Conicet-Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba (Argentina); Farías, E. [Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba (Argentina); Abraham, J.; Urreta, S.E. [Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba (Argentina)

    2015-04-05

    Highlights: • Low iron containing films are compact, with rounded, relatively uniform surfaces. • Larger Fe contents exhibit nanowall networks covering the surface. • Coercivity in the out of plane configuration is larger than in the easy axis direction. • Co-rich films nucleate and grow by a 3DP diffusion controlled mechanism. • For equiatomic Fe{sub 50}Co{sub 50} films, nucleation tends to become instantaneous. - Abstract: Co–Fe films are grown onto plane pre-treated Cu foils; the effects of the alloy composition on the morphology and the crystal texture of the electrodeposited films and their anisotropic magnetic hysteresis properties are explored. Nucleation and crystallization mechanisms in these Co-rich layers are also investigated with pulse-reverse plating techniques, using the first cathodic pulse current–time transients. In the diffusion controlled regime the deposition mechanism is found to involve progressive nucleation with three-dimensional (3D) growth, except for the equiatomic Fe{sub 50}Co{sub 50} solution where nucleation tends to become instantaneous. The different morphologies and size scales observed are described and correlated with coercivity. The films are electrodeposited onto electrochemically pre-treated Cu substrates from feeds of nominal Fe/Co mol ratios between 0/100 and 50/50. The composition of the deposited layers, as determined by energy dispersive X-ray spectroscopy, are quite close to the nominal values. Cyclic voltammetry determinations exhibit only a single reduction process on the cathode, indicating that a unique (Co{sub 100−x}Fe{sub x}) phase grows. Depending on composition and on the substrate pre-treatment, these layers exhibit textures with features of different sizes. X ray diffraction patterns indicate that the nanostructures with Fe contents above 20 at.% crystallize in a body-centered cubic cell, while samples with Fe contents below this value are fcc. Regarding the effect of composition on the

  17. Co100−xFex magnetic thick films prepared by electrodeposition

    International Nuclear Information System (INIS)

    Highlights: • Low iron containing films are compact, with rounded, relatively uniform surfaces. • Larger Fe contents exhibit nanowall networks covering the surface. • Coercivity in the out of plane configuration is larger than in the easy axis direction. • Co-rich films nucleate and grow by a 3DP diffusion controlled mechanism. • For equiatomic Fe50Co50 films, nucleation tends to become instantaneous. - Abstract: Co–Fe films are grown onto plane pre-treated Cu foils; the effects of the alloy composition on the morphology and the crystal texture of the electrodeposited films and their anisotropic magnetic hysteresis properties are explored. Nucleation and crystallization mechanisms in these Co-rich layers are also investigated with pulse-reverse plating techniques, using the first cathodic pulse current–time transients. In the diffusion controlled regime the deposition mechanism is found to involve progressive nucleation with three-dimensional (3D) growth, except for the equiatomic Fe50Co50 solution where nucleation tends to become instantaneous. The different morphologies and size scales observed are described and correlated with coercivity. The films are electrodeposited onto electrochemically pre-treated Cu substrates from feeds of nominal Fe/Co mol ratios between 0/100 and 50/50. The composition of the deposited layers, as determined by energy dispersive X-ray spectroscopy, are quite close to the nominal values. Cyclic voltammetry determinations exhibit only a single reduction process on the cathode, indicating that a unique (Co100−xFex) phase grows. Depending on composition and on the substrate pre-treatment, these layers exhibit textures with features of different sizes. X ray diffraction patterns indicate that the nanostructures with Fe contents above 20 at.% crystallize in a body-centered cubic cell, while samples with Fe contents below this value are fcc. Regarding the effect of composition on the morphology, Co and Co-rich layers are

  18. Progress towards high efficiency thin film CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, K.W.; Eberspacher, C.; Cohen, F.; Avery, J.; Duran, G.; Bottenberg, W.

    1988-01-15

    This paper describes work investigating high rate cadmium telluride (CdTe) film deposition by close-space vapor transport, leading to 4 cm/sup 2/ tin oxide/CdTe solar cells of efficiency greater than 10%. Under a 100 mW cm/sup -2/ air mass 1.5 global spectrum, a cell of efficiency 10.5% had a short-circuit current of 28.1 mA cm/sup -2/, an open circuit voltage of 0.663 V and a fill factor of 0.563. Our major achievements include (1) the use of completely nonvacuum processing, (2) the fabrication of simple transparent conductive oxide/CdTe cells without need of a CdS window layer, and (3) screenprinted back contacts.

  19. X-ray, electron microscopy and photovoltaic studies on CdTe thin films deposited normally at different substrate temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Saha, S.; Pal, U.; Samantaray, B.K.; Chaudhuri, A.K. (Indian Inst. of Tech., Kharagpur (IN). Dept. of Physics and Meteorology); Banerjee, H.D. (Indian Inst. of Tech., Kharagpur (India). Materials Science Centre)

    1990-12-01

    X-ray diffraction, transmission electron microscopy and electron diffraction studies were conducted on CdTe thin films deposited on glass substrates kept at different substrate temperatures. Variation of the different structural parameters, such as lattice constant, crystallite size, r.m.s. strain, dislocation density and stacking fault probability with substrate temperature, was investigated in the temperature range 300 to 498 K. An increase in the lattice constant and crystallite size values and a decrease in the other parameters with increase in temperature of the substrate was observed. A photovoltage was observed for CdTe film deposited normally on glass substrates kept at higher substrate temperatures. The development of photovoltage in the film is explained in the light of the formation of crystallites of variable structure. (author).

  20. Photoelectrochemistry of Cu(In,Ga)Se2 thin-films fabricated by sequential pulsed electrodeposition

    Science.gov (United States)

    Mandati, Sreekanth; Sarada, Bulusu V.; Dey, Suhash R.; Joshi, Shrikant V.

    2015-01-01

    A novel approach for the fabrication of compact stoichiometric copper indium gallium selenium (CIGS) thin-films is reported. It uses a solution of CuCl2, GaCl3 and H2SeO3, pH adjusted with HCl with LiCl as additive employing a high purity graphite plate anode and Mo sputtered glass cathode during a simplified sequential pulsed current electrodeposition which avoids impurities from the use of a reference electrode during deposition and a separate selenization step. A Cu-Ga-Se film is optimally deposited by optimizing the deposition voltage, followed by deposition of In from InCl3 solution, and then annealing of the Cu-Ga-Se/In thin-film in an Argon atmosphere at 550 °C. A single phase chalcopyrite CIGS forms with a compact morphology and well-controlled composition of individual elements. The flat-band potential and carrier density of CIGS thin-films are -0.15 V and 2.6 × 1016 cm-3, respectively, as determined by Mott-Schottky studies. The photoelectrochemical performance of CIGS films shows a photocurrent density of -0.8 mA cm-2 at -0.4 V vs. SCE, an eight fold increment compared to our previous reported value. This simplified preparation using pulse plating gives superior quality CIGS films which are promising for application in thin-film solar cells and photoelectrochemical cells.

  1. Controlled electrodeposition of Au monolayer film on ionic liquid

    Science.gov (United States)

    Ma, Qiang; Pang, Liuqing; Li, Man; Zhang, Yunxia; Ren, Xianpei; Liu, Shengzhong Frank

    2016-05-01

    Gold (Au) nanoparticles have been attractive for centuries for their vibrant appearance enhanced by their interaction with sunlight. Nowadays, there have been tremendous research efforts to develop them for high-tech applications including therapeutic agents, sensors, organic photovoltaics, medical applications, electronics and catalysis. However, there remains to be a challenge to fabricate a monolayer Au coating with complete coverage in controlled fashion. Here we present a facile method to deposit a uniform Au monolayer (ML) film on the [BMIM][PF6] ionic liquid substrate using an electrochemical deposition process. It demonstrates that it is feasible to prepare a solid phase coating on the liquid-based substrate. Moreover, the thickness of the monolayer coating can be controlled to a layer-by-layer accuracy.

  2. Nanostructured superhydrophobic films synthesized by electrodeposition of fluorinated polyindoles

    Directory of Open Access Journals (Sweden)

    Gabriela Ramos Chagas

    2015-10-01

    Full Text Available Materials with bioinspired superhydrophobic properties are highly desirable for many potential applications. Here, nine novel monomers derived from indole are synthesized to obtain these properties by electropolymerization. These monomers differ by the length (C4F9, C6F13 and C8F17 and the position (4-, 5- and 6-position of indole of the perfluorinated substituent. Polymeric films were obtained with C4F9 and C6F13 chains and differences in the surface morphology depend especially on the substituent position. The polyindoles exhibited hydrophobic and superhydrophobic properties even with a very low roughness. The best results are obtained with PIndole-6-F6 for which superhydrophobic and highly oleophobic properties are obtained due to the presence of spherical nanoparticles and low surface energy compounds.

  3. Investigation of deposition parameters for the non-aqueous electroplating of CdTe films and application in electrochemical photovoltaic cells

    Energy Technology Data Exchange (ETDEWEB)

    Gore, R.B.; Pandey, R.K.; Kulkarni, S.K.

    1989-03-01

    The cathodic deposition characteristics of Cd/sup 2+/ and Te/sup 4+/ in a non-aqueous electroplating bath have been studied. The deposition parameters have been optimised to yield uniform and well adhering films of CdTe in a non-aqueous medium. The influence of the potentiostatic and galvanostatic deposition conditions on the stoichiometry, structure and photoanodic behaviour of the CdTe films are also discussed.

  4. Effect of potential on the conductivity of electrodeposited Cu2O film

    Science.gov (United States)

    Yang, Ying; Han, Juan; Ning, Xiaohui; Tang, Hongsheng

    2015-09-01

    The conductivity (i.e., n-type or p-type) of Cu2O films is controlled by the electrodeposition potential. A slightly acidic solution (pH 4.93) containing cupric acetate and sodium dodecyl sulfate (SDS) is used. Photoelectrochemical measurements at zero bias indicate that the Cu2O films deposited at the potentials of 0.00 V and -0.05 V generate the ntype photocurrents and the films deposited at the potentials negative than -0.10 V generate the p-type photocurrents. The X-ray diffraction (XRD) results show that the n-type films are pure Cu2O, however, the metallic copper appear in the ptype Cu2O films. Mott-Schottky measurements show that the donor concentrations of the n-type Cu2O films decrease and the acceptor concentrations of the p-type Cu2O films increase with the decrease of the deposition potential. The SDS molecules adsorbed on electrode surface and the SDS micelles block the diffusion of Cu2+ ions, resulting in a low diffusion rate of Cu2+ ions. Under this circumstance, the growth of Cu2O films are affected significantly by the overpotential. When the potential is positive than -0.05 V, oxygen vacancies are formed in the films leading to the n-type conductivity; however, when the potential is negative than -0.10 V, the Cu2+ ions are reduced to Cu+ rapidly and part of Cu2+ are reduced to metallic copper, the diffused Cu2+ ions to supply to the growth of Cu2O films are insufficient, hence copper vacancies are formed in the films resulting in the p-type conductivity.

  5. Synthesis and magnetic characterization of a Cu80Co20 thin film obtained by electrodeposition technique

    International Nuclear Information System (INIS)

    Highlights: • A Cu80Co20 alloy was obtained by low cost electrodeposition. • The structure was investigated down to the atomic scale. • No oxides were formed. • Magnetoresistance is clearly related to superparamagnetic Co nanoparticles. - Abstract: A granular Cu80Co20 alloy was elaborated by a low cost electrodeposition technique consisting in reducing simultaneously the Cu2+ and Co2+ ions onto a silicon substrate. The deposition parameters were determined from current-potential curves. The structure of the film was characterized down to the atomic scale by transmission electron microscopy and atom probe tomography. The results show that the as-deposited Cu80Co20 thin film consists mainly of a paramagnetic Cu–Co solid solution containing 10–30% of Co, in which pure Co superparamagnetic nanoparticles are dissolved. Annealing at 500 °C for 1 h leads to the decomposition of the Cu–Co solid solution into purified Cu matrix containing ferromagnetic Co-rich precipitates. The magnetoresistance effect decreases after the heat treatment, in relation with the disappearance of the superparamagnetic Co nanoparticles upon annealing

  6. Preparation of Perpendicular GdFeCo Magnetic Thin Films with Pulse Electrodeposition Technique Utilizing Molten Salt as Electrolyte

    Science.gov (United States)

    Yang, Chao-Chen; Shu, Min-Fong

    2007-12-01

    We have utilized ZnCl2-dimethylsulfone (DMSO2) as the electrolyte with added GdCl3, FeCl2, and CoCl2, for electrodepositing a perpendicular GdFeCo magnetic thin film. The reaction at the electrode surface and the electrical conductivity of the ionic substance at different ionic concentrations were studied by cyclic voltammetry and a computerized direct current method. Moreover, the electrodeposition of the GdFeCo thin film was determined by a pulse potential method. Relation between the composition of the deposited thin film and control parameters including applied potentials was determined by EDS analysis. An amorphous structure and the thickness of the thin film were obtained by TEM analysis. Its roughness and uniformity were determined by AFM analysis. Meanwhile, a perpendicular magnetic property and pinning magnetic domain of the thin film were analyzed from results of AGM and MFM.

  7. Electrodeposition of Er-Ni Alloy Film in Dimethylsulfoxide

    Institute of Scientific and Technical Information of China (English)

    李高仁; 童叶翔; 刘冠昆

    2002-01-01

    The cyclic voltammetry and chronoamperometry were used to investigate the electrochemical behaviors of Er(Ⅲ) and Ni(Ⅱ) in LiClO4-DMSO(dimethylsufoxide) system on Pt and Cu electrodes. Experimental results indicated that the reduction of Er(Ⅲ) to Er and Ni(Ⅱ) to Ni were irreversible in one step on Pt and Cu electrodes. The diffusion coefficient and electron transfer coefficient of Er(Ⅲ) in 0.01 mol*L-1 ErCl3 -0.1 mol*L-1 LiClO4-DMSO system at 303K were 1.47×10-10 m2*s-1 and 0.108 respectively, and the diffusion coefficient and electron transfer coefficient of Ni(Ⅱ) in 0.01 mol*L-1 NiCl2-0.1 mol*L-1 LiClO4-DMSO system at 303K were 3.38×10-10 m2*s-1 and 0.160 respectively. The homogeneous, strong adhesive Er-Ni alloy films with metallic lu- stre was prepared by potentiostatic electrolysis on Cu electrode in ErCl3-NiCl2-LiClO4-DMSO system at -1.90~-2.55 V (vs SCE).

  8. Application of original assemblies of polyelectrolytes, urease and electrodeposited polyaniline as sensitive films of potentiometric urea biosensors

    International Nuclear Information System (INIS)

    Highlights: • Elaboration of original polymer materials using self-assembly and electrochemistry. • In situ monitoring of the growth of the polymer materials. • Development of urea electrochemical sensors using a home-made mini-potentiostat. - Abstract: Original assemblies were prepared for use as sensitive films of potentiometric enzyme urea sensors, and compared to identify the more efficient structure with respect to stability. These films included electrodeposited polyaniline, used as transducer, urease, used as catalyst, and biocompatible polyelectrolytes, used as a matrix to preserve the integrity of the enzyme in the sensitive film. Two kinds of assemblies were done: the first one consisted in the adsorption of urease onto a polyaniline film followed by the adsorption of a chitosan-carboxymethylpullulan multilayer film, while the second one consisted in the adsorption of a urease-chitosan multilayer film onto an electrodeposited polyaniline film. The morphological features and growth of these assemblies were characterized by scanning electron microscopy and quartz crystal microbalance, respectively. This allowed us to demonstrate that the assemblies are successfully formed onto the electrodes of the sensors. The potentiometric responses of both assemblies were then measured as a function of urea concentration using a home-made portable potentiostat. The electrochemical response of resulting sensors was fast and sensitive for both types of assemblies, but the stability in time was much better for the films obtained from alternative adsorption of urease and chitosan onto a layer of urease adsorbed over electrodeposited polyaniline

  9. Electrocatalytic oxidations at electrodeposited bismuth (III)-doped beta-lead dioxide film electrodes

    International Nuclear Information System (INIS)

    Heterogeneous rate constants for the anodic oxidation of many inorganic and organic compounds at electrolytically deposited beta-PbO2 film electrodes in 1.0M HClO4 are increased by doping the oxide with Bi(III). The rate constants at the mixed-oxide electrode rise sharply for a change from 0 to 10 mole percent (m/o) Bi(III) in the electrodeposition solution, and reach a mass transport-limited value for some compounds at 40 m/o Bi(III). Results of kinetic, voltammetric, and spectroscopic studies of these electrodes are described. In addition, the lifetime of Bi(III)-doped PbO2 film electrodes is discussed as a function of concentration, rotation speed, analyte, and applied voltage

  10. Electrodeposition of Co and Co-Fe Films on Platinum and on Copper Substrates

    Directory of Open Access Journals (Sweden)

    M. C. Vilchenski

    2003-01-01

    Full Text Available CoFe films were electrodeposited on platinum and copper from an acidic sulfate bath. The deposits surface morphology was analyzed using SEM and composition was determined by XPS. For deposition potentials lower than -0.80 V (SCE, the anodic stripping voltammogram showed a complex anodic current peak evidencing the complexity of the deposition process. Analysis of the deposition current transient curves showed that the nature of the substrate influenced the kinetic of the process: it was observed an instantaneous nucleation on Pt and a progressive nucleation on Cu. Pure cobalt and cobalt-iron films formed on Pt and on Cu presented binding energies for Co2p3/2 signal corresponding to cobalt oxide, while the Fe2p3/2 signal is related to metallic iron. The corresponding metallic cobalt was observed for the Co2p3/2 signal with binding energy of about 778.0 eV.

  11. Extremely durable biofouling-resistant metallic surfaces based on electrodeposited nanoporous tungstite films on steel

    Science.gov (United States)

    Tesler, Alexander B.; Kim, Philseok; Kolle, Stefan; Howell, Caitlin; Ahanotu, Onye; Aizenberg, Joanna

    2015-10-01

    Formation of unwanted deposits on steels during their interaction with liquids is an inherent problem that often leads to corrosion, biofouling and results in reduction in durability and function. Here we report a new route to form anti-fouling steel surfaces by electrodeposition of nanoporous tungsten oxide (TO) films. TO-modified steels are as mechanically durable as bare steel and highly tolerant to compressive and tensile stresses due to chemical bonding to the substrate and island-like morphology. When inherently superhydrophilic TO coatings are converted to superhydrophobic, they remain non-wetting even after impingement with yttria-stabilized-zirconia particles, or exposure to ultraviolet light and extreme temperatures. Upon lubrication, these surfaces display omniphobicity against highly contaminating media retaining hitherto unseen mechanical durability. To illustrate the applicability of such a durable coating in biofouling conditions, we modified naval construction steels and surgical instruments and demonstrated significantly reduced marine algal film adhesion, Escherichia coli attachment and blood staining.

  12. A study on electrodeposited NiFe1− alloy films

    Indian Academy of Sciences (India)

    M Bedir; Ö F Bakkaloğlu; İ H Karahan; M Öztaş

    2006-06-01

    NiFe1− (0.22 ≤ ≤ 0.62) alloy films were grown by electrodeposition technique. A shift in diffraction peaks of NiFe and Ni3Fe was detected with increasing Ni content. The highest positive magnetoresistance ratio was detected as 5% in Ni0.51Fe0.49. Positive and negative anisotropic magnetoresistance were observed in longitudinal and transverse geometries respectively. The highest anisotropic magnetoresistance ratio of 9.8% was also detected in Ni0.51Fe0.49. The angular variation of magnetoresistance was studied. Magnetisation loop curves show that NiFe alloy films have a linear decreasing anisotropy constant with increasing Ni deposit content and show a decreasing behavior of coercivity which indicates soft magnetic property with increasing Ni deposit content.

  13. Preparation of Bi2S3 thin films with a nanoleaf structure by electrodeposition method

    International Nuclear Information System (INIS)

    Nanoleaf-like Bi2S3 thin films were deposited on indium tin oxide (ITO) glass using Bi(NO3)3 and Na2S2O3 as precursors by a cathodic electrodeposition process. The as-deposited thin films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and photoluminescence spectrum (PL). The influence of precursor solution mole concentration ratios [Bi(NO3)3]/[Na2S2O3] on the phase compositions, morphologies and photoluminescence properties of the obtained thin films were investigated. Results show that a uniform Bi2S3 thin film with nanoleaf structure can be obtained with the precursor solution concentration ratio [Bi(NO3)3]/[Na2S2O3] = 1:7. The as-prepared thin films exhibit blue-green photoluminescence properties under ultraviolet light excitation. With the increase of concentration ratios [Bi(NO3)3]/[Na2S2O3] in the deposition solution, the crystallizations and PL properties of Bi2S3 thin films are obviously improved.

  14. Effect of samarium addition and annealing on the properties of electrodeposited ceria thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zivkovic, L. [Laboratoire d' Electrochimie, Chimie des Interfaces et Modelisation pour l' Energie, LECIME, CNRS UMR 7575, Chimie ParisTech (ENSCP)-Paris, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05 (France); The Vinca Institute of Nuclear Sciences, University of Belgrade, 11 001 Belgrade, PO BOX 522 (Serbia); Lair, V., E-mail: virginie-lair@ens.chimie-paristech.f [Laboratoire d' Electrochimie, Chimie des Interfaces et Modelisation pour l' Energie, LECIME, CNRS UMR 7575, Chimie ParisTech (ENSCP)-Paris, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05 (France); Lupan, O. [Laboratoire d' Electrochimie, Chimie des Interfaces et Modelisation pour l' Energie, LECIME, CNRS UMR 7575, Chimie ParisTech (ENSCP)-Paris, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05 (France); Department of Microelectronics and Semiconductor Devices, Technical University of Moldova, 168 Stefan cel Mare Blvd., Chisinau, MD-2004 (Moldova, Republic of); Ringuede, A. [Laboratoire d' Electrochimie, Chimie des Interfaces et Modelisation pour l' Energie, LECIME, CNRS UMR 7575, Chimie ParisTech (ENSCP)-Paris, 11 rue Pierre et Marie Curie, 75231 Paris cedex 05 (France)

    2011-03-31

    Samarium (Sm)-doped ceria (CeO{sub 2}) (SDC) is a promising material for high temperature electrochemical devices. Our work demonstrates that thin SDC films can be prepared by a cost-effective electrodeposition method at a low-temperature (30 {sup o}C) and - 0.8 V/SCE (saturated calomel electrode) potential. Analysis of the structural properties of the obtained SDC films, as-grown and annealed at 600 {sup o}C, has been carried out by X-ray diffraction (XRD). Morphology and film composition were studied using scanning electronic microscopy and energy dispersive X-ray analysis. Vibrational properties were determined by Raman spectroscopy. The effects of samarium addition into the deposition bath on the final film composition have been studied. According to XRD results, film crystallographic properties are directly linked to the percentage of Sm incorporated in the CeO{sub 2} lattice. We report on the electrochemical deposition of the SDC films performed over a large range of Sm additions (0-30%). The effect of temperature annealing has been studied as well.

  15. Red shift for CdTe nanoparticle thin films and suspensions during heating.

    Science.gov (United States)

    Dunn, S; Gardner, H C; Bertoni, C; Gallardo, D E; Gaponik, N; Eychmüller, A

    2008-05-01

    The work that we have conducted shows that temperature affects the wavelength of light emitted from CdTe nanoparticle clusters that are in a suspension or deposited into thin films via a layer-by-layer process. Compared with the stock suspension, the films show an initial photoluminescent shift, of circa 6-8 nm to the red, when the particles are deposited. A shift of circa 6-8 nm is also seen when the suspensions are first heated to 85 degrees C from room temperature (20 degrees C) having been stored in a fridge at 5 degrees C. This shift is non-recoverable. With continual cycling from room temperature to 85 degrees C the suspensions show a slight tendency for the emission to move increasingly to the red; whereas the films show no such tendency. In both cases, the range in emission is ca 10 nm from the room temperature state to 80 degrees C. The intensity of the emission from the film drops abruptly (ca 50% reduction) after one cycle of heating; in the suspension there is an initial increase (ca 3-5% increase) in intensity before it decays. We see that the shift towards the red has been attributed to energy transfer or a rearrangement of the packing of the particles in the thin films. After conducting analysis of the films using scanning probe microscopy we have determined that a change in the morphology is responsible for the permanent shift in emission wavelength associated with prolonged heating. The influence of traps has not been ruled out, but the morphological change in the samples is very large and is likely to be the dominating mechanism affecting change for the red shift at room temperature. PMID:18572681

  16. Effect of CdCl2 treatment on structural and electronic property of CdTe thin films deposited by magnetron sputtering

    International Nuclear Information System (INIS)

    The structural and electrical properties of the magnetron sputtered CdTe thin films with subsequent CdCl2 solution treatment have been studied with a major focus on the influence of CdCl2 treatment to achieve high quality thin films. In this study, CdTe films with a thickness of 1.5 to 2 μm have been grown using the magnetron sputtering technique on top of glass substrate at an optimized substrate temperature of 250 °C. Aqueous CdCl2 concentration varied from 0.3 mol to 1.2 mol with the annealing temperature from 360 °C to 450 °C. The surface roughness of the films increases with the increase of solution concentration, while it fluctuates with the increase of annealing temperature. The density of nucleation centers and the strain increases for the films treated at 360 °C with 0.3 M to1.2 M while the grain growth of the films reduces. However, these strains are released at higher annealing temperatures, resulting in reduced dislocation densities, structural defects as well as increased crystalline property and grain size. The carrier concentration increases with the increase of treated CdCl2 concentration and subsequent annealing temperature. The highest carrier concentration of 1.05 × 1014/cm3 was found for the CdTe thin films treated with 0.3 M CdCl2 solution followed by an annealing treatment at 420 °C for 20 min. - Highlights: • CdTe thin films are grown as absorption layers in CdTe solar cells by sputtering. • CdTe film quality in terms of structural and electronic properties is examined. • All growth parameters are optimized in the range of 1.5 to 2 μm CdTe films

  17. Effect of CdCl{sub 2} treatment on structural and electronic property of CdTe thin films deposited by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M.A. [Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Hossain, M.S.; Aliyu, M.M. [Department of Electrical, Electronic and Systems Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Karim, M.R. [Center of Excellence for Research in Engineering Materials (CEREM) College of Engineering, King Saud University, Riyadh, 11421 (Saudi Arabia); Razykov, T.; Sopian, K. [Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Amin, N., E-mail: nowshad@eng.ukm.my [Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Department of Electrical, Electronic and Systems Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Center of Excellence for Research in Engineering Materials (CEREM) College of Engineering, King Saud University, Riyadh, 11421 (Saudi Arabia)

    2013-11-01

    The structural and electrical properties of the magnetron sputtered CdTe thin films with subsequent CdCl{sub 2} solution treatment have been studied with a major focus on the influence of CdCl{sub 2} treatment to achieve high quality thin films. In this study, CdTe films with a thickness of 1.5 to 2 μm have been grown using the magnetron sputtering technique on top of glass substrate at an optimized substrate temperature of 250 °C. Aqueous CdCl{sub 2} concentration varied from 0.3 mol to 1.2 mol with the annealing temperature from 360 °C to 450 °C. The surface roughness of the films increases with the increase of solution concentration, while it fluctuates with the increase of annealing temperature. The density of nucleation centers and the strain increases for the films treated at 360 °C with 0.3 M to1.2 M while the grain growth of the films reduces. However, these strains are released at higher annealing temperatures, resulting in reduced dislocation densities, structural defects as well as increased crystalline property and grain size. The carrier concentration increases with the increase of treated CdCl{sub 2} concentration and subsequent annealing temperature. The highest carrier concentration of 1.05 × 10{sup 14}/cm{sup 3} was found for the CdTe thin films treated with 0.3 M CdCl{sub 2} solution followed by an annealing treatment at 420 °C for 20 min. - Highlights: • CdTe thin films are grown as absorption layers in CdTe solar cells by sputtering. • CdTe film quality in terms of structural and electronic properties is examined. • All growth parameters are optimized in the range of 1.5 to 2 μm CdTe films.

  18. CdTe thin film solar cells produced using a chamberless inline process via metalorganic chemical vapour deposition

    International Nuclear Information System (INIS)

    Cd1−xZnxS and CdTe:As thin films were deposited using a recently developed chamberless inline process via metalorganic chemical vapour deposition (MOCVD) at atmospheric pressure and assessed for fabrication of CdTe photovoltaic (PV) solar cells. Initially, CdS and Cd1−xZnxS coatings were applied onto 15 × 15 cm2 float glass substrates, characterised for their optical properties, and then used as the window layer in CdTe solar cells which were completed in a conventional MOCVD (batch) reactor. Such devices provided best conversion efficiency of 13.6% for Cd0.36Zn0.64S and 10% for CdS which compare favourably to the existing baseline MOCVD (batch reactor) devices. Next, sequential deposition of Cd0.36Zn0.64S and CdTe:As films was realised by the chamberless inline process. The chemical composition of a 1 μm CdTe:As/150 nm Cd0.36Zn0.64S bi-layer was observed via secondary ions mass spectroscopy, which showed that the key elements are uniformly distributed and the As doping level is suitable for CdTe device applications. CdTe solar cells formed using this structure provided a best efficiency of 11.8% which is promising for a reduced absorber thickness of 1.25 μm. The chamberless inline process is non-vacuum, flexible to implement and inherits from the legacy of MOCVD towards doping/alloying and low temperature operation. Thus, MOCVD enabled by the chamberless inline process is shown to be an attractive route for thin film PV applications. - Highlights: • CdS, CdZnS and CdTe thin films grown by a chamberless inline process • The inline films assessed for fabricating CdTe solar cells • 13.6% conversion efficiency obtained for CdZnS/CdTe cells

  19. Dependence of resistivity of electrodeposited Ni single layer and Ni/Cu multilayer thin films on the film thickness, and electron mean free path measurements of these films

    Directory of Open Access Journals (Sweden)

    Gholamreza Nabiyouni

    2007-09-01

    Full Text Available   The Boltzmann equation is a semiclassical approach to the calculation of the electrical conductivity. In this work we will first introduce a simple model for calculation of thin film resistivity and show that in an appropriate condition the resistivity of thin films depends on the electron mean free path, so that studying and measurement of thin films resistivity as a function of film thickness would lead to calculation of the electron mean free path in the films. Ni single layers and Ni/Cu multilayers were grown using electrodeposition technique in potentiostatic mode. The films also characterized using x-ray diffraction technique and the results show at least in the growth direction, the films were grown epitaxially and follow their substrate textures.

  20. Characterization of CdTe films with in situ CdCl{sub 2} treatment grown by a simple vapor phase deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Rios Flores, Araceli, E-mail: arios@mda.cinvestav.mx [Applied Physics Department, CINVESTAV-IPN Merida, C.P. 97310 Merida, Yucatan (Mexico); Castro-Rodriguez, R.; Pena, J.L. [Applied Physics Department, CINVESTAV-IPN Merida, C.P. 97310 Merida, Yucatan (Mexico); Romeo, N.; Bosio, A. [Dipartimento di fisica, Universita di Parma, Campus Universitario, Parco Area delle Scienza, 43100 Parma (Italy)

    2009-05-15

    A unique vapor phase deposition (VPD) technique was designed and built to achieve in situ CdCl{sub 2} treatment of CdTe film. The substrate temperature was 400 deg. C, and the temperature of CdTe mixture with CdCl{sub 2} source was 500 deg. C. The structural and morphological properties of CdTe have been studied as a function of wt.% CdCl{sub 2} concentration by using X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). XRD measurements show that the presence of CdCl{sub 2} vapor induces (1 1 1)-oriented growth in the CdTe film. SEM measurements have shown enhance growth of grains, in the presence of CdCl{sub 2}. From AFM the roughness of the films showed a heavy dependence on CdCl{sub 2} concentration. In the presence of 4% CdCl{sub 2} concentration, the CdTe films roughness has a root mean square (rms) value of about 275 A. This value is about 831 A for the non-treated CdTe films.

  1. Influence of thickness on physical properties of vacuum evaporated polycrystalline CdTe thin films for solar cell applications

    Science.gov (United States)

    Chander, Subhash; Dhaka, M. S.

    2016-02-01

    This paper presents the influence of thickness on physical properties of polycrystalline CdTe thin films. The thin films of thickness 450 nm, 650 nm and 850 nm were deposited employing thermal vacuum evaporation technique on glass and indium tin oxide (ITO) coated glass substrates. The physical properties of these as-grown thin films were investigated employing the X-ray diffraction (XRD), source meter, UV-Vis spectrophotometer, scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). The structural analysis reveals that the films have zinc-blende cubic structure and polycrystalline in nature with preferred orientation (111). The structural parameters like lattice constant, interplanar spacing, grain size, strain, dislocation density and number of crystallites per unit area are calculated. The average grain size and optical band gap are found in the range 15.16-21.22 nm and 1.44-1.63 eV respectively and observed to decrease with thickness. The current-voltage characteristics show that the electrical conductivity is observed to decrease with thickness. The surface morphology shows that films are free from crystal defects like pin holes and voids as well as homogeneous and uniform. The EDS patterns show the presence of cadmium and tellurium elements in the as grown films. The experimental results reveal that the film thickness plays significant role on the physical properties of as-grown CdTe thin films and higher thickness may be used as absorber layer to solar cells applications.

  2. Preparation and Properties of Evaporated CdTe and All Thin Film CdTe/CdS Solar Cells

    Science.gov (United States)

    Shahzad, Naseem

    1991-05-01

    Cadmium telluride thin films were prepared by vacuum evaporation of CdTe powder in an attempt to fabricate all thin film solar cells of the type CdTe/CdS. Characterization of CdTe has shown it to have a band gap of 1.522 eV and a resistivity of 22Ω-cm. As prepared, solar cells exhibited low values of output parameters. Given quantity of copper was then deposited on top of the CdTe/CdS solar cells and the whole system was annealed at 350° C. This copper doping changed the output parameters favorably with a maximum efficiency of 1.9%.

  3. A study on the electrodeposition of NiFe alloy thin films using chronocoulometry and electrochemical quartz crystal microgravimetry

    CERN Document Server

    Myung, N S

    2001-01-01

    Ni, Fe and NiFe alloy thin films were electrodeposited at a polycrystalline Au surface using a range of electrolytes and potentials. Coulometry and EQCM were used for real-time monitoring of electroplating efficiency of the Ni and Fe. The plating efficiency of NiFe alloy thin films was computed with the aid of ICP spectrometry. In general, plating efficiency increased to a steady value with deposition time. Plating efficiency of Fe was lower than that of Ni at -0.85 and -1.0 V but the efficiency approached to the similar plateau value to that of Ni at more negative potentials. The films with higher content of Fe showed different stripping behavior from the ones with higher content of Ni. Finally, compositional data and real-time plating efficiency are presented for films electrodeposited using a range of electrolytes and potentials.

  4. Effect of electrodeposition potential on composition and morphology of CIGS absorber thin film

    Indian Academy of Sciences (India)

    N D Sang; P H Quang; L T Tu; D T B Hop

    2013-08-01

    CuInGaSe (CIGS) thin films were deposited on Mo/soda-lime glass substrates by electrodeposition at different potentials ranging from −0.3 to −1.1 V vs Ag/AgCl. Cyclic voltammetry (CV) studies of unitary Cu, Ga, In and Se systems, binary Cu–Se, Ga–Se and In–Se systems and quaternary Cu–In–Ga–Se were carried out to understand the mechanism of deposition of each constituent. Concentration of the films was determined by energy dispersive spectroscopy. Structure and morphology of the films were characterized by X-ray diffraction and scanning electron microscope. The underpotential deposition mechanism of Cu–Se and In–Se phases was observed in voltammograms of binary and quaternary systems. Variation in composition with applied potentials was explained by cyclic voltammetry (CV) data. A suitable potential range from −0.8 to −1.0 V was found for obtaining films with desired and stable stoichiometry. In the post-annealing films, chalcopyrite structure starts forming in the samples deposited at −0.5 V and grows on varying the applied potential towards negative direction. By adjusting the composition of electrolyte, we obtained the desired stoichiometry of Cu(In0.7Ga0.3)Se2.

  5. Structural characterization of InSb thin films grown by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Joginder, E-mail: joginderchauhan82@gmail.com; Rajaram, P. [School of Studies in Physics, Jiwaji University, Gwalior-474011 (India)

    2015-06-24

    In the present work we have grown InSb thin films on brass substrates, using the electrodeposition technique. The electrochemical baths used in the growth were made up of aqueous solutions of InCl{sub 3} and SbCl{sub 3} mixed together in various proportions. The films grown were characterized by X-Ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive Analysis of X-rays (EDAX). Compositional studies show that stoichiometric InSb films can be prepared from a bath containing 0.05M InCl{sub 3} and 0.04M SbCl{sub 3}. XRD studies reveal that the films grown are polycrystalline having the zinc blende structure with (111) orientation. Crystallite size, dislocation density and strain were calculated using the XRD results. Optical transmission spectra were recorded using an FTIR spectrophotometer. The value of direct band gap was found to be around 0.20 eV for the thin films having the best stoichiometry.

  6. Electrodeposition of In2O3 thin films from a dimethylsulfoxide based electrolytic solution

    International Nuclear Information System (INIS)

    Indium (III) oxide (In2O3) thin films have been obtained after heat treatment of In(OH)3 precursor layers grown by a potential cycling electrodeposition (PCED) method from a dimethylsulfoxide (DMSO) based electrolytic solution onto fluorine-doped tin oxide (FTO) coated glass substrates. X-ray diffraction (XRD) measurements indicate the formation of a polycrystalline In2O3 phase with a cubic structure. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed a smooth morphology of the In2O3 thin films after an optimized heat treatment had been developed. The surface composition and chemical state of the semiconductor films was established by X-ray photoelectron spectroscopy analysis. The nature of the semiconductor material, flat band potential and donor density were determined from Mott-Schottky plots. This study reveals that the In2O3 films exhibited n-type conductivity with an average donor density of 2.2 x 1017 cm-3. The optical characteristics were determined through transmittance spectra. The direct and indirect band gap values obtained are according to the accepted values for the In2O3 films of 2.83 and 3.54 eV for the indirect and direct band gap values. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Thin-film-based CdTe photovoltaic module characterization: Measurements and energy prediction improvement

    Science.gov (United States)

    Lay-Ekuakille, A.; Arnesano, A.; Vergallo, P.

    2013-01-01

    Photovoltaic characterization is a topic of major interest in the field of renewable energy. Monocrystalline and polycrystalline modules are mostly used and, hence characterized since many laboratories have data of them. Conversely, cadmium telluride (CdTe), as thin-film module are, in some circumstances, difficult to be used for energy prediction. This work covers outdoor testing of photovoltaic modules, in particular that regarding CdTe ones. The scope is to obtain temperature coefficients that best predict the energy production. A First Solar (K-275) module has been used for the purposes of this research. Outdoor characterizations were performed at Department of Innovation Engineering, University of Salento, Lecce, Italy. The location of Lecce city represents a typical site in the South Italy. The module was exposed outdoor and tested under clear sky conditions as well as under cloudy sky ones. During testing, the global-inclined irradiance varied between 0 and 1500 W/m2. About 37 000 I-V characteristics were acquired, allowing to process temperature coefficients as a function of irradiance and ambient temperature. The module was characterized by measuring the full temperature-irradiance matrix in the range from 50 to 1300 W/m2 and from -1 to 40 W/m2 from October 2011 to February 2012. Afterwards, the module energy output, under real conditions, was calculated with the "matrix method" of SUPSI-ISAAC and the results were compared with the five months energy output data of the same module measured with the outdoor energy yield facility in Lecce.

  8. Low-resistivity Cu film electrodeposited with 3-N,N-dimethylaminodithiocarbamoyl-1-propanesulfonate for the application to the interconnection of electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sung Ki; Kim, Myung Jun; Koo, Hyo-Chol [Research Center for Energy Conversion and Storage, School of Chemical and Biological Engineering, Seoul National University, San 56-1, Shillim-dong, Kwanak-gu, Seoul, 151-744 (Korea, Republic of); Kwon, Oh Joong [Department of Mechanical Engineering, University of Incheon, 319 Incheondaegil, Nam-gu, Incheon, 402-749 (Korea, Republic of); Kim, Jae Jeong, E-mail: jjkimm@snu.ac.kr [Research Center for Energy Conversion and Storage, School of Chemical and Biological Engineering, Seoul National University, San 56-1, Shillim-dong, Kwanak-gu, Seoul, 151-744 (Korea, Republic of)

    2012-01-01

    In this study, we analyzed the properties of Cu films electrodeposited with 3-N,N-dimethylaminodithiocarbamoyl-1-propanesulfonate (DPS) as an organic additive in damascene Cu electrodeposition, in comparison with bis(sulfopropyl) disulfide (SPS). It was observed that the resistivity of Cu film electrodeposited with DPS was lower than that with SPS. Spectroscopic analyses showed that the impurity level and crystallinity of Cu films are almost the same, but the difference was found in the film roughness. Low roughness of Cu film electrodeposited with DPS led to the low resistivity, and it was speculated that the low roughness is related to the strong adsorption through the nitrogen atom in the DPS molecule.

  9. Design and optimization of large area thin-film CdTe detector for radiation therapy imaging applications

    International Nuclear Information System (INIS)

    Purpose: The authors investigate performance of thin-film cadmium telluride (CdTe) in detecting high-energy (6 MV) x rays. The utilization of this material has become technologically feasible only in recent years due to significant development in large area photovoltaic applications. Methods: The CdTe film is combined with a metal plate, facilitating conversion of incoming photons into secondary electrons. The system modeling is based on the Monte Carlo simulations performed to determine the optimized CdTe layer thickness in combination with various converter materials. Results: The authors establish a range of optimal parameters producing the highest DQE due to energy absorption, as well as signal and noise spatial spreading. The authors also analyze the influence of the patient scatter on image formation for a set of detector configurations. The results of absorbed energy simulation are used in device operation modeling to predict the detector output signal. Finally, the authors verify modeling results experimentally for the lowest considered device thickness. Conclusions: The proposed CdTe-based large area thin-film detector has a potential of becoming an efficient low-cost electronic portal imaging device for radiation therapy applications.

  10. A photoluminescence comparison of CdTe thin films grown by molecular-beam epitaxy, metalorganic chemical vapor deposition, and sputtering in ultrahigh vacuum

    Science.gov (United States)

    Feng, Z. C.; Bevan, M. J.; Krishnaswamy, S. V.; Choyke, W. J.

    1988-09-01

    High perfection CdTe thin films have been grown on (001) InSb and CdTe substrates by molecular-beam epitaxy, metalorganic chemical vapor deposition (MOCVD), and sputtering in ultrahigh vacuum techniques. The quality of the as-grown CdTe films are characterized by 2-K photoluminescence. The spectra show strong and sharp exciton transitions and weak 1.40-1.50-eV defect-related bands. Radiative defect densities of lower than 0.002 are realized. High-resolution spectroscopy shows that the full width at half maximum of the principal bound exciton lines is about 0.1 meV. Such small ρ values and narrow photoluminescence lines have not been previously reported. The largest luminescence efficiency is observed for MOCVD-CdTe films grown on CdTe substrates. A variety of impurities appear to be responsible for the observed radiative transitions in these three kinds of CdTe films. We attempt to assign the observed impurity related lines by a comparison with ``known'' impurities in bulk CdTe spectra given in the literature.

  11. Substrate heating effect on the growth of a CdTe film on an InSb substrate by vacuum evaporation

    Science.gov (United States)

    Jiann-Ruey, Chen; Mau-Phon, Houng; Fenq-Lin, Jenq; Chien-Shyong, Fang; Wan-Sun, Tse

    1991-07-01

    Epitaxial CdTe thin films were grown on the (111) oriented InSb substrate by vacuum evaporation, with the substrate kept at 190-225°C during the film deposition. The chamber pressure during film deposition was at 3.5 × 10-6 mbar. X-ray diffraction was used to determine the film structure, while the full width at half maximum (FWHM) of the X-ray diffraction peak was used to examine the crystallinity of the as-deposited films. The film morphology was observed by the scanning electron microscope (SEM), and the film composition was determined by electron probe microanalysis (EPMA). The film quality was examined by infrared transmission spectroscopy. Results indicate that the quality of the grown CdTe films was improved with the higher substrate temperature during the film deposition.

  12. Epitaxial growth of Bi ultra-thin films on GaAs by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Plaza, M. [Dpto. Fisica de Materiales, Universidad Complutense de Madrid, 28040 Madrid (Spain); Abuin, M. [Dpto. Fisica de Materiales, Universidad Complutense de Madrid, 28040 Madrid (Spain); Unidad Asociada IQFR(CSIC)-UCM, Madrid 28040 (Spain); Mascaraque, A., E-mail: arantzazu.mascaraque@fis.ucm.es [Dpto. Fisica de Materiales, Universidad Complutense de Madrid, 28040 Madrid (Spain); Unidad Asociada IQFR(CSIC)-UCM, Madrid 28040 (Spain); Gonzalez-Barrio, M.A. [Dpto. Fisica de Materiales, Universidad Complutense de Madrid, 28040 Madrid (Spain); Unidad Asociada IQFR(CSIC)-UCM, Madrid 28040 (Spain); Perez, L. [Dpto. Fisica de Materiales, Universidad Complutense de Madrid, 28040 Madrid (Spain); Instituto de Sistemas Optoelectronicos y Microtecnologia, Universidad Politecnica de Madrid, 28040 Madrid (Spain)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Electrodeposition of Bi films on GaAs substrates with different orientations. Black-Right-Pointing-Pointer Ultra thin films - 50 nm - are continuous and smooth. Black-Right-Pointing-Pointer Bi always grows with (0 1 L) orientations. Black-Right-Pointing-Pointer Epitaxial growth onto As terminated surfaces. Black-Right-Pointing-Pointer Proposed model based on structural and chemical considerations. - Abstract: We report on the growth of thin bismuth films on GaAs substrates with different orientations by means of electrochemical deposition. Atomic force microscopy reveals that the films are continuous and exhibit low roughness when they are grown under the appropriate overpotential. {omega}-2{theta} X-ray diffraction scans only show reflections that can be indexed as (0 1 L), meaning that Bi grows onto GaAs only in combinations of the (0 0 1) and (0 1 0) orientations. The matching between the GaAs substrate and the Bi layer has been studied by asymmetric X-ray scans, finding that Bi grows epitaxially on GaAs(1 1 0) and GaAs(1 1 1)B, both As-terminated surfaces. We explain these results by structural and chemical considerations.

  13. High electrical conductivity in out of plane direction of electrodeposited Bi2Te3 films

    Directory of Open Access Journals (Sweden)

    Miguel Muñoz Rojo

    2015-08-01

    Full Text Available The out of plane electrical conductivity of highly anisotropic Bi2Te3 films grown via electro-deposition process was determined using four probe current-voltage measurements performed on 4.6 - 7.2 μm thickness Bi2Te3 mesa structures with 80 - 120 μm diameters sandwiched between metallic film electrodes. A three-dimensional finite element model was used to predict the electric field distribution in the measured structures and take into account the non-uniform distribution of the current in the electrodes in the vicinity of the probes. The finite-element modeling shows that significant errors could arise in the measured film electrical conductivity if simpler one-dimensional models are employed. A high electrical conductivity of (3.2 ± 0.4 ⋅ 105 S/m is reported along the out of plane direction for Bi2Te3 films highly oriented in the [1 1 0] direction.

  14. Corrosion behaviour of super-hydrophobic electrodeposited nickel-cobalt alloy film

    Science.gov (United States)

    Khorsand, S.; Raeissi, K.; Ashrafizadeh, F.; Arenas, M. A.; Conde, A.

    2016-02-01

    Hierarchical super-hydrophobic Ni-Co film with enhanced corrosion resistance was fabricated on a copper substrate by one-step electrodeposition process. The contact angle and water repellence properties of the Ni-Co film were measured to determine its wettability. The Ni-Co film exhibited excellent super-hydrophobic properties with a static water contact angle of 158° and a sliding angle of ≤5°. The corrosion performance of the super-hydrophobic surface (SHS) was investigated by electrochemical potentiodynamic measurements and electrochemical impedance spectroscopy in NaCl solution (3.5 wt.%). Moreover, to study the long-term stability of the super-hydrophobic film, SHS samples were immersed into NaCl solution and their corrosion behaviour was investigated by the electrochemical impedance spectroscopy. Additionally, the changes of surface wettability were also monitored over the whole immersion time up to 11 days. Experimental results indicated that super-hydrophobic samples had much more corrosion resistance in comparison with freshly prepared samples or the bare substrate.

  15. CdTe devices and method of manufacturing same

    Science.gov (United States)

    Gessert, Timothy A.; Noufi, Rommel; Dhere, Ramesh G.; Albin, David S.; Barnes, Teresa; Burst, James; Duenow, Joel N.; Reese, Matthew

    2015-09-29

    A method of producing polycrystalline CdTe materials and devices that incorporate the polycrystalline CdTe materials are provided. In particular, a method of producing polycrystalline p-doped CdTe thin films for use in CdTe solar cells in which the CdTe thin films possess enhanced acceptor densities and minority carrier lifetimes, resulting in enhanced efficiency of the solar cells containing the CdTe material are provided.

  16. Influence of solution pH in electrodeposited iron diselenide thin films

    International Nuclear Information System (INIS)

    Highlights: → Number of works are available on preparation and characterization of iron diselenide thin films through some other techniques. → Among them, there are only few reports are available regarding growth and characterization of iron diselenide thin films through electrochemical route. → This is the first work to focus the solution pH effect in electrodeposited iron diselenide thin films. → Effect of solution pH on structural, morphological properties of the films are analyzed and reported. - Abstract: Thin films of iron diselenide (FeSe2) have been prepared on indium doped tin oxide coated conducting glass (ITO) substrates from an aqueous electrolytic bath containing FeSO4 and SeO2. Growth mechanism has been analyzed using cyclic voltammetry. The potential region in which the formation of FeSe2 occurs is found to be -450 mV versus SCE. X-ray diffraction analysis showed that the deposited films are found to exhibit orthorhombic structure with preferential orientation along (1 2 0) plane. X-ray line profile analysis has been carried out to determine the microstructural parameters such as crystallite size, rms microstrain, dislocation density and stacking fault probability. Surface morphology and film composition have been analyzed using scanning electron microscopy, atomic force microscopy and energy dispersive analysis by X-rays, respectively. Optical parameters such as band gap, refractive index, extinction coefficient, real and imaginary dielectric constants, dielectric susceptibility and optical conductivity have been determined from optical absorption measurements. The observed results are discussed in detail.

  17. Efficient Electrochemical Water Splitting Catalyzed by Electrodeposited Nickel Diselenide Nanoparticles Based Film.

    Science.gov (United States)

    Pu, Zonghua; Luo, Yonglan; Asiri, Abdullah M; Sun, Xuping

    2016-02-01

    In this contribution, we demonstrate that electrodeposited nickel diselenide nanoparticles based film on conductive Ti plate (NiSe2/Ti) is an efficient and robust electrode to catalyze both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in basic media. Electrochemical experiments show this electrode affords 10 mA cm(-2) at HER overpotential of 96 mV and 20 mA cm(-2) at OER overpotential of 295 mV with strong durability in 1.0 M KOH. The corresponding two-electrode alkaline water electrolyzer requires a cell voltage of only 1.66 V to achieve 10 mA cm(-2) water-splitting current. This development provides us an attractive non-noble-metal catalyst toward overall water splitting applications. PMID:26824878

  18. Roughness development in electrodeposited soft magnetic CoNiFe films in the presence of organic additives

    Directory of Open Access Journals (Sweden)

    STEVE RIEMER

    2003-05-01

    Full Text Available The effects of three additives, sodium lauryl sulfate (NaLS, saccharin (Sacc, and NaLS + Sacc, on roughness development during the electrodeposition of CoNiFe films were investigated. The characterization of these films by atomic force microscopy shows that the electrodeposits produced from NaLS containing solution result in a rough surface. The role of NaLS surfactant is to change the interfacial tension and clean non-polar species like hydrogen bubbles from the surface. In Sacc containing solution, the evolution of a smooth surface is controlled by adsorbed Sacc molecule at the interface. The kinetic roughening of these deposits was investigated by dynamic scaling analysis. It was demonstrated that the roughness of CoNiFe films, obtained in the presence of NaLS + Sacc additives, was also dependent on current density, roughness of substrate, and the temperature of plating bath.

  19. Analysis of Electrodeposited Nickel-Iron Alloy Film Composition Using Particle-Induced X-Ray Emission

    Directory of Open Access Journals (Sweden)

    Alyssa A. Frey

    2011-01-01

    Full Text Available The elemental composition of electrodeposited NiFe thin films was analyzed with particle-induced X-ray emission (PIXE. The thin films were electrodeposited on polycrystalline Au substrates from a 100 mM NiSO4, 10 mM FeSO4, 0.5 M H3BO3, and 1 M Na2SO4 solution. PIXE spectra of these films were analyzed to obtain relative amounts of Ni and Fe as a function of deposition potential and deposition time. The results show that PIXE can measure the total deposited metal in a sample over at least four orders of magnitude with similar fractional uncertainties. The technique is also sensitive enough to observe the variations in alloy composition due to sample nonuniformity or variations in deposition parameters.

  20. Optical and structural characterization of oleic acid-stabilized CdTe nanocrystals for solution thin film processing

    OpenAIRE

    Claudio Davet Gutiérrez-Lazos; Mauricio Ortega-López; Pérez-Guzmán, Manuel A; A. Mauricio Espinoza-Rivas; Francisco Solís-Pomar; Rebeca Ortega-Amaya; L. Gerardo Silva-Vidaurri; Virginia C. Castro-Peña; Eduardo Pérez-Tijerina

    2014-01-01

    This work presents results of the optical and structural characterization of oleic acid-stabilized cadmium telluride nanocrystals (CdTe-NC) synthesized by an organometallic route. After being cleaned, the CdTe-NC were dispersed in toluene to obtain an ink-like dispersion, which was drop-cast on glass substrate to deposit a thin film. The CdTe-NC colloidal dispersion as well as the CdTe drop-cast thin films were characterized with regard to the optical and structural properties. TEM analysis i...

  1. Enhanced electrochemiluminescence of CdTe quantum dots with carbon nanotube film and its sensing of methimazole

    International Nuclear Information System (INIS)

    A novel analytical method was reported based on electrochemiluminescence (ECL) of CdTe quantum dots (QDs) using carbon nanotube (CNT) modified glass carbon (GC) electrode. It was found that the CNT film on the GC electrode could greatly enhance the ECL intensity of CdTe QDs dispersed in aqueous solution, and the ECL peak potential and ECL onset potential both shifted positively. Influences of some factors on the ECL intensity were investigated using CNT modified GC electrode, and a high sensitive method for the determination of methimazole was developed under the optimal conditions. The ECL intensity decreased linearly in the concentration range of 1.0 x 10-9 to 4.0 x 10-7 M for methimazole with the relative coefficient of 0.995, which showed finer sensitivity than that at bare electrode. Thus, CNT modified electrode would have a great merit to expand the application of QD ECL

  2. Characterization of Sputtered CdTe Thin Films with Electron Backscatter Diffraction and Correlation with Device Performance.

    Science.gov (United States)

    Nowell, Matthew M; Scarpulla, Michael A; Paudel, Naba R; Wieland, Kristopher A; Compaan, Alvin D; Liu, Xiangxin

    2015-08-01

    The performance of polycrystalline CdTe photovoltaic thin films is expected to depend on the grain boundary density and corresponding grain size of the film microstructure. However, the electrical performance of grain boundaries within these films is not well understood, and can be beneficial, harmful, or neutral in terms of film performance. Electron backscatter diffraction has been used to characterize the grain size, grain boundary structure, and crystallographic texture of sputtered CdTe at varying deposition pressures before and after CdCl2 treatment in order to correlate performance with microstructure. Weak fiber textures were observed in the as-deposited films, with (111) textures present at lower deposition pressures and (110) textures observed at higher deposition pressures. The CdCl2-treated samples exhibited significant grain recrystallization with a high fraction of twin boundaries. Good correlation of solar cell efficiency was observed with twin-corrected grain size while poor correlation was found if the twin boundaries were considered as grain boundaries in the grain size determination. This implies that the twin boundaries are neutral with respect to recombination and carrier transport. PMID:26077102

  3. Spin-Coated vs. Electrodeposited Mn Oxide Films as Water Oxidation Catalysts

    Directory of Open Access Journals (Sweden)

    Simelys Hernández

    2016-04-01

    Full Text Available Manganese oxides (MnOx, being active, inexpensive and low-toxicity materials, are considered promising water oxidation catalysts (WOCs. This work reports the preparation and the physico-chemical and electrochemical characterization of spin-coated (SC films of commercial Mn2O3, Mn3O4 and MnO2 powders. Spin coating consists of few preparation steps and employs green chemicals (i.e., ethanol, acetic acid, polyethylene oxide and water. To the best of our knowledge, this is the first time SC has been used for the preparation of stable powder-based WOCs electrodes. For comparison, MnOx films were also prepared by means of electrodeposition (ED and tested under the same conditions, at neutral pH. Particular interest was given to α-Mn2O3-based films, since Mn (III species play a crucial role in the electrocatalytic oxidation of water. To this end, MnO2-based SC and ED films were calcined at 500 °C, in order to obtain the desired α-Mn2O3 crystalline phase. Electrochemical impedance spectroscopy (EIS measurements were performed to study both electrode charge transport properties and electrode–electrolyte charge transfer kinetics. Long-term stability tests and oxygen/hydrogen evolution measurements were also made on the highest-performing samples and their faradaic efficiencies were quantified, with results higher than 95% for the Mn2O3 SC film, finally showing that the SC technique proposed here is a simple and reliable method to study the electrocatalytic behavior of pre-synthesized WOCs powders.

  4. Electrical and magnetic properties of electrodeposited nickel incorporated diamond-like carbon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, B., E-mail: pandey.beauty@yahoo.com [Department of Applied Physics, Indian School of Mines, Dhanbad 826004 (India); Das, D. [UGC-DAE CSR, Sector III/LB-8, Bidhan Nagar, Kolkata 700098 (India); Kar, A.K. [Department of Applied Physics, Indian School of Mines, Dhanbad 826004 (India)

    2015-05-15

    Highlights: • Electrical and magnetic properties of DLC and Ni-DLC thin films are studied. • The ohmicity and conductivity of DLC films rise with nickel addition. • The ohmicity of Ni-DLC is enhanced with increase in dilution of electrolyte. • Dielectric loss is high for Ni-DLC and decreases with frequency till 100 kHz. • (m–H) and (m–T) curves of Ni-DLC indicate superparamagnetic behavior. - Abstract: Nanocomposite diamond-like carbon (DLC) thin films have been synthesized by incorporating nickel (Ni) nanoparticles in DLC matrix with varying concentration of nickel. DLC and Ni-DLC thin films have been deposited on ITO coated glass substrates employing low voltage electrodeposition method. Electrical properties of the samples were studied by measuring current–voltage characteristics and dielectric properties. The current approaches toward an ohmic behavior with metal addition. This tendency of increasing ohmicity is enhanced with increase in dilution of the electrolyte. The conductivity increases with Ni addition and interestingly it continues to increase with dilution of Ni concentration in the electrolyte in the range of our study. Magnetic properties for DLC and Ni-DLC thin film samples were examined by electron paramagnetic resonance (EPR) measurements and Super Conducting Quantum Interference Device (SQUID) measurements. g-Value for DLC is 2.074, whereas it decreases to 2.055 with Ni addition in the electrolyte. This decrement arises from the increased sp{sup 2} content in DLC matrix. The magnetic moment vs. magnetic field (m–H) curves of Ni-DLC indicate superparamagnetic behavior which may be due to ferromagnetic contribution from the incorporated nickel nanoparticles in the DLC matrix. The ZFC curve of Ni-DLC after the blocking temperature shows a combined contribution of ferromagnetic, superparamagnetic and paramagnetic nature of the materials persisting up to 300 K.

  5. Pulsed electrodeposition of oxygen-free tin monosulfide thin films using lactic acid/sodium lactate buffered electrolytes

    International Nuclear Information System (INIS)

    In this study, tin monosulfide (SnS) thin films have been prepared on indium-tin-oxide-covered glass substrates from an acidic electrolyte containing a pH buffer of lactic acid/sodium lactate using pulsed electrodeposition method. Results from Auger electron spectroscopy confirmed that nearly oxygen-free and stoichiometric SnS thin films were attained. X-ray diffraction and scanning electron micrograph studies indicated the formation of a smooth α-SnS thin film with the orthorhombic structure. Moreover, optical transmission spectroscopy showed a direct optical band gap of 1.39 eV and the photoelectrochemical measurements revealed the p-type conductivity.

  6. M(o)ssbauer study of the field induced uniaxial anisotropy in electro-deposited FeCo alloy films

    Institute of Scientific and Technical Information of China (English)

    Li Zhi-Wei; Yang Xu; Wang Hai-Bo; Liu Xin; Li Fa-Shen

    2009-01-01

    Thin ferromagnetic films with in-plane magnetic anisotropy are promising materials for obtaining high microwave permeability. The paper reports a M(o)ssbauer study of the field induced in-plane uniaxial anisotropy in electro-deposited FeCo alloy films. The FeCo alloy films were prepared by the electro-deposition method with and without an external magnetic field applied parallel to the film plane during deposition, Vibrating sample magnetometry and M(o)ssbauer spectroscopy measurements at room temperature indicate that the film deposited in external field shows an in-plane uniaxial anisotropy with an easy direction coinciding with the external field direction and a hard direction perpendicular to the field direction, whereas the film deposited without external field does not show any in-plane anisotropy. M(o)ssbauer spectra taken in three geometric arrangements show that the magnetic moments are almost constrained in the film plane for the film deposited with applied magnetic field. Also, the magnetic moments tend to align in the direction of the applied external magnetic field during deposition, indicating that the observed anisotropy should be attributed to directional ordering of atomic pairs.

  7. Innovative sputtering techniques for CIS and CdTe submodule fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, J.M.; Misra, M.S.; Lanning, B. (Martin Marietta Aerospace, Denver, CO (United States). Astronautics Group)

    1993-03-01

    This report describes work done during Phase 1 of the subject subcontract. The subcontract was designed to study innovative deposition techniques, such as the rotating cylindrical magnetron sputtering system and electrodeposition for large-area, low-cost copper indium diselenide (CIS) and cadmium telluride (CdTe) devices. A key issue for photovoltaics (PV) in terrestrial and future space applications is producibility, particularly for applications using a large quantity of PV. Among the concerns for fabrication of polycrystalline thin-film PV, such as CIS and CdTe, are production volume, cost, and minimization of waste. Both rotating cylindrical magnetron (C-Mag[trademark]) sputtering and electrodeposition have tremendous potential for the fabrication of polycrystalline thin-film PV due to scaleability, efficient utilization of source materials, and inherently higher deposition rates. In the case of sputtering, the unique geometry of the C-Mae facilitates innovative cosputtering and reactive sputtering that could lead to greater throughput reduced health and safety risks, and, ultimately, lower fabrication cost. Electrodeposited films appear to be adherent and comparable with low-cost fabrication techniques. Phase I involved the initial film and device fabrication using the two techniques mentioned herein. Devices were tested by both internal facilities, as well as NREL and ISET.

  8. Highly Luminescent Hybrid SiO2-Coated CdTe Quantum Dots Retained Initial Photoluminescence Efficiency in Sol-Gel SiO2 Film.

    Science.gov (United States)

    Sun, Hongsheng; Xing, Yugui; Wu, Qinan; Yang, Ping

    2015-02-01

    A highly luminescent silica film was fabricated using tetraethyl orthosilicate (TEOS) and 3-aminopropyltrimethoxysilane (APS) through a controlled sol-gel reaction. The pre-hydrolysis of TEOS and APS which resulted in the mixture of TEOS and APS in a molecular level is a key for the formation of homogenous films. The aminopropyl groups in APS play an important role for obtaining homogeneous film with high photoluminescence (PL). Red-emitting hybrid SiO2-coated CdTe nano-crystals (NCs) were fabricated by a two-step synthesis including a thin SiO2 coating via a sol-gel process and a subsequent refluxing using green-emitting CdTe NCs. The hybrid SiO2-coated CdTe NCs were embedded in a functional SiO2 film via a two-step process including adding the NCs in SiO2 sol with a high viscosity and almost without ethanol and a subsequent spinning coating. The hybrid SiO2-coated CdTe NCs retained their initial PL efficiency (54%) in the film. Being encapsulated with the hybrid NCs in the film, no change on the absorption and PL spectra of red-emitting CdTe NCs (632 nm) was observed. This indicates the hybrid NCs is stable enough during preparation. This phenomenon is ascribed to the controlled sol-gel process and a hybrid SiO2 shell on CdTe NCs. Because these films exhibited high PL efficiency and stability, they will be utilizable for potential applications in many fields. PMID:26353691

  9. Morphology-controlled electrodeposition of Cu2O microcrystalline particle films for application in photocatalysis under sunlight

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted Highlights: ► PEG was used to electro-deposit Cu2O microcrystalline particle films. ► Morphologies of Cu2O microcrystals could be controlled by the amount of PEG. ► The films showed regularly varied photocatalytic activities under sunlight. ► The films could be recycled and showed stable activities. -- Abstract: Morphology-controlled Cu2O microcrystalline particle films had been successfully electrodeposited on tin-doped indium oxide glass substrates in CuSO4 solutions containing different amounts of polyethylene glycol (PEG) additives. With an increase of PEG, microcrystals gradually changed from irregular shapes to cubes, octahedrons, and spherical shapes. Sizes increasingly became smaller with an increase of PEG under the same deposition time. These films had been first used as recyclable photocatalysts and showed excellent and photocatalytic activities in photodegradation of methylene blue (MB) under sunlight. Activities were regularly varied relative to the morphologies of films controlled by the amount of PEG and could be further enhanced by adding a little amount of hydrogen peroxide in the MB solution. The method for controllable preparation of Cu2O microcrystals with photocatalytic activities was simple and inexpensive. The as-prepared particle films could also be used in photodegradation of many other pollutants under sunlight.

  10. Corrosion resistance and long-term durability of super-hydrophobic nickel film prepared by electrodeposition process

    International Nuclear Information System (INIS)

    A super-hydrophobic nickel film with micro-nano structure was successfully fabricated by electrodeposition process. By controlling electrodeposition parameters and considering different storage times for the coatings in air, various nickel films with different wettability were fabricated. Surface morphology of nickel films was examined by means of scanning electron microscopy (SEM). The results showed that the micro-nano nickel film was well-crystallized and exhibited pine cone-like microstructure with nano-cone arrays randomly dispersed on each micro-protrusion. The wettability of the micro-nano nickel film varied from super-hydrophilicity (water contact angle 5.3°) to super-hydrophobicity (water contact angle 155.7°) by exposing the surface in air at room temperature. The corrosion resistance of the super-hydrophobic film was estimated by electrochemical impedance spectroscopy (EIS) and Tafel polarization measurements. The potentiodynamic curves revealed that the corrosion rate of superhydrophobic surface was only 0.16% of the bare copper substrate. Moreover, EIS measurements and appropriate equivalent circuit models revealed that the corrosion resistance of nickel films considerably improved with an increase in the hydrophobicity. The superhydrophobic surface also exhibited an excellent long-term durability in neutral 3.5 wt.% NaCl solution.

  11. Corrosion resistance and long-term durability of super-hydrophobic nickel film prepared by electrodeposition process

    Energy Technology Data Exchange (ETDEWEB)

    Khorsand, S., E-mail: s.khorsand@ma.iut.ac.ir; Raeissi, K., E-mail: k_raeissi@cc.iut.ac.ir; Ashrafizadeh, F., E-mail: ashrafif@cc.iut.ac.ir

    2014-06-01

    A super-hydrophobic nickel film with micro-nano structure was successfully fabricated by electrodeposition process. By controlling electrodeposition parameters and considering different storage times for the coatings in air, various nickel films with different wettability were fabricated. Surface morphology of nickel films was examined by means of scanning electron microscopy (SEM). The results showed that the micro-nano nickel film was well-crystallized and exhibited pine cone-like microstructure with nano-cone arrays randomly dispersed on each micro-protrusion. The wettability of the micro-nano nickel film varied from super-hydrophilicity (water contact angle 5.3°) to super-hydrophobicity (water contact angle 155.7°) by exposing the surface in air at room temperature. The corrosion resistance of the super-hydrophobic film was estimated by electrochemical impedance spectroscopy (EIS) and Tafel polarization measurements. The potentiodynamic curves revealed that the corrosion rate of superhydrophobic surface was only 0.16% of the bare copper substrate. Moreover, EIS measurements and appropriate equivalent circuit models revealed that the corrosion resistance of nickel films considerably improved with an increase in the hydrophobicity. The superhydrophobic surface also exhibited an excellent long-term durability in neutral 3.5 wt.% NaCl solution.

  12. Photoconductivity of CdTe Nanocrystal-Based Thin Films. Te2- Ligands Lead To Charge Carrier Diffusion Lengths Over 2 Micrometers

    Energy Technology Data Exchange (ETDEWEB)

    Crisp, Ryan W. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Callahan, Rebecca [National Renewable Energy Lab. (NREL), Golden, CO (United States); Reid, Obadiah G. [Univ. of Colorado, Boulder, CO (United States); Dolzhnikov, Dmitriy S. [Univ. of Chicago, IL (United States); Talapin, Dmitri V. [Univ. of Chicago, IL (United States); Rumbles, Garry [National Renewable Energy Lab. (NREL), Golden, CO (United States); Luther, Joseph M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kopidakis, Nikos [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-11-16

    We report on photoconductivity of films of CdTe nanocrystals (NCs) using time-resolved microwave photoconductivity (TRMC). Spherical and tetrapodal CdTe NCs with tunable size-dependent properties are studied as a function of surface ligand (including inorganic molecular chalcogenide species) and annealing temperature. Relatively high carrier mobility is measured for films of sintered tetrapod NCs (4 cm2/(V s)). Our TRMC findings show that Te2- capped CdTe NCs show a marked improvement in carrier mobility (11 cm2/(V s)), indicating that NC surface termination can be altered to play a crucial role in charge-carrier mobility even after the NC solids are sintered into bulk films.

  13. Health, safety and environmental risks from the operation of CdTe and CIS thin-film modules

    International Nuclear Information System (INIS)

    This paper identifies the materials embedded in on a type of CIS (Copper indium diselenide) and four different types of CdTe (cadmium telluride) thin-film modules. It refers to the results of our outdoor leaching experiments on photovoltaic (PV) samples broken into small fragments. Estimations for modules accidents on the roof or in the garden of a residential house, e.g. leaching of hazardous materials into water or soil, are given. The outcomes of our estimations show some module materials released into water or oil during leaching accidents. In a worst-case scenario for CdTe modules the leached cadmium concentration in the collected water is estimated to be no higher than the German drinking water limit concentration. For the CIS module scenario the estimated leached element concentrations are about one to two orders of magnitude below the German drinking water limit concentration. For broken CIS and CdTe modules on the ground no critical increase of the natural element concentration is observed after leaching into the soil for 1 year. (Author)

  14. Study of the electrodeposition of rhenium thin films by electrochemical quartz microbalance and X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Rhenium thin films were prepared by electrodeposition from an aqueous solution containing 0.1 M Na2SO4+H2SO4, pH 2 in presence of y mM HReO4. As substrates polycrystalline gold (y=0.75 mM HReO4) and monocrystalline n-Si(100) (y=40 mM HReO4) were used. The electrochemical growth of rhenium was studied by cyclic voltammetry and electrochemical quartz microbalance on gold electrodes. The results found in the potential region before the hydrogen evolution reaction (her) showed that ReO3, ReO2 and Re2O3 with different hydration grades can be formed. In the potential region where the her is occurring, either on gold or n-Si(100) the electrodeposition of metallic rhenium takes place. On both substrates, rhenium films were formed by electrolysis at constant potential and X-ray photoelectron spectroscopy technique was used to characterise these deposits. It was concluded that the electrodeposited films were of metallic rhenium and only the uppermost atomic layer contained rhenium oxide species

  15. Orientation of CdTe epitaxial films on GaAs(100) grown by vacuum evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Houng Mauphon; Fu Shenli; Jenq Fenqlin (Dept. of Electrical Engineering, National Cheng-Kung Univ., Tainan (Taiwan)); Chen Jiannruey (Dept. of Materials Science and Engineering, National Tsing Hua Univ., Hsinchu (Taiwan))

    1991-08-15

    The growth of (100)- and (111)-oriented CdTe epitaxial layers on (100)-oriented GaAs substrates were investigated. Ar{sup +} plasma bombardment was used to remove the surface oxide layer, while preheating the substrate before evaporation was performed to deplete arsenic on the GaAs substrate surface. Results indicate that the CdTe(100) will grow on GaAs(100) with an oxide layer remaining on the surface. For the GaAs(100) substrate with the oxide layer removed by plasma bombardment, CdTe(100) will grow on the arsenic-depleted GaAs substrate, while CdTe(111) will grow on the GaAs substrate without arsenic depletion. A model is proposed that a tellurium-rich surface is formed on the arsenic-depleted GaAs surface through Ga-Te bonding on which the CdTe(100) will grow, whereas CdTe(111) will grow on a tellurium-poor surface. The photoluminescence investigation conforms to our proposed model. (orig.).

  16. Electrochemical and surface characterisation of oxide films on nano-grain nickel films electrodeposited on INCOLOY-800

    International Nuclear Information System (INIS)

    Nano materials have different properties from the corresponding bulk materials because of fine grain size, large fraction of surface atoms, high surface energy and high grain boundary volume fraction. For similar reasons, the nano-alloy coatings show superior high-temperature corrosion resistance and are generally more resistant to stress corrosion cracking. Hence, it is of interest to know the materials performance, if the structural materials used in nuclear reactors are made of nano-grains. In Indian PHWRs, Incoloy-800 is being used as the steam generator tubing material. It's corrosion resistance property is very important as it forms not only the pressure boundary between the radioactive primary water and non-active secondary water but also from the view point of loss of heavy water, in case of any corrosion damage. In this paper, the corrosion resistance of the oxide films formed on nano-grain nickel film electrodeposited on Incoloy-800 (a) in the presence of saccharine (WS) and (b) in the absence of saccharine (WOS) were compared with that formed on Commercial Ni foil, using electrochemical dc polarization and ac impedance techniques. The surface morphology, elemental analysis and grain size were studied with SEM, EDX and XRD techniques respectively. The nano-grain nickel films were prepared on Incoloy-800 by electrodeposition using Watt's Bath with saccharine sodium as a surfactant. The oxide films were developed by exposing them to LiOH solution (pH-10.0) at 245 deg C for 3 days (A-group) and 7 days (B-group). XRD results showed that the grain size of Ni formed in the absence of saccharine (WOS) was ∼ 60 nm and did not change after being autoclaved. But, for Ni formed in the presence of saccharine (WS), the grain size was ∼ 16 nm which increased to 40-50 nm after being autoclaved. With both A and B-group specimens, the PDAP curves showed an active-passive transition, a passive region and a transpassive region in 2N H2SO4. However, the critical current

  17. [Spectral analyzing effects of atmosphere states on the structure and characteristics of CdTe polycrystalline thin films made by close-spaced sublimation].

    Science.gov (United States)

    Zheng, Hua-jing; Zheng, Jia-gui; Feng, Liang-huan; Zhang, Jing-quan; Xie, Er-qing

    2005-07-01

    The structure and characteristics of CdTe thin films are dependent on the working atmosphere states in close-spaced sublimation. In the present paper, CdTe polycrystalline thin films were deposited by CSS in mixture atmosphere of argon and oxygen. The physical mechanism of CSS was analyzed, and the temperature distribution in CSS system was measured. The dependence of preliminary nucleus creation on the atmosphere states (involving component and pressure) was studied. Transparencies were measured and optic energy gaps were calculated. The results show that: (1) The CdTe films deposited in different atmospheres are cubic structure. With increasing oxygen concentration, a increases and reaches the maximum at 6% oxygen concentration, then reduces, and increases again after passing the point at 12% oxygen concentration. Among them, the sample depositing at 9% oxygen concentration is the best. The optic energy gaps are 1.50-1.51 eV for all CdTe films. (2) The samples depositing at different pressures at 9% oxygen concentration are all cubical structure of CdTe, and the diffraction peaks of CdS and SnO2:F still appear. With the gas pressure increasing, the crystal size of CdTe minishes, the transparency of the thin film goes down, and the absorption side shifts to the short-wave direction. (3) The polycrystalline thin films with high quality deposit in 4 minutes under the depositing condition that the substrate temperature is 550 degrees C, and source temperature is 620 degrees C at 9% oxygen concentration. PMID:16241058

  18. CZTS absorber layer for thin film solar cells from electrodeposited metallic stacked precursors (Zn/Cu-Sn)

    Science.gov (United States)

    Khalil, M. I.; Atici, O.; Lucotti, A.; Binetti, S.; Le Donne, A.; Magagnin, L.

    2016-08-01

    In the present work, Kesterite-Cu2ZnSnS4 (CZTS) thin films were successfully synthesized from stacked bilayer precursor (Zn/Cu-Sn) through electrodeposition-annealing route. Adherent and homogeneous Cu-poor, Zn-rich stacked metal Cu-Zn-Sn precursors with different compositions were sequentially electrodeposited, in the order of Zn/Cu-Sn onto Mo foil substrates. Subsequently, stacked layers were soft annealed at 350 °C for 20 min in flowing N2 atmosphere in order to improve intermixing of the elements. Then, sulfurization was completed at 585 °C for 15 min in elemental sulfur environment in a quartz tube furnace with N2 atmosphere. Morphological, compositional and structural properties of the films were investigated using SEM, EDS and XRD methods. Raman spectroscopy with two different excitation lines (514.5 and 785 nm), has been carried out on the sulfurized films in order to fully characterize the CZTS phase. Higher excitation wavelength showed more secondary phases, but with low intensities. Glow discharge optical emission spectroscopy (GDOES) has also been performed on films showing well formed Kesterite CZTS along the film thickness as compositions of the elements do not change along the thickness. In order to investigate the electronic structure of the CZTS, Photoluminescence (PL) spectroscopy has been carried out on the films, whose results matched up with the literatures.

  19. Characterization of Highly Efficient CdTe Thin Film Solar Cells by the Capacitance-Voltage Profiling Technique

    Science.gov (United States)

    Okamoto, Tamotsu; Yamada, Akira; Konagai, Makoto

    2000-05-01

    The electrical properties of highly efficient CdTe thin film solar cells prepared by close-spaced sublimation (CSS) were investigated by capacitance-voltage (C-V) measurement. According to the dependence of the cell performance on the substrate temperature in the CSS process, the open-circuit voltage (Voc) increased with increasing the substrate temperature below 630°C@. The carrier concentration profiles revealed that the net acceptor concentration exponentially increased from the CdS/CdTe interface to the rear and that the acceptor concentration increased with increasing substrate temperature. This result suggests that Voc is improved as a result of the increase in the acceptor concentration.

  20. Oxygen Nanodistributions in Cobalt-Iron Electrodeposited Thin Films: Some Effects on Magnetic Properties High Resolution Analytical Electron Microscopy

    Science.gov (United States)

    Elhalawaty, Shereen

    Soft magnetic alloys play a significant role for magnetic recording applications and highly sensitivity magnetic field sensors. In order to sustain the magnetic areal density growth, development of new synthesis techniques and materials is necessary. In this work, the effect of oxygen incorporation during electrodeposition of CoFe alloys on magnetic properties, magnetoresistance and structural properties has been studied. Understanding the magnetic properties often required knowledge of oxygen distribution and structural properties of the grown films. Transmission electron microscopy (TEM) was a powerful tool in this study to correlate the oxygen-distribution nanostructure to the magnetic properties of deposited films. Off-axis electron holography in TEM was used to measure magnetic domain wall width in the deposited films. Elemental depth profiles of Fe, Co, O were investigated by secondary ion mass spectroscopy (SIMS). Magnetic properties have been determined by superconducting quantum interference device (SQUID) measurements. Oxygen content in the CoFe deposited films was controlled by electrolyte composition. Films were deposited on Si 100 substrates and on other substrates such as Cu and Al. However, a good film quality was achieved on Si substrate. Electron energy loss and x-ray spectroscopies showed that the low oxygen films contained intragranular Fe2+ oxide (FeO) particles and that the high oxygen films contained intergranular Fe 3+ (Fe2O3) along grain boundaries. The films with oxide present at the grain boundary had significantly increased coercivity, magnetoresistance and reduced saturation magnetization relative to the lower oxygen content films with intragranular oxide. The differences in magnetic properties between low oxygen and high oxygen concentration films were attributed to stronger mobile domain wall interactions with the grain boundary oxide layers. The very high magnetoresistance values were achieved for magnetic devices with nanocontact

  1. Single-step electrodeposition of a microcrystalline Cu2ZnSnSe4 thin film with a kesterite structure

    International Nuclear Information System (INIS)

    Highlights: ► Investigation of a single-step electrodeposition synthesis of a Cu2ZnSnSe4 thin film on a Mo-coated glass substrate. ► Cu2ZnSnSe4 as a main phase was obtained at appropriate applied potential ranges. ► Sulfurization of the as-deposited film at temperatures higher than 500 °C led to the formation of single-phase CZTSSe films. ► Sulfurized films exhibited p-type photoresponses. -- Abstract: Single-step electrodeposition synthesis of a Cu2ZnSnSe4 (CZTSe) film on a Mo-coated glass substrate from an acidic electrolyte containing Cu(II), Zn(II), Sn(IV), and Se(IV) species was investigated. The desired CZTSe film as the main phase was obtained at some selected applied potential ranges through reaction among binary selenides, Cu2Se, ZnSe and SnSe2, which were continuously formed in the present electrolyte containing all of the elements. Sulfurization of the as-deposited film at several temperatures under H2S gas flow resulted in the formation of corresponding mixed compounds of CZTSe and Cu2ZnSnS4 (CZTS), i.e., Cu2ZnSn(S,Se)4 (CZTSSe): specifically, sulfurization at temperatures higher than 500 °C resulted in the formation of single-phase CZTSSe with S-rich compositions. By analyzing linear sweep voltammograms (LSVs) of sulfurized films under chopped irradiation, the films were confirmed to have p-type photoresponses; the film obtained by 500 °C sulfurization showed the largest photoresponse because of its sufficiently large grain size and less voids, whereas the presence of an anodic spike in the LSV curve as well as the observation of a broad external quantum efficiency (EQE) spectrum suggested the requirement of further improvement in film quality for photovoltaic application

  2. Effective Ag doping by He-Ne laser exposure to improve the electrical and the optical properties of CdTe thin films for heterostructured thin film solar cells

    International Nuclear Information System (INIS)

    The cadmium telluride (CdTe) thin film solar cell is one of the strongest candidates due to the optimum band gap energy (about 1.4 eV) for solar energy absorption, high light absorption capability and lower cost requirements for solar cell production. However, the maximum efficiency of a CdTe thin film solar cell still remains just 16.5% despite its excellent absorption coefficient; i.e., the electrical properties of CdTe thin film, including the resistivity, must be improved to enhance the energy conversion efficiency. Silver (Ag) was doped by using helium-neon (He-Ne) laser (632.8 nm) exposure into sputtering-deposited p-type CdTe thin films. The resistivity of the Ag-doped CdTe thin films was reduced from 2.97 x 104 Ω-cm to the order of 5.16 x 10'-'2 Ω-cm. The carrier concentration of CdTe thin films had increased to 1.6 x 1018 cm-3 after a 15-minute exposure to the He-Ne laser. The average absorbance value of CdTe thin films was improved from 1.81 to 3.01 by the doping of Ag due to impurity-scattering. These improved properties should contribute to the efficiency of the photovoltaic effect of the photogenerated charged carriers. The methodology in this study is very simple and effective to dope a multilayered thin film solar cell with a relatively short process time, no wet-process, and selective treatment.

  3. Synthesis and tribological behaviors of diamond-like carbon films by electrodeposition from solution of acetonitrile and water

    International Nuclear Information System (INIS)

    Diamond-like carbon (DLC) films were prepared on silicon substrates by liquid phase electrodeposition from a mixture of acetonitrile and deionized water. The deposition voltage was clearly reduced owing to the presence of deionized water in the electrolyte by changing the basic properties (dielectric constant and dipole moment) of the electrolyte. Raman spectra reveal that the ratio of sp3/sp2 in the DLC films is related to the concentration of acetonitrile. The surface roughness and grain morphology determined by atomic force microscopy are also influenced by the concentration of the acetonitrile. The UMT-2 universal micro-tribometer was used to test the friction properties of the DLC films obtained from electrolytes with different concentration. The results convey that the DLC film prepared from the electrolyte containing 10 vol.% acetonitrile has the better surface morphology and friction behavior comparing with the other. In addition the growth mechanism of the film was also discussed

  4. Exploring sulfur solubility in ionic liquids for the electrodeposition of sulfide films with their electrochemical reactivity toward lithium

    International Nuclear Information System (INIS)

    Metal binary sulfides (TiS2, FeS2), in either powder or thin film forms, were the first studied Li insertion electrodes for rechargeable lithium batteries, with thin films made mainly by sputtering. Here we exploit the equilibrium solubility of molecular sulfur into ionic liquids at its melting point (120 °C), which we estimated to be at a maximum level of 80 mM by both electrochemical and microwave studies, to prepare thin films of both Co9S8 and FeSx showing initial capacities of 559 mAh g−1 and 708 mAh g−1 versus lithium in coin cells, respectively. We demonstrate that the growth of Co9S8 films involves the reaction of soluble sulfur with the electrodeposited Co metallic layer, while the formation of FeSx films enlists a precipitation between the reduced Fe(II) cations and the electrochemically produced Sxy− species in the ionic liquid bath. Such findings, namely the solubility of sulfur into ionic liquids, open opportunities to electrodeposit sulfur-based compounds as well as capture sulfur from various media enabling a better environment

  5. The influence of electrochemical pre-treatment of B-doped diamond films on the electrodeposition of Pt

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Mauro C.; Silva, Leide G. da; Sumodjo, Paulo T.A. [Sao Paulo Univ., SP (Brazil). Inst. de Quimica]. E-mail: ptasumod@iq.usp.br

    2006-08-15

    The influence of the substrate electrochemical pre-treatment in 0.5 mol L{sup -1} H{sub 2}SO{sub 4} on the Pt electrodeposition on boron-doped diamond, BDD, film electrodes was investigated. Platinum cannot be electrodeposited on a freshly prepared BDD electrode; however, potentiodynamic cycling or anodic potential steps at short times does activate the electrode. Anodic pre-treatment plays a dual role in the behavior of Pt deposition on BDD surfaces: Pt deposition is increased at short-term anodic pre-treatments, whereas at longer pre-treatment times Pt deposition was inhibited. These facts are explained in terms of wettability changes and passivation of the surface. Conversely, the oxide layer formed in these treatments increases the dispersion level of the catalyst. (author)

  6. Atomic-resolution characterization of the effects of CdCl2 treatment on poly-crystalline CdTe thin films

    Science.gov (United States)

    Paulauskas, T.; Buurma, C.; Colegrove, E.; Guo, Z.; Sivananthan, S.; Chan, M. K. Y.; Klie, R. F.

    2014-08-01

    Poly-crystalline CdTe thin films on glass are used in commercial solar-cell superstrate devices. It is well known that post-deposition annealing of the CdTe thin films in a CdCl2 environment significantly increases the device performance, but a fundamental understanding of the effects of such annealing has not been achieved. In this Letter, we report a change in the stoichiometry across twin boundaries in CdTe and propose that native point defects alone cannot account for this variation. Upon annealing in CdCl2, we find that the stoichiometry is restored. Our experimental measurements using atomic-resolution high-angle annular dark field imaging, electron energy-loss spectroscopy, and energy dispersive X-ray spectroscopy in a scanning transmission electron microscope are supported by first-principles density functional theory calculations.

  7. Optimization of the Electrodeposition Parameters to Improve the Stoichiometry of In2S3 Films for Solar Applications Using the Taguchi Method

    Directory of Open Access Journals (Sweden)

    Maqsood Ali Mughal

    2014-01-01

    Full Text Available Properties of electrodeposited semiconductor thin films are dependent upon the electrolyte composition, plating time, and temperature as well as the current density and the nature of the substrate. In this study, the influence of the electrodeposition parameters such as deposition voltage, deposition time, composition of solution, and deposition temperature upon the properties of In2S3 films was analyzed by the Taguchi Method. According to Taguchi analysis, the interaction between deposition voltage and deposition time was significant. Deposition voltage had the largest impact upon the stoichiometry of In2S3 films and deposition temperature had the least impact. The stoichiometric ratios between sulfur and indium (S/In: 3/2 obtained from experiments performed with optimized electrodeposition parameters were in agreement with predicted values from the Taguchi Method. The experiments were carried out according to Taguchi orthogonal array L27 (3^4 design of experiments (DOE. Approximately 600 nm thick In2S3 films were electrodeposited from an organic bath (ethylene glycol-based containing indium chloride (InCl3, sodium chloride (NaCl, and sodium thiosulfate (Na2S2O3·5H2O, the latter used as an additional sulfur source along with elemental sulfur (S. An X-ray diffractometer (XRD, energy dispersive X-ray spectroscopy (EDS unit, and scanning electron microscope (SEM were, respectively, used to analyze the phases, elemental composition, and morphology of the electrodeposited In2S3 films.

  8. Optical and structural characterization of oleic acid-stabilized CdTe nanocrystals for solution thin film processing

    Directory of Open Access Journals (Sweden)

    Claudio Davet Gutiérrez-Lazos

    2014-06-01

    Full Text Available This work presents results of the optical and structural characterization of oleic acid-stabilized cadmium telluride nanocrystals (CdTe-NC synthesized by an organometallic route. After being cleaned, the CdTe-NC were dispersed in toluene to obtain an ink-like dispersion, which was drop-cast on glass substrate to deposit a thin film. The CdTe-NC colloidal dispersion as well as the CdTe drop-cast thin films were characterized with regard to the optical and structural properties. TEM analysis indicates that the CdTe-NC have a nearly spherical shape (3.5 nm as mean size. Electron diffraction and XRD diffraction analyses indicated the bulk-CdTe face-centered cubic structure for CdTe-NC. An additional diffraction line corresponding to the octahedral Cd3P2 was also detected as a secondary phase, which probably originates by reacting free cadmium ions with trioctylphosphine (the tellurium reducing agent. The Raman spectrum exhibits two broad bands centered at 141.6 and 162.3 cm−1, which could be associated to the TO and LO modes of cubic CdTe nanocrystals, respectively. Additional peaks located in the 222 to 324 cm−1 range, agree fairly well with the wavenumbers reported for TO modes of octahedral Cd3P2.

  9. Eects of Post Deposition Treatments on Vacuum Evaporated CdTe Thin Films and CdS=CdTe Heterojunction Devices

    Science.gov (United States)

    Bayhan, Habibe; Erçelebý, Çiðdem

    1998-05-01

    CdTe, CdS thin films and n-CdS/p-CdTe heterostructures have been prepared by conventional vacuum evaporation technique. Some post deposition treatments to optimize the device efficiency have been analyzed and the effects of the individual process steps on the material and device properties were investigated. Annealing in air with and without CdCl2-treatment decreased the CdTe resistivity. The CdCl2-dip followed by annealing in air at 300°C for 5 min improved the grain size and polycrystalline nature of CdTe thin films. Solar efficiency improvements were achieved when heterojunctions were prepared on successively treated (i.e. etched, air annealed, CdCl2-processed) CdTe surfaces. Etching of the CdTe surface with potassium dichromate solution prior to metal contact deposition lead to the formation of low-resistance Au contacts and increase in open circuit voltage and fill factor values.

  10. Phase-Change Memory Properties of Electrodeposited Ge-Sb-Te Thin Film

    Science.gov (United States)

    Huang, Ruomeng; Kissling, Gabriela P.; Jolleys, Andrew; Bartlett, Philip N.; Hector, Andrew L.; Levason, William; Reid, Gillian; De Groot, C. H. `Kees'

    2015-11-01

    We report the properties of a series of electrodeposited Ge-Sb-Te alloys with various compositions. It is shown that the Sb/Ge ratio can be varied in a controlled way by changing the electrodeposition potential. This method opens up the prospect of depositing Ge-Sb-Te super-lattice structures by electrodeposition. Material and electrical characteristics of various compositions have been investigated in detail, showing up to three orders of magnitude resistance ratio between the amorphous and crystalline states and endurance up to 1000 cycles.

  11. Investigation on the electrodeposition of Pt-(Bi,Sb)2Te3 nanocomposite as film and wires

    International Nuclear Information System (INIS)

    In this work we have investigated the electrochemical processes by which Pt nanoparticles were included in (Bi,Sb)2Te3 films and submicrometer wires. Solutions containing ions of Bi3+, HTeO2+ and Sb3+ as well as Pt nanoparticles or [PtCl6]2− ions were used for this study. For comparison, a solution with the same composition in Bi3+, HTeO2+ and Sb3+ ions was used to study the electrodeposition process of (Bi,Sb)2Te3 films and submicrometer wires. Linear and cyclic voltammetry was employed in experiments to find the influences of addition to electrodeposition bath of Pt nanoparticles or [PtCl6]2− ions on deposition process of (Bi,Sb)2Te3 film. Pt-(Bi,Sb)2Te3 nanocomposites has been characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectrometry (EDX) to determine structural, morphological and compositional properties. Two mechanisms for Pt nanoparticles embedding in (Bi,Sb)2Te3 films and wires have been proposed

  12. Influence of secondary phases during annealing on re-crystallization of CuInSe{sub 2} electrodeposited films

    Energy Technology Data Exchange (ETDEWEB)

    Gobeaut, A. [Laboratoire de Reactivite et Chimie des Solides, 33 rue St Leu, 80039 Amiens (France); Laffont, L., E-mail: lydia.laffont@u-picardie.f [Laboratoire de Reactivite et Chimie des Solides, 33 rue St Leu, 80039 Amiens (France); Tarascon, J.-M. [Laboratoire de Reactivite et Chimie des Solides, 33 rue St Leu, 80039 Amiens (France); Parissi, L.; Kerrec, O. [Institut de Recherche et de Developpement de l' Energie Photovoltaique, 6 quai Watier, 78401 Chatou cedex (France)

    2009-06-01

    Electrodeposited CuInSe{sub 2} thin films are of potential importance, as light absorber material, in the next generation of photovoltaic cells as long as we can optimize their annealing process to obtain dense and highly crystalline films. The intent of this study was to gain a basic understanding of the key experimental parameters governing the structural-textural-composition evolution of thin films as function of the annealing temperature via X-ray diffraction, scanning/transmission electron microscopy and thermal analysis measurements. The crystallization of the electrodeposited CuInSe{sub 2} films, with the presence of Se and orthorhombic Cu{sub 2} {sub -} {sub x}Se (o-Cu{sub 2} {sub -} {sub x}Se) phases, occurs over two distinct temperature ranges, between 220 {sup o}C and 250 {sup o}C and beyond 520 {sup o}C. Such domains of temperature are consistent with the melting of elemental Se and the binary CuSe phase, respectively. The CuSe phase forming during annealing results from the reaction between the two secondary species o-Cu{sub 2} {sub -} {sub x}Se and Se (o-Cu{sub 2} {sub -} {sub x}Se + Se {yields} 2 CuSe) but can be decomposed into the cubic {beta}-Cu{sub 2} {sub -} {sub x}Se phase by slowing down the heating rate. Formation of liquid CuSe beyond 520{sup o}C seems to govern both the grain size of the films and the porosity of the substrate-CuInSe{sub 2} film interface. A simple model explaining the competitive interplay between the film crystallinity and the interface porosity is proposed, aiming at an improved protocol based on temperature range, which will enable to enhance the film crystalline nature while limiting the interface porosity.

  13. Recent Developments of Flexible CdTe Solar Cells on Metallic Substrates: Issues and Prospects

    Directory of Open Access Journals (Sweden)

    M. M. Aliyu

    2012-01-01

    Full Text Available This study investigates the key issues in the fabrication of CdTe solar cells on metallic substrates, their trends, and characteristics as well as effects on solar cell performance. Previous research works are reviewed while the successes, potentials, and problems of such technology are highlighted. Flexible solar cells offer several advantages in terms of production, cost, and application over glass-based types. Of all the metals studied as substrates for CdTe solar cells, molybdenum appears the most favorable candidate, while close spaced sublimation (CSS, electrodeposition (ED, magnetic sputtering (MS, and high vacuum thermal evaporation (HVE have been found to be most common deposition technologies used for CdTe on metal foils. The advantages of these techniques include large grain size (CSS, ease of constituent control (ED, high material incorporation (MS, and low temperature process (MS, HVE, ED. These invert-structured thin film CdTe solar cells, like their superstrate counterparts, suffer from problems of poor ohmic contact at the back electrode. Thus similar strategies are applied to minimize this problem. Despite the challenges faced by flexible structures, efficiencies of up to 13.8% and 7.8% have been achieved in superstrate and substrate cell, respectively. Based on these analyses, new strategies have been proposed for obtaining cheaper, more efficient, and viable flexible CdTe solar cells of the future.

  14. Synthesis of CuInSe2 thin films from electrodeposited Cu11In9 precursors by two-step annealing

    Directory of Open Access Journals (Sweden)

    TSUNG-WEI CHANG

    2014-02-01

    Full Text Available In this study, copper indium selenide (CIS films were synthesized from electrodeposited Cu-In-Se precursors by two-step annealing. The agglomeration phenomenon of the electrodeposited In layer usually occurred on the Cu surface. A thermal process was adopted to turn Cu-In precursors into uniform Cu11In9 binary compounds. After deposition of the Se layer, annealing was employed to form chalcopyrite CIS. However, synthesis of CIS from Cu11In9 requires sufficient thermal energy. Annealing temperature and time were investigated to grow high quality CIS film. Various electrodeposition conditions were investigated to achieve the proper atomic ratio of CIS. The properties of the CIS films were characterized by scanning electron microscopy (SEM, X-ray Diffraction (XRD, and Raman spectra.

  15. High-Efficiency CdTe and CIGS Thin-Film Solar Cells: Highlights and Challenges; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Noufi, R.; Zweibel, K.

    2006-05-01

    Thin-film photovoltaic (PV) modules of CdTe and Cu(In,Ga)Se2 (CIGS) have the potential to reach cost-effective PV-generated electricity. These technologies have transitioned from the laboratory to the market place. Pilot production and first-time manufacturing are ramping up to higher capacity and enjoying a flood of venture-capital funding. CIGS solar cells and modules have achieved 19.5% and 13% efficiencies, respectively. Likewise, CdTe cells and modules have reached 16.5% and 10.2% efficiencies, respectively. Even higher efficiencies from the laboratory and from the manufacturing line are only a matter of time. Manufacturing-line yield continues to improve and is surpassing 85%. Long-term stability has been demonstrated for both technologies; however, some failures in the field have also been observed, emphasizing the critical need for understanding degradation mechanisms and packaging options. The long-term potential of the two technologies require R&D emphasis on science and engineering-based challenges to find solutions to achieve targeted cost-effective module performance, and in-field durability. Some of the challenges are common to both, e.g., in-situ process control and diagnostics, thinner absorber, understanding degradation mechanisms, protection from water vapor, and innovation in high-speed processing and module design. Other topics are specific to the technology, such as lower-cost and fast-deposition processes for CIGS, and improved back contact and voltage for CdTe devices.

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

    Science.gov (United States)

    Pedigo, Aaron E.

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

  17. Eects of Post Deposition Treatments on Vacuum Evaporated CdTe Thin Films and CdS=CdTe Heterojunction Devices

    OpenAIRE

    BAYHAN, Habibe; ERÇELEBİ, Çiğdem

    1998-01-01

    CdTe, CdS thin films and n-CdS/p-CdTe heterostructures have been prepared by conventional vacuum evaporation technique. Some post deposition treatments to optimize the device efficiency have been analyzed and the effects of the individual process steps on the material and device properties were investigated. Annealing in air with and without CdCl2-treatment decreased the CdTe resistivity. The CdCl2-dip followed by annealing in air at 300\\circC for 5 min improved the grain size and polycrystal...

  18. A Comparative Study on the Optical Properties of Multilayer CdSe / CdTe Thin Film with Single Layer CdTe and CdSe Films

    Directory of Open Access Journals (Sweden)

    M. Melvin David Kumar

    2013-07-01

    Full Text Available CdTe and CdSe single layer thin films and CdSe / CdTe multilayer (ML thin film were prepared by using physical vapour deposition method. Optical properties of CdSe / CdTe multilayer thin film shows different behavior due to type II band structure alignment. Energy band gap value of CdSe / CdTe ML thin film is shifted to higher value than that of single layer CdTe film. This is due to decrease in crystallite size to dimension smaller than the Bohr exciton radius of CdTe (14 nm. Crystallite size of the multilayer sample was calculated with the predictions of the effective mass approximation model (i.e., Brus model. It is observed that the photoluminescence peak of CdSe / CdTe ML thin film is red shifted compared to the peaks corresponding to individual CdSe and CdTe thin films. This may be due to the presence of type II quantum dot formation in the CdSe / CdTe heterostructure multilayer thin film.

  19. Influence of a Boron Precursor on the Growth and Optoelectronic Properties of Electrodeposited Zinc Oxide Thin Film.

    Science.gov (United States)

    Tsin, Fabien; Thomere, Angélica; Bris, Arthur Le; Collin, Stéphane; Lincot, Daniel; Rousset, Jean

    2016-05-18

    Highly transparent and conductive materials are required for many industrial applications. One of the interesting features of ZnO is the possibility to dope it using different elements, hence improving its conductivity. Results concerning the zinc oxide thin films electrodeposited in a zinc perchlorate medium containing a boron precursor are presented in this study. The addition of boron to the electrolyte leads to significant effects on the morphology and crystalline structure as well as an evolution of the optical properties of the material. Varying the concentration of boric acid from 0 to 15 mM strongly improves the compactness of the deposit and increases the band gap from 3.33 to 3.45 eV. Investigations were also conducted to estimate and determine the influence of boric acid on the electrical properties of the ZnO layers. As a result, no doping effect effect by boron was demonstrated. However, the role of boric acid on the material quality has also been proven and discussed. Boric acid strongly contributes to the growth of high quality electrodeposited zinc oxide. The high doping level of the film can be attributed to the perchlorate ions introduced in the bath. Finally, a ZnO layer electrodeposited in a boron rich electrolyte was tested as front contact of a Cu(In, Ga)(S, Se)2 based solar cell. An efficiency of 12.5% was measured with a quite high fill factor (>70%) which confirms the high conductivity of the ZnO thin film. PMID:27111517

  20. Chemical and microstructural study in radio frequency sputtered CdTe oxide films prepared at different N{sub 2}O pressures. Oxygen incorporation and film resputtering

    Energy Technology Data Exchange (ETDEWEB)

    Caballero-Briones, F. [CICATA-IPN Unidad Altamira, Km 14.5 Carretera Tampico-Puerto Industrial Altamira, 89600, Altamira, Tamps (Mexico)], E-mail: fcaballerobriones@ub.edu; Oliva, A.I.; Bartolo-Perez, P. [Applied Physics Department, CINVESTAV-IPN Unidad Merida, A.P. 73 Cordemex, 97310 Merida, Yucatan (Mexico); Zapata-Navarro, A. [CICATA-IPN Unidad Legaria, Legaria 694 Col. Irrigacion 11500, Mexico, D.F. (Mexico); Pena, J.L. [Applied Physics Department, CINVESTAV-IPN Unidad Merida, A.P. 73 Cordemex, 97310 Merida, Yucatan (Mexico)

    2008-10-01

    CdTe oxide films were grown by radio frequency sputtering in Ar-N{sub 2}O plasma at different N{sub 2}O partial pressures. The film oxygen content determined by Auger electron spectroscopy ranged from 15 to 60 at.%. The free O{sub 2} production during film deposition was monitored by in situ mass spectroscopy and it was found that it increases linearly over a critical N{sub 2}O pressure {approx} 4.7 x 10{sup -3} Pa alike the oxygen in the films. Film microstructure was studied by Raman spectroscopy and atomic force microscopy. Evidence of bands related to terminal Te-O vibrations was found in films prepared below the N{sub 2}O critical pressure, becoming predominant in films with higher oxygen content. The morphology and roughness evolution of the films confirm that they consist of a mixture of phases. Surface structures of the Ia-type and of the Ib-type were observed below and above the critical N{sub 2}O pressure. Eventually, ion bombardment process caused film resputtering.

  1. Chemical and microstructural study in radio frequency sputtered CdTe oxide films prepared at different N2O pressures. Oxygen incorporation and film resputtering

    International Nuclear Information System (INIS)

    CdTe oxide films were grown by radio frequency sputtering in Ar-N2O plasma at different N2O partial pressures. The film oxygen content determined by Auger electron spectroscopy ranged from 15 to 60 at.%. The free O2 production during film deposition was monitored by in situ mass spectroscopy and it was found that it increases linearly over a critical N2O pressure ∼ 4.7 x 10-3 Pa alike the oxygen in the films. Film microstructure was studied by Raman spectroscopy and atomic force microscopy. Evidence of bands related to terminal Te-O vibrations was found in films prepared below the N2O critical pressure, becoming predominant in films with higher oxygen content. The morphology and roughness evolution of the films confirm that they consist of a mixture of phases. Surface structures of the Ia-type and of the Ib-type were observed below and above the critical N2O pressure. Eventually, ion bombardment process caused film resputtering

  2. Size dependent electron transfer from CdTe quantum dots linked to TiO2 thin films in quantum dot sensitized solar cells

    International Nuclear Information System (INIS)

    In this present study, we demonstrate the size dependent charge transfer from CdTe quantum dots (QDs) into TiO2 substrate and relate this charge transfer to the actual behavior of a CdTe sensitized solar cell. CdTe QDs was synthesized using mercaptopropionic acid as the capping agent. The conduction band offset for TiO2 and CdTe QDs indicates thermodynamically favorable band edge positions for smaller QDs for the electron-transfer at the QD–TiO2 interface. Time-resolved emission studies were carried out for CdTe QD on glass and CdTe QD on TiO2 substrates. Results on the quenching of QD luminescence, which relates to the transfer kinetics of electrons from the QD to the TiO2 film, showed that at the smaller QD sizes the transfer kinetics are much more rapid than at the larger sizes. I–V characteristics of quantum dot sensitized solar cells (QDSSC) with different sized QDs were also investigated indicating higher current densities at smaller QD sizes consistent with the charge transfer results. The maximum injection rate constant and photocurrent were obtained for 2.5 nm CdTe QDs. We have been able to construct a solar cell with reasonable characteristics (Voc = 0.8 V, Jsc = 1 mA cm−2, FF = 60%, η = 0.5%). - Highlights: • Size dependant charge transfer from quantum dots to TiO2. • Smaller quantum dot sizes promote higher current densities in solar cell. • Smaller quantum dots have favorable band edge positions and transport kinetics

  3. Influence of post-deposition heat treatment on optical properties derived from UV–vis of cadmium telluride (CdTe) thin films deposited on amorphous substrate

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Annealing-induced change in optical parameters of CdTe film was derived from UV–vis study. • Optical constants of the films were evaluated using Swanepoel method. • Dispersion energy data obeyed the single oscillator of the Wemple−Didomenico model. • Cd deficiency of the film confirmed the p-type conductive nature. - Abstract: In this work, we report on post-deposition heat treatment (annealing)-induced change in optical properties derived from UV–vis study of CdTe thin films prepared on amorphous glass substrate by electron beam evaporation technique. Annealing effect gives rise to the enhancement in crystalline nature (zinc blende structure) of CdTe films with (1 1 1) preferred orientation. The average transmittance was increased with the annealing temperature and the slight shift in transmission threshold towards higher wavelength region revealed the systematic reduction in optical energy band gap. The existence of shallow level just below the conduction band, within the band gap was identified in the range of 0.23 and 0.14 eV for the films annealed at 200 and 450 °C, respectively. The optical quality of deposited films was confirmed by the photoluminescence study. In addition, the scanning electron microscopic measurement supports the result of X-ray diffraction study. The Swanepoel, Hervé-Vandamme, and Wemple−DiDomenico models have been employed to evaluate the various optical parameters of CdTe films. These results are correlated well with other physical properties and discussed with the possible concepts underlying the phenomena

  4. Cd-Te-In oxide thin films as possible transparent buffer layer in CdTe based solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Castro-Rodriguez, R; Camacho, J M; Pena, J L [Applied Physics Department, CINVESTAV-IPN Merida, C.P. 97310, Merida, Yucatan (Mexico); Martel, A; Mendez-Gamboa, J, E-mail: romano@mda.cinvestav.m [Facultad de Ingenieria, Universidad Autonoma de Yucatan. AP 150 Cordemex, 97310 Merida, Yucatan (Mexico)

    2009-05-01

    Cd-Te-In-oxide thin films were grown by Pulsed Laser Deposition (PLD) technique using CdTe powder embedded in a matrix of indium metallic as target. The films were deposited at different oxygen pressures (P{sub o2}) from 15 to 50 mTorr at substrate temperature of 420{sup 0}C. Sheet resistance (R{sub sheet}) and transmission spectrum were measured as a function of P{sub o2}. From measurements of optical transmission, the Photonic Flux Density (PFD) spectrum were obtained and the integral of these PFD for each film were evaluated between energy range of 1.5 eV and 2.4 eV for obtain the amount of photons that can be transferred across the film in this range of solar energy spectrum. These values were evaluated over the R{sub sheet} to be used as a figure of merit. The best choice in our conditions was the films with P{sub o2} =28.5 mTorr, where the figure of merit reaches the maximum value.

  5. Effect of thickness and cold substrate on transport properties of thermally evaporated CdTe thin films

    Energy Technology Data Exchange (ETDEWEB)

    El-Mongy, A.Abd; Hashem, H.M.; Ramadan, A.A. [Physics Department, Faculty of Science, Helwan University, Helwan, Cairo (Egypt)

    2005-08-01

    The correlation between the structural characteristics (stoichiometry and crystallite size) of CdTe films and their electronic transport properties were the aims of the present study to bring attention to the dual importance of grain size and conversion of the semiconductivity type with changing film thickness. Two main parameters were considered: the substrate temperature and film thickness. Transport properties were influenced by grain boundaries as well as by native doping. Optical measurements showed two main direct transitions at energies: E{sub 1} {approx}1.55 eV (fundamental gap) and E{sub 2}{approx}2.49 eV (due to valence band splitting). Both transitions were found to be thickness dependent with a marked change at a film thickness of about 300 nm. In the case of low substrate temperature, the scaling relation between resistivity and grain size showed a deviation from linear behavior at a size of 20 nm and the transmission coefficient is reduced. Also, the deposition on cold substrate enhanced both dark and photoconductivity for films of thickness {>=}300 nm. It is also proved that the carrier transport was affected by the transmission coef-ficient for carriers to pass a single grain boundary as well as the number of grain boundaries per mean free path. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Raman investigation on thin and thick CdTe films obtained by close spaced vacuum sublimation technique

    International Nuclear Information System (INIS)

    The CdTe thin and thick films were obtained by the close spaced vacuum sublimation technique on a glass substrate under the following growth conditions: the evaporator temperature was 620 C; and the substrate temperature was varied in the range from 250 C to 550 C. High purity CdTe powder was used as a charge for evaporation. The Raman spectra were measured using TRIAX 320 and TRIAX 550 spectrometers at room temperature. The 488-nm line and 514.5-nm line of an Ar+ laser and a 785-nm diode laser were used as excitation sources. The signal was collected by the liquid nitrogen cooled charge-coupled-device (CCD) detector. A number of intense Raman peaks at 140, 167, 190, 271, 332 and 493 cm-1 were observed and were interpreted as TO (140 cm-1), 1LO (167 cm-1), 2LO (332 cm-1), 3LO (493 cm-1) phonon modes and plasmon-phonon mode (190 cm-1). The presence of several phonon replicas in the Raman spectra confirms high crystal quality of the samples. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Growth of ZnO nanowires through thermal oxidation of metallic zinc films on CdTe substrates

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, O., E-mail: oscar@fmc.uva.es [Optronlab Group, Dpto. Fisica Materia Condensada, Edificio I-D, Universidad de Valladolid, Paseo de Belen 1, 47011, Valladolid (Spain); Hortelano, V.; Jimenez, J. [Optronlab Group, Dpto. Fisica Materia Condensada, Edificio I-D, Universidad de Valladolid, Paseo de Belen 1, 47011, Valladolid (Spain); Plaza, J.L.; Dios, S. de; Olvera, J.; Dieguez, E. [Laboratorio de Crecimiento de Cristales, Departamento de Fisica de Materiales, Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Fath, R.; Lozano, J.G.; Ben, T.; Gonzalez, D. [Dpto. Ciencia de los Materiales e Ingenieria Metalurgica y Q.I., Facultad de Ciencias, Apdo. 40, 11510 Puerto Real, Cadiz (Spain); Mass, J. [Dpto. de Fisica, Universidad del Norte, Km.5 Via Puerto Colombia, Barranquilla (Colombia)

    2011-04-28

    Research highlights: > ZnO nanowires grown from thermal Zn oxidation. > TEM reveals high quality thin nanowires several microns long. > New phase formation at long oxidation time. > Good spectroscopic properties measured by Raman, Photo and Cathodoluminsecence spectroscopies. - Abstract: <112-bar 0> wurtzite ZnO nanowires (NWs) have been obtained by oxidizing in air at 500 deg. C thermally evaporated Zn metal films deposited onto CdTe substrates. The presence of Cd atoms from the substrate on the ZnO seeding layer and NWs seems to affect the growth of the NWs. The effects of the oxidation time on the structural and optical properties of the NWs are described in detail. It is shown that the NWs density decreases and their length increases when increasing the oxidation time. Thicker Zn layers result in thinner and longer ZnO NWs. Very long oxidation times also lead to the formation of a new CdO phase which is related to the partial destruction and quality reduction of the NWs. The possible process for ZnO NW formation on CdTe substrates is discussed.

  8. Investigation of polycrystalline CdZnTe, CdMnTe, and CdTe films for photovoltaic applications

    Energy Technology Data Exchange (ETDEWEB)

    Rohatgi, A.; Ringel, S.A.; Sudharsanan, R. (School of Electrical Engineering, Georgia Inst. of Tech., Atlanta, GA (USA)); Meyers, P.V.; Liu, C.H.; Ramanthan, V. (Ametek Applied Materials Lab., Harleysville, PA (USA))

    1989-10-15

    Polycrystalline thin films of CdZnTe and CdMnTe have been grown by molecular beam epitaxy and metal-organic chemical vapor deposition, respectively, on CdS/SnO{sub 2}/glass substrates, with bandgaps of 1.65-1.75 eV for the top of a two-cell tandem design. P-i-n cells were fabricated and tested using Ni/p{sup +}-ZnTe as a back contact to the ternary films. CdTe cells were also fabricated using both growth techniques, which resulted in 9-10% efficiency and provided a baseline for ternary cell development. It was found that standard CdTe processing (400deg C air annealing) reduces the ternary bandgaps from about 1.7 to about 1.55 eV, resulting in significantly reduced subgap transmission with cell efficiencies of 3-4%. Optimum air-annealing conditions were determined to retain the 1.7 eV bandgaps; however, the cell performance was still limited by both poor CdZnTe/CdS interface quality and high series resistance. The junction interface was found to improve by annealing in the presence of hydrogen, which resulted in V{sub oc} values from 0.500 V to as high as 0.65 V, but the cell performance became increasingly limited by series resistance. The effects of cell processing on the properties of the CdZnTe/CdS interface, the bulk CdZnTe film, and the back-contact region have been investigated to provide guidelines for achieving high efficiency in widegap ternary cells. (orig.).

  9. Effect of methanol ratio in mixed solvents on optical properties and wettability of ZnO films by cathodic electrodeposition

    International Nuclear Information System (INIS)

    Highlights: • Different surface morphologies of ZnO films were prepared by cathodic electrodeposition. • The surface morphologies are controlled through add different ratio methanol to electrolyte. • The morphology changes from nanorods with hexagonal structure to net-like nanostructure. • The wettability of films shows obvious change with increasing methanol ratio. • The maximum light-induced CA change has been observed with the methanol ratio of 0.8. - Abstract: ZnO thin films were prepared in the electrolyte with different methanol ratio by cathodic electrodeposition method. Microstructure, surface morphology, optical properties and wettability of the thin films were investigated by X-ray diffractometer, field-emission scanning electron microscope, ultraviolet–visible spectroscope, fluorescence spectrometer and water contact angle apparatus. Increase of methanol ratio in the solvents may restrain the (0 0 2) plane preferential orientation in some extent. Change of current density curves with the ratio of methanol in the solution play a vital role on electrochemical reaction kinetics, microstructure and/or surface morphology of ZnO thin films. With the methanol ratio increase from 0 to 0.8, the surface morphology changes from nanorods to net-like nanostructure. The adsorbed NO3− ions on the polar planes hinder the crystal growth along the c-axis and redirect the growth direction along the nonpolar planes. The maximum and minimum band gaps have been obtained in the ZnO thin films with the methanol ratio of 0.4 and 0.6, respectively. Change of contact angle before UV irradiation may be related to surface morphology and oxygen vacancies. The maximum light-induced water contact angle change has been observed in the sample with the methanol ratio of 0.8. The results may be attributed to the higher surface roughness and net-like morphology

  10. Fabrication of nickel hexacyanoferrate film on carbon fibers by unipolar pulse electrodeposition method for electrochemically switched ion exchange application

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • NiHCF film was uniformly deposited on the surface of single carbon fiber by UPED method. • High pulse potential resulted in excellent ESIX performances of NiHCF film. • The optimum fabrication condition was found. • Insoluble NiHCF film showed good regeneration ability and long-term cycle stability. • Fabric ESIX film could be prepared for separation of Cs ions from radioactive liquid wastes. - Abstract: Nickel hexacyanoferrate (NiHCF) film was successfully deposited on carbon fibers by unipolar pulse electrodeposition (UPED) method. The effects of pulse potential and cycle number during the film deposition on the composition, regeneration ability and cycle stability of the film were investigated.The morphology, composition and electrochemical behavior of the as-fabricated NiHCF film were varied with the deposition conditions, and two structural analogues, i.e., soluble and insoluble NiHCFs, could be appeared together or alone in the finally obtained films. Especially, it is found that higher pulse potential was necessary to obtain high-quality NiHCF film on the carbon fiber than on metal electrode. In this study, when the pulse potential during the unipolar deposition of NiHCF film was set at a condition of 0.8 V with 0.5 s on-time, 0.5 s off-time and 3000 cycles, a film with insoluble structural analogue was obtained and it showed large ion exchange capacity, good regeneration ability and long-term cycle stability

  11. Controllable degradation of medical magnesium by electrodeposited composite films of mussel adhesive protein (Mefp-1) and chitosan.

    Science.gov (United States)

    Jiang, Ping-Li; Hou, Rui-Qing; Chen, Cheng-Dong; Sun, Lan; Dong, Shi-Gang; Pan, Jin-Shan; Lin, Chang-Jian

    2016-09-15

    To control the degradation rate of medical magnesium in body fluid environment, biocompatible films composed of Mussel Adhesive Protein (Mefp-1) and chitosan were electrodeposited on magnesium surface in cathodic constant current mode. The compositions and structures of the films were characterized by atomic force microscope (AFM), scanning electron microscope (SEM) and infrared reflection absorption spectroscopy (IRAS). And the corrosion protection performance was investigated using electrochemical measurements and immersion tests in simulated body fluid (Hanks' solution). The results revealed that Mefp-1 and chitosan successfully adhered on the magnesium surface and formed a protective film. Compared with either single Mefp-1 or single chitosan film, the composite film of chitosan/Mefp-1/chitosan (CPC (chitosan/Mefp-1/chitosan)) exhibited lower corrosion current density, higher polarization resistance and more homogenous corrosion morphology and thus was able to effectively control the degradation rate of magnesium in simulated body environment. In addition, the active attachment and spreading of MC3T3-E1 cells on the CPC film coated magnesium indicated that the CPC film was significantly able to improve the biocompatibility of the medical magnesium. PMID:27309944

  12. Electrodeposition of Mg doped ZnO thin film for the window layer of CIGS solar cell

    Science.gov (United States)

    Wang, Mang; Yi, Jie; Yang, Sui; Cao, Zhou; Huang, Xiaopan; Li, Yuanhong; Li, Hongxing; Zhong, Jianxin

    2016-09-01

    Mg doped ZnO (ZMO) film with the tunable bandgap can adjust the conduction band offset of the window/chalcopyrite absorber heterointerface to positive to reduce the interface recombination and resulting in an increasement of chalcopyrite based solar cell efficiency. A systematic study of the effect of the electrodeposition potential on morphology, crystalline structure, crystallographic orientation and optical properties of ZMO films was investigated. It is interestingly found that the prepared doped samples undergo a significant morphological change induced by the deposition potential. With negative shift of deposition potential, an obvious morphology evolution from nanorod structrue to particle covered films was observed. A possible growth mechanism for explaining the morphological change is proposed and briefly discussed. The combined optical techniques including absorption, transmission and photoluminescence were used to study the obtained ZMO films deposited at different potential. The sample deposited at -0.9 V with the hexagonal nanorods morphology shows the highest optical transparency of 92%. The photoluminescence spectra reveal that the crystallization of the hexagonal nanorod ZMO thin film deoposited at -0.9 V is much better than the particles covered ZMO thin film. Combining the structural and optical properties analysis, the obtained normal hexagonal nanorod ZMO thin film could potentially be useful in nanostructured chalcopyrite solar cells to improve the device performance.

  13. Electrodeposition on Ni from a Sulfamate Electrolyte Part 1: Effect of a Stress Relief on Annealing Behavior and Film Metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    James J. Kelly

    2002-02-01

    Ni and Ni alloys are being developed as baseline materials for LIGA technology and prototyping at Sandia National Laboratories. A conventional, additive-free sulfamate electrolyte has been chosen for pure Ni electrodeposition due to its simplicity and ability to produce ductile, low-stress films. When depositing certain Ni alloys, saccharin is typically employed as an electrolyte bath additive. While saccharin is well known and effective as a stress reliever, it has a significant impact on the microstructure of the deposit and its annealing behavior. The electrodeposition of pure Ni in the presence of saccharin is studied here to understand its effects in the absence of an alloying element (such as Co or Fe). The grain structure and Vickers hardness of Ni deposited with and without saccharin on a rotating disk electrode were all found to be consistent with previous studies available in the literature. The following observations were made: (1) The fine, columnar morphology obtained without saccharin became an equiaxed, nano-sized grain structure with saccharin (from {approx}1.5 {micro}m to {approx}40 nm nominal grain size, respectively). The grain refinement resulting from saccharin is not accompanied with an increase in film stress, in contrast to the grain refinement associated with certain Ni alloys. (2) A change in the deposit texture from weak (210) to (111) along the film growth direction with the addition of saccharin. (3) An increase in Vickers hardness by a factor of {approx}2 (from {approx}170 to {approx}320) upon the addition of saccharin. (4) A rapid decrease in hardness with annealing from the high, as-deposited values for films deposited with saccharin to a value lower than that of annealed Ni from an additive-free bath. (5) Accelerated grain growth during annealing for films deposited with saccharin; this has not been observed previously in the literature to the authors' best knowledge.

  14. In situ scanning tunneling microscopy study of cobalt thin film electrodeposited on Pt(1 1 1) electrode

    International Nuclear Information System (INIS)

    Thanks to the availability of single crystal electrodes and the advance of scanning probes, it is now possible to characterize the process of electrodeposition in real time and the atomic structure of ultrathin film. Reported here is an in situ scanning tunneling microscopy (STM) study of cobalt electrodeposition on an ordered Pt(1 1 1) electrode in a pH 3 chloride-containing medium. It was found to be a two-staged process, involving an underpotential deposition (UPD) stage and an overpotential deposition (OPD) occurring at potentials positive and negative of the Nernst potential of −0.57 V (versus Ag/AgCl) calculated for 0.04 M CoCl2. Time-dependent STM imaging revealed Co nucleated mainly in one atom high islands on terraces and at steps in the UPD stage, followed by quasi layer-by-layer growth to form a smooth thin film up to five layers in thickness. The UPD layer comprised Co atoms arranging in disarray, possibly resulting from competitive adsorption of hydrogen at the Pt electrode. Starting from the second layer, the Co film assumed ordered microstructures featuring a long range undulation of atomic height. This moire structure consisted of Co(0 0 0 1) like plane stacked on the Pt(1 1 1) substrate with an in-plane interatomic spacing of 0.257 nm in the bilayer film. Due to different lattice constants of Co and Pt, the Co/Pt(1 1 1) was strained, but the degree of this interfacial strain gradually decreased with the thickness of Co deposit, as revealed by the diminish of the moire pattern when the Co film grew to more than five layer in thickness. Meanwhile, the morphology of the Co deposit became rougher with thickness, which suggests a Stranski–Krastanov growth

  15. Biaxially oriented CdTe films on glass substrate through nanostructured Ge/CaF2 buffer layers

    Science.gov (United States)

    Lord, R. J.; Su, P.-Y.; Bhat, I.; Zhang, S. B.; Lu, T.-M.; Wang, G.-C.

    2015-09-01

    Heteroepitaxial CdTe films were grown by metal organic chemical vapor deposition on glass substrates through nanostructured Ge/CaF2 buffer layers which were biaxially oriented. It allows us to explore the structural properties of multilayer biaxial semiconductor films which possess small angle grain boundaries and to test the principle of a solar cell made of such low-cost, low-growth-temperature semiconductor films. Through the x-ray diffraction and x-ray pole figure analysis, the heteroepitaxial relationships of the mutilayered films are determined as [111] in the out-of-plane direction and CdTe//Ge//{ }{{{CaF}}2} in the in-plane direction. The I-V curves measured from an ITO/CdS/CdTe/Ge/CaF2/glass solar cell test structure shows a power conversion efficiency of ˜η = 1.26%, illustrating the initial success of such an approach. The observed non-ideal efficiency is believed to be due to a low shunt resistance and high series resistance as well as some residual large-angle grain boundary effects, leaving room for significant further improvement.

  16. Synthesis and magnetic characterization of a Cu{sub 80}Co{sub 20} thin film obtained by electrodeposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Bran, Julien; Jean, Malick; Lardé, Rodrigue; Sauvage, Xavier [Groupe de Physique des Matériaux, UMR 6634 CNRS, Université et INSA de Rouen, 76801 St Etienne du Rouvray (France); Breton, Jean-Marie Le, E-mail: jean-marie.lebreton@univ-rouen.fr [Groupe de Physique des Matériaux, UMR 6634 CNRS, Université et INSA de Rouen, 76801 St Etienne du Rouvray (France); Morin-Grognet, Sandrine [Laboratoire de Biophysique et Biomatériaux, MERCI EA 3829, Centre Universitaire d’Evreux, Université de Rouen, 1 rue du 7ème Chasseurs, 27002 Evreux Cedex (France); Pautrat, Alain [Laboratoire Crismat, UMR 6508 CNRS ENSICAEN, 6 boulevard du maréchal Juin, 14050 Caen Cedex (France)

    2014-05-01

    Highlights: • A Cu{sub 80}Co{sub 20} alloy was obtained by low cost electrodeposition. • The structure was investigated down to the atomic scale. • No oxides were formed. • Magnetoresistance is clearly related to superparamagnetic Co nanoparticles. - Abstract: A granular Cu{sub 80}Co{sub 20} alloy was elaborated by a low cost electrodeposition technique consisting in reducing simultaneously the Cu{sup 2+} and Co{sup 2+} ions onto a silicon substrate. The deposition parameters were determined from current-potential curves. The structure of the film was characterized down to the atomic scale by transmission electron microscopy and atom probe tomography. The results show that the as-deposited Cu{sub 80}Co{sub 20} thin film consists mainly of a paramagnetic Cu–Co solid solution containing 10–30% of Co, in which pure Co superparamagnetic nanoparticles are dissolved. Annealing at 500 °C for 1 h leads to the decomposition of the Cu–Co solid solution into purified Cu matrix containing ferromagnetic Co-rich precipitates. The magnetoresistance effect decreases after the heat treatment, in relation with the disappearance of the superparamagnetic Co nanoparticles upon annealing.

  17. Pulse-reverse electrodeposition for mesoporous metal films: combination of hydrogen evolution assisted deposition and electrochemical dealloying.

    Science.gov (United States)

    Cherevko, Serhiy; Kulyk, Nadiia; Chung, Chan-Hwa

    2012-01-21

    Hydrogen evolution assisted electrodeposition is a new bottom-up technique allowing the fast and simple synthesis of nanometals. Electrochemical dealloying is a top-down approach with the same purpose. In this work, we show that a combination of these two methods in sequence by pulse-reverse electrodeposition can be used to prepare high-surface-area nanostructured metals. Highly porous adherent platinum is obtained by the deposition of CuPt alloy during the cathodic cycles and the selective dissolution of copper during the anodic cycles. The convection created by the movement of the hydrogen bubbles increases the deposition rate and removes the dissolved copper ions from the diffusion layer, which ensures the deposition of a film with the same stoichiometry throughout the whole process. Due to the relatively high ratio of copper atoms on the surface in the as-deposited layer, it is proposed that the dealloying kinetics is significantly higher than that usually observed during the dealloying process in a model system. The proposed approach has several advantages over other methods, such as a very high growth rate and needlessness of any post-treatment processes. A detailed analysis of the effect of pulse-reverse waveform parameters on the properties of the films is presented. Mesoporous platinum with pores and ligaments having characteristic sizes of less than 10 nm, an equivalent surface area of up to ca. 220 m(2) cm(-3), and a roughness factor of more than 1000 is fabricated. PMID:22139451

  18. Effects of cathodic electrodeposition parameters of cerium oxide film on the corrosion resistance of the 2024 Al alloy

    Energy Technology Data Exchange (ETDEWEB)

    Brunelli, K.; Bisaglia, F.; Magrini, M.; Dabala, M. [DIMEG University of Padua, Padua (Italy); Kovac, J. [Department of Surface Engineering and Optoelectronics, Jozef Stefan Institute, Ljubljana, (Slovenia)

    2009-07-15

    Cerium oxide thin films obtained by cathodic electrodeposition on 2024 aluminium alloy have been studied. The coatings, obtained with electrochemical deposition, offer an effective corrosion protection and require a lower deposition time when compared to chemical conversion coatings. The coatings were obtained at room temperature by deposition from CeCl{sub 3}/H{sub 2}O{sub 2} aqueous solutions and the influence of several parameters (CeCl{sub 3} concentration, H{sub 2}O{sub 2} concentration, deposition time, current intensity) on the corrosion resistance was studied. The composition, morphology and microstructure of the films have been characterized by SEM, XPS and AFM. The corrosion resistance was investigated through potentiodynamic tests in 3% NaCl solution. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  19. Fabrication of metal-oxide nano-composite films from aqueous solution by metal-oxide co-electrodeposition

    International Nuclear Information System (INIS)

    Fe-Ce-O films were synthesized by a newly developed electrochemical method called the 'metal-oxide co-electrodeposition method', i.e. the simultaneous deposition of Fe and Ce-O from a reaction solution containing FeSO4, CeCl3 (NH4)2SO4, and L-ascorbic acid. L-ascorbic acid prevents the oxidation of Fe2+ to Fe3+. (NH4)2SO4 acts as the complexing agent for Fe2+ and was effective in avoiding the precipitation of Fe-OH. Therefore, ferromagnetic Fe and Ce-O coexisted films were successfully formed. The Fe-Ce-O films prepared had a uniform surface. The Fe content in the deposited films was subject to change from 0 to 100 vol% depending on the concentration of the FeSO4 in the reaction solution. The saturation magnetization of the films fabricated from the reaction solution with (NH4)2SO4 became larger than that of the films prepared from a non-(NH4)2SO4 solution

  20. SIMS analysis for detection of contaminants in thin film photovoltaics

    Science.gov (United States)

    Morris, G. C.; Lyons, L. E.; Tandon, R. K.; Wood, B. J.

    1988-12-01

    Minor contaminants in electrodeposited thin film CdTe which produce efficient solar cells have been investigated by secondary ion mass spectroscopy (SIMS) using three different primary ions and three different SIMS instruments. To obtain SIMS data which represent what is present in the sample, a number of precautions must be taken. These are illustrated and positive SIMS data from an electrodeposited film show that it has fewer impurities than commercial crystal CdTe specified as 5N pure. The impurities in the film had not been intentionally added, so their source was investigated by SIMS and found to be the starting chemicals and deposition vessels. For quantification, inductively coupled plasma-atomic emission spectroscopy and atomic absorption spectroscopy of the deposition solutions provided upper limits for the impurity concentration.

  1. New Sunshine Program for fiscal 2000. Development of photovoltaic system commercialization technology - Development of thin-film solar cell manufacturing technology - Development of low-cost/large area module manufacturing technology (Development of high-reliability CdTe solar cell module manufacturing technology); 2000 nendo New sunshine keikaku seika hokokusho. Taiyoko hatsuden system jitsuyoka gijutsu kaihatsu, Hakumaku taiyodenchi no seizo gijutsu kaihatsu, Tei cost dai menseki mojuru seizo gijutsu kaihatsu (Koshinraisei CdTe taiyo denchi mojuru no seizo gijutsu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Research and development was conducted for reliable CdTe solar cell modules, large in area and high in efficiency. In the study of large-area CdS thin film fabrication, a conversion efficiency of 12.5-14.2% was achieved in a cell in a large-area substrate using a mist method-aided process of continuous CdS film fabrication. In the study of large-area CdTe thin film fabrication, the optimization was studied of the base-forming CdS film fabrication conditions and of the CdTe film fabrication conditions in a method using a CdTe powder processed by dry kneading, and a conversion efficiency peak was found to exist when the CdS film thickness was in the range of 700-900 angstrom. In the fabrication of large-area submodules, a large-area substrate was taken up, and TCO (transparent conducting oxide) film was fabricated by the mist method, CdTe film by the normal pressure CSS method, electrodes by the screen printing method, and CdTe film patterns by the blast method. As the result, a conversion efficiency of 11.0% was achieved. In a cost estimation for large-area CdTe solar cell modules, 140 yen/Wp (conversion efficiency: 11.0%, annual production: 100 MW) was obtained. (NEDO)

  2. Growth of polycrystalline CdS and CdTe thin layers for high efficiency thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Romeo, N.; Bosio, A.; Tedeschi, R.; Canevari, V. [Parma Univ. (Italy). Dipartimento di Fisica

    2000-10-16

    Recently, conversion efficiencies close to 16% for thin film solar cells based on the CdS/CdTe heterojunction have been reported. These relevant results, however, have not yet solved the problems which arise when industrial production is undertaken as the demand for low cost imposes constraints which considerably limit the final efficiency of the cells. In this paper, we will show that very high conversion efficiencies can still be achieved even making use of low cost soda-lime glass as substrate. In fact, the Na contained in this kind of glass diffuses during the fabrication of the cell into the active layers of the device causing a substantial decrease of the fill factor and consequently of the efficiency of the cell. In particular, we will describe the methods and the magnetron sputtering techniques used to grow a polycrystalline CdS thin film with a controlled Na content. We will also describe the details of the growth via the close-spaced sublimation (CSS) technique of the CdTe polycrystalline film, which are crucial for the heterojunction and the back contact which has been fabricated exploiting the characteristics of Sb{sub 2}Te{sub 3} which is a low gap p-type semiconductor with a high conductivity. (orig.)

  3. Grain boundaries in CdTe thin film solar cells: a review

    Science.gov (United States)

    Major, Jonathan D.

    2016-09-01

    The current state of knowledge on the impact of grain boundaries in CdTe solar cells is reviewed with emphasis being placed on working cell structures. The role of the chemical composition of grain boundaries as well as growth processes are discussed, along with characterisation techniques such as electron beam induced current and cathodoluminescence, which are capable of extracting information on a level of resolution comparable to the size of the grain boundaries. Work which attempts to relate grain boundaries to device efficiency is also assessed and gaps in the current knowledge are highlighted.

  4. Preparation of p-type Na-doped Cu2O by electrodeposition for a p-n homojunction thin film solar cell

    Science.gov (United States)

    Elfadill, Nezar G.; Hashim, M. R.; Chahrour, Khaled M.; Mohammed, S. A.

    2016-06-01

    In this work, a method of enhancing the electrical properties of the electrodeposited p-type Cu2O film is described. Sodium doped Cu2O was achieved by adding sodium aluminate complex solution to the electrodeposition alkaline Cu (II) lactate electrolyte. The optimal Na content [Na at% atomic ratio] incorporated in the Cu2O film was found to be approximately 1.34 at.%. The XPS result shows that the binding energy at 1072.4 ± 0.2 eV corresponds to the presence of sodium in sodium oxide. The optimized resistivity and the hole concentration were approximately 291 Ω cm and 2.13 × 1018 cm3, respectively. A Cu2O p-n homojunction solar cell with 2.05% efficiency was fabricated using a Cl-doped n-type Cu2O film and an optimized Na-doped Cu2O film.

  5. Influence of plasma parameters and substrate temperature on the structural and optical properties of CdTe thin films deposited on glass by laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Quiñones-Galván, J. G.; Santana-Aranda, M. A.; Pérez-Centeno, A. [Departamento de Física, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Boulevard Marcelino García Barragán 1421, Guadalajara, Jalisco C.P. 44430 (Mexico); Camps, Enrique [Departamento de Física, Instituto Nacional de Investigaciones Nucleares, Apartado Postal 18-1027, D.F., C.P. 11801 (Mexico); Campos-González, E.; Guillén-Cervantes, A.; Santoyo-Salazar, J.; Zelaya-Angel, O. [Departamento de Física, CINVESTAV-IPN, Apartado Postal 14-740, D. F. C.P. 07360 (Mexico); Hernández-Hernández, A. [Escuela Superior de Apan, Universidad Autónoma del Estado de Hidalgo, Calle Ejido de Chimalpa Tlalayote s/n Colonia Chimalpa, Apan Hidalgo (Mexico); Moure-Flores, F. de [Facultad de Química, Materiales, Universidad Autónoma de Querétaro, Querétaro C.P. 76010 (Mexico)

    2015-09-28

    In the pulsed laser deposition of thin films, plasma parameters such as energy and density of ions play an important role in the properties of materials. In the present work, cadmium telluride thin films were obtained by laser ablation of a stoichiometric CdTe target in vacuum, using two different values for: substrate temperature (RT and 200 °C) and plasma energy (120 and 200 eV). Structural characterization revealed that the crystalline phase can be changed by controlling both plasma energy and substrate temperature; which affects the corresponding band gap energy. All the thin films showed smooth surfaces and a Te rich composition.

  6. Influence of plasma parameters and substrate temperature on the structural and optical properties of CdTe thin films deposited on glass by laser ablation

    International Nuclear Information System (INIS)

    In the pulsed laser deposition of thin films, plasma parameters such as energy and density of ions play an important role in the properties of materials. In the present work, cadmium telluride thin films were obtained by laser ablation of a stoichiometric CdTe target in vacuum, using two different values for: substrate temperature (RT and 200 °C) and plasma energy (120 and 200 eV). Structural characterization revealed that the crystalline phase can be changed by controlling both plasma energy and substrate temperature; which affects the corresponding band gap energy. All the thin films showed smooth surfaces and a Te rich composition

  7. Electrodeposition of In{sub 2}O{sub 3} thin films from a dimethylsulfoxide based electrolytic solution

    Energy Technology Data Exchange (ETDEWEB)

    Henriquez, R.; Munoz, E.; Gomez, H. [Instituto de Quimica, Facultad de Ciencias, Pontificia Universidad Catolica de Valparaiso, Curauma Valparaiso (Chile); Dalchiele, E.A.; Marotti, R.E. [Instituto de Fisica and CINQUIFIMA, Facultad de Ingenieria, Montevideo (Uruguay); Martin, F.; Leinen, D.; Ramos-Barrado, J.R. [Laboratorio de Materiales y Superficie, Departamento de Fisica Aplicada and Ingenieria Quimica, Universidad de Malaga (Spain)

    2013-02-15

    Indium (III) oxide (In{sub 2}O{sub 3}) thin films have been obtained after heat treatment of In(OH){sub 3} precursor layers grown by a potential cycling electrodeposition (PCED) method from a dimethylsulfoxide (DMSO) based electrolytic solution onto fluorine-doped tin oxide (FTO) coated glass substrates. X-ray diffraction (XRD) measurements indicate the formation of a polycrystalline In{sub 2}O{sub 3} phase with a cubic structure. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed a smooth morphology of the In{sub 2}O{sub 3} thin films after an optimized heat treatment had been developed. The surface composition and chemical state of the semiconductor films was established by X-ray photoelectron spectroscopy analysis. The nature of the semiconductor material, flat band potential and donor density were determined from Mott-Schottky plots. This study reveals that the In{sub 2}O{sub 3} films exhibited n-type conductivity with an average donor density of 2.2 x 10{sup 17} cm{sup -3}. The optical characteristics were determined through transmittance spectra. The direct and indirect band gap values obtained are according to the accepted values for the In{sub 2}O{sub 3} films of 2.83 and 3.54 eV for the indirect and direct band gap values. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Influence of pH and bath composition on properties of Ni–Fe alloy films synthesized by electrodeposition

    Indian Academy of Sciences (India)

    Xinghua Su; Chengwen Qiang

    2012-04-01

    Fe–Ni films were electrodeposited on ITO glass substrates from the electrolytes with different molar ratio of Ni2+/Fe2+ and different pH values (2.1, 2.9, 3.7 and 4.3) at 25°C. The properties of Fe–Ni alloy films depend on both Ni2+ and Fe2+ concentrations in electrolyte and pH values. The content of Ni increases from 38% to 84% as the mole ratio of NiSO4/FeSO4 increasing from 0.50/0.50 to 0.90/0.10 in electrolyte and slightly decreases from 65% to 42% as the pH values increase from 2.1 to 4.3. The X-ray diffraction analysis reveals that the structures of the films strongly depend on the Ni content in the binary films. The magnetic performance of the films shows that the saturation magnetization (s) decreases from 1775.01 emu/cm3 to 1501.46 emu/cm3 with the pH value increasing from 2.1 to 4.3 and the saturation magnetization (s) and coercivity (c) move up from 1150.44 emu/cm3 and 58.86 Oe to 2498.88 emu/cm3 and 93.12 Oe with the increase of Ni2+ concentration in the electrolyte, respectively.

  9. Precisely Controlled Synthesis of High Quality Kesterite Cu2ZnSnS4 Thin Film via Co-Electrodeposited CuZnSn Alloy Film.

    Science.gov (United States)

    Hreid, Tubshin; Tiong, Vincent Tiing; Cai, Molang; Wang, Hongxia; Will, Geoffrey

    2016-06-01

    In this work, a facile co-electrodeposition method was used to fabricate CuZnSn alloy films where the content of copper, zinc and tin could be precisely controlled through manipulating the mass transfer process in the electrochemical deposition. By finely tuning the concentration of the cations of Cu2+, Zn2+ and Sn2+ in the electrochemical bath solution, uniform CuZnSn film with desired composition of copper poor and zinc rich was made. Sulphurisation of the CuZnSn alloy film led to the formation of compact and large grains Cu2ZnSnS4 thin film absorber with an optimum composition of Cu/(Zn+Sn) ≈ 0.8, Zn/Sn ≈ 1.2. Both SEM morphology and EDS mapping results confirmed the uniformity of the CuZnSn and Cu2ZnSnS4 films and the homogeneous distribution of Cu, Zn, Sn and S elements in the bulk films. The XRD and Raman measurements indicated that the synthesized Cu2ZnSnS4 film was kesterite phase without impurities detected. Photoelectrochemical tests were carried out to evaluate the CZTS film's photocurrent response under illumination of green light. PMID:27427618

  10. Monte Carlo computer simulation of the deposition of CdTe thin films by close-spaced sublimation

    Energy Technology Data Exchange (ETDEWEB)

    Romeo, N.; Tedeschi, R.; Ferrari, L.; Pasquali, S.; Bosio, A.; Canevari, V. [Parma Univ. (Italy). Dipartimento di Fisica

    2000-10-16

    Thin film solar cells based on the CdS/CdTe heterojunction, where the CdTe polycrystalline layer is deposited making use of the close-spaced sublimation (CSS) technique have attained a very good level of conversion efficiency in recent times. Despite this apparently consolidated situation the debate on the formation of the CdS/CdTe heterojunction is still open indicating that a certain margin of improvement is still possible. In particular, the conclusion that a CdS{sub x}Te{sub 1-x} alloy is formed at the CdS/CdTe interface due to interdiffusion that takes place during fabrication. The extent of the interdiffusion and the value of x depend on many factors such as deposition temperature, gas pressure and geometrical parameters. The situation is even more complicated because while the deposition is in progress, the ratio between the number of Te and the Cd atoms which are reaching the target is invariably greater than one. To shed some light on these issues it is mandatory to know at least the exact Te/Cd ratio as a function of the deposition parameters. To this end we carried out a Monte Carlo computer simulation of the CdTe deposition in our CSS equipment. The computer code was implemented starting from very simple hypotheses simulating the deposition in perfect gas at constant temperature. Subsequently, we added more physical reality including temperature gradient between source and target. The code was then finally optimized introducing the usual null-event method which confirmed the consistency of our results. (orig.)

  11. High Efficiency Thin Film CdTe and a-Si Based Solar Cells: Annual Technical Report, 4 March 1999 - 3 March 2000; ANNUAL

    International Nuclear Information System (INIS)

    This report describes the research on high-efficiency CdTe-based thin-film solar cells and on high-efficiency a-Si-based thin-film solar cells. Implemented a diode-array spectrograph system and used optical emission spectroscopy to help optimize the reactive sputtering of N-doped ZnTe for CdTe back-contact structures. Identified the photoluminescence signatures of various defect states in CdTe related to Cd vacancies, CuCd acceptors, Cu-VCd complexes, and donor-acceptor pairs, and related these states to instabilities in the hole concentration at room temperature. Showed that Cu is an important non-radiative center in CdS, reducing the PL efficiency. Studied band tailing in CdS weakly alloyed with CdTe and CdTe weakly alloyed with CdS. Fabricated superstrate ITO/CdS/CdTe cells on Mo substrates with efficiencies above 7.5%. Collaborated in studies of EXAFS of Cu in CdTe which indicate a Cu-Te bond length of 2.62(angstrom) or 6.7% shorter than the CdTe, bond in agreement with calculations of Wei et al. Provided assistance to two groups on laser scribing. Comparatively studied the performance of a-SiGe solar cells and properties of a-SiGe single-layer films deposited using a wide range of H dilution, observed transition from a-SiGe to(mu)c-SiGe at high H dilution and the impact on cell performances. Comparatively studied the performance of a-SiGe solar cells and properties of a-SiGe single-layer films with different Ge contents, suitable for use as component cells of triple-junction devices. Fabricated a-Si-based solar cells on ultra-thin stainless-steel substrate (7.5 micron) and obtained equivalent performance and yield as on the regular SS substrates (127 microns). Comparatively studied the performance of a-Si-based solar cells on SS substrates and on SnO2-coated glass substrates. Studied the performance of p-layers deposited under various deposition conditions for n-i-p type solar cells. Performed an analysis for the component cell current-matching within a triple

  12. High Efficiency Thin Film CdTe and a-Si Based Solar Cells: Annual Technical Report, 4 March 1999 - 3 March 2000

    Energy Technology Data Exchange (ETDEWEB)

    Compaan, A. D.; Deng, X.; Bohn, R. G. (The University of Toledo)

    2001-08-29

    This report describes the research on high-efficiency CdTe-based thin-film solar cells and on high-efficiency a-Si-based thin-film solar cells. Implemented a diode-array spectrograph system and used optical emission spectroscopy to help optimize the reactive sputtering of N-doped ZnTe for CdTe back-contact structures. Identified the photoluminescence signatures of various defect states in CdTe related to Cd vacancies, CuCd acceptors, Cu-VCd complexes, and donor-acceptor pairs, and related these states to instabilities in the hole concentration at room temperature. Showed that Cu is an important non-radiative center in CdS, reducing the PL efficiency. Studied band tailing in CdS weakly alloyed with CdTe and CdTe weakly alloyed with CdS. Fabricated superstrate ITO/CdS/CdTe cells on Mo substrates with efficiencies above 7.5%. Collaborated in studies of EXAFS of Cu in CdTe which indicate a Cu-Te bond length of 2.62 {angstrom} or 6.7% shorter than the CdTe, bond in agreement with calculations of Wei et al. Provided assistance to two groups on laser scribing. Comparatively studied the performance of a-SiGe solar cells and properties of a-SiGe single-layer films deposited using a wide range of H dilution, observed transition from a-SiGe to {mu}c-SiGe at high H dilution and the impact on cell performances. Comparatively studied the performance of a-SiGe solar cells and properties of a-SiGe single-layer films with different Ge contents, suitable for use as component cells of triple-junction devices. Fabricated a-Si-based solar cells on ultra-thin stainless-steel substrate (7.5 micron) and obtained equivalent performance and yield as on the regular SS substrates (127 microns). Comparatively studied the performance of a-Si-based solar cells on SS substrates and on SnO2-coated glass substrates. Studied the performance of p-layers deposited under various deposition conditions for n-i-p type solar cells. Performed an analysis for the component cell current-matching within a

  13. Functional Nanowires Array Electrodeposited into Nano-porous Membrane Thin Films

    International Nuclear Information System (INIS)

    Ni, Co, Fe and Co/Cu multilayered nanowires were electrodeposited into a nano-well template to synthesize novel functional ferromagnetic devices. Growth rate of Co/Co multilayered nanowires was around 40 nm.sec−1 and the cylindrical shape was precisely transferred from the nanochannels to the nanowires and the aspect ratio reached up to ca. 150. Magnetic hysteresis loops of Ni, Co and Fe nanowires with diameter 40 nm showed typical perpendicular magnetization behavior due to the uni-axial shape anisotropy and the coercive force reached up to around 1 kOe. 2% of anisotropic magnetoresistance effect was observed in Ni nanowires electrodeposited into anodized aluminum oxide template, while 20% of giant magnetoresistance effect was observed in Co/Cu multilayered nanowires.

  14. New Method of Pulsed Electrodeposition of Nanostructure of ZnS Films

    OpenAIRE

    M. B. Dergacheva; K.A. Urazov; G.M. Khussurova; K.A. Leontyeva

    2016-01-01

    The voltammetry method of analysis is used to investigate the electrochemical behavior of zinc(II) and thiosulfate (\\(\\text{S}_{2}\\text{O}_{3}^{2-}\\)) ions in acidic solutions and their electrochemical deposition onto glass coated with a conductive layer of tin oxide. It is found that electrodeposition conducted according to the two-electrode scheme using the pulse current generated by the industrial alternating current produces sound zinc sulfide deposits. Physical and chemical properties of...

  15. Effects of Substrate Local Strain on Microstructure of Electrodeposited Aluminum Film

    Institute of Scientific and Technical Information of China (English)

    TAN Yuehua; YAN Bo; GAO Ge; YANG Yuxin

    2006-01-01

    The aluminum coating layer was formed on a copper substrate with local strain region by using the electrodeposited method. It was found that the particle shape of the coating deposited on the copper substrate is very sensitive to the strain extent of substrate. The large needle-like aluminum particles were observed on the substrate region with large local strain, indicating that substrate local strain may affect the shape of the deposited particles and promote the nucleation and growth of the deposited particles.

  16. Electrodeposition of aluminium film on P90 Li-Al alloy as protective coating against corrosion

    OpenAIRE

    U. Bardi; Caporali, S; M. Craig; A. Giorgetti; Perissi, I; Nicholls, J. R.

    2009-01-01

    In this paper we report on the electrodeposition of thin aluminium layers on P90 lithium–aluminium alloy at room temperature from a chloroaluminate ionic liquid (1-butyl-3-methyl imidazolium heptachloroaluminate [BMIm]Al2Cl7). We found that the treatment of the P90 sample's surface is a key point to obtain good quality coatings. On freshly mechanically polished surfaces, thin (about 24 µm), homogeneous and dense aluminium layers were obtained at 10 µm h− 1 deposition rate. F...

  17. Pulse-reverse electrodeposition for mesoporous metal films: combination of hydrogen evolution assisted deposition and electrochemical dealloying

    Science.gov (United States)

    Cherevko, Serhiy; Kulyk, Nadiia; Chung, Chan-Hwa

    2012-01-01

    Hydrogen evolution assisted electrodeposition is a new bottom-up technique allowing the fast and simple synthesis of nanometals. Electrochemical dealloying is a top-down approach with the same purpose. In this work, we show that a combination of these two methods in sequence by pulse-reverse electrodeposition can be used to prepare high-surface-area nanostructured metals. Highly porous adherent platinum is obtained by the deposition of CuPt alloy during the cathodic cycles and the selective dissolution of copper during the anodic cycles. The convection created by the movement of the hydrogen bubbles increases the deposition rate and removes the dissolved copper ions from the diffusion layer, which ensures the deposition of a film with the same stoichiometry throughout the whole process. Due to the relatively high ratio of copper atoms on the surface in the as-deposited layer, it is proposed that the dealloying kinetics is significantly higher than that usually observed during the dealloying process in a model system. The proposed approach has several advantages over other methods, such as a very high growth rate and needlessness of any post-treatment processes. A detailed analysis of the effect of pulse-reverse waveform parameters on the properties of the films is presented. Mesoporous platinum with pores and ligaments having characteristic sizes of less than 10 nm, an equivalent surface area of up to ca. 220 m2 cm-3, and a roughness factor of more than 1000 is fabricated.Hydrogen evolution assisted electrodeposition is a new bottom-up technique allowing the fast and simple synthesis of nanometals. Electrochemical dealloying is a top-down approach with the same purpose. In this work, we show that a combination of these two methods in sequence by pulse-reverse electrodeposition can be used to prepare high-surface-area nanostructured metals. Highly porous adherent platinum is obtained by the deposition of CuPt alloy during the cathodic cycles and the selective

  18. Effects of CdCl sub 2 on the growth of CdTe on CdS films for solar cells by isothermal close-spaced vapour transport

    Energy Technology Data Exchange (ETDEWEB)

    Vaccaro, P.O.; Meyer, G.; Saura, J. (Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche)

    1991-10-14

    CdS/CdTe solar cells were made by depositing CdTe films by an isothermal close-spaced vapour transport method on sintered CdS/glass substrates. The influence of amounts of CdCl{sub 2} ranging from O wt.% to 8 wt% in the CdTe source on the solar cell performance was studied. Increasing the CdCl{sub 2} content enhances the CdTe grain size but degrades the spectral response and increases the reverse saturation current. An optimal CdCl{sub 2} concentration of 1wt% was found for a growth temperature of 620{sup o}C. (author).

  19. Electrodeposited Co-doped NiSe2 nanoparticles film: a good electrocatalyst for efficient water splitting

    Science.gov (United States)

    Liu, Tingting; Asiri, Abdullah M.; Sun, Xuping

    2016-02-01

    In this communication, we report that a Co-doped NiSe2 nanoparticles film electrodeposited on a conductive Ti plate (Co0.13Ni0.87Se2/Ti) behaves as a robust electrocatalyst for both HER and OER in strongly basic media, with good activity over a NiSe2/Ti counterpart. This Co0.13Ni0.87Se2/Ti catalytic electrode delivers 10 mA cm-2 at an overpotential of 64 mV for HER and 100 mA cm-2 at an overpotential of 320 mV for OER in 1.0 M KOH. A voltage of only 1.62 V is required to drive 10 mA cm-2 for the two-electrode alkaline water electrolyzer using Co0.13Ni0.87Se2/Ti as an anode and cathode.In this communication, we report that a Co-doped NiSe2 nanoparticles film electrodeposited on a conductive Ti plate (Co0.13Ni0.87Se2/Ti) behaves as a robust electrocatalyst for both HER and OER in strongly basic media, with good activity over a NiSe2/Ti counterpart. This Co0.13Ni0.87Se2/Ti catalytic electrode delivers 10 mA cm-2 at an overpotential of 64 mV for HER and 100 mA cm-2 at an overpotential of 320 mV for OER in 1.0 M KOH. A voltage of only 1.62 V is required to drive 10 mA cm-2 for the two-electrode alkaline water electrolyzer using Co0.13Ni0.87Se2/Ti as an anode and cathode. Electronic supplementary information (ESI) available: Experimental section and supplementary figures. See DOI: 10.1039/c5nr07170d

  20. Multilayered films incorporating CdTe quantum dots with tunable optical properties for antibacterial application

    International Nuclear Information System (INIS)

    Tunable absorption/emission and antibacterial activity are highly desirable for antibacterial decorative coating layers. In this study, films with both tunable optical and effective antibacterial properties were fabricated with cadmium telluride quantum dots (QDs) and poly-L-lysine (PLL) via layer-by-layer assembly. Absorption and photoluminescence spectra as well as surface morphology were examined to monitor the film growth. The films are fabricated in a logarithmic growth mode, exhibiting effective antibacterial activity against Escherichia coli and good biocompatibility to Hela cells. By changing sizes of the incorporated QDs, optical properties of the films can be easily tailored. The PLL/QDs' multilayered films may be used as colorful coating layers for applications requiring both unique optical and antibacterial properties. - Highlights: • A layer-by-layer film incorporating quantum dots and poly-L-lysine was fabricated. • The film shows tunable optical properties and antibacterial activity. • The film is built up in a logarithmic growth mode

  1. Preparation of p-type NiO films by reactive sputtering and their application to CdTe solar cells

    Science.gov (United States)

    Ishikawa, Ryousuke; Furuya, Yasuaki; Araki, Ryouichi; Nomoto, Takahiro; Ogawa, Yohei; Hosono, Aikyo; Okamoto, Tamotsu; Tsuboi, Nozomu

    2016-02-01

    Transparent p-type NiO films were prepared by reactive sputtering using the facing-target system under Ar-diluted O2 gas at Tsub of 30 and 200 °C. The increasing intensity of dominant X-ray diffraction (XRD) peaks indicates improvements in the crystallinity of NiO films upon Cu doping. In spite of the crystallographic and optical changes after Cu-doping, the electrical properties of Cu-doped NiO films were slightly improved. Upon Ag-doping at 30 °C under low O2 concentration, on the other hand, the intensity of the dominant (111) XRD peaks was suppressed and p-type conductivity increased from ˜10-3 to ˜10-1 S cm-1. Finally, our Ag-doped NiO films were applied as the back contact of CdTe solar cells. CdTe solar cells with a glass/ITO/CdS/CdTe/NiO structure exhibited an efficiency of 6.4%, suggesting the high potential of using p-type NiO for the back-contact film in thin-film solar cells.

  2. Effects of annealing temperature on the physicochemical, optical and photoelectrochemical properties of nanostructured hematite thin films prepared via electrodeposition method

    Energy Technology Data Exchange (ETDEWEB)

    Phuan, Yi Wen [School of Engineering, Chemical Engineering Discipline, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 46150 Selangor DE (Malaysia); Chong, Meng Nan, E-mail: Chong.Meng.Nan@monash.edu [School of Engineering, Chemical Engineering Discipline, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 46150 Selangor DE (Malaysia); Sustainable Water Alliance, Advanced Engineering Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 46150 Selangor DE (Malaysia); Zhu, Tao; Yong, Siek-Ting [School of Engineering, Chemical Engineering Discipline, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 46150 Selangor DE (Malaysia); Chan, Eng Seng [School of Engineering, Chemical Engineering Discipline, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 46150 Selangor DE (Malaysia); Sustainable Water Alliance, Advanced Engineering Platform, Monash University Malaysia, Jalan Lagoon Selatan, Bandar Sunway 46150 Selangor DE (Malaysia)

    2015-09-15

    Highlights: • Nanostructured hematite thin films were synthesized via electrodeposition method. • Effects of annealing on size, grain boundary and PEC properties were examined. • Photocurrents generation was enhanced when the thin films were annealed at 600 °C. • The highest photocurrent density of 1.6 mA/cm{sup 2} at 0.6 V vs Ag/AgCl was achieved. - Abstract: Hematite (α-Fe{sub 2}O{sub 3}) is a promising photoanode material for hydrogen production from photoelectrochemical (PEC) water splitting due to its wide abundance, narrow band-gap energy, efficient light absorption and high chemical stability under aqueous environment. The key challenge to the wider utilisation of nanostructured hematite-based photoanode in PEC water splitting, however, is limited by its low photo-assisted water oxidation caused by large overpotential in the nominal range of 0.5–0.6 V. The main aim of this study was to enhance the performance of hematite for photo-assisted water oxidation by optimising the annealing temperature used during the synthesis of nanostructured hematite thin films on fluorine-doped tin oxide (FTO)-based photoanodes prepared via the cathodic electrodeposition method. The resultant nanostructured hematite thin films were characterised using field emission-scanning electron microscopy (FE-SEM) coupled with energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), UV-visible spectroscopy and Fourier transform infrared spectroscopy (FTIR) for their elemental composition, average nanocrystallites size and morphology; phase and crystallinity; UV-absorptivity and band gap energy; and the functional groups, respectively. Results showed that the nanostructured hematite thin films possess good ordered nanocrystallites array and high crystallinity after annealing treatment at 400–600 °C. FE-SEM images illustrated an increase in the average hematite nanocrystallites size from 65 nm to 95 nm when the annealing temperature was varied from 400 °C to 600

  3. Effects of annealing temperature on the physicochemical, optical and photoelectrochemical properties of nanostructured hematite thin films prepared via electrodeposition method

    International Nuclear Information System (INIS)

    Highlights: • Nanostructured hematite thin films were synthesized via electrodeposition method. • Effects of annealing on size, grain boundary and PEC properties were examined. • Photocurrents generation was enhanced when the thin films were annealed at 600 °C. • The highest photocurrent density of 1.6 mA/cm2 at 0.6 V vs Ag/AgCl was achieved. - Abstract: Hematite (α-Fe2O3) is a promising photoanode material for hydrogen production from photoelectrochemical (PEC) water splitting due to its wide abundance, narrow band-gap energy, efficient light absorption and high chemical stability under aqueous environment. The key challenge to the wider utilisation of nanostructured hematite-based photoanode in PEC water splitting, however, is limited by its low photo-assisted water oxidation caused by large overpotential in the nominal range of 0.5–0.6 V. The main aim of this study was to enhance the performance of hematite for photo-assisted water oxidation by optimising the annealing temperature used during the synthesis of nanostructured hematite thin films on fluorine-doped tin oxide (FTO)-based photoanodes prepared via the cathodic electrodeposition method. The resultant nanostructured hematite thin films were characterised using field emission-scanning electron microscopy (FE-SEM) coupled with energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), UV-visible spectroscopy and Fourier transform infrared spectroscopy (FTIR) for their elemental composition, average nanocrystallites size and morphology; phase and crystallinity; UV-absorptivity and band gap energy; and the functional groups, respectively. Results showed that the nanostructured hematite thin films possess good ordered nanocrystallites array and high crystallinity after annealing treatment at 400–600 °C. FE-SEM images illustrated an increase in the average hematite nanocrystallites size from 65 nm to 95 nm when the annealing temperature was varied from 400 °C to 600 °C. As the

  4. Investigation of electrodeposited cerium oxide based films on carbon steel and of the induced formation of carbonated green rusts

    International Nuclear Information System (INIS)

    Cerium oxide based films on carbon steel were deposited using a cathodic electrodeposition approach and from relatively concentrated solutions. The effects of the relatively high cerium nitrate concentrations (0.1 and 0.25 M) and of applied current density (0.25 mA cm-2 ≤ j ≤ 3 mA cm-2) on the composition and microstructure of the films were thoroughly investigated with the support of scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman and Fourier transformed infrared (FTIR) spectroscopies. The results showed that the use of 0.25 M solutions brought about immediate formation of the films compared to the 0.1 M. As the applied current density was increased, the time elapsed for achieving a stabilisation of the potential decreased. Also, the CeO2 crystallite size decreased with increasing applied current density. However, at high cathodic current densities, the crystallite size was similar regardless of the concentration, hence suggesting that the precipitation mechanisms became predominant. CeO2 was the major species deposited on carbon steel. Ce(OH)3 was also well distinguished in the deposits elaborated from 0.25 M solutions. Both concentrations led to the formation of a carbonated green rust in which some carbonates were probably replaced by nitrate anions. The mechanisms of formation of the green rust and its evolution with time are also elucidated in this work

  5. Investigation of electrodeposited cerium oxide based films on carbon steel and of the induced formation of carbonated green rusts

    Energy Technology Data Exchange (ETDEWEB)

    Hamlaoui, Y. [Laboratoire d' Etudes des Materiaux en Milieux Agressifs (LEMMA), Pole Sciences et Technologie, Universite de La Rochelle Avenue Michel Crepeau, 17042 La Rochelle Cedex 1 (France); Pedraza, F. [Laboratoire d' Etudes des Materiaux en Milieux Agressifs (LEMMA), Pole Sciences et Technologie, Universite de La Rochelle Avenue Michel Crepeau, 17042 La Rochelle Cedex 1 (France)], E-mail: fpedraza@univ-lr.fr; Tifouti, L. [Laboratoire de Genie de l' Environnement, Universite Badji Mokhtar, BP 1223, 23020 El Hadjar-Annaba (Algeria)

    2008-08-15

    Cerium oxide based films on carbon steel were deposited using a cathodic electrodeposition approach and from relatively concentrated solutions. The effects of the relatively high cerium nitrate concentrations (0.1 and 0.25 M) and of applied current density (0.25 mA cm{sup -2} {<=} j {<=} 3 mA cm{sup -2}) on the composition and microstructure of the films were thoroughly investigated with the support of scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman and Fourier transformed infrared (FTIR) spectroscopies. The results showed that the use of 0.25 M solutions brought about immediate formation of the films compared to the 0.1 M. As the applied current density was increased, the time elapsed for achieving a stabilisation of the potential decreased. Also, the CeO{sub 2} crystallite size decreased with increasing applied current density. However, at high cathodic current densities, the crystallite size was similar regardless of the concentration, hence suggesting that the precipitation mechanisms became predominant. CeO{sub 2} was the major species deposited on carbon steel. Ce(OH){sub 3} was also well distinguished in the deposits elaborated from 0.25 M solutions. Both concentrations led to the formation of a carbonated green rust in which some carbonates were probably replaced by nitrate anions. The mechanisms of formation of the green rust and its evolution with time are also elucidated in this work.

  6. Study of in situ CdCl{sub 2} treatment on CSS deposited CdTe films and CdS/CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Paulson, P.D.; Dutta, V. [Indian Inst. of Tech., New Delhi (India). Centre for Energy Studies

    2000-07-17

    Effect of in situ CdCl{sub 2} treatment on the morphological, structural and electrical properties of CdTe films as well as on solar cell characteristics of CdS/CdTe junction has been investigated. XRD measurements show that the presence of CdCl{sub 2} vapours induces left angle 111 right angle oriented growth in the CdTe films. CdCl{sub 2} concentration required for this oriented growth is found to be directly proportional to the substrate temperature. SEM measurements show enhanced grain growth in the presence of CdCl{sub 2}. Spectral response of the CdCl{sub 2} treated CdS/CdTe solar cells shows an enhanced CdS diffusion in to the CdTe, which results in an improved spectral response in UV range and a consequent reduction in the interface states density. A drastic reduction in the deep levels due to the CdCl{sub 2} treatment, as seen in the photo-capacitance studies, has results in CdS/CdTe solar cells having efficiency >8%. (orig.)

  7. A statistical approach for optimizing parameters for electrodeposition of indium (III) sulfide (In2S3) films, potential low-hazard buffer layers for photovoltaic applications

    Science.gov (United States)

    Mughal, Maqsood Ali

    Clean and environmentally friendly technologies are centralizing industry focus towards obtaining long term solutions to many large-scale problems such as energy demand, pollution, and environmental safety. Thin film solar cell (TFSC) technology has emerged as an impressive photovoltaic (PV) technology to create clean energy from fast production lines with capabilities to reduce material usage and energy required to manufacture large area panels, hence, lowering the costs. Today, cost ($/kWh) and toxicity are the primary challenges for all PV technologies. In that respect, electrodeposited indium sulfide (In2S3) films are proposed as an alternate to hazardous cadmium sulfide (CdS) films, commonly used as buffer layers in solar cells. This dissertation focuses upon the optimization of electrodeposition parameters to synthesize In2S3 films of PV quality. The work describe herein has the potential to reduce the hazardous impact of cadmium (Cd) upon the environment, while reducing the manufacturing cost of TFSCs through efficient utilization of materials. Optimization was performed through use of a statistical approach to study the effect of varying electrodeposition parameters upon the properties of the films. A robust design method referred-to as the "Taguchi Method" helped in engineering the properties of the films, and improved the PV characteristics including optical bandgap, absorption coefficient, stoichiometry, morphology, crystalline structure, thickness, etc. Current density (also a function of deposition voltage) had the most significant impact upon the stoichiometry and morphology of In2S3 films, whereas, deposition temperature and composition of the solution had the least significant impact. The dissertation discusses the film growth mechanism and provides understanding of the regions of low quality (for example, cracks) in films. In2S3 films were systematically and quantitatively investigated by varying electrodeposition parameters including bath

  8. Effect of in situ UHV CdCl2-activation on the electronic properties of CdTe thin film solar cells

    International Nuclear Information System (INIS)

    To reach reasonable conversion efficiencies of approximately 10% and above with CdTe thin film solar cells an activation step involving chlorine at elevated temperatures seems to be necessary before back contact formation. This activation process has been simulated in an ultrahigh-vacuum (UHV) system. Solar cells with a maximum efficiency of 9.1% have been prepared using this process. In addition the effect of the CdCl2 activation process on the electronic properties of each solar cell layer, SnO2, CdS and CdTe has been investigated in situ using photoelectron spectroscopy. The effects of the activation on the Fermi level position of all investigated layers is presented and discussed

  9. Characterization and corrosion resistance of anodic electrodeposited titanium oxide/phosphate films on Ti-20Nb-10Zr-5Ta bioalloy

    Energy Technology Data Exchange (ETDEWEB)

    Popa, Monica; Vasilescu, Cora; Drob, Silviu I.; Osiceanu, Petre; Anastasescu, Mihai; Calderon-Moreno, Jose M., E-mail: josecalderonmoreno@yahoo.com [Institute of Physical Chemistry ' Ilie Murgulescu' of the Romanian Academy, Bucharest (Romania)

    2013-07-15

    In this work, the anodic galvanostatic electrodeposition of an oxidation film containing phosphates on Ti-20Nb-10Zr-5Ta alloy from orthophosphoric acid solution is presented. Its composition was determined by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman micro-spectroscopy, and its topography by atomic force microscopy (AFM). The corrosion resistance of the coated alloy in simulated human fluid (by linear polarization method and monitoring of open circuit potentials, corresponding open circuit potential gradients) as well as the characterization of the coating (by Raman spectroscopy and depth profile X-ray photoelectron spectroscopy (XPS)) deposited in a period of 300 h soaking in simulated human body fluid were studied. The electrodeposited film was composed of amorphous titanium dioxide and contained phosphate groups. The corrosion resistance of the coated Ti-20Nb-10Zr-5Ta alloy in neutral and alkaline Ringer's solutions was higher than that of the bare alloy due to the protective properties of the electrodeposited film. The corrosion parameters improved over time as result of the thickening of the surface film by the deposition from the physiological solution. The deposited coating presented a variable composition in depth: at the deeper layer nucleated nanocrystalline hydroxyapatite and at the outer layer amorphous calcium phosphate. (author)

  10. Characterization and corrosion resistance of anodic electrodeposited titanium oxide/phosphate films on Ti-20Nb-10Zr-5Ta bioalloy

    International Nuclear Information System (INIS)

    In this work, the anodic galvanostatic electrodeposition of an oxidation film containing phosphates on Ti-20Nb-10Zr-5Ta alloy from orthophosphoric acid solution is presented. Its composition was determined by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman micro-spectroscopy, and its topography by atomic force microscopy (AFM). The corrosion resistance of the coated alloy in simulated human fluid (by linear polarization method and monitoring of open circuit potentials, corresponding open circuit potential gradients) as well as the characterization of the coating (by Raman spectroscopy and depth profile X-ray photoelectron spectroscopy (XPS)) deposited in a period of 300 h soaking in simulated human body fluid were studied. The electrodeposited film was composed of amorphous titanium dioxide and contained phosphate groups. The corrosion resistance of the coated Ti-20Nb-10Zr-5Ta alloy in neutral and alkaline Ringer's solutions was higher than that of the bare alloy due to the protective properties of the electrodeposited film. The corrosion parameters improved over time as result of the thickening of the surface film by the deposition from the physiological solution. The deposited coating presented a variable composition in depth: at the deeper layer nucleated nanocrystalline hydroxyapatite and at the outer layer amorphous calcium phosphate. (author)

  11. Depth profiling sulphur in bulk CdTe and {CdTe}/{CdS} thin film heterojunctions

    Science.gov (United States)

    Lane, D. W.; Conibeer, G. J.; Romani, S.; Healy, M. J. F.; Rogers, K. D.

    1998-03-01

    Polycrystalline CdTeCdS heterojunction solar cells are a possible candidate for the low cost, high efficiency conversion of solar energy. The formation of an intermediate CdS xTe 1- x layer during a high temperature annealing stage is believed to increase optical absorption and decrease cell efficiency. S diffusion in single crystal CdTe has been investigated by NRA using the 32S (d,p o) 33S nuclear reaction, at a deuteron energy of 2 MeV. Details of the NRA depth profiling procedure are given, which was found to be relatively straightforward and suitable for use on a small Van de Graaff accelerator. The resulting diffusion parameters are compared to those obtained by SIMS using a Cs + primary ion beam, examining negative secondary ions. The diffusion coefficients were found to be 1.1 × 10 -15cm 2 s -1 at 450°C and ˜8 × 10 -15cm -1 s at 550°C. S diffusion in thin films was also investigated by 2 MeV 4He + RBS on annealed polycrystalline CdSCdTe multilayers.

  12. Improved Intrinsic Stability of CdTe Polycrystalline Thin Film Devices

    Energy Technology Data Exchange (ETDEWEB)

    Albin, D.; Berniard, T.; McMahon, T.; Noufi, R.; Demtsu, S.

    2005-01-01

    A systems-driven approach linking upstream solar cell device fabrication history with downstream performance and stability has been applied to CdS/CdTe small-area device research. The best resulting initial performance (using thinner CdS, thicker CdTe, no oxygen during VCC, and the use of NP etch) was shown to simultaneously correlate with poor stability. Increasing the CdS layer thickness significantly improved stability at only a slight decrease in overall performance. It was also determined that cell perimeter effects can accelerate degradation in these devices. A ''margined'' contact significantly reduces the contribution of edge shunting to degradation, and thus yields a more accurate determination of the intrinsic stability. Pspice discrete element models demonstrate how spatially localized defects can effectively dominate degradation. Mitigation of extrinsic shunting improved stabilized efficiency degradation levels (SEDL) to near 20% in 100 C tests. Further process optimization to reduce intrinsic effects improved SEDL to better than 10% at the same stress temperatures and times.

  13. Nucleation and growth in electrodeposition of thin copper films on pyrolytic graphite

    Energy Technology Data Exchange (ETDEWEB)

    Kinaci, F.S.; Muller, R.H.

    1992-05-01

    Electrodeposition of Cu on graphite electrodes was studied, with emphasis on nucleation. Various ex-situ and in-situ methods were investigated for determining the number density of nuclei. Two direct methods were studied (scanning electron microscopy and scanning tunneling microscopy); indirect determinations included Raman spectroscopy and analysis of potentiostatic current transients. Though some of the techniques correctly predicted the nucleation densities under special conditions, SEM was the most reliable tool. The large scatter in the data necessitated steps to minimize this effect. To electrodeposit Cu on graphite, a nucleation overpotential of 250 mV was measured with cyclic voltammetry; such a large overpotential does not occur on a Pt or on a Cu-covered graphite electrode. The deposition potential is the dominant parameter governing nucleation density. There is a sharp increase in the nucleation density with applied potential. Cu can be deposited on highly oriented pyrolytic graphite only between the nucleation overpotential and the hydrogen evolution potential. To increase the Cu nucleation density, while avoiding excessive H evolution, a double pulse potential technique was used; nucleation densities on the order of 10{sup 10} nuclei/cm{sup 2} were achieved. The use of inhibitors (PVA, benzotriazole) was also investigated. Deposition on conducting polymer electrodes was also studied; initial results with polyaniline show promise. 57 figs, 6 tabs, refs. (DLC)

  14. Photo-assisted electrodeposition of polypyrrole back contact to CdS/CdTe solar cell structures

    International Nuclear Information System (INIS)

    Glass/indium tin oxide/CdS/CdTe photovoltaic structures were prepared using the high vacuum evaporation method, followed by a typical activation procedure, which involves annealing of the structures at 415–430 °C in the presence of CdCl2 in air. The main purpose of this work was to prepare and evaluate the performance of complete CdS/CdTe solar cell structures with polypyrrole (PPy) back contact and compare it to the structures with standard, copper containing back contact. Back contact layers of PPy doped with ß-naphthalene sulfonate were deposited onto activated CdTe layers by photo-assisted electrodeposition technique in a three-electrode electrochemical cell. It was found that intensive white light illumination from a xenon lamp facilitates PPy deposition at a lower applied potential range and improves quality of obtained polymer films. Applied technique gives the possibility to deposit the PPy layer strictly onto illuminated photoactive CdTe surface eliminating possible short-circuiting through pinholes and cracks in CdTe photoabsorber layer. Furthermore, relatively low deposition potential values give the possibility to reduce electrochemical degradation of CdS/CdTe photovoltaic structure in an electrochemical cell. - Highlights: ► Polypyrrole (PPy) conductive polymer back contact (BC) to CdTe semiconductor. ► Hybrid organic/inorganic photovoltaic structures. ► PPy layer to CdTe by photo-assisted electrodeposition technique ► Comparable efficiency of cells with PPy and conventional inorganic CuxTe BC

  15. Electrodeposited nanostructures

    Science.gov (United States)

    Schwarzacher, W.; Attenborough, K.; Michel, A.; Nabiyouni, G.; Meier, J. P.

    1997-01-01

    Electrodeposition may be used to prepare a range of nanostructured materials with interesting magnetic and magnetotransport properties. For example, on annealing, Co-Ni-Cu/Cu alloy superlattices electrodeposited from a single electrolyte show a previously unreported transition from giant magnetoresistance (GMR), to anisotropic magnetoresistance (AMR), and then back to GMR. Superlattice nanowires, electrodeposited in the pores of nuclear track-etched polycarbonate membranes, are another example of an electrodeposited nanostructure. They may be considered as columns of disc-shaped magnetic particles with diameter e.g. 80 nm and thickness e.g. 1 nm separated by non-magnetic material. Here we present evidence for demagnetizing interactions in such samples.

  16. Non-enzymatic Glucose Biosensor Based on Cu/SWNTs Composite Film Fabricated by One-step Electrodeposition

    Institute of Scientific and Technical Information of China (English)

    SUN Fang; LIU Peng; LI Li; LIANYong-fu

    2011-01-01

    Based on the adsorption of copper ions on single-walled carbon nanotubes(SWNTs)in electrolyte,Cu/SWNTs nanocomposite film was initially prepared on indium-doped tin oxide(ITO)substrate by one-step electrodeposition.This method may provide a versatile and facile pathway to fabricate other SWNTs-supported metal composite films.Electrochemical experiments revealed that the obtained Cu/SWNTs/ITO electrode offered an excellent electrocatalytic activity towards the oxidation of glucose and could be applied to the construction of non-enzymatic glucose biosensor.The linear range of the sensor was 1.0× 10-6to 6.0× 10-4 mol/L and the response time was within 2 s.Particularly,its sensitivity reached as high as 1434.67 μA.L·mmol-1·cm-2,which was superior to any other non-enzymatic glucose biosensor based on copper-carbon nanotubes electrode reported previously.

  17. Electrodeposition and properties of Zn, Cu, and Cu{sub 1−x} Zn{sub x} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Özdemir, Rasim [Kilis Vocational High School, Kilis 7 Aralık University, 79000 Kilis (Turkey); Karahan, İsmail Hakkı, E-mail: ihkarahan@gmail.com [Department of Metallurgical and Materials Engineering, Faculty of Technology, Mustafa Kemal University, 31040 Hatay (Turkey)

    2014-11-01

    Highlights: • Cu, Zn and Cu–Zn deposits successfully deposited from the non-cyanide sulphate electrolyte. • The effect of alloying element was investigated on the electrical resistivity and the structure of Cu–Zn alloy. • The average crystallite size of the samples varied from 66 to 161 nm and decreased when the Zn and Cu combined in Cu–Zn. • Microstrain has been decreased with increasing crystallite size. • Electrical resistivity of alloy was obtained between the Zn and Cu films. - Abstract: The electrodeposition of Cu, Zn and Cu–Zn deposits from the non-cyanide Zn sulphate and Cu sulphate reduced by citrate at constant stirring speed has been investigated. The composition of the Cu–Zn bath was shown to influence the morphology, electrical resistivity, phase composition, and Cu and Zn content of the Cu–Zn deposits. Their structural and electrical properties have been investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDAX), cyclic voltammeter (CV) and current–voltage measurements against the temperature for electrical resistivity, respectively. XRD shows that Cu–Zn samples are polycrystalline phase. Resistivity results show that the copper film exhibits bigger residual resistivity than both the zinc and the Cu–Zn alloy. Theoretical calculations of the XRD peaks demonstrate that the average crystallite size of the Cu–Zn alloy decreased and microstrain increased when the Cu alloyed with zinc.

  18. Electrodeposited tungsten oxide films: annealing effects on structure and electrochromic performance

    International Nuclear Information System (INIS)

    A potentiostatic electrochemical procedure employing an ethanolic solution of peroxotungstic acid yielded tungsten oxide (WO3) films specifically for transmissive electrochromic devices (ECDs) such as 'smart windows'. The structure-property correlation for the as-deposited thin films of WO3 and the films annealed at different temperatures (60, 100, 250 and 500 deg. C) is described. While the as-deposited film comprises of a small volume fraction of nanocrystals, the films annealed at 60 and 100 deg. C are X-ray amorphous, the 250 deg. C film is triclinic and the 500 deg. C film is characterized by mixed triclinic and hexagonal crystalline phases. Scanning electron micrographs (SEMs) clearly reveal the presence of nanograins/crystallite aggregates in the heat-treated films. Coloration renders the 250 deg. C film amorphous and reduces the crystallite size in the as-deposited and 500 deg. C films. Thermal analysis provides information pertaining to the critical temperatures at which dehydration, peroxo group decomposition and crystallization occur. Fourier transform infrared (FTIR) spectroscopic data show that while the as-deposited WO3 film is composed of a peroxopolytungstate ion network with water molecules acting as bridging groups, the crystalline film annealed at 500 deg. C shows absorption bands characteristic of the W-O-W network (polytungstate ions linked through oxygens). Coloration efficiency (CE; η) and transmission modulation (ΔT) are slightly higher for the amorphous 60 deg. C film when compared with the nanocrystalline as-deposited film in the 450-2) and a coloration efficiency of 60.5 cm2 C-1 at 632.8 nm observed for the as-deposited film render it to be a suitable candidate for electrochromic window applications. An operational lifetime of more than 104 cycles has been tested successfully for the as-deposited film against a platinum sheet as an auxiliary electrode

  19. Hydrogen peroxide biosensor based on electrodeposition of zinc oxide nanoflowers onto carbon nanotubes film electrode

    Institute of Scientific and Technical Information of China (English)

    Hui Ping Bai; Xu Xiao Lu; Guang Ming Yang; Yun Hui Yang

    2008-01-01

    A new amperometric biosensor for hydrogen peroxide was developed based on adsorption of horseradish peroxidase at the glassy carbon electrode modified with zinc oxide nanoflowers produced by electrodeposition onto multi-walled carbon nanotubes (MWNTs) firm. The morphology of the MWNTs/nano-ZnO electrode has been investigated by scanning electron microscopy (SEM), and the electrochemical performance of the electrode has also been studied by amperometric method. The resulting electrode offered an excellent detection for hydrogen peroxide at -0.11 V with a linear response range of 9.9 × 10(-7) to 2.9 × 10(-3) mol/L with a correlation coefficient of 0.991, and response time <5 s. The biosensor displays rapid response and expanded linear response range, and excellent stability.

  20. Correlations of Capacitance-Voltage Hysteresis with Thin-Film CdTe Solar Cell Performance During Accelerated Lifetime Testing

    Energy Technology Data Exchange (ETDEWEB)

    Albin, D.; del Cueto, J.

    2011-03-01

    In this paper we present the correlation of CdTe solar cell performance with capacitance-voltage hysteresis, defined presently as the difference in capacitance measured at zero-volt bias when collecting such data with different pre-measurement bias conditions. These correlations were obtained on CdTe cells stressed under conditions of 1-sun illumination, open-circuit bias, and an acceleration temperature of approximately 100 degrees C.

  1. Electrodeposited Pd-Ni-Mo film as a cathode material for hydrogen evolution reaction

    International Nuclear Information System (INIS)

    A Pd-Ni-Mo film was prepared on stainless steel substrate as a novel electrode material for hydrogen evolution reaction catalysis. The surface micro-morphology, chemical composition and microstructure of the Pd-Ni-Mo film were characterizated with SEM, EDS, XPS and TEM. The obtained film is a multiple phase ternary alloy containing crystallines and amorphous phases. The electrochemical measurements showed that the Pd-Ni-Mo film has excellent catalytic activity for hydrogen evolution reaction with good corrosion resistance in 1 M NaOH solution. The proton discharge electrosorption is the rate determining step of hydrogen evolution reaction on Pd-Ni-Mo film surface. The better electrocatalysis performance of the Pd-Ni-Mo film is attributed to its larger real surface as well as the enhanced electrochemical activity of the film surface due to the alloying effect

  2. Properties of CdTe films deposited by electron beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Murali, K.R.; Radhakrishna, I.; Nagaraja Rao, K.; Venkatesan, V.K. (Central Electrotechnical Research Inst., Karaikudi (India))

    1990-04-01

    Cadmium telluride thin films were prepared by electron beam evaporation on glass substrates kept at different temperatures in the range 30-300degC. The films were characterized by X-ray diffraction, scanning electron microscopy and optical absorption measurements. The conductivity of the films was measured in the temperature range 100-300 K. While the low temperature data (100-200 K) could be explained by the variable range hopping process, the high temperature data (200-300 K) could be explained on the basis of Seto's model for thermionic emission of the carriers over the grain boundaries. Transmission spectra have indicated a direct and gap around 1.55 eV. (orig.).

  3. Characterization of Cu1.4Te Thin Films for CdTe Solar Cells

    Directory of Open Access Journals (Sweden)

    Guangcan Luo

    2014-01-01

    Full Text Available The copper telluride thin films were prepared by a coevaporation technique. The single-phase Cu1.4Te thin films could be obtained after annealing, and annealing temperature higher than 220°C could induce the presence of cuprous telluride coexisting phase. Cu1.4Te thin films also demonstrate the high carrier concentration and high reflectance for potential photovoltaic applications from the UV-visible-IR transmittance and reflectance spectra, and Hall measurements. With contacts such as Cu1.4Te and Cu1.4Te/CuTe, cell efficiencies comparable to those with conventional back contacts have been achieved. Temperature cycle tests show that the Cu1.4Te contact buffer has also improved cell stability.

  4. Investigation of gallium redistribution processes during Cu(In,Ga)Se{sub 2} absorber formation from electrodeposited/annealed oxide precursor films

    Energy Technology Data Exchange (ETDEWEB)

    Sidali, T., E-mail: tarik.sidali@edf.fr; Duchatelet, A.; Chassaing, E.; Lincot, D.

    2015-05-01

    A way to prepare metallic precursors for CuIn{sub 1−x},Ga{sub x}Se{sub 2} (CIGS) solar cells has been recently introduced leading to efficiencies above 12.4%. It consists in the electrodeposition of Cu-In-Ga mixed oxides in an acidic nitrate aqueous solution followed by thermal reduction and selenization. This paper investigates, in a first part, the nucleation and growth mechanisms taking place during the co-electrodeposition of Cu-In-Ga oxide/hydroxide film. Scanning Electron Microscope observations coupled to Energy Dispersive X-ray spectrometry point out that the deposition is initiated by the formation of metallic copper nuclei. These nuclei enable the growth of Cu-In-Ga oxide film. This observation confirms that freshly deposited copper catalyzes nitrate reduction leading to an increase in the surface pH enabling the precipitation of the Cu-In-Ga hydroxides. In a second part, precursor films were elaborated with increasing Ga(NO{sub 3}){sub 3} concentration. After reduction of the films in hydrogen and selenization heat treatments, X-ray diffraction analysis shows the incorporation of Ga into the CIGS phase with increasing Ga content in the optimal composition range for photovoltaic applications (x = 0.25-0.34). Gallium composition profiles are evidenced in the films with a tendency to higher concentration near the Mo surface. Increasing annealing temperature allows a better homogenization of Ga in the film. The consequences are correlated to optoelectronic measurements (Eg and cell efficiency) with bandgap measurement and cell efficiencies (10 to 12%). - Highlights: • Electrodeposition starts with copper nucleation. • Gallium content in the precursor is tuned by Ga(III) concentration. • Increasing selenization temperature promotes Ga homogenization in CIGS.

  5. Analysis of the diode characteristics of thin film solar cells based on CdTe

    International Nuclear Information System (INIS)

    A physical approach to the optimization of photoelectric processes in thin film multilayer systems has been developed. By means of a simulation of the influence of light-diode characteristics on the efficiency factor, it is concluded that the optimization of the photoelectric processes in ITO/CdS/CdTe/Cu/Au film solar cells is mainly determined by two competing physical mechanisms: an increase in the efficiency of the process of distribution of nonequilibrium charge carriers and a reduction in the efficiency of their generation, as the CdS layer thickness grows

  6. Synergy effect over electrodeposited submicron Cu2O films in photocatalytic degradation of methylene blue

    International Nuclear Information System (INIS)

    In the study, we report a simple method to fabricate semiconductor Cu2O films by using a potentiostatic method. The obtained thin films have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM). The obtained Cu2O films are composed of submicron particles with sizes in the range from tens to several hundreds of nanometers. The photocatalytic activity over the Cu2O films was investigated under simulated solar light. A strong synergy effect between H2O2 and Cu2O films in the photocatalytic degradation of methylene blue has been observed. The binary H2O2/Cu2O systems exhibit high catalytic ability under the solar irradiation. The results show that Cu2O films can be used as a reliable platform for environmental remediation by using solar energy.

  7. Study of the Mg incorporation in CdTe for developing wide band gap Cd{sub 1-x}Mg{sub x}Te thin films for possible use as top-cell absorber in a tandem solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Omar S. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, 62580 Temixco, Morelos (Mexico); Universidad Politecnica del Estado de Guerrero, Comunidad de Puente Campuzano, C.P. 40325 Taxco de Alarcon, Guerrero (Mexico); Millan, Aduljay Remolina [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, 62580 Temixco, Morelos (Mexico); Huerta, L.; Santana, G. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico. C.P 04510 Mexico D.F. (Mexico); Mathews, N.R.; Ramon-Garcia, M.L.; Morales, Erik R. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, 62580 Temixco, Morelos (Mexico); Mathew, X., E-mail: xm@cie.unam.mx [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, 62580 Temixco, Morelos (Mexico)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Thin films of Cd{sub 1-x}Mg{sub x}Te with high spatial uniformity and band gap in the range of 1.6-1.96 eV were deposited by vacuum co-evaporation of CdTe and Mg. Black-Right-Pointing-Pointer Obtained Cd{sub 1-x}Mg{sub x}Te films have the structural characteristics of the CdTe, evidence of the change in atomic scattering due to incorporation of Mg was observed. Black-Right-Pointing-Pointer XRD and XPS data confirmed the incorporation of Mg in the lattice of CdTe. Black-Right-Pointing-Pointer SEM images revealed the impact of Mg incorporation on the morphology of the films, the changes in grain size and grain morphology are noticeable. - Abstract: Thin films of Cd{sub 1-x}Mg{sub x}Te with band gap in the range of 1.6-1.96 eV were deposited by vacuum co-evaporation of CdTe and Mg on glass substrates heated at 300 Degree-Sign C. Different experimental techniques such as XRD, UV-vis spectroscopy, SEM, and XPS were used to study the effect of Mg incorporation into the lattice of CdTe. The band gap of the films showed a clear tendency to increase as the Mg content in the film is increased. The Cd{sub 1-x}Mg{sub x}Te films maintain all the structural characteristics of the CdTe, however, diminishing of intensity for the XRD patterns is observed due to both change in preferential orientation and change in atomic scattering due to the incorporation of Mg. SEM images showed significant evidences of morphological changes due to the presence of Mg. XRD, UV-vis spectroscopy, and XPS data confirmed the incorporation of Mg in the lattice of CdTe. The significant increase in band gap of CdTe due to incorporation of Mg suggests that the Cd{sub 1-x}Mg{sub x}Te thin film is a candidate material to use as absorber layer in the top-cell of a tandem solar cell.

  8. High throughput manufacturing of thin-film CdTe photovoltaic modules. Annual subcontract report, 16 November 1993--15 November 1994

    Energy Technology Data Exchange (ETDEWEB)

    Sandwisch, D W [Solar Cells, Inc., Toledo, OH (United States)

    1995-11-01

    This report describes work performed by Solar Cells, Inc. (SCI), under a 3-year subcontract to advance SCI`s PV manufacturing technologies, reduce module production costs, increase module performance, and provide the groundwork for SCI to expand its commercial production capacities. SCI will meet these objectives in three phases by designing, debugging, and operating a 20-MW/year, automated, continuous PV manufacturing line that produces 60-cm {times} 120-cm thin-film CdTe PV modules. This report describes tasks completed under Phase 1 of the US Department of Energy`s PV Manufacturing Technology program.

  9. Nano-particle size-dependent charging and electro-deposition in dielectric barrier discharges at atmospheric pressure for thin SiO{sub x} film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Jidenko, N [Equipe Decharges Electriques et Environnement du Laboratoire de Physique des Gaz et des Plasmas, UMR 8578 CNRS - Universite Paris-Sud Orsay, F-91405 Supelec, Plateau Moulon, F-91192 Gif Sur Yvette (France); Jimenez, C [Laboratoire de Genie Electrique de Toulouse, CNRS - Universite Paul Sabatier, Universite Paul Sabatier, 118 route de Narbonne, 31060 Toulouse (France); Massines, F [Laboratoire de Genie Electrique de Toulouse, CNRS - Universite Paul Sabatier, 118 route de Narbonne, 31060 Toulouse (France); Borra, J-P [Equipe Decharges Electriques et Environnement du Laboratoire de Physique des Gaz et des Plasmas, UMR 8578 CNRS - Universite Paris-Sud Orsay, F-91405 Supelec, Plateau Moulon, F-91192 Gif Sur Yvette (France)

    2007-07-21

    This paper focuses on charging and electro-deposition of nano-particles produced in a mixture of silane and nitrous oxide diluted in N{sub 2}, by dielectric barrier discharge (DBD) at atmospheric pressure for SiO{sub x} film deposition. Townsend discharge (TD) and filamentary discharge (FD) are compared with and without SiH{sub 4}. Without SiH{sub 4}, particles are produced by filament-surface interaction. Both filament-surface and plasma-silane interactions lead to bimodal particle size distributions from nucleation and agglomeration. With SiH{sub 4}, particle formation and growth imply the same mechanisms in TD and FD. Faster dynamics in FD are related to higher local volume energy density than in TD. From scanning electron microscope images of the film and measurements downstream of the DBD reactor, the diameter of the particle produced is below 50 nm. An analytical model of electro-collection in an ac electric field is used to investigate nano-particle charging. To account for selective electro-deposition leading to particles smaller than 50 nm being included in the layer and to particle size distribution measured downstream of the DBD, the same size-dependent charging and electro-deposition of particle are involved, with different charging dynamics in TD and FD.

  10. Challenges of sample preparation for cross sectional EBSD analysis of electrodeposited nickel films

    DEFF Research Database (Denmark)

    Alimadadi, Hossein; Pantleon, Karen

    2009-01-01

    Thorough microstructure and crystallographic orientation analysis of thin films by means of electron backscatter diffraction requires cross section preparation of the film-substrate compound. During careful preparation, changes of the rather non-stable as-deposited microstructure must be avoided...

  11. Properties of Electrodeposited Cadmium Sulfide Films for Photovoltaic Devices With Comparison to CdS Films Prepared by Other Methods

    OpenAIRE

    KADIRGAN, Figen

    2000-01-01

    Films of CdS for photovoltaic devices were electrochemically deposited on tin oxide coated glass substrates at different conditions. The films were found to be smooth and uniform with a small grain size. X-ray diffraction measurement and analysis indicated a hexagonal phase rather than the cubic phase. The surface composition of the films was investigated by Auger Spectroscopy. Electrochemical deposition parameters were studied to obtain the optimum conditions for the best CdS film...

  12. Correlation between physical properties and growth mechanism of In2S3 thin films fabricated by electrodeposition technique with different deposition times

    Science.gov (United States)

    Braiek, Zied; Gannouni, Mounir; Ben Assaker, Ibtissem; Bardaoui, Afrah; Lamouchi, Amina; Brayek, A.; Chtourou, Radhouane

    2015-10-01

    Indium sulfide (In2S3) thin films were grown on ITO-coated glass substrate using the electrodeposition method. The effect of the deposition time on the structural, morphological, optical and electrical properties of the as-grown In2S3 thin films was studied. XRD spectra of the obtained films reveal the polycrystalline nature of (β-In2S3) with a tetragonal crystal structure along the (109) plane, and exhibit a sharp transition to the (0012) plane when the deposition time is extended beyond 20 min. Using atomic force microscope (AFM), the surface morphology shows a remarkable change in the grain size, thickness, and surface roughness when varying the deposition time. UV-VIS spectrophotometer show that the optical band gap values of In2S3 decrease from about 2.82 to 1.93 eV by extending the electrodeposition duration from 5 to 20 min. All films were found to have an n-type character with a lower electrical resistivity of about 1.8×10-3 Ω cm for films deposited at 20 min.

  13. Composition Control of CuInSe2 Thin Films Using Cu/In Stacked Structure in Coulometric Controlled Electrodeposition Process.

    Science.gov (United States)

    Kwon, Yong Hun; Do, Hyun Woo; Kim, Hyoungsub; Cho, Hyung Koun

    2015-10-01

    Cu/In bi-metal stacked structures were prepared on Mo coated soda lime glass substrates using electrodeposition method. These metallic precursors were selenized at 550 °C for 60 min to synthesize the CuInSe2 (CIS) thin films in a thermal evaporator chamber with an Se overpressure atmosphere. The composition ratios of CIS thin films were systematically controlled using the coulometric method of the electrodeposition, where the accumulated coulomb of In layers was varied from 1062 to 6375 mC/cm2. As a result, the stoichiometric CIS film was obtained in the Cu/In coulomb ratio of 0.6. Highly crystallized CIS films were produced from the liquid Cu-Se phase in the Cu/In coulomb ratio of ≥0.6. In contrast, the crystallinity and grain size were degraded in the In-rich region. We found that the Cu/In composition ratio of CIS films was linearly proportional to the precursor thickness determined by the coulomb ratio. PMID:26726424

  14. Electrodeposition of Silver Nanoparticles on MWCNT Film Electrodes for Hydrogen Peroxide Sensing

    Institute of Scientific and Technical Information of China (English)

    DING,Yan-Feng; JIN,Guan-Ping; YIN,Jun-Guang

    2007-01-01

    Silver (Ag) nanoparticles were directly electrodeposited on multi-walled carbon nanotubes (MWCNT) in AgNO3/LiNO3 containing EDTA (ethylenediaminetetraacetic acid). The structure and nature of the resulting Ag/MWNT composite were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD), and the distribution shape of Ag nanoparticles was found to be dependent on the presence of EDTA. The modified electrode showed excellent electrocatalytic activity to redox reaction of hydrogen peroxide and the mechanism of hydrogen peroxide was partly reversible procession with oxidation and reduction peaks at 0.77 and -0.83 V, respectively. The oxidation and reduction peak currents were linearly related to hydrogen peroxide concentration in the range of 1×10-6-3×10-4 and 1×10-8-7×10-4 mol·L-1 with correlation coefficients of 0.996 and 0.986, and 3s-detection limit of 9 × 10-7 and 7 × 10-9 mol·L-1.

  15. Involvement of nanoparticles in the electrodeposition of hydrous iridium oxide films

    International Nuclear Information System (INIS)

    The highly dispersed nature of hydrous iridium oxide combined with its electrochemical properties makes it a very interesting material. Possible applications can be found in electrocatalysis, neural stimulation, electrochromic devices and pH sensors. In the present work a commonly used electrodeposition solution, based on IrCl4, oxalic acid, H2O2 and NaCO3, was studied with electrochemical methods as well as UV–vis spectroscopy. The hexachloroiridate (IV) complex was initially observed in both UV–vis and cyclic voltammetry. No oxalato complexes were detected, instead oxalate is proposed to act as a stabilising agent in nanoparticle formation. Initially hydrogen peroxide was found to reduce Ir(IV) complexes to Ir(III). However, after increasing the pH by addition of sodium carbonate it was shown to act as an oxidising agent instead. During development of the solution UV–vis showed the formation of multinuclear complexes and with aging also scattering from solid materials was observed. Transmission electron microscopy confirmed the formation of nanoparticles of iridium oxide with a diameter of ∼3 nm. The role of nanoparticles and non-particulate species in the deposition process is discussed.

  16. Effect of Applied Current Density on Morphological and Structural Properties of Electrodeposited Fe-Cu Films

    Institute of Scientific and Technical Information of China (English)

    Umut Sarac; M. Celalettin Baykul

    2012-01-01

    A detailed study has been carried out to investigate the effect of applied current density on the composition, crystallographic structure, grain size, and surface morphology of Fe-Cu films. X-ray diffraction (XRD) results show that the films consist of a mixture of face-centered cubic (fcc) Cu and body centered cubic (bcc) ~-Fe phases. The average crystalline size of both Fe and Cu particles decreases as the applied current density becomes more negative. Compositional analysis of Fe-Cu films indicates that the Fe content within the films increases with decreasing current density towards more negative values. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) have been used to investigate the surface morphology of Fe-Cu films. It is observed that the surface morphology of the films changes from dendritic structure to a cauliflower structure as the applied current density becomes more negative. The surface roughness and grain size of the Fe-Cu films decrease with decreasing applied current density towards more negative values.

  17. Electrodeposition and Capacitive Behavior of Films for Electrodes of Electrochemical Supercapacitors

    Directory of Open Access Journals (Sweden)

    Shi C

    2010-01-01

    Full Text Available Abstract Polypyrrole films were deposited by anodic electropolymerization on stainless steel substrates from aqueous pyrrole solutions containing sodium salicylate and tiron additives. The deposition yield was studied under galvanostatic conditions. The amount of the deposited material was varied by the variation of deposition time at a constant current density. SEM studies showed the formation of porous films with thicknesses in the range of 0–3 μm. Cyclic voltammetry data for the films tested in 0.5 M Na2SO4 solutions showed capacitive behavior and high specific capacitance (SC in a voltage window of 0.9 V. The films prepared from pyrrole solutions containing tiron showed better capacitive behavior compared to the films prepared from the solutions containing sodium salicylate. A highest SC of 254 F g−1 was observed for the sample with a specific mass of 89 μg cm−2 at a scan rate of 2 mV s−1. The SC decreased with an increasing film thickness and scan rate. The results indicated that the polypyrrole films deposited on the stainless steel substrates by anodic electropolymerization can be used as electrodes for electrochemical supercapacitors (ES.

  18. Electrodeposition and Capacitive Behavior of Films for Electrodes of Electrochemical Supercapacitors

    Science.gov (United States)

    Shi, C.; Zhitomirsky, I.

    2010-03-01

    Polypyrrole films were deposited by anodic electropolymerization on stainless steel substrates from aqueous pyrrole solutions containing sodium salicylate and tiron additives. The deposition yield was studied under galvanostatic conditions. The amount of the deposited material was varied by the variation of deposition time at a constant current density. SEM studies showed the formation of porous films with thicknesses in the range of 0-3 μm. Cyclic voltammetry data for the films tested in 0.5 M Na2SO4 solutions showed capacitive behavior and high specific capacitance (SC) in a voltage window of 0.9 V. The films prepared from pyrrole solutions containing tiron showed better capacitive behavior compared to the films prepared from the solutions containing sodium salicylate. A highest SC of 254 F g-1 was observed for the sample with a specific mass of 89 μg cm-2 at a scan rate of 2 mV s-1. The SC decreased with an increasing film thickness and scan rate. The results indicated that the polypyrrole films deposited on the stainless steel substrates by anodic electropolymerization can be used as electrodes for electrochemical supercapacitors (ES).

  19. Electrodeposition of nanostructured CoNi thin films and their anomalous infrared properties

    International Nuclear Information System (INIS)

    Different composition, thickness and structure of CoNi thin films supported on glassy carbon were prepared by electrochemical codeposition. Potential step method was applied to prepare CoNi thin films with different composition which was controlled by varying the concentration ratio of Co2+/Ni2+ (x:y) in the deposition solution, thus this type of CoNi thin film was defined as CoNi(x:y). Nevertheless, CoNi thin films with different thickness and structure (denoted as CoNi(n)) were synthesized in a fixed Co2+/Ni2+ solution under cyclic voltammetric conditions by varying the cyclic numbers (n) within a defined potential range. AES and EDS analysis revealed that the atomic ratio of Co/Ni in the film (including both outer and inner layer) was in good accordance with the initial Co2+/Ni2+ ratio. XRD investigation indicated that the CoNi(20:0) and CoNi(15:5) thin films were hexagonal closed-packed (hcp) structure, however, the CoNi(10:10), CoNi(5:15) and CoNi(0:20) thin films were face centered cubic (fcc) structure. SEM studies demonstrated that the CoNi(x:y) thin films were uniformly composed of irregular nanoparticles. In the case of CoNi(n), with n increasing, the structure of nanoparticles inside the CoNi thin films underwent a transition from imperfectly spherical particles to multiform particles, and finally to irregular polyhedral particles, accompany with an increase of average size. In situ FTIR reflection spectroscopic studies demonstrated that the mainly chemisorbed CO species (COad) on CoNi(x:y) surfaces were transferred from linearly bonded CO (COL) to bridge bonded CO (COB) as a function of the content of Ni and the crystal phase structure of CoNi thin films. CoNi(x:y) and CoNi(n) thin films all exhibited anomalous IR properties, corresponding respectively to abnormal IR effects (AIREs), Fano-like IR effects and surface-enhanced IR absorption effects. AIREs characterized mostly with inversion of IR band was found on CoNi(x:y), CoNi(4), CoNi(8) thin films

  20. Electrodeposition behavior of nanocrystalline CoNiFe soft magnetic thin film

    Institute of Scientific and Technical Information of China (English)

    LI Jing-feng; ZHANG Zhao; YIN Jun-ying; YU Geng-hua; CAI Chao; ZHANG Jian-qing

    2006-01-01

    The electroplating behavior of nanocrystalline CoNiFe soft magnetic thin film with high saturation magnetic flux density (Bs>2.1 T) and low coercivity (Hc) was investigated using cyclic voltammetry and chronoamperometry methods in conjunction with the scanning electron microscopy (SEM/EDX). The results show that, under the experimental conditions, the co-deposition of CoNiFe film behaves anomalously due to the atomic radii of iron series elements following the order of rFe>rCo > rNi. In the case of lower electroplating current density, the co-deposition of CoNiFe film follows a 3-D progressive nucleation/growth mechanism,while in the case of higher electroplating current density, which follows a 3-D instantaneous nucleation/growth mechanism.Meanwhile, the change of nucleation mechanism of CoNiFe film with electroplating current density was interpreted theoretically in the light of quantum chemistry.

  1. Electrodeposition and Capacitive Behavior of Films for Electrodes of Electrochemical Supercapacitors

    OpenAIRE

    Shi C; Zhitomirsky I

    2010-01-01

    Abstract Polypyrrole films were deposited by anodic electropolymerization on stainless steel substrates from aqueous pyrrole solutions containing sodium salicylate and tiron additives. The deposition yield was studied under galvanostatic conditions. The amount of the deposited material was varied by the variation of deposition time at a constant current density. SEM studies showed the formation of porous films with thicknesses in the range of 0–3 μm. Cyclic voltammetry data for the...

  2. Microstructure and magnetic properties of electrodeposited Gd-Co alloy films

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Gd-Co alloy films were synthesized by potentiostatic electrolysis on Cu substrates in urea-aeetamide-NaBr-KBr melt at 353 K.The electroreduction of Co2+ and Gd3+ was investigated by cyclic voltammetry.The reduction of Co2+ is an irreversible process.Gd3+ cannot be reduced alone,but it can be inductively co-deposited with Co2+.Both the Gd content and microstructure of the prepared Gd-Co alloy films can be controlled by the deposited potential.The content of Gd was analyzed using an inductively coupled plasma emission spectrometer(ICPES),and the microstructure was observed by scanning electron mierograph (SEM).The films were crystallized by heat-treatment at 823 K for 30 s in Ar atmosphere,and then were investigated by XRD.The hysteresis loops of the Gd-Co alloy films were measured by a vibrating sample magnetometer (VSM).The experimental results reveal that the deposited Gd-Co alloy films are amorphous,while the annealing causes the samples to change from amorphous to polycrystalline,thus enhancing their magnetoerystalline anisotropy and coercivity.Moreover,the magnetic properties of the Gd-Co alloy films depend strongly on the Gd content.

  3. 半导体硅上电沉积Cu/Co层状薄膜%Preparation of Cu/Co Layer Film by Electrodeposition on Semiconductor Silicon

    Institute of Scientific and Technical Information of China (English)

    刘冰; 龚正烈; 姚素薇; 郭鹤桐; 袁华堂; 张允什

    1999-01-01

    The Cu/Co layer film on the semiconductor silicon was obtained by electrodeposition for the first time. The results of current-time transient curves and STM image showed that the growth of Cu film is two dimensional while an island three dimension growth for the Co film was formed. The addition of CrO3 changed the current-time transient curves,and affected the growth of crystal.The addition of CrO3 decreased the nucleation rate of Cu,while it changed the shape of current-time transient curves of the deposition of Co at higher deposition potentials.For the deposition of Co,addition of CrO3 can form the adhesive film [Co· xCr2O3· yH2O]ad or [CoOH· nCr(OH)3]ad,which decreased the nucleation rate of Co.

  4. Effect of Y2O3 on microstructure and oxidation of γ-Ni+γ'-Ni3Al coatings transformed from electrodeposited Ni-Al films at 1 000 ℃

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yue-bo; ZHANG Hai-jun; WANG Zhen-ting

    2008-01-01

    The electrodeposited Y2O3-dispersed γ-Ni+γ'-Ni3Al coatings on Ni substrates were developed by the conversion of electrodeposited Ni-Al-Y2O3 films with dispersed Al microparticles in Ni matrix into Ni3Al by vacuum annealing at 800 ℃ for 3 h. For comparison, Y2O3-free (γ-Ni+γ'-Ni3Al coatings with a similar Al content were also prepared by vacuum annealing the electrodeposited microparticle-dispersed composite coatings of Ni-Al under the same condition. SEM and TEM characterizations show that the electrodeposited Y2O3-dispersed γ+γ' coatings exhibit finer grains, a more homogeneous distribution of γ', and a narrowed γ' phase spacing compared with the electrodeposited Y2O3-free γ+γ' coatings. The oxidation at 1 000 ℃ shows that the addition of Y2O3 significantly improves the oxidation resistance of the electrodeposited γ+γ'coatings. The effect of Y2O3 particles on the microstructure and oxidation behavior of the electrodeposited γ+γ' coatings was discussed in detail.

  5. High-efficiency CdTe thin-film solar cells using metalorganic chemical vapor deposition techniques

    Science.gov (United States)

    Nouhi, A.; Stirn, R. J.; Meyers, P. V.; Liu, C. H.

    1989-06-01

    Energy conversion efficiency of metalorganic chemical vapor deposited CdTe as an intrinsic active layer in n-i-p solar cell structures is reported. Small-area devices with efficiencies over 9 percent have been demonstrated. I-V characteristics, photospectral response, and the results of Auger profiling of structural composition for typical devices will be presented. Also presented are preliminary results on similar photovoltaic devices having Cd(0.85)Mn(0.15)Te in place of CdTe as an i layer.

  6. High-efficiency CdTe thin-film solar cells using metalorganic chemical vapor deposition techniques

    Energy Technology Data Exchange (ETDEWEB)

    Nouhi, A.; Stirn, R.J.; Meyers, P.V.; Liu, C.H.

    1989-05-01

    Energy conversion efficiency of metalorganic chemical vapor deposited CdTe as an intrinsic active layer in n-i-p solar cell structures is reported. Small-area devices with efficiencies over 9% have been demonstrated. I--V characteristics, photospectral response, and the results of Auger profiling of structural composition for typical devices will be presented. Also presented are preliminary results on similar photovoltaic devices having Cd/sub 0.85/Mn/sub 0.15/Te in place of CdTe as an i layer.

  7. High-efficiency CdTe thin-film solar cells using metalorganic chemical vapor deposition techniques

    Science.gov (United States)

    Nouhi, A.; Stirn, R. J.; Meyers, P. V.; Liu, C. H.

    1989-01-01

    Energy conversion efficiency of metalorganic chemical vapor deposited CdTe as an intrinsic active layer in n-i-p solar cell structures is reported. Small-area devices with efficiencies over 9 percent have been demonstrated. I-V characteristics, photospectral response, and the results of Auger profiling of structural composition for typical devices will be presented. Also presented are preliminary results on similar photovoltaic devices having Cd(0.85)Mn(0.15)Te in place of CdTe as an i layer.

  8. Polycrystalline thin-film technology: Recent progress in photovoltaics

    Science.gov (United States)

    Mitchell, R. L.; Zweibel, K.; Ullal, H. S.

    1991-12-01

    Polycrystalline thin films have made significant technical progress in the past year. Three of these materials that have been studied extensively for photovoltaic (PV) power applications are copper indium diselenide (CuInSe2), cadmium telluride (CdTe), and thin film polycrystalline silicon (x-Si) deposited on ceramic substrates. The first of these materials, polycrystalline thin film CuInSe2, has made some rapid advances in terms of high efficiency and long term reliability. For CuInSe2 power modules, a world record has been reported on a 0.4 sq m module with an aperture-area efficiency of 10.4 pct. and a power output of 40.4 W. Additionally, outdoor reliability testing of CuInSe2 modules, under both loaded and open-circuit conditions, has resulted in only minor changes in module performance after more than 1000 days of continuous exposure to natural sunlight. CdTe module research has also resulted in several recent improvements. Module performance has been increased with device areas reaching nearly 900 sq cm. Deposition has been demonstrated by several different techniques, including electrodeposition, spraying, and screen printing. Outdoor reliability testing of CdTe modules was also carried out under both loaded and open-circuit conditions, with more than 600 days of continuous exposure to natural sunlight. These tests were also encouraging and indicated that the modules were stable within measurement error. The highest reported aperture-area module efficiency for CdTe modules is 10 pct.; the semiconductor material was deposited by electrodeposition. A thin-film CdTe photovoltaic system with a power output of 54 W has been deployed in Saudi Arabia for water pumping. The Module Development Initiative has made significant progress in support of the Polycrystalline Thin-Film Program in the past year, and results are presented in this paper.

  9. Polycrystalline thin-film technology: Recent progress in photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, R.L.; Zweibel, K.; Ullal, H.S.

    1991-12-01

    Polycrystalline thin films have made significant technical progress in the past year. Three of these materials that have been studied extensively for photovoltaic (PV) power applications are copper indium diselenide (CuInSe{sub 2}), cadmium telluride (CdTe), and thin-film polycrystalline silicon (x-Si) deposited on ceramic substrates. The first of these materials, polycrystalline thin-film CuInSe{sub 2}, has made some rapid advances in terms of high efficiency and long-term reliability. For CuInSe{sub 2} power modules, a world record has been reported on a 0.4-m{sup 2} module with an aperture-area efficiency of 10.4% and a power output of 40.4 W. Additionally, outdoor reliability testing of CuInSe{sub 2} modules, under both loaded and open-circuit conditions, has resulted in only minor changes in module performance after more than 1000 days of continuous exposure to natural sunlight. CdTe module research has also resulted in several recent improvements. Module performance has been increased with device areas reaching nearly 900 cm{sup 2}. Deposition has been demonstrated by several different techniques, including electrodeposition, spraying, and screen printing. Outdoor reliability testing of CdTe modules was also carried out under both loaded and open-circuit conditions, with more than 600 days of continuous exposure to natural sunlight. These tests were also encouraging and indicated that the modules were stable within measurement error. The highest reported aperture-area module efficiency for CdTe modules is 10%; the semiconductor material was deposited by electrodeposition. A thin-film CdTe photovoltaic system with a power output of 54 W has been deployed in Saudi Arabia for water pumping. The Module Development Initiative has made significant progress in support of the Polycrystalline Thin-Film Program in the past year, and results are presented in this paper.

  10. Cathodic electrodeposition of MnO {sub x} films for electrochemical supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Nagarajan, N. [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ont., L8S 4L7 (Canada); Humadi, H. [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ont., L8S 4L7 (Canada); Zhitomirsky, I. [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ont., L8S 4L7 (Canada)]. E-mail: zhitom@mcmaster.ca

    2006-04-01

    Cathodic electrosynthesis has been utilized for the fabrication of MnO {sub x} films. The use of polyethylenimine (PEI) as an additive enabled the formation of adherent films, which exhibited enhanced resistance to cracking during drying. The polymer content in the deposits can be varied by the variation of the polymer concentration in the solutions. The mechanism of PEI deposition was proposed which is based on the use of PEI-Mn{sup 2+} complexes. The deposition yield has been studied at different deposition durations. X-ray diffraction analysis showed the crystallization of Mn{sub 3}O{sub 4} phase at 300 deg. C and Mn{sub 2}O{sub 3} at 500 deg. C. The electrochemical performance of the MnO {sub x} films sintered at different temperatures was studied by cyclic voltammetry (CV), chronopotentiometry and impedance spectroscopy in Na{sub 2}SO{sub 4} solutions. The films showed excellent pseudocapacitive behavior. The specific capacitance (SC) of 425 F/g in a potential window of 0-0.9 V was obtained from the CV data at a scan rate of 10 mV/s. The SC calculated from the chronopotentiometry data is about 445 F/g. The SC decreased by {approx}20% after 1000 cycles. SEM investigations revealed changes in the film morphology during cycling. Obtained results indicate that the proposed method can be used for the fabrication of electrodes for electrochemical supercapacitors.

  11. Cathodic electrodeposition of MnO{sub x} films for electrochemical supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Nagarajan, N.; Humadi, H.; Zhitomirsky, I. [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ont. (Canada)

    2006-04-01

    Cathodic electrosynthesis has been utilized for the fabrication of MnO{sub x} films. The use of polyethylenimine (PEI) as an additive enabled the formation of adherent films, which exhibited enhanced resistance to cracking during drying. The polymer content in the deposits can be varied by the variation of the polymer concentration in the solutions. The mechanism of PEI deposition was proposed which is based on the use of PEI-Mn{sup 2+} complexes. The deposition yield has been studied at different deposition durations. X-ray diffraction analysis showed the crystallization of Mn{sub 3}O{sub 4} phase at 300{sup o}C and Mn{sub 2}O{sub 3} at 500{sup o}C. The electrochemical performance of the MnO{sub x} films sintered at different temperatures was studied by cyclic voltammetry (CV), chronopotentiometry and impedance spectroscopy in Na{sub 2}SO{sub 4} solutions. The films showed excellent pseudocapacitive behavior. The specific capacitance (SC) of 425F/g in a potential window of 0-0.9V was obtained from the CV data at a scan rate of 10mV/s. The SC calculated from the chronopotentiometry data is about 445F/g. The SC decreased by {approx} 20% after 1000 cycles. SEM investigations revealed changes in the film morphology during cycling. Obtained results indicate that the proposed method can be used for the fabrication of electrodes for electrochemical supercapacitors. (author)

  12. Cathodic electrodeposition of MnO x films for electrochemical supercapacitors

    International Nuclear Information System (INIS)

    Cathodic electrosynthesis has been utilized for the fabrication of MnO x films. The use of polyethylenimine (PEI) as an additive enabled the formation of adherent films, which exhibited enhanced resistance to cracking during drying. The polymer content in the deposits can be varied by the variation of the polymer concentration in the solutions. The mechanism of PEI deposition was proposed which is based on the use of PEI-Mn2+ complexes. The deposition yield has been studied at different deposition durations. X-ray diffraction analysis showed the crystallization of Mn3O4 phase at 300 deg. C and Mn2O3 at 500 deg. C. The electrochemical performance of the MnO x films sintered at different temperatures was studied by cyclic voltammetry (CV), chronopotentiometry and impedance spectroscopy in Na2SO4 solutions. The films showed excellent pseudocapacitive behavior. The specific capacitance (SC) of 425 F/g in a potential window of 0-0.9 V was obtained from the CV data at a scan rate of 10 mV/s. The SC calculated from the chronopotentiometry data is about 445 F/g. The SC decreased by ∼20% after 1000 cycles. SEM investigations revealed changes in the film morphology during cycling. Obtained results indicate that the proposed method can be used for the fabrication of electrodes for electrochemical supercapacitors

  13. Nanostructured Cu2O thin film electrodes prepared by electrodeposition for rechargeable lithium batteries

    International Nuclear Information System (INIS)

    Uniform films of Cu2O with thickness below 1 μm were prepared from a Cu(II) lactate solution. The deposits were compact and of high purity with the particle size varying from 60 to 400 nm. They were tested as electrodes in lithium batteries and their electrochemical response was consistent with the Cu2O + 2e- + 2Li+ ↔ 2Cu + Li2O reaction. Nevertheless, the reversibility of this reaction was dependent on thickness. Kinetic factors associated with the poor electronic conductivity of Cu2O could account for the relevance of the influence of film thickness. The thinnest film, about 300 nm thick, exhibited the best electrochemical performance by sustaining a specific capacity as high as 350 Ah kg-1

  14. Oxidatively Electrodeposited Thin-Film Transition Metal (Oxy)hydroxides as Oxygen Evolution Catalysts.

    Science.gov (United States)

    Morales-Guio, Carlos G; Liardet, Laurent; Hu, Xile

    2016-07-20

    The electrolysis of water to produce hydrogen and oxygen is a simple and attractive approach to store renewable energies in the form of chemical fuels. The oxygen evolution reaction (OER) is a complex four-electron process that constitutes the most energy-inefficient step in water electrolysis. Here we describe a novel electrochemical method for the deposition of a family of thin-film transition metal (oxy)hydroxides as OER catalysts. The thin films have nanodomains of crystallinity with lattice spacing similar to those of double-layered hydroxides. The loadings of these thin-film catalysts were accurately determined with a resolution of below 1 μg cm(-2) using an electrochemical quartz microcrystal balance. The loading-activity relations for various catalysts were established using voltammetry and impedance spectroscopy. The thin-film catalysts have up to four types of loading-activity dependence due to film nucleation and growth as well as the resistance of the films. A zone of intrinsic activity has been identified for all of the catalysts where the mass-averaged activity remains constant while the loading is increased. According to their intrinsic activities, the metal oxides can be classified into three categories: NiOx, MnOx, and FeOx belong to category I, which is the least active; CoOx and CoNiOx belong to category II, which has medium activity; and FeNiOx, CoFeOx, and CoFeNiOx belong to category III, which is the most active. The high turnover frequencies of CoFeOx and CoFeNiOx at low overpotentials and the simple deposition method allow the fabrication of high-performance anode electrodes coated with these catalysts. In 1 M KOH and with the most active electrode, overpotentials as low as 240 and 270 mV are required to reach 10 and 100 mA cm(-2), respectively. PMID:27344954

  15. Morphologically controlled electrodeposition of CdSe on mesoporous TiO2 film for quantum dot-sensitized solar cells

    International Nuclear Information System (INIS)

    Highlights: • CdSe QDs were deposited onto mesoporous TiO2 film via a one-step electrodeposition method. • The morphology and microstructure of TiO2/CdSe photoanodes can be controlled by electrodeposition current density. • A ZnS coating layer and thermal annealing could further enhance the performance of the TiO2/CdSe photoanodes. • A maximum power conversion efficiency of 2.72% was achieved with the optimum TiO2/CdSe/ZnS photoanodes. -- Abstract: CdSe quantum dots (QDs)-sensitized mesoporous TiO2 (TiO2/CdSe) films were fabricated using a facile one-step electrodeposition method in an aqueous electrolyte. This technique has the advantage of being simple, low cost, and easily scalable to the sensitization of large-area panels. By adjusting the electrodeposition current density, the morphology and microstructure of the prepared TiO2/CdSe films can be precisely controlled, which influences the photovoltaic performances of quantum dot-sensitized solar cells based on the TiO2/CdSe films. At a moderate current density of 0.2 mA cm−2, CdSe QDs can penetrate deep into the inner pores of the mesoporous TiO2 film, thus leading to a dense and uniform distribution of QDs throughout the whole TiO2 matrix, while higher current densities result in growth of larger, isolated CdSe nanoclusters. Furthermore, a ZnS passivation layer coated on TiO2/CdSe photoanodes and thermal annealing could significantly improve the photovoltaic performance. As a result, a quantum dot-sensitized solar cell based on a TiO2/CdSe/ZnS photoanode (350 °C, 30 min calcination), polysulfide electrolyte and Pt counter electrode achieves a power conversion efficiency of 2.72% under AM 1.5 G one sun illumination

  16. Nucleant layer effect on nanocolumnar ZnO films grown by electrodeposition

    OpenAIRE

    Reyes Tolosa, María Dolores; Damonte, Laura Cristina; Brine, Hicham; Bolink, Henk J.; Hernández Fenollosa, María De Los Ángeles

    2013-01-01

    Different ZnO nanostructured films were electrochemically grown, using an aqueous solution based on ZnCl2, on three types of transparent conductive oxides grow on commercial ITO (In2O3:Sn)-covered glass substrates: (1) ZnO prepared by spin coating, (2) ZnO prepared by direct current magnetron sputtering, and (3) commercial ITO-covered glass substrates. Although thin, these primary oxide layers play an important role on the properties of the nanostructured films grown on top of ...

  17. Electrodeposited MnO(x)/PEDOT Composite Thin Films for the Oxygen Reduction Reaction.

    Science.gov (United States)

    Vigil, Julian A; Lambert, Timothy N; Eldred, Kaitlyn

    2015-10-21

    Manganese oxide (MnOx) was anodically coelectrodeposited with poly(3,4-ethylenedioxythiophene) (PEDOT) from an aqueous solution of Mn(OAc)2, 3,4-ethylenedioxythiophene, LiClO4 and sodium dodecyl sulfate to yield a MnOx/PEDOT composite thin film. The MnOx/PEDOT film showed significant improvement over the MnOx only and PEDOT only films for the oxygen reduction reaction, with a >0.2 V decrease in onset and half-wave overpotential and >1.5 times increase in current density. Furthermore, the MnOx/PEDOT films were competitive with commercial benchmark 20% Pt/C, outperforming it in the half-wave ORR region and exhibiting better electrocatalytic selectivity for the oxygen reduction reaction upon methanol exposure. The high activity of the MnOx/PEDOT composite is attributed to synergistic charge transfer capabilities, attained by coelectrodepositing MnOx with a conductive polymer while simultaneously achieving intimate substrate contact. PMID:26444641

  18. Electrodeposition modeling and optimization to improve thin film patterning with orchestrated structure evolution

    Science.gov (United States)

    Abbasi, Shaghayegh; Kitayaporn, Sathana; Siedlik, Michael J.; Schwartz, Daniel T.; Böhringer, Karl F.

    2012-08-01

    Orchestrated structure evolution is an alternative nanomanufacturing approach that combines the advantages of top-down patterning and bottom-up self-organizing growth. It relies upon tool-directed patterning to create ‘seed’ locations on a surface from which a subsequent deposition process produces the final, merged film. Despite its demonstrated ability to reduce patterning time by orders of magnitude, our prior reliance on mass transfer limited deposition and square seed arrays resulted in extraneous film growth along pattern edges, thereby limiting the pattern quality of the final film. Here, quality improvements are demonstrated by modeling and tuning the growth mechanism of the deposition step to include charge transfer effects. In addition, a seed positioning optimization technique derived from simulated annealing is introduced as a method for relocating the seeds to minimize film overgrowth at the pattern edges. These improvements enable OSE to maintain geometric quality while substantially reducing the time and cost compared to traditional direct-write manufacturing methods.

  19. Electrodeposition modeling and optimization to improve thin film patterning with orchestrated structure evolution

    International Nuclear Information System (INIS)

    Orchestrated structure evolution is an alternative nanomanufacturing approach that combines the advantages of top-down patterning and bottom-up self-organizing growth. It relies upon tool-directed patterning to create ‘seed’ locations on a surface from which a subsequent deposition process produces the final, merged film. Despite its demonstrated ability to reduce patterning time by orders of magnitude, our prior reliance on mass transfer limited deposition and square seed arrays resulted in extraneous film growth along pattern edges, thereby limiting the pattern quality of the final film. Here, quality improvements are demonstrated by modeling and tuning the growth mechanism of the deposition step to include charge transfer effects. In addition, a seed positioning optimization technique derived from simulated annealing is introduced as a method for relocating the seeds to minimize film overgrowth at the pattern edges. These improvements enable OSE to maintain geometric quality while substantially reducing the time and cost compared to traditional direct-write manufacturing methods. (paper)

  20. Fabrication of stable, large-area thin-film CdTe photovoltaic modules

    Science.gov (United States)

    Zhou, T. X.

    1995-06-01

    During the period of this subcontract, May 1991 through February 1995, Solar Cells, Inc. has developed and demonstrated a low-cost process to fabricate stable large-area cadmium telluride based thin-film photovoltaic modules. This report summarizes the final phase of the project which is concentrated on process optimization and product life tests. One of the major post-deposition process steps, the CdCl2 heat treatment, has been experimentally replaced with alternative treatments with vapor chloride or chlorine gas. Material and device qualities associated with alternative treatments are comparable or superior to those with the conventional treatment. Extensive experiments have been conducted to optimize the back-electrode structure in order to ensure long term device stability. Numerous small-area cells and minimodules have been subjected to a variety of stress tests, including but not limited to continuous light soak under open or short circuit or with resistive load, for over 10,000 hours. Satisfactory stability has been demonstrated on 48 and 64 sq cm minimodules under accelerated tests and on 7200 sq cm large modules under normal operating conditions. The conversion efficiency has also been significantly improved during this period. The total area efficiency of 7200 sq cm module has reached 8.4%, corresponding to a 60.3 W normalized output; the efficiency of 64 sq cm minimodules and 1.1 sq cm cells has reached 10.5% (aperture area) and 12.4% (total area), respectively.

  1. Electrodeposition of epitaxial ZnSe films on InP and GaAs from an aqueous zinc sulfate-selenosulfate solution

    Energy Technology Data Exchange (ETDEWEB)

    Riveros, G.; Guillemoles, J.F.; Lincot, D. [Laboratoire d' Electrochimie et de Chimie Analytique (UMR CNRS 7575), Ecole Nationale Superieure de Chimie de Paris, 11 rue Pierre et Marie Curie, F-75231 Paris Cedex 05 (France); Gomez Meier, H. [Instituto de Chimica, Faculdad de Ciencas Basicas y Matematicas, Universidad Catolica de Valparaiso, Avda. Brasil 2950, Casila, Valparaiso (Chile); Froment, M.; Bernard, M.C.; Cortes, R. [Laboratoire de Physique des Liquides et Electrochimie (UPR CNRS 15), Universite Pierre et Marie Curie, 4 place Jussieu, F-75232 Paris Cedex 05 (France)

    2002-09-16

    Epitaxial growth of ZnSe thin films on InP(111) and GaAs(100) substrates has been achieved by electrodeposition from a zinc sulfate/selenosulfate solution. The deposition was observed over a wide range of applied potentials (-1.6-1.9 V vs. mercury/mercury sulfate). The epitaxy was characterized by reflective high energy electron diffraction (see Figure for a ZnSe epitaxial layer) and grazing angle X-ray diffraction. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  2. One-step electrodeposition of TiO2/dye hybrid films

    Czech Academy of Sciences Publication Activity Database

    Wessels, K.; Maekawa, M.; Rathouský, Jiří; Oekermann, T.

    2007-01-01

    Roč. 515, č. 16 (2007), s. 6497-6500. ISSN 0040-6090 Grant ostatní: DFG(DE) OE 420/3-1 Institutional research plan: CEZ:AV0Z40400503 Source of funding: R - rámcový projekt EK Keywords : electrochemical deposition * dye-sensitized solar cells * surfactants * organic -inorganic hybrid film s Subject RIV: CG - Electrochemistry Impact factor: 1.693, year: 2007

  3. Low-temperature electrodeposition approach leading to robust mesoscopic anatase TiO2 films

    Science.gov (United States)

    Patra, Snehangshu; Andriamiadamanana, Christian; Tulodziecki, Michal; Davoisne, Carine; Taberna, Pierre-Louis; Sauvage, Frédéric

    2016-02-01

    Anatase TiO2, a wide bandgap semiconductor, likely the most worldwide studied inorganic material for many practical applications, offers unequal characteristics for applications in photocatalysis and sun energy conversion. However, the lack of controllable, cost-effective methods for scalable fabrication of homogeneous thin films of anatase TiO2 at low temperatures (ie. cell technology translates into a remarkable power conversion efficiency of 7.2% under A.M.1.5G conditions.

  4. Structures and magnetic properties for electrodeposited Co ultrathin films on copper

    Energy Technology Data Exchange (ETDEWEB)

    Mangen, T.; Bai, H.S. [Department of Physics, National Taiwan Normal University, 88, Section 4, Ting-Chou Rd. Taipei 116, Taiwan (China); Tsay, J.S., E-mail: jstsay@phy.ntnu.edu.t [Department of Physics, National Taiwan Normal University, 88, Section 4, Ting-Chou Rd. Taipei 116, Taiwan (China)

    2010-07-15

    The formation of Co films on polycrystalline copper in diluted sulphuric acid was investigated by employing cyclic voltammetry (CV), atomic force microscopy, and in-situ magneto-optic Kerr effect (MOKE) techniques. By comparing CV measurements in the pure supporting electrolyte (11 mM K{sub 2}SO{sub 4}/1 mM H{sub 2}SO{sub 4}) and the cobalt sulphate solution (10 mM K{sub 2}SO{sub 4}/1 mM H{sub 2}SO{sub 4}/1 mM CoSO{sub 4}), peaks from voltammetric cycling for copper dissolution, readsorption of dissolved copper ions, cobalt bulk dissolution and oxidation of hydrogen could be resolved. As the electroplating time increases, the size of the Co clusters increases and the deposition of Co corresponds to island growth. The first hysteresis loop occurs at a Co thickness of 0.33 nm in the longitudinal configuration. For films thinner than 7 nm, the Kerr intensity increases linearly because the Curie temperature of the film is well above 300 K.

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

    Science.gov (United States)

    Lobanov, Nikolai R.

    2015-12-01

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

  6. Landfill waste and recycling: Use of a screening-level risk assessment tool for end-of-life cadmium telluride (CdTe) thin-film photovoltaic (PV) panels

    International Nuclear Information System (INIS)

    Grid-connected solar photovoltaic (PV) power is currently one of the fastest growing power-generation technologies in the world. While PV technologies provide the environmental benefit of zero emissions during use, the use of heavy metals in thin-film PV cells raises important health and environmental concerns regarding the end-of-life disposal of PV panels. To date, there is no published quantitative assessment of the potential human health risk due to cadmium leaching from cadmium telluride (CdTe) PV panels disposed in a landfill. Thus, we used a screening-level risk assessment tool to estimate possible human health risk associated with disposal of CdTe panels into landfills. In addition, we conducted a literature review of potential cadmium release from the recycling process in order to contrast the potential health risks from PV panel disposal in landfills to those from PV panel recycling. Based on the results of our literature review, a meaningful risk comparison cannot be performed at this time. Based on the human health risk estimates generated for PV panel disposal, our assessment indicated that landfill disposal of CdTe panels does not pose a human health hazard at current production volumes, although our results pointed to the importance of CdTe PV panel end-of-life management. - Highlights: • Analysis of possible human health risk posed by disposal of CdTe panels into landfills. • Qualitative comparison of risks associated with landfill disposal and recycling of CdTe panels. • Landfill disposal of CdTe panels does not pose a human health hazard at current production volumes. • There could be potential risks associated with recycling if not properly managed. • Factors other than concerns over toxic substances will likely drive the decisions of how to manage end-of-life PV panels

  7. Limits of ZnO Electrodeposition in Mesoporous Tin Doped Indium Oxide Films in View of Application in Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Christian Dunkel

    2014-04-01

    Full Text Available Well-ordered 3D mesoporous indium tin oxide (ITO films obtained by a templated sol-gel route are discussed as conductive porous current collectors. This paper explores the use of such films modified by electrochemical deposition of zinc oxide (ZnO on the pore walls to improve the electron transport in dye-sensitized solar cells (DSSCs. Mesoporous ITO film were dip-coated with pore sizes of 20–25 nm and 40–45 nm employing novel poly(isobutylene-b-poly(ethylene oxide block copolymers as structure-directors. After electrochemical deposition of ZnO and sensitization with the indoline dye D149 the films were tested as photoanodes in DSSCs. Short ZnO deposition times led to strong back reaction of photogenerated electrons from non-covered ITO to the electrolyte. ITO films with larger pores enabled longer ZnO deposition times before pore blocking occurred, resulting in higher efficiencies, which could be further increased by using thicker ITO films consisting of five layers, but were still lower compared to nanoporous ZnO films electrodeposited on flat ITO. The major factors that currently limit the application are the still low thickness of the mesoporous ITO films, too small pore sizes and non-ideal geometries that do not allow obtaining full coverage of the ITO surface with ZnO before pore blocking occurs.

  8. The mechanism of cathodic electrodeposition of epoxy coatings and the corrosion behaviour of the electrodeposited

    OpenAIRE

    VESNA B. MISKOVIC-STANKOVIC

    2002-01-01

    The model of organic film growth on a cathode during electrodeposition process proposes the current density-time and film thickness-time relationships and enables the evaluation of the rate contants for the electrochemical reaction of OH ion evolution and for the chemical reaction of organic film deposition. The dependences of film thickness and rate constants on the applied voltage, bath temperature and resin concentration in the electrodeposition bath have also been obtained. The deposition...

  9. Preparation and characterization of pulsed laser deposited a novel CdS/CdSe composite window layer for CdTe thin film solar cell

    Science.gov (United States)

    Yang, Xiaoyan; Liu, Bo; Li, Bing; Zhang, Jingquan; Li, Wei; Wu, Lili; Feng, Lianghuan

    2016-03-01

    A novel CdS/CdSe composite window structure was designed and then the corresponding films were prepared by pulsed laser deposition as an improved window layer for CdTe-based solar cells. Two types of this composite window structure with 5 cycles and 10 cycles CdS/CdSe respectively both combined with CdS layers were prepared at 200 °C compared with pure CdS window layer and finally were applied into CdTe thin film solar cells. The cross section and surface morphology of the two composite window layers were monitored by using scanning electron microscopy and the result shows that the pulsed laser deposited composite window layers with good crystallinity are stacking together as the design. The devices based on CdS/CdSe composite window layers have demonstrated the enhanced photocurrent collection from both short and long wavelength regions compared to CdS/CdTe solar cell. The efficiency of the best reference CdS/CdTe solar cell was 10.72%. And the device with 5 cycles CdS/CdSe composite window showed efficiency of 12.61% with VOC of 772.92 mV, JSC of 25.11 mA/cm2 and FF of 64.95%. In addition, there are some differences which exist within the optical transmittance spectra and QE curves between the two CdS/CdSe composite window samples, indicating that the volume proportion of CdSe may influence the performance of CdTe thin film solar cell.

  10. Characterization of electrodeposited coatings containing niobium

    International Nuclear Information System (INIS)

    The role of metallurgically processed niobium in the applications of superconductivity has remained supreme for the past two decades. Niobium coatings electrodeposited at room temperature can potentially afford certain advantages over those metallurgically prepared. These advantages include the ability to form a superconductive thin film on a substrate of unconventional geometry, a lower incidence of thermally induced film defects compared to those prepared at high temperatures, and the ability to control the grain size via electrochemical parameters. In this paper, microscopic and spectroscopic techniques are used to characterize the film electrodeposited from various halide-containing niobium complexes in organic solvents. Scanning electron microscope is used to examine the microstructure of the electrodeposit, and the ancillary technique of energy dispersive X-ray fluorescence determines the elemental composition. In general, the choice of organic solvent for electrodeposition plays a key role in determining the film thickness, uniformity, homogeneity, smoothness, grain size, and the presence of strain-induced cracks in the film

  11. Force modulation atomic force microscopy: background, development and application to electrodeposited cerium oxide films

    Science.gov (United States)

    Li, Feng-Bin; Thompson, G. E.; Newman, R. C.

    1998-04-01

    In force modulation atomic force microscopy (FMAFM), vertical oscillation of the scanning tip of the AFM is added purposely and the deflection of the tip, which is influenced by surface features of the sample, is used as the z dimension to construct images. FMAFM represents a powerful technique for scientific research, but its merit has not been realized adequately to date. In this paper, the basic principles and particular features, as well as potential drawbacks of the technique, are presented and demonstrated systematically, through its application to electrochemically deposited cerium oxide films. Comparisons are also made with the more familiar contact mode AFM (CMAFM) and tapping mode AFM (TMAFM). It is shown that FMAFM reveals the major topographic features of CMAFM, but affords (i) greater resolution for sample features that are difficult in CMAFM, and (ii) continuous two-dimensional mapping of local mechanical properties on a scale of nanometres that the CMAFM, TMAFM and any other techniques, are not capable of sensing. This information can be used to elucidate other properties of the investigated surface, such as crystallinity variation, phase separation and distribution, and mechanisms of formation of deposited films. Major artifacts associated with the technique include `wedge cavity effect' and `tip slip effect', for which a geometric model is proposed to elucidate their origins. The cerium oxide films are shown to be composed of relatively hard crystalline grains, of well-defined individual geometry and comparatively regular packing, alongside relatively soft amorphous patches, devoid of distinct geometry and assembled disorderly. These features are consistent with a nucleation and growth mechanism of the deposition, in which crystalline nuclei arise and grow from an intermediate cerium gel mass, produced in the interfacial region during deposition.

  12. Structural and optical properties of electrodeposited culnSe{sub 2} thin films for photovoltaic solar cells; Propiedades estructurales y opticas de laminas delgadas de CulnSe2 electrodepositadas para su aplicacion en celulas solares fotovoltaicas

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, C.; Herrero, J.; Galiano, F.

    1990-07-01

    Optical an structural properties of electrodeposited copper indium diselenide, CulnSe2, thin films were studied for its application in photovoltaic devices. X-ray diffraction patterns showed that thin films were grown in chalcopyrite phase after suitable treatments. Values of Eg for the CulnSe2 thin films showed a dependence on the deposition potential as determined by optical measurements. (Author) 47 refs.

  13. Flexible polycrystalline thin-film photovoltaics for space applications

    Science.gov (United States)

    Armstrong, J. H.; Lanning, B. R.; Misra, M. S.; Kapur, V. K.; Basol, B. M.

    1993-01-01

    Polycrystalline thin-film photovoltaics (PV), such as CIS and CdTe, have received considerable attention recently with respect to space power applications. Their combination of stability, efficiency, and economy from large-scale monolithic-integration of modules can have significant impact on cost and weight of PV arrays for spacecraft and planetary experiments. An added advantage, due to their minimal thickness (approximately 6 microns sans substrate), is the ability to manufacture lightweight, flexible devices (approximately 2000 W/kg) using large-volume manufacturing techniques. The photovoltaic effort at Martin Marietta and ISET is discussed, including large-area, large-volume thin-film deposition techniques such as electrodeposition and rotating cylindrical magnetron sputtering. Progress in the development of flexible polycrystalline thin-film PV is presented, including evaluation of flexible CIS cells. In addition, progress on flexible CdTe cells is presented. Finally, examples of lightweight, flexible arrays and their potential cost and weight impact is discussed.

  14. Effects of glycine and current density on the mechanism of electrodeposition, composition and properties of Ni-Mn films prepared in ionic liquid

    Science.gov (United States)

    Guo, Jiacheng; Guo, Xingwu; Wang, Shaohua; Zhang, Zhicheng; Dong, Jie; Peng, Liming; Ding, Wenjiang

    2016-03-01

    The effects of glycine on the mechanism of electrodeposition of Ni-Mn alloy film prepared in ChCl-urea ionic liquid were studied in order to control the composition, microstructure and properties of the film. The cyclic voltammograms revealed that the presence of glycine in the ionic liquid can inhibit the reduction of Ni2+ ions but promote the reduction of Mn2+ ions in the cathodic scan. However, it promoted the dissolution of both Ni and Mn deposits in the ChCl-urea ionic liquids during the reverse scan. Glycine changed the mode of Ni-Mn film growth from Volmer-Weber mode into Stranski-Krastanov mode. The Mn content in the Ni-Mn film increased with the increase of concentration of glycine and current density. The Ni-Mn alloy film with 3.1 at.% Mn exhibited the lowest corrosion current density of 3 × 10-7 A/cm2 compared with other films prepared and exhibited better corrosion resistance than pure Ni film in 3.5 wt.% NaCl solution.

  15. Characterization of CdS thin films electrodeposited by an alternating current electrolysis method

    International Nuclear Information System (INIS)

    Conventional electrochemical methods of making CdS films are anodic oxidation of cadmium in a solution containing sulfide ions, and cathodic reduction from solutions containing soluble metal and sulfur compounds. In this paper a method is presented in which a CdS layer is deposited by a.c. electrolysis. The substrate is a glass plate covered by a layer of tin oxide. The electrolyte is an aqueous solution containing cadmium sulphate, ammonium sulphate, sodium thiosulphate, sodium chloride and glycerol. The applied a.c. voltages correspond to symmetrical and asymmetrical rectangular waves. During the electrolysis two electrodes are alternately connected to positive and negative potentials. As a result, Cd/sup 2+/ and S/sup 2-/ particles deposit at each electrode by turns, which results in the formation of a CdS layer

  16. Electrodeposition on Ni from a Sulfamate Electrolyte Part 1: Effect of a Stress Relief on Annealing Behavior and Film Metallurgy; TOPICAL

    International Nuclear Information System (INIS)

    Ni and Ni alloys are being developed as baseline materials for LIGA technology and prototyping at Sandia National Laboratories. A conventional, additive-free sulfamate electrolyte has been chosen for pure Ni electrodeposition due to its simplicity and ability to produce ductile, low-stress films. When depositing certain Ni alloys, saccharin is typically employed as an electrolyte bath additive. While saccharin is well known and effective as a stress reliever, it has a significant impact on the microstructure of the deposit and its annealing behavior. The electrodeposition of pure Ni in the presence of saccharin is studied here to understand its effects in the absence of an alloying element (such as Co or Fe). The grain structure and Vickers hardness of Ni deposited with and without saccharin on a rotating disk electrode were all found to be consistent with previous studies available in the literature. The following observations were made: (1) The fine, columnar morphology obtained without saccharin became an equiaxed, nano-sized grain structure with saccharin (from(approx)1.5(micro)m to(approx)40 nm nominal grain size, respectively). The grain refinement resulting from saccharin is not accompanied with an increase in film stress, in contrast to the grain refinement associated with certain Ni alloys. (2) A change in the deposit texture from weak (210) to (111) along the film growth direction with the addition of saccharin. (3) An increase in Vickers hardness by a factor of(approx)2 (from(approx)170 to(approx)320) upon the addition of saccharin. (4) A rapid decrease in hardness with annealing from the high, as-deposited values for films deposited with saccharin to a value lower than that of annealed Ni from an additive-free bath. (5) Accelerated grain growth during annealing for films deposited with saccharin; this has not been observed previously in the literature to the authors' best knowledge

  17. Thin film solar cells based on CdTe and Cu(In,Ga)Se{sub 2} (CIGS) compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gladyshev, P P [International University of Nature, Society and Man ' Dubna' , Dubna (Russian Federation); Filin, S V; Puzynin, A I; Tanachev, I A; Rybakova, A V; Tuzova, V V; Kozlovskiy, S A [Center of High Technologies of FSUE ' Applied Acoustics Research Institute' , Dubna (Russian Federation); Gremenok, V F; Mudryi, A V; Zaretskaya, E P [State Scientific and Production Association ' Scientific-Practical Materials, Researcher Center of National Academy of Sciences of Belarus' , Minsk (Belarus); Zalesskiy, V B; Kravchenko, V M; Leonova, U R; Khodin, A A; Pilipovich, V A; Polikanin, A M [Institute of Physics of National Academy of Sciences of Belarus, Minsk (Belarus); Khrypunov, G S; Chernyh, E P; Kovtun, N A [National Technical University ' Kharkov Politechnical Institute' , Kharkov (Ukraine); Belonogov, E K, E-mail: pavel.gladyshev@niipa.ru [Voronej State Technical University, Voronej (Russian Federation)

    2011-04-01

    We are publishing recent results in chalcogenide photoelectric convertors fabrication, which are efforts of many scientific teams from Russia, Belarus, Ukraine, and Kazakhstan. Competitively high efficiency of photoelectric convertors (11.4% for CdTe and 11% for CIGS) was achieved in the process of our work. Furthermore, luminescent filters for improvement of spectral response of such chalcogenide solar cells in a short wavelengths region were also developed and investigated here.

  18. Optimization of the front contact to minimize short-circuit current losses in CdTe thin-film solar cells

    Science.gov (United States)

    Kephart, Jason Michael

    With a growing population and rising standard of living, the world is in need of clean sources of energy at low cost in order to meet both economic and environmental needs. Solar energy is an abundant resource which is fundamentally adequate to meet all human energy needs. Photovoltaics are an attractive way to safely convert this energy to electricity with little to no noise, moving parts, water, or arable land. Currently, thin-film photovoltaic modules based on cadmium telluride are a low-cost solution with multiple GW/year commercial production, but have lower conversion efficiency than the dominant technology, crystalline silicon. Increasing the conversion efficiency of these panels through optimization of the electronic and optical structure of the cell can further lower the cost of these modules. The front contact of the CdTe thin-film solar cell is critical to device efficiency for three important reasons: it must transmit light to the CdTe absorber to be collected, it must form a reasonably passive interface and serve as a growth template for the CdTe, and it must allow electrons to be extracted from the CdTe. The current standard window layer material, cadmium sulfide, has a low bandgap of 2.4 eV which can block over 20% of available light from being converted to mobile charge carriers. Reducing the thickness of this layer or replacing it with a higher-bandgap material can provide a commensurate increase in device efficiency. When the CdS window is made thinner, a degradation in electronic quality of the device is observed with a reduction in open-circuit voltage and fill factor. One commonly used method to enable a thinner optimum CdS thickness is a high-resistance transparent (HRT) layer between the transparent conducting oxide electrode and window layer. The function of this layer has not been fully explained in the literature, and existing hypotheses center on the existence of pinholes in the window layer which are not consistent with observed results

  19. Preparation of Er-Fe Alloy Films in Dimethylsulfoxide by Electrodeposition Method

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Cyclic voltammetry and chronoamperometry were used to investigate the electrochemical behavior of Fe(Ⅱ) and Er(Ⅲ) in a LiClO4-DMSO(dimethylsufoxide) system at Pt and Cu electrodes. Experimental results indicate that the reductions of Fe(Ⅱ) to Fe(0) and Er(Ⅲ) to Er(0) were irreversible at Pt and Cu electrodes. The diffusion coefficient and the electron transfer coefficient of Fe(Ⅱ) in a 0.01 mol/L FeCl2-0.1 mol/L LiClO4-DMSO system at 303 K were 1.70×10-10 m2/s and 0.08 respectively, the diffusion coefficient and the electron transfer coefficient of Er(Ⅲ) in a 0.01 mol/L ErCl3-0.1mol/L LiClO4-DMSO system at 303 K were 1.47×10-10 m2/s and 0.108 respectively. The homogeneous, strong adhesive Er-Fe alloy films containing Er of 31.39%-42.12% in mass fraction with metallic lustre were prepared by potentiostatic electrolysis on a Cu electrode in a ErCl3-FeCl2-LiClO4-DMSO system at -1.75--2.50 V(vs. SCE).

  20. XPS Study of CdTe Thin Films Doped with Gd%掺Gd-CdTe薄膜的XPS研究

    Institute of Scientific and Technical Information of China (English)

    安晓晖; 李蓉萍; 田磊; 何志刚; 吴蓉; 李忠贤

    2012-01-01

    CdTe thin film doped with Gd has been obtained by vacuum evaporation technique with two sources , and chemical state has been studied by X-ray photo-electron spectroscopy. XPS data show that Cd,Te,O,C and Gd elements exist on the surface of the film. C1s and O1s binding energy indicates that the two elements mainly exist in the form of physical adsorption. The experiment results show that Cd and Te atoms exist in oxidation state as in well as in CdTe. Due to carbon pol-lution, Gd element does not appear on the surface, only appears in the etching process. Erosion analysis shows the Cd element s content is greater than Te, and the ratio between them tends to 1:0. 8.%应用双源法真空蒸发制备掺Gd的CdTe薄膜,并借助XPS对其进行组份分析.实验表明,Gd掺杂的CdTe薄膜的组分为Cd、Te、O、C、Gd等元素,其中C、O主要以物理吸附方式存在于薄膜表面;Cd、Te元素的存在方式为CdTe化合物及其氧化物形式;而Gd元素由于碳污染的原因在其表面未曾出现,只在刻蚀过程中出现;深度剥蚀分析表明在样品内部Cd元素的含量大于Te元素的含量,且接近于1∶0.8,趋于稳定.

  1. Differential pulse voltammetric determination of ascorbic acid in the presence of folic acid at electro-deposited NiO/graphene composite film modified electrode

    International Nuclear Information System (INIS)

    This paper demonstrated an electrochemical sensor based on NiO nanoparticles-graphene composite film (NiO/GR) modified glassy carbon electrode for detecting ascorbic acid (AA) in the presence of folic acid using differential pulse voltammetry. The obtained NiO/GR nanocomposite was fabricated by electro-deposition technology. The morphologies and interface properties of NiO/GR composite film were examined by scanning electron microscopy, energy dispersive X-ray spectroscopy and electrochemical impedance spectroscopy. The modified electrode exhibits excellent sensing performance for detecting AA with linear range from 0.05 to 1100 μM and a detection limit of 0.0167 μM (S/N = 3). Under optimal conditions, the sensor displays excellent stability and satisfactory results in real samples analysis

  2. Characterisation, corrosion resistance and in vitro bioactivity of manganese-doped hydroxyapatite films electrodeposited on titanium.

    Science.gov (United States)

    Huang, Yong; Ding, Qiongqiong; Han, Shuguang; Yan, Yajing; Pang, Xiaofeng

    2013-08-01

    This work elucidated the corrosion resistance and in vitro bioactivity of electroplated manganese-doped hydroxyapatite (MnHAp) film on NaOH-treated titanium (Ti). The NaOH treatment process was performed on Ti surface to enhance the adhesion of the MnHAp coating on Ti. Scanning electron microscopy images showed that the MnHAp coating had needle-like apatite crystals, and the approximately 10 μm thick layer was denser than HAp. Energy-dispersive X-ray spectroscopy analysis revealed that the MnHAp crystals were Ca-deficient and the Mn/P molar ratio was 0.048. X-ray diffraction confirmed the presence of single-phase MnHAp, which was aligned vertically to the substrate. Fourier transform infrared spectroscopy indicated the presence of phosphate bands ranging from 500 to 650 and 900 to 1,100 cm(-1), and a hydroxyl band at 3,571 cm(-1), which was characteristic of HAp. Bond strength test revealed that adhesion for the MnHAp coating was more enhanced than that of the HAp coating. Potentiodynamic polarisation test showed that the MnHAp-coated surface exhibited superior corrosion resistance over the HAp single-coated surface. Bioactivity test conducted by immersing the coatings in simulated body fluid showed that MnHAp coating can rapidly induce bone-like apatite nucleation and growth. Osteoblast cellular tests revealed that the MnHAp coating was better at improving the in vitro biocompatibility of Ti than the HAp coating. PMID:23686354

  3. Electrodeposited Nanoporous versus Nanoparticulate ZnO Films of Similar Roughness for Dye-Sensitized Solar Cell Applications

    Czech Academy of Sciences Publication Activity Database

    Guerin, V. M.; Magne, C.; Pauporté, T.; Le Bahers, T.; Rathouský, Jiří

    2010-01-01

    Roč. 2, č. 12 (2010), s. 3677-3685. ISSN 1944-8244 Institutional research plan: CEZ:AV0Z40400503 Keywords : ZnO * dye sensitized solar cells * electrodeposition Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.925, year: 2010

  4. Electrodeposited ZnS Precursor Layer with Improved Electrooptical Properties for Efficient Cu2ZnSnS4 Thin-Film Solar Cells

    Science.gov (United States)

    Mkawi, E. M.; Ibrahim, K.; Ali, M. K. M.; Farrukh, M. A.; Mohamed, A. S.

    2015-10-01

    Zinc sulfide (ZnS) thin films were prepared on indium tin oxide-coated glass by electrodeposition using aqueous zinc sulfate, thiourea, and ammonia solutions at 80°C. The effects of sulfurization at temperatures of 350°C, 400°C, 450°C, and 500°C on the morphological, structural, optical, and electrical properties of the ZnS thin films were investigated. X-ray diffraction analysis showed that the ZnS thin films exhibited cubic zincblende structure with preferred (111) orientation. The film crystallization improved with increasing annealing temperature. Field-emission scanning electron microscopy images showed that the film morphology became more compact and uniform with increasing annealing temperature. The percentage of sulfur in the ZnS thin films increased after sulfurization until a stoichiometric S/Zn ratio was achieved at 500°C. The annealed films showed good adhesion to the glass substrates, with moderate transmittance (85%) in the visible region. Based on absorption measurements, the direct bandgap increased from 3.71 eV to 3.79 eV with annealing temperature, which is attributed to the change of the buffer material composition and suitable crystal surface properties for effective p- n junction formation. The ZnS thin films were used as a buffer layer in thin-film solar cells with the structure of soda-lime glass/Mo/Cu2ZnSnS4/ZnS/ZnO/Al grid. The best solar cell efficiency was 1.86%.

  5. Electrochemical Properties of Porous Co(OH){sub 2} Nano-flake Thin Film Prepared by Electro-deposition for Supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeon Jeong; Jin, En Mei; Jeong, Sang Mun [Chungbuk National University, Cheongju (Korea, Republic of)

    2016-04-15

    Porous Co(OH){sub 2} nano-flake thin films were prepared by a potential-controlled electro-deposition technique at various deposition voltage (−0.75, −1.0, −1.2, and −1.4 V) on Ti-mesh substrates for supercapacitor application. The potential of electrode was controlled to regulate the film thickness and the amount of Co(OH){sub 2} nano-flake on the titanium substrate. The film thickness was shown to reach the maximum value of 34 μm at −1.4 V of electrode potential, where 17.2 g of Co(OH){sub 2} was deposited on the substrate. The specific discharge capacitances were measured to be 226, 370, 720, and 1008 mF cm{sup -2} in the 1st cycle corresponding to the films which were formed at −0.75, −1.0, −1.2, and −1.4 V of electrode potentials, respectively. Then the discharge capacities were decreased to be 206, 349, 586 and 866 mF/cm{sup 2}, where the persistency rates were 91, 94, 81, and 86%, respectively.

  6. Development of CdTe radiation detectors and their applications

    International Nuclear Information System (INIS)

    We have been developing radiation detectors using cadmium telluride (CdTe), which has the high radiation absorption characteristic. The image pickup tube using polycrystalline CdTe thin film has been developed at the first stage. Furthermore, the X-ray imaging line sensor with high scanning speed and the radiation spectrometer with thermo-electric Peltier cooler were developed by using CdTe single crystal, which has high electric charge collection characteristics. At present, the energy discriminating photon counting radiation line sensors are developing. In this presentation, the feature of the detector using CdTe and their applications are described examples of development until now. (author)

  7. Technology Support for High-Throughput Processing of Thin-Film CdTe PV Modules Annual Technical Report, Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Rose, D.H.; Powell, R.C.; Karpov, V.; Grecu, D.; Jayamaha, U.; Dorer, G.L. (First Solar, L.L.C.)

    2001-02-05

    Results and conclusions from Phase II of a three-year subcontract are presented. The subcontract, entitled Technology Support for High-Throughput Processing of Thin-Film CdTe PV Modules, is First Solar's portion of the Thin-Film Photovoltaic Partnership Program. The research effort of this subcontract is divided into four areas of effort: (1) process and equipment development, (2) efficiency improvement, (3) characterization and analysis, and (4) environmental, health, and safety. As part of the process and equipment development effort, a new semiconductor deposition system with a throughput of 3 m2/min was completed, and a production line in a new 75,000 ft2 facility was started and is near completion. As part of the efficiency-improvement task, research was done on cells and modules with thin CdS and buffer layers as way to increase photocurrent with no loss in the other photovoltaic characteristics. A number of activities were part of the characterization and analysis task, including developing a new admittance spectroscopy system, with a range of 0.001 Hz to 100 kHz, to characterize cells. As part of the environmental, health, and safety task, the methanol-based CdCl2 process was replaced with aqueous-CdCl2. This change enabled the retention of a De Minimus level of emissions for the manufacturing plant, so no permitting is required.

  8. Conditions for the deposition of CdTe by electrochemical atomic layer epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Gregory, B.W.; Suggs, D.W.; Stickney, J.L. (School of Chemical Sciences, Univ. of Georgia, Athens, GA (US))

    1991-05-01

    In this paper the method of electrochemical atomic layer epitaxy (ECALE) is described. It involves the alternated electrochemical deposition of atomic layers of elements to form compound semiconductors. It is being investigated as a method for forming epitaxial thin films. Presently, it appears that the method is applicable to a wide range of compound semiconductors composed of a metal and one of the following main group elements: S, Se, Te, As, Sb, or Br. Initial studies have involved CdTe deposition. Factors controlling deposit structure and composition are discussed here. Preliminary results which show that ordered electrodeposits of CdTe can be formed by the ECALE method are also presented. Results reported here were obtained with both a polycrystalline Au thin-layer electrochemical cell and a single-crystal Au electrode with faces oriented to the (111), (110), and (100) planes. The single-crystal electrode was contained in a UHV surface analysis instrument with an integral electrochemical cell. Deposits were examined without their exposure to air using LEED and Auger electron spectroscopy. Coverages were determined using coulometry in the thin-layer electrochemical cell.

  9. Influence of water-soluble conjugated/non-conjugated polyelectrolytes on electrodeposition of nanostructured MnO{sub 2} film for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-Kyung; Shrestha, Nabeen K. [Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of); Lee, Wonjoo [Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of); Department of Defense Ammunitions, Daeduk College, Daejeon 305-715 (Korea, Republic of); Cai, Gangri, E-mail: caigangri@naver.com [Department of Applied Chemistry, TianJin University of Technology, Tianjin 300384 (China); Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of); Han, Sung-Hwan, E-mail: shhan@hanyang.ac.kr [Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2015-04-01

    Manganese dioxide (MnO{sub 2}) thin films are deposited electrochemically on an indium–tin-oxide (ITO) electrode using aqueous bath in presence of conjugated water soluble sulfonated polyaniline (SPAN) or a non-conjugated polyacrylic acid (PAA) polyelectrolyte surfactant. The surface morphology and nature of the electrodeposited MnO{sub 2} films are found to be influenced strongly by the amount and type of polyelectrolyte in the deposition bath. Increasing the SPAN concentration, a porous structure resulting from the reduction of voids between the MnO{sub 2} nano-flakes is obtained. In contrast, by increasing the PAA concentration, dense and spherical MnO{sub 2} nanostructures have been deposited. These results may be caused by initiation of different kinetics and orientation of nucleation of MnO{sub 2} deposits on ITO surface in presence of different types of polyelectrolytes. Cyclic voltammetry study of these films shows the supercapacitor behavior. The porous MnO{sub 2} films grown from the SPAN containing electrolyte demonstrates a specific capacitance of 368.53 F/g at scan rate of 10 mV/s, which is approximately 10 times higher (i.e., 30.29 F/g) than that of the spherical MnO{sub 2} dense films grown from PAA containing electrolyte. - Highlights: • Conjugated/non-conjugated polyelectrolytes were used in deposition of MnO{sub 2}. • The two kinds of MnO{sub 2} film showed entirely different morphology. • Conjugated polyelectrolyte worked as template and also affected the growth rate. • Non-conducting polyelectrolyte could work as template but hindered MnO{sub 2} growth. • The specific capacitance of MnO{sub 2}–S was 10 times higher than MnO{sub 2}–P.

  10. Influence of water-soluble conjugated/non-conjugated polyelectrolytes on electrodeposition of nanostructured MnO2 film for supercapacitors

    International Nuclear Information System (INIS)

    Manganese dioxide (MnO2) thin films are deposited electrochemically on an indium–tin-oxide (ITO) electrode using aqueous bath in presence of conjugated water soluble sulfonated polyaniline (SPAN) or a non-conjugated polyacrylic acid (PAA) polyelectrolyte surfactant. The surface morphology and nature of the electrodeposited MnO2 films are found to be influenced strongly by the amount and type of polyelectrolyte in the deposition bath. Increasing the SPAN concentration, a porous structure resulting from the reduction of voids between the MnO2 nano-flakes is obtained. In contrast, by increasing the PAA concentration, dense and spherical MnO2 nanostructures have been deposited. These results may be caused by initiation of different kinetics and orientation of nucleation of MnO2 deposits on ITO surface in presence of different types of polyelectrolytes. Cyclic voltammetry study of these films shows the supercapacitor behavior. The porous MnO2 films grown from the SPAN containing electrolyte demonstrates a specific capacitance of 368.53 F/g at scan rate of 10 mV/s, which is approximately 10 times higher (i.e., 30.29 F/g) than that of the spherical MnO2 dense films grown from PAA containing electrolyte. - Highlights: • Conjugated/non-conjugated polyelectrolytes were used in deposition of MnO2. • The two kinds of MnO2 film showed entirely different morphology. • Conjugated polyelectrolyte worked as template and also affected the growth rate. • Non-conducting polyelectrolyte could work as template but hindered MnO2 growth. • The specific capacitance of MnO2–S was 10 times higher than MnO2–P

  11. Electrodeposition and photoelectrochemical properties of p-type BiOIαCl1-α nanoplatelet thin films

    International Nuclear Information System (INIS)

    Graphical abstract: In this paper, a series of BiOIαCl1-α solid solution electrodes were successfully prepared through a simple electrodeposition method. It is interestingly found that all prepared electrodes exhibited p-type conductivity, and the BiOIαCl1-α solid solution showed the best photoelectrochemical activity at α = 0.5 due to the balance between the level of conduction band and the light absorption ability of solid solutions. -- Highlights: •A series of BiOIαCl1-α solid solution electrode were successfully prepared through a simple electrodeposition method. •All prepared BiOIαCl1-α electrodes exhibited p-type conductivity. •The BiOIαCl1-α solid solution showed the best photoelectrochemical activity at α = 0.5. -- Abstract: In this paper, a series of BiOIαCl1-α solid solution electrodes were successfully prepared through a simple electrodeposition method. The obtained electrodes were characterized by X-ray diffraction, scanning electron microscopy, UV–vis diffuse reflectance spectroscopy and photocurrent response. We found that all prepared electrodes exhibited p-type conductivity in accordance with reports employing other deposition strategies. What's more, the BiOIαCl1-α solid solution showed the best photoelectrochemical activity at α = 0.5 due to the balance between the level of conduction band and the light absorption ability of solid solutions. Finally, wet photovoltaic cells with p-BiOI0.5Cl0.5 and n-TiO2 nanotube array electrodes were also constructed

  12. Crystallite size measurement and micro-strain analysis of electrodeposited copper thin film using Williamson-Hall method

    Science.gov (United States)

    Augustin, Arun; Udupa, K. Rajendra; Udaya Bhat, K.

    2016-05-01

    The improvement in hydrophilicity of copper coating on aluminium for better antimicrobial activity can be achieved by increase in surface energy. The surface energy depends on the micro-strain of the coating. Micro-strain in the coatingincreases with reduction in crystallite size. In this investigation, the crystallite size in the electrodeposited copper coating was varied by varying deposition current density. Crystallite size and micro-strain in the coating were estimated using Williamson-Hall method. Values of crystallite sizes using TEM micrographs were in agreement with that using Williamson-Hall method. Also, presence of nano-twins in the coating contributed for micro-strain in copper coating.

  13. Texture properties of nanoporous TiO2 films prepared by anodic electrodeposition using a structure directing agent

    Czech Academy of Sciences Publication Activity Database

    Rathouský, Jiří; Wessels, K.; Wark, M.; Oekermann, T.

    Amsterdam : Elsevier B.V./Ltd, 2007 - (Xu, R.; Gao, Z.; Chen, J.; Yan, W.), s. 1494-1501 ISBN 978-0-444-53186-5. - (Studies in surface science and catalysis. Vol. 170 B) R&D Projects: GA MŠk 1M0577 Grant ostatní: Deutsche Forschungsgemeinschaft(DE) OE 420/3-1 Institutional research plan: CEZ:AV0Z40400503 Source of funding: V - iné verejné zdroje Keywords : TiO2 * anodic electrodeposition * mesoporous layers Subject RIV: CF - Physical ; Theoretical Chemistry

  14. Doping studies of spray-deposited CdTe films. [CdTe:In; CdTe:Na

    Energy Technology Data Exchange (ETDEWEB)

    Berry, A.K. (Electrical and Computer Engineering Dept., George Mason Univ., Fairfax, VA (USA))

    1991-04-01

    The results of doping spray-deposited cadmium telluride films on glass substrates are reported. The films were 1-4 {mu}m thick, displayed excellent adhesion to the substrate and possessed good surface morphology. The doping was achieved by incorporating the dopant source into the spraying solution. The films doped with indium and sodium show a decrease in resistivity by a factor of 100 with respect to the resistivity of undoped films grown under similar conditions. Attempts to dope with caesium and phosphorus were not satisfactory. Transport measurements were performed and they were found to be influenced significantly by the built-in potential at the grain boundaries. (orig.).

  15. Electrochemical deposition and characterization of phosphorous doped p-CdTe thin films

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishnan, K.S.; Rastogi, A.C. (National Physical Lab., New Delhi (India))

    1991-11-01

    An electrodeposition process for formation of low resistivity phosphorous doped p-type CdTe films is described. The deposition is carried out in organic electrolyte which enables ionic doping by phosphorous in situ with the growth of CdTe films. Te to P atomic ratios in the film, their electrolytic concentrations and activation energy analysis establishes that p-conversion is due to acceptor states at E{sub v} +0.05 eV formed by P atoms selectively occupying Te sites in CdTe. The lower resistivity limit of 5-10 {Omega} cm of p-CdTe films is set by generation of interstitial P related defects if the P concentration exceeds a threshold value of 6x10{sup -4} M. Analysis of space charge limited current transport in these films establishes hole concentrations of 8x10{sup 16} cm{sup -3} and associated low defect densities around 9x10{sup 14} cm{sup -3} obtained through good stoichiometric control inherent to this technique. Codeposition of P modifies nucleation and growth, resulting in p-CdTe films having hexagonal structure and oriented crystallites of over 0.8 {mu}m grain size. Due to these properties p-CdTe films are well suited for application to solar cells. (orig.).

  16. Electrodeposited ZnIn{sub 2}S{sub 4} onto TiO{sub 2} thin films for semiconductor-sensitized photocatalytic and photoelectrochemical applications

    Energy Technology Data Exchange (ETDEWEB)

    Assaker, Ibtissem Ben, E-mail: ibtissem.ben-assaker@laposte.net [Laboratoire Photovoltaïque, Centre de Recherches et des Technologies de l’Energie Technopole borj cedria, Bp 95, Hammamm lif 2050 (Tunisia); Gannouni, Mounir; Naceur, Jamila Ben [Laboratoire Photovoltaïque, Centre de Recherches et des Technologies de l’Energie Technopole borj cedria, Bp 95, Hammamm lif 2050 (Tunisia); Almessiere, Munirah Abdullah; Al-Otaibi, Amal Lafy; Ghrib, Taher [Laboratory of Physical Alloys (LPA), College of Science, University of Dammam (Saudi Arabia); Shen, Shouwen [Advanced Analysis Unit, Technical Service Division Research & Development Center Saudi Aramco, Dhahran (Saudi Arabia); Chtourou, Radhouane [Laboratoire Photovoltaïque, Centre de Recherches et des Technologies de l’Energie Technopole borj cedria, Bp 95, Hammamm lif 2050 (Tunisia)

    2015-10-01

    Graphical abstract: - Highlights: • ZnIn{sub 2}S{sub 4} thin films was grown using electrodeposition route onto TiO{sub 2}/ITO coated glass substrate. • Study of the heterostructure ZnIn{sub 2}S{sub 4}/TiO{sub 2} thin films. • Photocatalytic activity of ZnIn{sub 2}S{sub 4}/TiO{sub 2} heterostructure under visible light irradiation. • High performance of Photoelectrochemical properties in the presence of the junction ZnIn{sub 2}S{sub 4}/TiO{sub 2}. - Abstract: In this study, ZnIn{sub 2}S{sub 4}/TiO{sub 2} heterostructure was successfully synthesized on ITO-coated glass substrates via a facile two-step process from aqueous solution. First, TiO{sub 2} thin film was prepared by sol–gel and deposited onto ITO coated glass substrate by spin-coating method. Then the zinc indium sulfide semiconductor was fabricated via electrodeposition technique onto TiO{sub 2}/ITO coated glass electrode. The X-ray diffraction patterns confirm that the heterostructure is mixed of both Anatase TiO{sub 2} and Rhombohedric ZnIn{sub 2}S{sub 4}. The scanning electron microscopy (SEM) images show that the morphology change with the deposition of ZnIn{sub 2}S{sub 4} over TiO{sub 2} thin film and a total coverage of the electrode surface was obtained. Optical absorption spectroscopy study of ZnIn{sub 2}S{sub 4}/TiO{sub 2} heterostructure exhibits a remarkable red-shift compared to the TiO{sub 2} and ZnIn{sub 2}S{sub 4} achieve the best efficiency of visible light absorption. Therefore, it is expected to apply to visible-light photocatalysis and solar cells. To investigate the effect of the heterojunction on the photocatalytic activity of ZnIn{sub 2}S{sub 4}/TiO{sub 2} thin films, photodegradation of methylene blue in the presence of ZnIn{sub 2}S{sub 4} was performed. ZnIn{sub 2}S{sub 4}/TiO{sub 2} heterostructure exhibited strong photocatalytic activity, and the degradation of methylene blue eached 91% after irradiation only for 4 h. Also, the study of the photocurrent density produced

  17. Auger relative sensitivivity factors for CdTe oxide

    OpenAIRE

    Bartolo-Pérez, P.; Peña, J. L.; M.H. Farías

    1999-01-01

    The Auger lineshape of Te MNN in measurements of Auger spectra of CdTe oxide films with various degrees of oxidation was analyzed. By using standards from stoichiometric compounds, Auger relative sensitivity factors (RSF´s) of Cd, Te and O for CdTe oxide thin films were obtained. The value of the RFS of oxygen is about constant, 0.27-0.28, for the standard compound, CdO, TeO2 and CdTeO3 (considering the RSF of Cd as 1). However, the obtained RSF of Te changes from 0.69 in CdTe up to 0.87 in C...

  18. Process Development for High Voc CdTe Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Ferekides, C. S.; Morel, D. L.

    2011-05-01

    This is a cumulative and final report for Phases I, II and III of this NREL funded project (subcontract # XXL-5-44205-10). The main research activities of this project focused on the open-circuit voltage of the CdTe thin film solar cells. Although, thin film CdTe continues to be one of the leading materials for large-scale cost-effective production of photovoltaics, the efficiency of the CdTe solar cells have been stagnant for the last few years. This report describes and summarizes the results for this 3-year research project.

  19. Effect of Substrate Temperature on CdTe Thin Film Property and Solar Cell Performance%衬底温度对碲化镉薄膜性质及太阳电池性能的影响

    Institute of Scientific and Technical Information of China (English)

    曹胜; 武莉莉; 冯良桓; 王文武; 张静全; 郁骁骑; 李鑫鑫; 李卫; 黎兵

    2016-01-01

    蒸汽输运法是制备高质量且大面积均匀的 CdTe 薄膜的一种优良的方法。采用自主研发的一套蒸汽输运沉积系统制备了 CdTe 多晶薄膜,并研究了衬底温度对 CdTe 薄膜性质及太阳电池性能的影响。利用 XRD、SEM、UV-Vis和Hall等测试手段研究了衬底温度对薄膜的结构、光学性质和电学性质的影响。结果表明,蒸汽输运法制备的CdTe薄膜具有立方相结构,且沿(111)方向高度择优。随着衬底温度的升高(520℃~640℃), CdTe薄膜的平均晶粒尺寸从2mm增大到约6mm, CdTe薄膜的载流子浓度也从1.93×1010 cm–3提高到2.36×1013 cm–3,说明提高衬底温度能够降低CdTe薄膜的缺陷复合,使薄膜的p型更强。实验进一步研究了衬底温度对CdTe薄膜太阳电池性能的影响,结果表明适当提高衬底温度,能够大幅度提高电池的效率、开路电压和填充因子,但是过高的衬底温度又会降低电池的长波光谱响应,导致电池转换效率的下降。经过参数优化,在衬底温度为610℃、无背接触层小面积CdTe薄膜太阳电池的转换效率达到11.2%。%Vapor transport deposition is an excellent method for preparing large area CdTe thin films with high quality and uniformity. Polycrystalline CdTe thin films were deposited by home-made vapor transport deposition system (VTD). The effects of substrate temperature on the property of CdTe film and the performance of CdTe solar cell were inves-tigated. CdTe thin films were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), UV-Vis spectrometer, and Hall Effect system. The results show that the CdTe thin films deposited by vapor transport deposi-tion are cubic phase with a preferred orientation in (111) direction. The average grain size increases from 2mm to 6mm and the carrier concentration increases from 1.93×1010 cm–3 to 2.36×1013 cm–3 when the substrate temperature increases from 520 ℃ to 620 ℃. This

  20. Fabrication of ionic liquid electrodeposited Cu--Sn--Zn--S--Se thin films and method of making

    Science.gov (United States)

    Bhattacharya, Raghu Nath

    2016-01-12

    A semiconductor thin-film and method for producing a semiconductor thin-films comprising a metallic salt, an ionic compound in a non-aqueous solution mixed with a solvent and processing the stacked layer in chalcogen that results in a CZTS/CZTSS thin films that may be deposited on a substrate is disclosed.

  1. The crystal structure of CdS-CdTe thin film heterojunction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, K.D.; Painter, J.D.; Healy, M.J.; Lane, D.W. [Cranfield Univ. (United Kingdom). Dept. of Mater. and Medical Sci.; Ozsan, M.E. [B.P. Solar Ltd., Middlesex (United Kingdom)

    1999-02-08

    A detailed structural analysis of electrodeposited CdS-CdTe thin film heterojunction solar cells was undertaken. X-ray diffraction and Rutherford backscattering spectrometry were used to provide stoichiometric and microcrystalline data at increasing depths through the CdTe and CdS films. A model of the nature and extent of interdiffusion caused by a post deposition anneal is developed. A region in both pre-annealed and post-annealed samples which possesses a significantly different microstructure to that of the bulk CdTe, was identified. Within this region a stoichiometric gradient occurs and the grain size and preferred orientation decrease with increasing depth. Maximum CdTe film stress (post anneal) is estimated to be 140 MPa close to the interface and a shift in optical band gap of 6 x 10{sup -3} eV was also determined from structural measurements. We provide evidence that sulphur diffusion into CdTe is structurally rather than thermodynamically limited within these systems. (orig.) 15 refs.

  2. Study of the physical properties of Bi doped CdTe thin films deposited by close space vapour transport

    International Nuclear Information System (INIS)

    Bi doped cadmium telluride (CdTe:Bi) thin films were grown on glass-substrates by the close space vapour transport method. CdTe:Bi crystals grown by the vertical Bridgman method, varying the nominal Bi concentration in the range between 1 x 1017 and 8 x 1018 cm-3, were used in powder form for CdTe:Bi thin film deposition. Dark conductivity and photoconductivity measurements in the 90-300 K temperature range and determination by photoacoustic spectroscopy of the optical-absorption coefficient of the films in the 1.0 to 2.4 eV spectral region were carried out. The influence of Bi doping levels upon the intergrain barrier height and other associated grain boundary parameters of the polycrystalline CdTe:Bi thin films were determined from electrical, optical and morphological characterization

  3. Electro-Deposition Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The electro-deposition laboratory can electro-deposit various coatings onto small test samples and bench level prototypes. This facility provides the foundation for...

  4. Photoelectrochemical (PEC) studies on CdSe thin films electrodeposited from non-aqueous bath on different substrates

    Indian Academy of Sciences (India)

    Y G Gudage; N G Deshpande; A A Sagade; R P Sharma; S M Pawar; C H Bhosale

    2007-08-01

    Thin films of CdSe were deposited by potentiostatic mode on different substrates such as stainless steel, titanium and fluorine tin–oxide (FTO) coated glass using non-aqueous bath. The preparative parameters were optimized to get good quality CdSe thin films. These films were characterized by X-ray diffraction (XRD), optical absorption and photoelectrochemical (PEC) techniques. XRD study revealed that the films were polycrystalline in nature with hexagonal phase. Optical absorption study showed that CdSe films were of direct band gap type semiconductor with a band gap energy of 1.8 eV. PEC study revealed that CdSe film deposited on FTO coated glass exhibited maximum values of fill factor (FF) and efficiency () as compared to the films deposited on stainless steel and titanium substrate.

  5. Nanowire and core-shell-structures on flexible Mo Foil for CdTe solar cell applications

    OpenAIRE

    Williams, Ben; Durose, Ken; Kartopu, Giray; Barrioz, Vincent; Lamb, Daniel; Irvine, Stuart; Zoppi, Guillaume; Forbes, Ian

    2011-01-01

    CdTe films, nanowires, film-nanowire combinations and CdS-CdTe core-shell structures have been fabricated in a preliminary survey of growth methods that will generate structures for PV applications. Selectivity between film, nanowire and film plus nanowire growth was achieved by varying the pressure of N2 gas present during Au-catalysed VLS growth of CdTe, on either Mo or Si substrates. Metamorphic growth of CdTe nanowires on sputtered CdTe films, deposited on glass substrates, was demonstrat...

  6. Development of a computer model for polycrystalline thin-film CuInSe sub 2 and CdTe solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Gray, J.L.; Schwartz, R.J.; Lee, Y.J. (Purdue Univ., Lafayette, IN (United States))

    1992-04-01

    This report describes work to develop a highly accurate numerical model for CuInSe{sub 2} and CdTe solar cells. ADEPT (A Device Emulation Program and Toolbox), a one-dimensional semiconductor device simulation code developed at Purdue University, was used as the basis of this model. An additional objective was to use ADEPT to analyze the performance of existing and proposed CuInSe{sub 2} and CdTe solar cell structures. The work is being performed in two phases. The first phase involved collecting device performance parameters, cell structure information, and material parameters. This information was used to construct the basic models to simulate CuInSe{sub 2} and CdTe solar cells. This report is a tabulation of information gathered during the first phase of this project on the performance of existing CuInSe{sub 2} and CdTe solar cells, the material properties of CuInSr{sub 2}, CdTe, and CdS, and the optical absorption properties of CuInSe{sub 2}, CdTe, and CdS. The second phase will entail further development and the release of a version of ADEPT tailored to CuInSe{sub 2} and CdTe solar cells that can be run on a personal computer. In addition, ADEPT will be used to analyze the performance of existing and proposed CuInSe{sub 2} and CdTe solar cell structures. 110 refs.

  7. Influence of ethanol content in the precursor solution on anodic electrodeposited CeO2 thin films

    International Nuclear Information System (INIS)

    Ceria thin films have been anodically deposited onto 316L stainless steel in bath solutions containing different volume ratios of ethanol (0, 10, 40, 70 and 100% v/v). The influence of ethanol content on the electroplating behavior, and the structural and corrosion properties of the cerium oxide films were studied with electrochemical impedance spectroscopy, scanning electron microscopy, ellipsometry, X-ray diffraction, and Raman and X-ray photoelectron spectroscopy. Results show that ethanol content plays a significant role on the properties of the deposited ceria films but negligible effect on their electroplating behavior. The as-deposited films are mostly in the Ce(IV) oxidation state and the stoichiometry is around CeO1.90 for all samples. With the increase of ethanol content from 0 to 100% v/v, the average grain diameter and film thickness of the obtained ceria film decrease from 16.8 nm to 11.1 nm and from 32.9 nm to 15.8 nm, respectively. Using a deposition bath solution containing 10% v/v ethanol, a layer of compacted yellowish gold ceria film with the minimum porosity of 19.9%, mean crystalline diameter of 15.4 nm, and maximum corrosion resistance of 3.31 × 10−5 Ω has been obtained. - Highlights: • Ethanol plays a negligible effect on ceria film anodic electroplating behavior. • Average grain diameter and thickness of the film decrease with the ethanol addition. • Appropriate amount of ethanol can markedly improve the film quality. • Film color changes gradually with increasing ethanol addition into deposition bath. • Nanocrystalline CeO1.90 films of golden yellowish have been obtained

  8. Electrodeposited polypyrrole (PPy)/para (toluene sulfonic acid) (pTS) free-standing film for lithium secondary battery application

    International Nuclear Information System (INIS)

    Highlights: ► Free-standing polypyrrole-para (toluene sulfonic acid) (PPy-pTS) film. ► The films are soft, lightweight, mechanically robust, and highly electrically conductive. ► Application as cathode material for lithium secondary battery ► PPy-pTS film with 30 min deposition time exhibited higher discharge capacity (85 mAh g−1) beyond 80 cycles than the PPy-pTS films with 1 h deposition time (76 mAh g−1) and 2 h deposition time (55 mAh g−1). - Abstract: Highly flexible and bendable free-standing polypyrrole-para (toluene sulfonic acid) (PPy-pTS) films were prepared using the electropolymerization method. The films are soft, lightweight, mechanically robust, and highly electrically conductive. The films display a cauliflower-like structure consisting of micron-scale spherical grains, which are related to dopant intercalation in the polymeric chains. The electrochemical behaviour of the free-standing films was examined as cathode against lithium counter electrode. Electrochemical tests demonstrated that the PPy-pTS film with 30 min deposition time exhibited higher discharge capacity (85 mAh g−1) beyond 80 cycles than the PPy-pTS films with 1 h deposition time (76 mAh g−1) and 2 h deposition time (55 mAh g−1) at 0.1 mA cm−2 over a potential range of 2.5–4.3 V. The free-standing films can be used as electrode materials to satisfy the new market demand for flexible and bendable polymer batteries.

  9. Electrodeposition From Acidic Solutions of Nickel Bis(benzenedithiolate) Produces a Hydrogen-Evolving Ni-S Film on Glassy Carbon

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Ming; Engelhard, Mark H.; Zhu, Zihua; Helm, Monte L.; Roberts, John A.

    2014-01-03

    Films electrodeposited onto glassy carbon electrodes from acidic acetonitrile solutions of [Bu4N][Ni(bdt)2] (bdt = 1,2-benzenedithiolate) are active toward electrocatalytic hydrogen production at potentials 0.2-0.4 V positive of untreated electrodes. This activity is preserved on rinsing the electrode and transfer to fresh acid solution. X-ray photoelectron spectra indicate that the deposited material contains Ni and S. Correlations between voltammetric and spectroscopic results indicate that the deposited material is active, i.e. that catalysis is heterogeneous rather than homogeneous. Control experiments establish that obtaining the observed catalytic response requires both Ni and the 1,2 benzenedithiolate ligand to be present during deposition. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy. A portion of the research was performed using EMSL, a 17 national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

  10. Temperature dependent electroreflectance study of CdTe solar cells

    International Nuclear Information System (INIS)

    Cadmium telluride is a promising material for large scale photovoltaic applications. In this paper we study CdS/CdTe heterojunction solar cells with electroreflectance spectroscopy. Both CdS and CdTe layers in solar cells were grown sequentially without intermediate processing by the close-space sublimation method. Electroreflectance measurements were performed in the temperature range of T = 100–300 K. Two solar cells were investigated with conversion efficiencies of 4.1% and 9.6%. The main focus in this work was to study the temperature dependent behavior of the broadening parameter and the bandgap energy of CdTe thin film in solar cells. Room temperature bandgap values of CdTe were Eg = 1.499 eV and Eg = 1.481 eV for higher and lower efficiency solar cells, respectively. Measured bandgap energies are lower than for single crystal CdTe. The formation of CdTe1−xSx solid solution layer on the surface of CdTe is proposed as a possible cause of lower bandgap energies. - Highlights: ► Temperature dependent electroreflectance measurements of CdS/CdTe solar cells ► Investigation of junction properties between CdS and CdTe ► Formation of CdTe1− xSx solid solution layer in the junction area

  11. Intrinsic Doping in Electrodeposited ZnS Thin Films for Application in Large-Area Optoelectronic Devices

    Science.gov (United States)

    Madugu, Mohammad Lamido; Olusola, Olajide Ibukun-Olu; Echendu, Obi Kingsley; Kadem, Burak; Dharmadasa, Imyhamy Mudiy

    2016-06-01

    Zinc sulphide (ZnS) thin films with both n- and p-type electrical conductivity were grown on glass/fluorine-doped tin oxide-conducting substrates from acidic and aqueous solution containing ZnSO4 and (NH4)2S2O3 by simply changing the deposition potential in a two-electrode cell configuration. After deposition, the films were characterised using various analytical techniques. X-ray diffraction analysis reveals that the materials are amorphous even after heat treatment. Optical properties (transmittance, absorbance and optical bandgap) of the films were studied. The bandgaps of the films were found to be in the range (3.68-3.86) eV depending on the growth voltage. Photoelectrochemical cell measurements show both n- and p-type electrical conductivity for the films depending on the growth voltage. Scanning electron microscopy shows material clusters on the surface with no significant change after heat treatment at different temperatures. Atomic force microscopy shows that the surface roughness of these materials remain fairly constant reducing only from 18 nm to 17 nm after heat treatment. Thickness estimation of the films was also carried out using theoretical and experimental methods. Direct current conductivity measurements on both as-deposited and annealed films show that resistivity increased after heat treatment.

  12. Electrodeposition of perpendicular Gd x (FeCo) y magnetic thin film from ZnCl2-DMSO2 electrolyte

    International Nuclear Information System (INIS)

    In this work, we have utilized ZnCl2-dimethylsulfone (DMSO2) as the electrolyte for preparing a perpendicular Gd x (FeCo) y magnetic thin film by the pulse potential with a voltage of -0.001 V and pulse ratio (t on/t off) of 0.1 and 0.2. A perpendicularly magnetic property of the thin film was investigated by alternating gradient magnetometer (AGM). Moreover, a crystal structure and cross-section of the thin film were observed by transmission electron microscope (TEM)

  13. CdTe Photovoltaics for Sustainable Electricity Generation

    Science.gov (United States)

    Munshi, Amit; Sampath, Walajabad

    2016-09-01

    Thin film CdTe (cadmium telluride) is an important technology in the development of sustainable and affordable electricity generation. More than 10 GW of installations have been carried out using this technology around the globe. It has been demonstrated as a sustainable, green, renewable, affordable and abundant source of electricity. An advanced sublimation tool has been developed that allows highly controlled deposition of CdTe films onto commercial soda lime glass substrates. All deposition and treatment steps can be performed without breaking the vacuum within a single chamber in an inline process that can be conveniently scaled to a commercial process. In addition, an advanced cosublimation source has been developed to allow the deposition of ternary alloys such as Cd x Mg1- x Te to form an electron reflector layer which is expected to address the voltage deficits in current CdTe devices and to achieve very high efficiency. Extensive materials characterization, including but not limited to scanning electron microscopy, transmission electron microscopy, energy dispersive x-ray spectroscopy, high resolution transmission electron microscopy and electron back-scatter diffraction, has been performed to get a better understanding of the effects of processing conditions on CdTe thin film photovoltaics. This combined with computer modeling such as density function theory modeling gives a new insight into the mechanism of CdTe photovoltaic function. With all these efforts, CdTe photovoltaics has seen great progress in the last few years. Currently, it has been recorded as the cheapest source of electricity in the USA on a commercial scale, and further improvements are predicted to further reduce the cost while increasing its utilization. Here, we give an overview of the advantages of thin film CdTe photovoltaics as well as a brief review of the challenges that need to be addressed. Some fundamental studies of processing conditions for thin film CdTe are also presented

  14. CdTe Photovoltaics for Sustainable Electricity Generation

    Science.gov (United States)

    Munshi, Amit; Sampath, Walajabad

    2016-04-01

    Thin film CdTe (cadmium telluride) is an important technology in the development of sustainable and affordable electricity generation. More than 10 GW of installations have been carried out using this technology around the globe. It has been demonstrated as a sustainable, green, renewable, affordable and abundant source of electricity. An advanced sublimation tool has been developed that allows highly controlled deposition of CdTe films onto commercial soda lime glass substrates. All deposition and treatment steps can be performed without breaking the vacuum within a single chamber in an inline process that can be conveniently scaled to a commercial process. In addition, an advanced cosublimation source has been developed to allow the deposition of ternary alloys such as Cd x Mg1-x Te to form an electron reflector layer which is expected to address the voltage deficits in current CdTe devices and to achieve very high efficiency. Extensive materials characterization, including but not limited to scanning electron microscopy, transmission electron microscopy, energy dispersive x-ray spectroscopy, high resolution transmission electron microscopy and electron back-scatter diffraction, has been performed to get a better understanding of the effects of processing conditions on CdTe thin film photovoltaics. This combined with computer modeling such as density function theory modeling gives a new insight into the mechanism of CdTe photovoltaic function. With all these efforts, CdTe photovoltaics has seen great progress in the last few years. Currently, it has been recorded as the cheapest source of electricity in the USA on a commercial scale, and further improvements are predicted to further reduce the cost while increasing its utilization. Here, we give an overview of the advantages of thin film CdTe photovoltaics as well as a brief review of the challenges that need to be addressed. Some fundamental studies of processing conditions for thin film CdTe are also presented

  15. Photoluminescence and Electroluminescence Properties of CdTe Nanoparticles in Conjugated Polymer Hosts

    Institute of Scientific and Technical Information of China (English)

    GUO, Fengqi; XIE, Puhui

    2009-01-01

    The photoinduced energy transfer process from conjugated polymer (PPE4+) to CdTe nanocrystals was found both in solutions and in thin films by a fluorescence spectroscopic technique. Films of PPE4+ blended with CdTe-2 nanocrystals were formed by an electrostatic layer-by-layer assembly technique. Light emitting diodes were fabricated using CdTe-2 as an emitter in PPE4+ host. PPE4+ works as a molecular wire in the energy transfer process from the polymer to the CdTe-2 nanocrystals.

  16. Green and controllable strategy to fabricate well-dispersed graphene–gold nanocomposite film as sensing materials for the detection of hydroquinone and resorcinol with electrodeposition

    International Nuclear Information System (INIS)

    Highlights: ► We reported firstly green and controllable strategy to fabricate graphene–gold composite. ► The strategy provides control over reaction parameters and excellent repeatability. ► The composite offers faster electron transfer than pure graphene and gold nanoparticles. ► The composite was used to fabricate sensor for detection of hydroquinone and resorcinol. ► The sensor displays the best sensitivity for hydroquinone and resorcinol up to now. - Abstract: The paper described a green and controllable strategy to fabricate well-dispersed graphene–gold nanocomposite film. To prepare graphene–gold nanocomposite film, graphene and gold nanoparticles were alternately electrodeposited on the surface of glassy carbon electrode. Since electrochemical technique offers control over reaction parameters and excellent repeatability, the amounts of graphene and gold nanoparticles for the each layer can be pre-determined by controlling concentrations of graphene oxide and chlorauric acid. The as-prepared graphene–gold nanocomposite film was characterized by infrared spectrum, scanning electron microscope, Raman spectrum and X-ray diffraction, and its electrocatalytic activity was estimated by Laviron's model. The apparent heterogeneous electron transfer rate constant of 37.67 ± 0.19 cm s−1 was obtained, indicating fast electron transfer of Fe(CN)64− to the electrode. Further, the film was investiaged as sensing materials for synchronously detection of hydroquinone and resorcinol. When the cencentrations are in the ranges of 1.6 × 10−8 to 1.2 × 10−4 mol l−1 for hydroquinone and 1.0 × 10−8 to 2 × 10−6 mol l−1 for resorcinol, differential pulse voltammetric peak current of the sensor linearly increases. The sensitivities of differential pulse voltammetric response are 30.5 μA μM−1 cm−2 for hydroquinone and 117.83 μA μM−1 cm−2 for resorcinol. The detection limits were found to be 5.2 × 10−9 mol l−1 for hydroquinone and

  17. Radiative and interfacial recombination in CdTe heterostructures

    International Nuclear Information System (INIS)

    Double heterostructures (DH) were produced consisting of a CdTe film between two wide band gap barriers of CdMgTe alloy. A combined method was developed to quantify radiative and non-radiative recombination rates by examining the dependence of photoluminescence (PL) on both excitation intensity and time. The measured PL characteristics, and the interface state density extracted by modeling, indicate that the radiative efficiency of CdMgTe/CdTe DHs is comparable to that of AlGaAs/GaAs DHs, with interface state densities in the low 1010 cm−2 and carrier lifetimes as long as 240 ns. The radiative recombination coefficient of CdTe is found to be near 10−10 cm3s−1. CdTe film growth on bulk CdTe substrates resulted in a homoepitaxial interface layer with a high non-radiative recombination rate

  18. Studies of key technologies for CdTe solar modules

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In this paper, CdS thin films, which act as the window layer and n-type partner to the p-type CdTe layer, were prepared by chemical bath deposition (CBD). CdTe thin films were deposited by the close-spaced sublimation (CSS) method. To obtain high-quality back contacts, a Te-rich layer was created with chemical etching and back contact materials were applied after CdTe annealing. The results indicate that the ZnTe/ZnTe:Cu complex layers show superior performance over other back contacts. Finally, by using laser scribing and mechanical scribing, the CdTe mini-modules were fabricated, in which a glass/SnO2:F/CdS/CdTe/ZnTe/ZnTe:Cu/Ni solar module with a PWQC-confirmed total-area efficiency of 7.03% (54 cm2) was achieved.

  19. Evolution of Principle and Practice of Electrodeposited Thin Film: A Review on Effect of Temperature and Sonication

    Directory of Open Access Journals (Sweden)

    A. Mallik

    2011-01-01

    Full Text Available This review discusses briefly the important aspects of thin films. The introduction of the article is a summary of evolution of thin films from surface engineering, their deposition methods, and important issues. The fundamental aspects of electrochemical deposition with special emphasis on the effect of temperature on the phase formation have been reviewed briefly. The field of sonoelectrochemistry has been discussed in the paper. The literature regarding the effects of temperature and sonication on the structure and morphology of the deposits and nucleation mechanisms, residual stress, and mechanical properties has also been covered briefly.

  20. Degradation sources of CdTe thin film PV: CdCl{sub 2} residue and shunting pinholes

    Energy Technology Data Exchange (ETDEWEB)

    Gorji, Nima E. [University of Bologna, Department of Electrical, Electronics and Information Engineering, Bologna (Italy)

    2014-09-15

    The present work considers two observable phenomena through the experimental fabrication and electrical characterization of the rf-sputtered CdS/CdTe thin film solar cells that extremely reduce the overall conversion efficiency of the device: CdCl{sub 2} residue on the surface of the semiconductor and shunting pinholes. The former happens through nonuniform treatment of the As-deposited solar cells before annealing at high temperature and the latter occurs by shunting pinholes when the cell surface is shunted by defects, wire-like pathways or scratches on the metallic back contact caused from the external contacts. Such physical problems may be quite common in the experimental activities and reduce the performance down to 4-5 % which leads to dismantle the device despite its precise fabrication. We present our electrical characterization on the samples that received wet CdCl{sub 2} surface treatment (uniform or nonuniform) and are damaged by the pinholes. (orig.)

  1. Vapor phase epitaxy of CdTe on sapphire and GaAs

    Science.gov (United States)

    Kasuga, Masanobu; Futami, Hiroyuki; Iba, Yoshihiro

    1991-12-01

    CdTe films were deposited on three kinds of sapphire substrate and two kinds of GaAs substrate by open tube vapor transport. X-ray Laue diffraction study showed that CdTe(111) film grew on every kind of sapphire substrate used, i.e. on the (0001) basal plane, the (11 overline20)A plane and the (1 overline102)R plane, and that there exist a few degrees of tilt angel between CdTe(111) and the lattice plane of each substrate. The process of making the tilt angle may be explained by the atomistic mismatch model of the Cd and Al arrangement which is projected on the film-substrate interface. On GaAs(100), either CdTe(111) or CdTe(100) was obtained, whereas only a twin crystalline film was obtained on GaAs(111). These results are also consistent with the mismatch model of Cd and Ga atoms.

  2. The mechanism of cathodic electrodeposition of epoxy coatings and the corrosion behaviour of the electrodeposited

    Directory of Open Access Journals (Sweden)

    VESNA B. MISKOVIC-STANKOVIC

    2002-05-01

    Full Text Available The model of organic film growth on a cathode during electrodeposition process proposes the current density-time and film thickness-time relationships and enables the evaluation of the rate contants for the electrochemical reaction of OH– ion evolution and for the chemical reaction of organic film deposition. The dependences of film thickness and rate constants on the applied voltage, bath temperature and resin concentration in the electrodeposition bath have also been obtained. The deposition parameters have a great effect on the cathodic electrodeposition process and on the protective properties of the obtained electrodeposited coatings. From the time dependences of the pore resistance, coating capacitance and relative permittivity, obtained from impedance measurements, the effect of applied voltage, bath temperature and resin concentration on the protective properties of electrodeposited coatings has been shown. Using electrochemical impedance spectroscopy, thermogravimetric analysis, gravimetric liquid sorption experiments, differential scanning calorimetry and optical miscroscopy, the corrosion stability of epoxy coatings was investigated. A mechanism for the penetration of electrolyte through an organic coating has been suggested and the shape and dimensions of the conducting macropores have been determined. It was shown that conduction through a coating depends only on the conduction through the macropores, although the quantity of electrolyte in the micropores of the polymer net is about one order of magnitude greater than that inside the conducting macropores.

  3. ZnO solar cells with an indoline sensitizer: a comparison between nanoparticulate films and electrodeposited nanowire arrays

    Czech Academy of Sciences Publication Activity Database

    Guillén, E.; Azaceta, E.; Peter, L. M.; Zukal, Arnošt; Tena-Zaera, R.; Anta, J. A.

    2011-01-01

    Roč. 4, č. 9 (2011), s. 3400-3407. ISSN 1754-5692 Institutional research plan: CEZ:AV0Z40400503 Keywords : HIGH-CONVERSION- EFFICIENCY * HYBRID THIN-FILMS * ZINC-OXIDE Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 9.610, year: 2011

  4. Electrodeposition from supercritical fluids

    OpenAIRE

    Bartlett, P.; Cook, D.A.; George, M.W.; Hector, A; Ke, J; Levason, W.; Reid, G; Smith, D.; W. Zhang

    2014-01-01

    Recent studies have shown that it is possible to electrodeposit a range of materials, such as Cu, Ag and Ge, from various supercritical fluids, including hydrofluorocarbons and mixtures of CO2 with suitable co-solvents. In this perspective we discuss the relatively new field of electrodeposition from supercritical fluids. The perspective focuses on some of the underlying physical chemistry and covers both practical and scientific aspects of electrodeposition from supercritical fluids. We also...

  5. Defect structure of electrodeposited chromium layers

    International Nuclear Information System (INIS)

    Positron annihilation spectroscopy was applied to study the effects of pre-treatment and composition of substrates on the quality and defect structure of electrodeposited thick chromium coatings. The results show that both parameters are important, and a scenario is proposed why the mechanically polished substrate gives more defective film than the electro polished one.

  6. Defect structure of electrodeposited chromium layers

    CERN Document Server

    Marek, T; Vertes, A; El-Sharif, M; McDougall, J; Chisolm, C U

    2000-01-01

    Positron annihilation spectroscopy was applied to study the effects of pre-treatment and composition of substrates on the quality and defect structure of electrodeposited thick chromium coatings. The results show that both parameters are important, and a scenario is proposed why the mechanically polished substrate gives more defective film than the electro polished one.

  7. Elucidating PID Degradation Mechanisms and In-Situ Dark I-V Monitoring for Modeling Degradation Rate in CdTe Thin-Film Modules

    DEFF Research Database (Denmark)

    Hacke, Peter; Spataru, Sergiu; Johnston, Steve;

    2016-01-01

    A progression of potential-induced degradation (PID) mechanisms are observed in CdTe modules, including shunting/junction degradation and two different manifestations of series resistance depending on the stress level and water ingress. The dark I-V method for in-situ characterization of Pmax based...

  8. Electrodeposition from supercritical fluids.

    Science.gov (United States)

    Bartlett, P N; Cook, D A; George, M W; Hector, A L; Ke, J; Levason, W; Reid, G; Smith, D C; Zhang, W

    2014-05-28

    Recent studies have shown that it is possible to electrodeposit a range of materials, such as Cu, Ag and Ge, from various supercritical fluids, including hydrofluorocarbons and mixtures of CO2 with suitable co-solvents. In this perspective we discuss the relatively new field of electrodeposition from supercritical fluids. The perspective focuses on some of the underlying physical chemistry and covers both practical and scientific aspects of electrodeposition from supercritical fluids. We also discuss possible applications for supercritical fluid electrodeposition and suggest some key developments that are required to take the field to the next stage. PMID:24469309

  9. Interfacial investigation and strengthening behaviour of Zn-Ni multifacial TEA/MEA thin films induced by electrodeposition

    Science.gov (United States)

    Fayomi, O. S. I.; Tau, V.; Popoola, A. P. I.; Abdulwahab, M.; Madhilabar, R.

    2015-11-01

    Zinc-nickel films were obtained by electrocodeposition using electrolytic deposition techniques in the presence of TEOA (C6H15NO3) and a surfactants consisting of triethylamine and monoethylamine with other bath additives. The modified structure of the films was analysed with scanning electron microscopy attached to energy-dispersive spectrometer, atomic force microscope and X-ray diffraction. Micro-hardness and corrosion of the coated body was examined and used as a criterion to justify the adhesion of the crystal deposited. The corrosion resistance of the coated and uncoated composites was studied in 3.5 % sodium chloride static solution using linear polarization technique. The hardness value increased from 38HV—substrate to 180HV—coated body, indicating a 78.89 % improvement. Equally, the corrosion resistance of the deposited matrix was enhanced by 84.62 %.

  10. CdTe钝化介质膜的溅射沉积及其X射线光电子能谱研究%The Sputtering Deposition and the X-ray Photoelectron Spectroscopy Study for the CdTe Thin Film

    Institute of Scientific and Technical Information of China (English)

    周咏东; 李言谨; 吴小山; 徐国森; 方家熊; 汤定元

    2001-01-01

    用Ar+束溅射沉积技术实现了CdTe薄膜的低温沉积生长。用X射线光电子能谱(XPS)分析技术对溅射沉积CdTe薄膜以及CdTe体晶中的Cd元素、Te元素化学环境进行了对比实验研究。实验表明:溅射沉积CdTe薄膜具有很好的组份均匀性,未探测到有元素(Cd、Te)沉积存在。%The CdTe film was grown by using the low-temperature ion beam sputtering technique. The Cd and Te elements in the sputtering CdTe film sample were studied and compared with those in the CdTe bulk using X-ray photoelectron spectroscopy (XPS) technique. It is proved that the constituent elements in the sputtering CdTe film are homogeneous. No element deposition (Cd, Te) is detceted.

  11. 具有复合背接触层的 CdTe多晶薄膜太阳电池%Polycrystalline CdTe thin- film solar cells with complex back contact layers

    Institute of Scientific and Technical Information of China (English)

    覃文治; 夏庚培; 郑家贵; 李卫; 蔡伟; 冯良桓; 蔡亚平; 黎兵; 张静全; 武莉莉

    2005-01-01

    To improve the properties of back contacts of CdTe solar cells, ZnTe:Cu and polycrystalline Cd1- xZnxTe films were deposited by simultaneous evaporation. Investigative data of the configuration and performance indicate that energy gap of Cd1- xZnxTe films assume quadratic connection with zinc content. With increasing of Cu content, energy gap of polycrystalline ZnTe:Cu will decrease. ZnTe/ZnTe:Cu or Cd1- xZnxTe/ZnTe:Cu back contacted cells can reduce the heterogeneous interface state density and modify the structure of energy band of the solar cells. Furthermore, diffusion of Cu can avoid by this compound films in CdTe solar cells. An efficiency of 13.38% of solar cell with dimension of 0.502cm2was fabricated.%为了提高 CdTe太阳电池的背接触性能,用共蒸发法制备了 ZnTe:Cu和 Cd1- xZnxTe多晶薄膜. 研究结果表明: Cd1- xZnxTe多晶薄膜的能隙与锌含量呈二次方关系, ZnTe:Cu多晶薄膜能隙随着掺 Cu浓度的增加而减小.分别用 ZnTe/ZnTe:Cu和 Cd1- xZnxTe/ZnTe:Cu复合膜作为背接触层,既能 修饰异质结界面,改善电池的能带结构,又能防止 Cu原子向电池内部扩散.因此获得了面积 0.502cm2,转换效率为 13.38%的 CdTe多晶薄膜太阳电池.

  12. CdTe Solar Cells: The Role of Copper

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Da [Arizona State University; Akis, Richard [Arizona State University; Brinkman, Daniel [Arizona State University; Sankin, Igor [First Solar; Fang, Tian [First Solar; Vasileska, Dragica [Arizona State University; Ringhofer, Christain [Arizona State University

    2014-06-06

    In this work, we report on developing 1D reaction-diffusion solver to understand the kinetics of p-type doping formation in CdTe absorbers and to shine some light on underlying causes of metastabilities observed in CdTe PV devices. Evolution of intrinsic and Cu-related defects in CdTe solar cell has been studied in time-space domain self-consistently with free carrier transport and Poisson equation. Resulting device performance was simulated as a function of Cu diffusion anneal time showing pronounced effect the evolution of associated acceptor and donor states can cause on device characteristics. Although 1D simulation has intrinsic limitations when applied to poly-crystalline films, the results suggest strong potential of the approach in better understanding of the performance and metastabilities of CdTe photovoltaic device.

  13. INTEGRATIION STYDY OF CdTe THIN FILMS PV MODULE%CdTe组件集成结构模拟优化及前、背电极接触电阻测定

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

    设计特定的测试结构,测量CdTe太阳电池组件的相邻单元电池的前电极与背电极的接触电阻,研究接触电阻与激光刻蚀刻痕的关系;使用module design simulator软件模拟分析相关膜层电子学性质、集成结构、单元电池性能对电池组件性能的影响.对CdTe电池组件接触电阻测量结果表明:随Ni层厚度增加,接触电阻减小,镍电极镀层较厚(410nm)时,接触电阻在10-3Ω·cm2数量级;加宽刻痕宽度使接触电阻略有下降;基频刻蚀CdTe层所得刻痕的接触电阻比倍频刻蚀高1~2个数量级.module design simulator软件模拟分析结果表明:CdTe薄膜太阳电池组件性能除与单元电池性能参数(转换效率、填充因子、短路电流、开路电压)相关外,单元电池宽度、TCO层方块电阻(或透过率)、CdTe层方块电阻、集成接触区接触电阻都对电池组件的性能存在影响.%The CdTe thin films PV module had been studied by measuring the contact resistance between the back contact metal and the front TCO film of the adjacent elementary cells. The "MODULE DESIGN SIMULATOR" software had been used to simulate the effects of the film electronic performance, the integration structure, and the contact elementary cell characteristics on module characteristics. The contact resistance decreases with the increasing of the thickness of Ni film. And the contact resistance increases 1 -2 orders of magnitude when the CdTe films were etched by basic frequency laser. The highest efficiency corresponds with the optimized cell width and the width of the notches. The unit cell width, sheet resistance of TCO & CdTe, and TCO/Ni contact resistance have great effect on the property of the module, respectively. With the increasing of TCO sheet resistance, the conversion efficiency firstly increase sharply and then decrease slowly. Increasing the sheet resistance of CdTe will lead to the increasing of both conversion efficiency and fill factor.

  14. Catalytic growth of CdTe nanowires by closed space sublimation method

    International Nuclear Information System (INIS)

    CdTe nano-/micro-structures with various morphologies were grown by using the closed space sublimation (CSS) method on a sapphire substrate by Au-catalyzed vapor–liquid–solid (VLS) mechanism. Length, diameter, and morphology of the CdTe nano-/micro-structures depended on the growth time and temperature gradient between the substrate and powdered CdTe source. Scanning electron microscopy images showed that an Au catalyst droplet existed at the tips of CdTe nanowires, which confirms that CdTe nanowires were grown by an Au-catalyzed VLS mechanism. Also, we observed that the two-dimensional CdTe film layer initially formed before the growth of the CdTe nano-/micro-wires. The optical and structural properties of CdTe nano-/micro-structures were characterized by X-ray diffraction technique and micro-Raman spectroscopy. Our study demonstrates that diverse CdTe nano-/micro-structures can be fabricated by using Au-catalyzed VLS growth process in a simple CSS chamber by controlling the temperature gradient and growth time. - Highlights: • We demonstrated CdTe nanowires using closed space sublimation method. • Au-catalyst droplets at the tips confirmed vapor–liquid–solid mechanism. • Diameters and lengths increased with increasing temperature gradient and time

  15. A novel method for fabricating hybrid biobased nanocomposites film with stable fluorescence containing CdTe quantum dots and montmorillonite-chitosan nanosheets.

    Science.gov (United States)

    Guo, Yawen; Ge, Xuesong; Guan, Jing; Wu, Lin; Zhao, Fuhua; Li, Hui; Mu, Xindong; Jiang, Yijun; Chen, Aibing

    2016-07-10

    A method was presented for fabricating the fluorescent nanocomposites containing CdTe quantum dots (QDs) and montmorillonite (MMT)-chitosan (CS). MMT-CS/CdTe QDs nanocomposites were prepared via a simple, versatile and robust approach combination of covalent and electrostatic assembly methods (Scheme 1). The negatively charged MMT was initially modified with positively charged CS through electrostatic assembly, followed by incorporation of CdTe-QDs into the MMT-CS nanosheets by covalent connections between the amino groups of CS and the carboxylic acid groups of thioglycollic acid (TGA). The X-ray diffraction (XRD), High resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM) and the FTIR were used to prove the QDs have intercalated into the MMT-CS matrix. The fluorescence emission spectra showed that the MMT-CS/CdTe QDs nanocomposites had the best fluorescence intensity compared with the bare CdTe QDs and CS-QDs. PMID:27106146

  16. Recent Advances in Superhydrophobic Electrodeposits

    OpenAIRE

    Jason Tam; Gino Palumbo; Uwe Erb

    2016-01-01

    In this review, we present an extensive summary of research on superhydrophobic electrodeposits reported in the literature over the past decade. As a synthesis technique, electrodeposition is a simple and scalable process to produce non-wetting metal surfaces. There are three main categories of superhydrophobic surfaces made by electrodeposition: (i) electrodeposits that are inherently non-wetting due to hierarchical roughness generated from the process; (ii) electrodeposits with plated surfa...

  17. Electrodeposited platinum thin films with preferential (100) orientation: Characterization and electrocatalytic properties for ammonia and formic acid oxidation

    Science.gov (United States)

    Bertin, Erwan; Garbarino, Sébastien; Guay, Daniel; Solla-Gullón, José; Vidal-Iglesias, Francisco J.; Feliu, Juan M.

    2013-03-01

    The electrocatalytic activity of preferentially oriented {100} Pt electrodes for the electro-oxidation of ammonia (0.2 M NaOH + 0.1 M NH3) and formic acid (0.5 M HCOOH + 0.5 M H2SO4) was assessed. They were prepared without using any surfactant through potentiostatic deposition (Ed = -0.10 V vs RHE, [HCl] = 10 mM and [Na2PtCl6·6H2O] = 0.5 mM) and by varying the deposition charge. For comparison, polycrystalline Pt thin films were prepared using the same solution but with Ed = +0.10 V vs RHE. Quantification of the fraction of (111) and (100) sites was performed by bismuth irreversible adsorption and deconvolution of the hydrogen region, respectively. Samples with as much as 47% of (100) surface sites were obtained. The preferential orientation was further confirmed by CO stripping voltammetry that exhibits similar characteristic features, as well as a similar potential of zero total charge than those expected for a preferential (100) surface. As compared to polycrystalline Pt, the occurrence of Pt (100) surface sites leads to an electrocatalytic activity enhancement by a factor of 4.8 and 2.6 (expressed as μA cmPt-2) for the oxidation of ammonia and formic acid, respectively.

  18. 2012 ELECTRODEPOSITION GORDON RESEARCH CONFERENCE AND GORDON RESEARCH SEMINAR, JULY 29 - AUGUST 3, 2012

    Energy Technology Data Exchange (ETDEWEB)

    Gewirth, Andrew

    2013-08-03

    The 2012 Gordon Conference on Electrodeposition: Electrochemical Materials Synthesis and Applications will present cutting-edge research on electrodeposition with emphasis on (i) advances in basic science, (ii) developments in next-generation technologies, and (iii) new and emerging areas. The Conference will feature a wide range of topics, from atomic scale processes, nucleation and growth, thin film deposition, and electrocrystallization, to applications of electrodeposition in devices including microelectronics, batteries, solar energy, and fuel cells.

  19. Electrodeposition of platinum and silver into chemically modified microporous silicon electrodes

    OpenAIRE

    Koda, Ryo; Fukami, Kazuhiro; Sakka, Tetsuo; Ogata, Yukio H.

    2012-01-01

    Electrodeposition of platinum and silver into hydrophobic and hydrophilic microporous silicon layers was investigated using chemically modified microporous silicon electrodes. Hydrophobic microporous silicon enhanced the electrodeposition of platinum in the porous layer. Meanwhile, hydrophilic one showed that platinum was hardly deposited within the porous layer, and a film of platinum on the top of the porous layer was observed. On the other hand, the electrodeposition of silver showed simil...

  20. Band diagrams and performance of CdTe solar cells with a Sb2Te3 back contact buffer layer

    OpenAIRE

    Songbai Hu; Zhe Zhu; Wei Li; Lianghuan Feng; Lili Wu; Jingquan Zhang; Jingjing Gao

    2011-01-01

    Sb2Te3 thin films were prepared by vacuum co-evaporation and the crystallinity of the films was greatly improved after annealing at 573 K in N2 ambient. Then they were deposited on the CdTe thick films. Band diagrams of the as-deposited and annealed CdTe/Sb2Te3 interfaces were constructed. Consequently, Sb2Te3 was used as a back contact layer for CdTe thin film solar cells and the cell performance was investigated. It was found that the Sb impurities accumulated in the CdTe grain boundaries d...