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1.
Surface sulfurization of Cu(In,Ga)Se2 (CIGS) thin films was carried out using two alternative techniques that do not utilize toxic H2S gas; a sequential evaporation of In2S3 after CIGS deposition and the annealing of CIGS thin films in sulfur vapor. A Cu(In,Ga) (S,Se)2 thin layer was grown on the surface of the CIGS thin film after sulfurization using In2S3, whereas this layer was not observed for CIGS thin films after sulfurization using sulfur vapor, although a trace quantity of S was confirmed by AES analysis. In spite of the difference in the surface modification techniques, the cell performance and process yield of the ZnO:Al/CdS/CIGS/Mo/glass thin-film solar cells were remarkably improved by using both surface sulfurization techniques. 相似文献
2.
Kazuya MaedaKunihiko Tanaka Yuki FukuiHisao Uchiki 《Solar Energy Materials & Solar Cells》2011,95(10):2855-2860
Cu2ZnSnS4 (CZTS) thin films prepared by a non-vacuum process based on the sulfurization of precursor coatings, consisting of a sol-gel solution of Cu, Zn, and Sn, under H2S+N2 atmosphere were investigated. The structure, microstructure, and electronic properties of the CZTS thin films as well as solar cell parameters were studied in dependence on the H2S concentration. The sulfurization process was carried out at 500 °C for 1 h in an H2S+N2 mixed-gas atmosphere with H2S concentrations of 3%, 5%, 10%, and 20%. As the H2S concentration decreased from 20% to 5%, the S content of the CZTS thin films decreased. However, when the H2S concentration was decreased below 3%, the S content of the films began to increase. A CZTS thin film prepared with an H2S concentration of 3% had grains in the order of 1 μm in size, which were larger than those of films prepared at other H2S concentrations. Furthermore, the most efficient solar cell, with a conversion efficiency of 2.23%, was obtained from a sample sulfurized at an H2S concentration of 3%. 相似文献
3.
Takayuki Watanabe Hidenobu Nakazawa Masahiro Matsui Hiroki Ohbo Tokio Nakada 《Solar Energy Materials & Solar Cells》1997,49(1-4)
The controlled incorporation of sodium into the absorber layer of CuInS2 solar cells improved cell performance remarkably. Without toxic KCN treatment, conversion efficiencies of over 6% were achieved by sulfurization of sodium-containing precursors. We also investigated the characteristics of the sodium-incorporated CuInS2 films by intentional addition and diffusion from a soda-lime glass. The ternary compound semiconductor of NaInS2 was found to form mainly on the surface of each of the CuInS2 films. 相似文献
4.
Prasad Manjusri Sirimanne Satoshi Shiozaki Noriyuki Sonoyama Tadayoshi Sakata 《Solar Energy Materials & Solar Cells》2000,62(3)
Microcrystals of In2S3 were formed on sintered In2O3 pellets by sulfurizing in H2S atmosphere. The flat band potential of compound In2S3|In2O3 electrodes was evaluated as −1.0 V vs Ag|AgCl in 1 M KOH, 1 M Na2S, 10−2 M S. Significantly enhanced photocurrent was observed on compound In2S3|In2O3 electrodes with a lower degree of sulfurization to that of compound In2S3|In2O3 electrodes with higher degree of sulfurization. Photocurrent generation of compound In2S3|In2O3 electrodes was explained from the viewpoint of semiconductor sensitization. 相似文献
5.
CuInS2 thin films were prepared by sulfurization of electrodeposited Cu–In precursors. Morphological improvement enabled us to fabricate the solar cells using electrodeposited Cu–In precursors. The photovoltaic property of a conversion efficiency of 1.3% was obtained. 相似文献
6.
C. Broussillou M. Andrieux M. Herbst-Ghysel M. Jeandin J.S. Jaime-Ferrer S. Bodnar E. Morin 《Solar Energy Materials & Solar Cells》2011
Cu–In electrodeposited layers were annealed using rapid thermal processing (RTP) in a reactive atmosphere containing sulfur vapors. The CuInS2 formation mechanism during sulfurization of electrodeposited precursors proceeds mainly through direct sulfurization of the metallic Cu–In alloy, forming spinel CuIn5S8 and chalcopyrite CuInS2 ternary phases. During the heating step, the Cu–In metallic alloy gets richer in copper as the temperature increases and transforms from CuIn2 to Cu11In9, then Cu16In9 and finally to Cu7In3. The use of rapidly cooled samples stopped after different durations of the process along with ex-situ XRD analysis enabled us to differentiate the Cu16In9 and Cu7In3 phases. Finally, the efficiency of the solar cells made with the two-step electrodeposition and RTP low-cost process reaches 11% (active area 0.421 cm2), which is close to the results obtained for cells made with PVD precursors. 相似文献
7.
A. Neisser I. Hengel R. Klenk Th. W. Matthes J. lvarez-García A. Prez-Rodríguez A. Romano-Rodríguez M. -Ch. Lux-Steiner 《Solar Energy Materials & Solar Cells》2001,67(1-4)
Thin film CuInS2:Ga solar cell absorber films were prepared by sequential evaporation of Cu–In–Ga precursors and sulfurization in sulfur vapor. The depth distribution of Ga was found to be highly inhomogeneous caused by CuGaS2 phase segregation at the back contact. Depending on overall Ga content and sulfurization temperature a quaternary CuGaxIn1−xS2 compound formed exhibiting a shift in absorber lattice constant and band gap. Micro Raman measurements showed that crystal quality was also affected by Ga. Open-circuit voltages well above 800 mV were achieved while sustaining high fill factors of 71%. 相似文献
8.
CuInS2 thin films were deposited by single source vacuum thermal evaporation method on substrates submitted to longitudinal thermal gradient. Some of these films were annealed in sulfur atmosphere and converted into CuInS2 homogenous layers. Both of the as-deposited and sulfurated films were characterized by X-ray diffraction, optical transmission and reflection measurements. The optical band gap of films after sulfurization was 1.50 eV which is near the optimum value for photovoltaic energy conversion. 相似文献
9.
A. Yamamoto M. Nakamura A. Seki E. L. Li A. Hashimoto S. Nakamura 《Solar Energy Materials & Solar Cells》2003,75(3-4):451-456
A simple spray method for the preparation of pyrite (FeS2) thin films has been studied using FeSO4 and (NH4)2Sx as precursors for Fe and S, respectively. Aqueous solutions of these precursors are sprayed alternately onto a substrate heated up to 120°C. Although Fe–S compounds including pyrite are formed on the substrate by the spraying, sulfurization of deposited films is needed to convert other phases such as FeS or marcasite into pyrite. A single-phase pyrite film is obtained after the sulfurization in a H2S atmosphere at around 500°C for 30 min. All pyrite films prepared show p-type conduction. They have a carrier concentration (p) in the range 1016–1020 cm−3 and a Hall mobility (μH) in the range 200–1 cm2/V s. The best electrical properties (p=7×1016 cm−3, μH=210 cm2/V s) for a pyrite film prepared here show the excellence of this method. The use of a lower concentration FeSO4 solution is found to enhance grain growth of pyrite crystals and also to improve electrical properties of pyrite films. 相似文献
10.
Preparation and properties of CuInS2 thin film prepared from electroplated precursor 总被引:1,自引:1,他引:1
Yoshio Onuma Kenji Takeuchi Sumihiro Ichikawa Yasunari Suzuki Ryo Fukasawa Daisuke Matono Kenji Nakamura Masao Nakazawa Koji Takei 《Solar Energy》2006,80(1):132-138
Thin CuInS2 films were prepared by sulfurization of Cu/In bi-layers. First, the precursor layer was electroplated onto the treated surface of Mo-coated glass. Observation of the cross-section prepared by focused ion beam (FIB) etching revealed that the void-free film was initially formed on the top surface of the precursor layer and continued to grow until the advancing front of the film reached the Mo layer. The nucleation of voids near the bottom of the CuInS2 film followed. To determine whether the condition of the Cu/In alloy influences the CuInS2 quality we investigated the Cu/In alloy state using FIB. We found that the annealed precursor of low Cu/In ratio (1.2) has several voids in the mid position in the layer compared with Cu-rich precursor (1.6). The cross-sectional view of the Cu-rich absorber layer is uniform compared with the low copper absorber layer. Thin film solar cells were fabricated using the CuInS2 film (Cu/In ratio: 1.2) as an optical absorber layer. It was found that the optimization of a sulfurization period is important in order to improve the cell efficiency. We have not yet obtained good results with high Cu-rich absorber because of a blister problem. This blister was found before sulfurization. So, we are going to solve this blister problem before sulfurization. 相似文献
11.
B. Asenjo A.M. Chaparro M.T. Gutierrez J. Herrero J. Klaer 《Solar Energy Materials & Solar Cells》2005,87(1-4):647
Solar cells of CuInS2/In2S3/ZnO type are studied as a function of the In2S3 buffer deposition conditions. In2S3 is deposited from an aqueous solution containing thioacetamide (TA), as sulfur precursor and In3+. In parallel, variable amounts of In2O3 are deposited that have an important influence on the buffer layer behavior. Starting from deposition conditions determined in a preliminary study, a set of parameters is chosen to be most determining for the buffer layer behavior, namely the solution temperature, the concentration of thioacetamide [TA], and the buffer thickness. The solar cell results are discussed in relation with these parameters. Higher efficiency is attained with buffer deposited at high temperature (70 °C) and [TA] (0.3 M). These conditions are characterized by short induction time, high deposition rate and low In2O3 content in the buffer. On the other hand, the film deposited at lower temperature has higher In2O3 content, and gives solar cell efficiency sharply decreasing with buffer thickness. This buffer type may attain higher conversion efficiencies if deposited on full covering very thin film. 相似文献
12.
Teny Theresa John Meril Mathew C. Sudha Kartha K.P. Vijayakumar T. Abe Y. Kashiwaba 《Solar Energy Materials & Solar Cells》2005,89(1):27-36
Copper indium sulfide (CuInS2)/In2S3 solar cells were fabricated using spray pyrolysis method and high short circuit current density and moderate open circuit voltage were obtained by adjusting the condition of deposition and thickness of both the layers. Consequently, a relatively high efficiency of 9.5% (active area) was obtained without any anti-reflection coating. The cell structure was ITO/CuInS2/In2S3/Ag. We avoided the usual cyanide etching and CdS buffer layer, both toxic, for the fabrication of the cell. 相似文献
13.
Angel Susan Cherian K.B. Jinesh Y. Kashiwaba T. Abe A.K. Balamurugan Sitaram Dash A.K. Tyagi C. Sudha Kartha K.P. Vijayakumar 《Solar Energy》2012,86(6):1872-1879
In the fabrication of CuInS2/In2S3 solar cell using chemical spray pyrolysis (CSP) deposition technique, one of the major problems is the diffusion of Cu towards the In2S3 layer affecting stability and repeatability of the CuInS2/In2S3 cells. In order to ensure a Cu-free In2S3 layer, a ‘double layer structure’ of CuInS2 film, having a Cu-rich first layer and In-rich second layer was deposited using manual CSP technique. In this paper, we present the difference in material properties of single and double layered CuInS2 films and the results of characterisation of the junctions prepared using such films with β-In2S3 films. Better crystallinity as well as larger and densely packed grains were observed for the CuInS2 films having ‘double layer structure’. Such samples also possessed two band gaps, which was not due to the presence of different phases, but due to the Cu-rich and Cu-poor layers. In addition, their low resistivity makes the double layered CuInS2 film more beneficial for photovoltaic applications. 相似文献
14.
Tokio Nakada Hiroki Ohbo Takayuki Watanabe Hidenobu Nakazawa Masahiro Matsui Akio Kunioka 《Solar Energy Materials & Solar Cells》1997,49(1-4)
Surface sulfurization was developed as a technique for fabricating efficient ZnO : Al/CdS/graded Cu(In,Ga)(S,Se)2/ Mo/glass solar cells. Prior to the sulfurization, single-graded Cu(In,Ga)Se2 (CIGS) films were deposited by a multi-stage process. The sulfurization of CIGS films was carried out using a H2S---Ar mixture at elevated temperatures. The crystallographic and compositional properties of the absorber layers were investigated by XRD, SEM and AES analyses. After sulfurization, sulfur atoms were substituted for selenium atoms at the surface layer of CIGS films to form a Cu(In,Ga)(S,Se)2 absorber layer. The diffusion of sulfur depends strongly on the grain structure of CIGS film. The cell efficiency of the 8–11% range before sulfurization was improved dramatically to 14.3% with Voc = 528 mV, Jsc = 39.9 mA/cm2 and FF = 0.68 after the sulfurization process. 相似文献
15.
I. Riedel J. RiedigerJ. Ohland J. KellerM. Knipper J. ParisiR. Mainz S. Merdes 《Solar Energy Materials & Solar Cells》2011,95(1):270-273
CuInS2-based solar cells have a strong potential of achieving high efficiencies due to their ideal band gap of 1.5 eV. A further increase in the efficiency is expected from doping the absorber film with gallium due to enlargement of the band gap (Eg) and correspondingly the open-circuit voltage (VOC). We investigated Cu(In,Ga)S2 solar cells obtained from stacked metal layers sputtered from In and (Cu,Ga) targets followed by rapid thermal processing (RTP) in sulfur vapor. Depending on the actual RTP temperature profile, the films might exhibit CuInS2/CuGaS2 (top/bottom) segregation, which is rather detrimental for a large VOC. We found that only precursors sulfurized at sufficiently high temperatures exhibit the desired interdiffusion of the segregated CuInS2/CuGaS2 layers resulting in an increased VOC. Moreover, temperature dependent current-voltage profiling (suns-VOC-analysis) yielded strong indications for improved current collection and reduced losses for devices with proper interdiffusion of the CuInS2/CuGaS2 layers. A more fundamental question is related to the variation and formation of defect states in differently processed absorber films. The studied samples were thus further investigated by means of admittance spectroscopy, which allowed us to confirm the presence of three individual defect states in both absorber configurations. Two defects exhibit activation energies, which remain unchanged upon varying the RTP temperature whereas a third state exhibits significantly increased activation energy in devices showing interdiffusion of CuInS2/CuGaS2 layers. According to the characteristic shift of the conduction band edge upon Ga-doping we conclude that the latter defect level corresponds with the minority carriers in the p-type absorbers. 相似文献
16.
β-In2S3 films were grown on glass as well as on quartz substrates by rapid heating of metallic indium films in H2S atmosphere. The effect of sulfurization temperature and time on the growth, structural, electrical and photoelectrical properties of β-In2S3 films has been investigated. Highly oriented single-phase β-In2S3 films were grown by the sulfurization technique. The morphology and composition of films have been characterized. The optical band gap of β-In2S3 is found to vary from 1.9 to 2.5 eV when the sulfurization temperature is varied from 300 to 600 °C or by increasing the sulfurization time. The electrical properties of the thin films have also been studied; they have n-type electrical conductivity. The photoelectrical properties of the β-In2S3 films are also found to depend on the sulfurizing temperature. A high photoresponse is obtained for films prepared at a sulfurizing temperature of 600 °C. β-In2S3 can be used as an alternative to toxic CdS as a window layer in photovoltaic technology. 相似文献
17.
Rohana Garuthara Ruwan Wijesundara Withana Siripala 《Solar Energy Materials & Solar Cells》2003,79(3):331-338
Potentiostatic electrodeposition and sulfurization techniques were used to prepare polycrystalline CuInS2 thin films. X-ray diffraction and photoresponse measurements in a photoelectrochemical cell (PEC) revealed that photoactive polycrystalline CuInS2 films can be deposited on Ti substrate. Photoluminescence (PL) spectroscopy was used to investigate the prepared thin films and optically characterize them. PL spectra revealed the defect structure of the samples with an acceptor energy level at 109 meV above the valance band and a donor energy level at 71 meV below the conduction band. The CuInS2 thin films prepared in this investigation are observed to be In-rich material with n-type electrical conductivity. 相似文献
18.
X.H. Xu F. Wang J.J. Liu K.C. ParkM. Fujishige 《Solar Energy Materials & Solar Cells》2011,95(2):791-796
Copper indium disulfide (CuInS2) thin films have been successfully prepared on Ni substrates using a novel one-step potentiostatic electrodeposition combined with a potassium hydrogen phthalate (C8H5KO4) complexing agent, accompanied by annealing at 350 °C. Electrodeposition in the solution of Cu and In salts and sodium thiosulfate (Na2S2O3) containing an adequate concentration of C8H5KO4 (e.g., [C8H5KO4]=23 mM) provides thin films comprised of a CuInS2 single phase as the bulk composition, without forming CuxS secondary phases. In addition to the effect on bulk-phase compositions, the adjustment of [C8H5KO4] causes variation in morphology and atomic composition of the film surface. The surface states of the films change from the Cu-rich rough surface at low [C8H5KO4] (15 mM) to the In-rich smooth surface at high [C8H5KO4] (23 mM). The higher [C8H5KO4] induces the grains constructing the film to interconnect and form a densely packed CuInS2 film without voids and pinholes. The single-phase and void-free CuInS2 film shows a band gap of 1.54 eV, satisfying the requirement of the absorber layers in solar cells. The electrical properties tests denote its n-type conductivity with a resistivity of 9.6×10−5 Ω cm, a carrier concentration of 2.9×1021 cm−3 and a carrier mobility of 22.2 cm2 V−1 s−1. 相似文献
19.
R.B.V. ChalapathyGwang Sun Jung Byung Tae Ahn 《Solar Energy Materials & Solar Cells》2011,95(12):3216-3221
Cu2ZnSnS4 (CZTS) absorbers were grown by sulfurization of Cu/ZnSn/Cu precursors in sulfur atmosphere. The reaction mechanism of CZTS formation from the precursor was analyzed using XRD and Raman spectroscopy. The films with a single phase CZTS were formed at 560 and 580 °C by sulfurization for 30 min. The film grown at 560 °C showed bi-layer morphology with grooved large grains on the top and dense small grains near the bottom of the film. On the other hand, the film grown at 580 °C showed large grains with grooves that are extended from surface top to bottom of the film. The solar cell fabricated with the CZTS film grown at 560 °C showed the best conversion efficiency of 4.59% for 0.44 cm2 with Voc=0.545 V, Jsc=15.44 mA/cm2, and FF=54.6. We found that further improvement of the microstructure of CZTS films can increase the efficiency of CZTS solar cells. 相似文献
20.
Christian-Herbert Fischer Nicholas A. Allsop Sophie E. GledhillTristan Köhler Martin KrügerRodrigo Sáez-Araoz Yanpeng FuRobert Schwieger Johannes RichterPeter Wohlfart Peter BartschNils Lichtenberg Martha C. Lux-Steiner 《Solar Energy Materials & Solar Cells》2011,95(6):1518-1526
The spray Ion Layer Gas Reaction (ILGAR) process starts with ultrasonic nebulisation of the precursor solution, e.g. InCl3/ethanol for our successful buffer material In2S3. In an aerosol assisted chemical vapour deposition (AACVD) type reaction an In(O,OH,Cl) film is deposited on a heated substrate and is subsequently converted to In2S3 by H2S gas. The cycle of these steps is repeated until the required layer thickness is obtained. The robust and reproducible process allows a wide control of composition and morphology.Results of this “spray-ILGAR” method with respect to process, material properties and its application depositing the buffer layer in chalcopyrite solar cells are reviewed. New aspects such as the investigation of the complex chemical mechanism by mass spectrometry, the process acceleration by the addition of H2S gas to the aerosol, the controlled deposition of ZnS nano-dot films and finally the latest achievements in process up-scaling are also included.Solar cells based on industrial Cu(In,Ga)(S,Se)2 absorbers (Avancis GmbH) with a Spray-ILGAR In2S3 buffer reached 14.7% efficiency (certified) and 15.3% with a ZnS/In2S3 bi-layer buffer comparable to reference cells using standard CdS buffer layers deposited by chemical bath deposition (CBD).The quasi-dry, vacuum-free ILGAR method for In2S3 buffer layers is well suited for industrial in-line production and is capable of not only replacing the standard buffer material (the toxic CdS) but also the often slow CBD process. A tape coater for 10 cm wide steel tape was constructed. It was shown that In2S3 layers could be produced with an indium yield better than 30% and a linear production speed of 1m/min. A roll-to-roll pilot production line for electrochemically deposited Cu(In,Ga)Se2 with ILGAR buffer is running in industry (CIS-Solartechnik, Hamburg). A 30x30 cm2 prototype of an ILGAR in-line coater developed by Singulus and Helmholtz Zentrum Berlin is currently being optimised. First 30×30 cm2 encapsulated modules achieved efficiencies up to 13.0% (CdS buffered reference 13.3%). 相似文献