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1.
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
2.
D.Y. Lyu T.Y. Lin J.H. Lin S.C. Tseng J.S. Hwang H.P. Chiang C.C. Chiang S.M. Lan 《Solar Energy Materials & Solar Cells》2007,91(10):888-891
A set of In2Se3 films was grown on (1 1 1) Si substrate with AlN buffer by metalorganic chemical vapor deposition (MOCVD) using H2Se as the metalogramic precursors for Se. The In2Se3 films on (1 1 1) Si substrate were pinhole-free with homogeneous and lamellar structures. It was found that by properly controlling the substrate temperatures, single-phase γ-In2Se3 films with fairly good optical properties can be well fabricated. Photoluminescence spectra of single-phase γ-In2Se3 show exciton emissions at 2.140 eV at 10 K. The band gap of single-phase γ-In2Se3 at room temperature is estimated at 1.943 eV. 相似文献
3.
R. Sreekumar R. Jayakrishnan C. Sudha Kartha K.P. Vijayakumar Y. Kashibawa T. Abe 《Solar Energy Materials & Solar Cells》2006,90(17):2908-2917
Thin films of indium selenide were prepared by annealing Indium/Selenium stack layers at different temperatures ranging from 100 to 400 °C. Structural and optical characterizations were done using X-ray diffraction and optical absorption studies, respectively. Compositional analysis was done by employing Rutherford backscattering spectroscopy and X-ray photoelectron spectroscopy confirmed the compound formation. Photosensitivity and sheet resistance of these samples were also determined at room temperature. It was found that multi-phased films were formed at lower annealing temperatures and single phase films at higher annealing temperatures. A structural re-orientation as well as a phase transformation from β-In2Se3 to γ-In2Se3 was observed on annealing at 400 °C. 相似文献
4.
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
5.
CuInSe2 thin films were prepared using sequential vacuum evaporation of In, Se and Cu at moderately low substrate temperatures, avoiding any treatment using toxic H2Se gas. The samples were annealed at 400 °C at a pressure of 10−5 mbar to form CuInSe2. Structural, optical, electrical, compositional and morphological characterizations were carried out on these films. We could obtain highly stoichiometric film, using this simple method, without opting for co-evaporation or high substrate temperature for deposition. 相似文献
6.
Prasad Manjusri Sirimanne Kazunori Takahashi Noriyuki Sonoyama Tadayoshi Sakata 《Solar Energy Materials & Solar Cells》2002,73(2)
Sintered Bi2O3 pellets exhibited insulating properties at room temperature. Partial reduction of sintered Bi2O3 pellets increased the conductivity. Reduced Bi2O3 pellets exhibited n-type semiconductor properties. Microcrystals of Bi2S3 were formed on sintered Bi2O3 pellets by sulfurizing them in H2S atmosphere. The direct band-gap and indirect band-gap of Bi2S3 were evaluated as 1.2 and 0.4 eV, respectively. A high incident photon to current conversion efficiency in the near IR region was observed on Bi2S3|Bi2O3 electrodes. Photocurrent generation of Bi2S3|Bi2O3 electrodes was explained from the viewpoint of semiconductor sensitization. The flat band potential of Bi2S3 was evaluated as −1.1 V vs. Ag|AgCl in aqueous polysulfide redox electrolyte (1 M OH−, 1 M S2−, 10−2 M S). 相似文献
7.
Single phase CuGaS2 thin film with a highest diffraction peak of (1 1 2) at a diffraction angle (2θ) of 28.8° was made at a substrate temperature of 70°C, an annealing temperature of 350°C and an annealing time of 60 min. Second highest (2 0 4) peak was shown at diffraction angle of (2θ) 49.1°. Lattice constant of a and c of that CuGaS2 thin film was 5.37 and 10.54 Å, respectively. The greatest grain size of the thin film was about 1 μm. The (1 1 2) peak of single phase of CuGaS2 thin film at an annealing temperature of 350°C with excess S supply appeared at a little higher about 10% than that of no excess S supply. The resistivity, mobility and hole density at room temperature of p-type CuGaS2 thin film was 1.4 Ω cm, 15 cm2/V s and 2.9×1017 cm−3, respectively. It was known that carrier concentration had considerable effect than mobility on a variety of resistivity of the fabricated CuGaS2 thin film, and the polycrystalline CuGaS2 thin films were made at these conditions were all p-type. 相似文献
8.
β-Ga2O3 is a transparent oxide and intrinsically an insulator. Doping allows the variation of the conductivity for both p- and n-type over a wide range. There are a number of potential applications in optoelectronics such as insulating or conductive window material, or as a substrate. Consequently, the influence of doping on the electrical and optical properties is an issue of crucial importance for pushing this material forward to applications. We report on the successful growth of undoped, Ge- and Ti-doped β-Ga2O3 single crystals by the floating zone technique. Both electrical and optical properties were characterized. 相似文献
9.
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
10.
Transparent conducting fluorine doped indium oxide (In2O3:F) thin films have been deposited on Corning 7059 glass substrates by the spray pyrolysis technique. The structural, electrical, and optical properties of these films were investigated as a function of substrate temperature. The X-ray diffraction pattern of the films deposited at lower substrate temperature (Ts=300 °C) showed no peaks of In2O3:F. In the useful range for deposition (i.e. 425–600 °C), the orientation of the films was predominantly [400]. For the 4500 Å thick In2O3:F deposited with an F content of 10-wt%, the minimum sheet resistance was 120 Ω and average transmission in the visible wavelength rang (400–700 nm) was 88%. 相似文献
11.
The n-CdZn(S1−xSex) and p-CuIn(S1−xSex)2 thin films have been grown by the solution growth technique (SGT) on glass substrates. Also the heterojunction (p–n) based on n-CdZn (S1−xSex)2 and p-CuIn (S1−xSex)2 thin films fabricated by same technique. The n-CdZn(S1−xSex)2 thin film has been used as a window material which reduced the lattice mismatch problem at the junction with CuIn (S1−xSex)2 thin film as an absorber layer for stable solar cell preparation. Elemental analysis of the n-CdZn (S1−xSex)2 and p-CuIn(S1−xSex)2 thin films was confirmed by energy-dispersive analysis of X-ray (EDAX). The structural and optical properties were changed with respect to composition ‘x’ values. The best results of these parameters were obtained at x=0.5 composition. The uniform morphology of each film as well as the continuous smooth thickness deposition onto the glass substrates was confirmed by SEM study. The optical band gaps were determined from transmittance spectra in the range of 350–1000 nm. These values are 1.22 and 2.39 eV for CuIn(S0.5Se0.5)2 and CdZn(S0.5Se0.5)2 thin films, respectively. J–V characteristic was measured for the n-CdZn(S1−xSex)2/p-CuIn(S1−xSex)2 heterojunction thin films under light illumination. The device parameters Voc=474.4 mV, Jsc=13.21 mA/cm2, FF=47.8% and η=3.5% under an illumination of 85 mW/cm2 on a cell active area of 1 cm2 have been calculated for solar cell fabrication. The J–V characteristic of the device under dark condition was also studied and the ideality factor was calculated which is equal to 1.9 for n-CdZn(S0.5Se0.5)2/p-CuIn(S0.5Se0.5)2 heterojunction thin films. 相似文献
12.
S.P. Yadav P.S. Shinde K.Y. Rajpure C.H. Bhosale 《Solar Energy Materials & Solar Cells》2008,92(4):453-456
Zinc indium selenide (ZnIn2Se4) thin films have been prepared by spraying a mixture of an equimolar aqueous solution of zinc sulphate (ZnSO4), indium trichloride (InCl3), and selenourea (CH4N2Se), onto preheated fluorine-doped tin oxide (FTO)-coated glass substrates at optimized conditions of substrate temperature and a solution concentration. The photoelectrochemical (PEC) cell configuration of n-ZnIn2Se4/1 M (NaOH+Na2S+S)/C has been used for studying the current voltage (I–V), spectral response, and capacitance voltage (C–V) characteristics of the films. The PEC study shows that the ZnIn2Se4 thin films exhibited n-type conductivity. The junction quality factor in dark (nd) and light (nl), series and shunt resistance (Rs and Rsh), fill factor (FF) and efficiency (η) for the cell have been estimated. The measured (FF) and η of the cell are, respectively, found to be 0.435% and 1.47%. 相似文献
13.
A hybrid model for estimating global solar radiation 总被引:3,自引:0,他引:3
In view of the site-dependence of Ångström correlation, this study developed a hybrid model to estimate global radiation H. Unlike Ångström correlation H=(α+βS/S0)H0, this model suggested that H=(a+b S/S0)Hb+(c+d S/S0)Hd, Hb and Hd are effective beam radiation and effective diffuse radiation, which imply latitude, elevation and seasonal effect on radiation. Hb and Hd are calculated by an arithmetic model derived from spectral model. The hybrid model was designed for estimating monthly mean daily global radiation with hourly-recorded bright sunshine time, and its applicability was verified at observatories in Japan. 相似文献
14.
Tomoaki Terasako Seiki Inoue Tetsuya Kariya Sho Shirakata 《Solar Energy Materials & Solar Cells》2007,91(12):1152-1159
Structural, optical and electrical properties of polycrystalline Cu–In–Se films, such as CuInSe2 and ordered vacancy compounds (OVC), prepared by three-stage process of sequential chemical spray pyrolysis (CSP) of In–Se (first stage), Cu–Se (second stage) and In–Se (third stage) solutions have been studied in terms of substrate temperature at the second stage (TS2). The films grown at TS2420 °C exhibited larger grains in comparison with the Cu–In–Se films grown by the usual CSP method. Optical gap energy was approximately 1.06 eV for 360 °CTS2420 °C, but increased dramatically from 1.06 to 1.35 eV when the TS2 rose from 420 to 500 °C. Conductivity type was p-type for TS2<420 °C, but n-type for TS2>420 °C. 相似文献
15.
S. Jost F. Hergert R. Hock J. Schulze A. Kirbs T. Voß M. Purwins M. Schmid 《Solar Energy Materials & Solar Cells》2007,91(7):636-644
In this article, we present results of a detailed real-time X-ray diffraction (XRD) study on the formation of CuInSe2 from electroplated precursors. The solid-state reactions observed during the selenisation of three different types of precursors are presented. The first type of precursors (I) consists of the nanocrystalline phases Cu2−xSe and InSe at room temperature, which react to CuInSe2 starting at 470 K. The second type of precursor (II) shows an inhibited CuInSe2 formation out of the initial phases Cu2−xSe and γ-In2Se3 starting at 400 K. The third precursor type (III) shows completely different selenisation behaviour. Starting from the intermetallic compound Cu11In9 and amorphous selenium, the formation of the binary selenides In4Se3 and CuSe is observed after the melting point of selenium at 494 K. After selenium transfer reactions, the compound semiconductor CuInSe2 is formed out of Cu2−xSe and InSe. This type (III) reaction path is well known for the selenisation of SEL precursors (stacked elemental layers of sputtered copper and indium and thermally evaporated selenium). 相似文献
16.
The properties of CuFeO2 have been studied according to the catalytic hydrogen production upon visible light. CuFeO2 with a low band gap Eg, a good chemical stability and a suitable flat band potential appears as a suitable candidate. The potential of photoelectrons allows favorably a thermodynamically H2-evolution from alkaline thiosulfate S2O32− solution. There is a major difference between pure and loaded oxide with some metal catalysts. Our best results have been obtained with unloaded CuFeO2 at 50 °C and pH 13.60. Thiosulfate S2O32− ions can be oxidized to sulfite SO32− and subsequently to sulfate SO42− and the electronic exchange occurs via mediation of surface states. The quite high H2-formation at the beginning shows a tendency towards saturation, it competes with SO32− produced by parallel oxidation of S2O32−. 相似文献
17.
La1−xSrxMnO3 (LSMO) compounds (0.175x0.30) were prepared by conventional solid-state reaction method. Temperature dependence of the total hemispherical emittance (εH) of the compounds from 173 to 373 K was measured on a calorimetric emissometer (CE) which was constructed based on the steady-state calorimetric method. The compounds show thermochromic properties and εH's have low value at low temperature and have high value at high temperature, because the compounds are dominated by metallic phase and insulator phase, respectively. We use the phase separation model to interpret the temperature dependence of εH. 相似文献
18.
Z. Aissa T. Ben Nasrallah M. Amlouk J.C. Bernde S. Belgacem 《Solar Energy Materials & Solar Cells》2006,90(7-8):1136-1146
AgInS2 thin films have been prepared on glass substrates by the spray pyrolysis process using an aqueous solution which contains silver acetate (AgCH3CO2), thiourea (SC(NH2)2) and indium chloride (InCl3) as precursors. The depositions were carried out in the range of the substrate temperature from 260 to 420 °C. The value of the concentration ratio in the spray solution of indium and silver elements x=[Ag+]/[In3+] was varied from 1 to 1.5 with [In3+]=10−2 M and [S2−]/[In3+] was taken constant, equal to 4. The structural study shows that AgInS2 thin film, prepared at 420 °C using optimal concentration ratio x=1.3 crystallizes in the chalcopyrite phase with a strong (1 1 2) X-ray diffraction line. Moreover, microprobe analysis (EPMA) shows that a nearly stoichiometric composition is obtained for these experimental conditions. Indeed, the atomic percentage of elements were. 24.5, 25.0, 49.5 for Ag, In and S, respectively. On the other hand from transmission and reflectance spectra, the obtained band gap energy is 1.83 eV for such film. 相似文献
19.
The fabrication process for a-Si:H solar cells with p–i–n structure contains a problem of damage to the SnO2 substrate particularly at higher process temperatures. We have reported that the suppression of darkening and wide optical gap (Eopt) are obtained by using SiH2Cl2 instead of SiH4 as a source gas (Mater. Res. Soc. Symp. Proc. 609 (2000), in press). In this paper, p-type a-Si:H:(Cl) was investigated. Comparable Eopt and dark conductivity (σdark) to those of conventional a-SiC:H were obtained. Solar cells using this a-Si:H:(Cl) show higher current density (Jsc) and higher collection efficiency in all wavelength regions as compared to a p-layer not using chlorine processes. The newly developed p-layer has been applied to solar cells with p–i–n structure fabricated at higher substrate temperatures (Ts). Although the a-Si:H material deposited at higher substrate temperatures has been reported as being more stable against light soaking (21st IEEE PVSC Proceeding, Florida, USA, 1990, p. 1656), the high temperature processing is difficult to apply to the a-Si:H p–i–n structure because of the significant darkening of SnO2 at higher Ts. With an a-Si:H:(Cl) buffer layer, a-Si:H solar cells can be fabricated at higher Ts (300°C) with reasonable cell performance. The best stabilized efficiency was 7.5% obtained at a Ts of 250°C. 相似文献
20.
Efficiencies of CuIn1−xGaxSe2−ySy (CIGSS) modules are comparable to those of lower end crystalline-Si modules. CIGSS layers are prepared by reactive co-evaporation, selenization/sulfurization of metallic or compound precursors, reactive co-sputtering and non-vacuum techniques. CuIn1−xGaxS2 (CIGS2) layers are prepared by sulfurization of Cu-rich metallic precursors and etching of excess Cu2−xS. Usually heterojunction partner CdS and transparent-conducting bilayer ZnO/ZnO:Al layers are deposited by chemical bath deposition (CBD) or RF magnetron sputtering. CIGSS solar cell efficiencies have been improved by optimizing Cu, Ga and S proportions and providing a minute amount of Na. This paper reviews preparation and efficiency improvement techniques for CIGSS solar cells. 相似文献