Preparation and analysis of CdS-Cu2S solar cells

Preliminary studies of CdS-Cu₂S solar cells prepared by the wet process were carried out. As the quality of the CdS layers has a marked influence on the performance of the final solar cell, our first concern was a study of the reproducibility of these layers. This was achieved through the characterization of AuCdS Schottky diodes. Some physical and chemical properties of the CdS layers were also investigated. The first results obtained on these cells are encouraging but more works needs to be done.     

Solar photocatalysis: oxidation of aniline on CdS

The photooxidation of aniline to azobenzene in ethanol on CdS with natural sunlight and UV irradiation (365 nm) was studied as a function of [aniline], catalyst loading, airflow rate, solvent composition, etc. The metal sulfide shows sustainable catalytic activity. The product formation is larger with illumination at 254 nm than at 365 nm. Electron donors like triphenylphosphine, diphenylamine and hydroquinone favor the photocatalysis. Singlet oxygen quencher, azide ion does not inhibit the oxidation. The photocatalysis occurs in protic and aprotic solvents. The mechanism of photocatalyzed oxidation is discussed and the product formation examined using a kinetic equation.     

Energy analysis of CdS:Cu2S sputtered solar cells

Energy analysis can play a useful role in the research and development planning of energy technologies. By using it we can identify those technologies which will give good paybacks on the energy invested in their construction and whose costs are relatively insensitive to energy price rises. Such technologies have the potential to become economically viable as general sources of energy. They are distinguished from the technologies which give only poor energy paybacks on the energy invested in construction. The costs of these technologies will rise in step with energy price rises and they probably do not have the potential to be economically viable general sources of energy. It is well known that sliced silicon solar cells fall in the latter category. The studies reported here show, however, that sputtered thin film CdS:Cu₂S cells should give good energy paybacks.It is likely that the systematic application of energy analysis to solar cell fabrication techniques will reveal those which should give good energy paybacks and hence have the potential to become economically viable general sources of energy. It would be rational to concentrate scarce research and development funds on these technologies.     

Technology of All Electroplated CdS:CuxS Solar Cells

Electrolytic deposition of CdS and Cu_xS for realizing solar cells holds considerable low cost potential. An electrodeposition technique from non-aqueous electrolytes is described and effect of important deposition variables on electrical and structural properties of films is discussed. Heterojunctions in frontwall configuration have been fabricated and the effect of Cu_xS bath composition on photovoltaic performance is evaluated. Voc = .412 V and Isc = 5.95 mA/sq cm have been achieved.     

Insights into the mechanisms of H2S adsorption and dissociation on CdS surfaces by DFT-D3 calculations

The adsorption and dissociation of H₂S on CdS surfaces is investigated using dispersion-corrected density functional theory (DFT-D3) to provide quantum-level insights into their (photo)catalytic performance for H₂S splitting. Calculations of structural parameters, electronic properties and energies of intermediates adsorption on perfect CdS surfaces indicate that the (110) facet is the most stable surface, while the most active surface (100) is quickly covered by sulfur formed during the reaction, unfavorable for catalyst stability and reuse. Calculations of CdS (110) surfaces with an S vacancy demonstrate that the vacancy serves as an electron donor center and atomic S1 capture center, favoring the adsorption of dissociative species, and significantly reducing the energy barriers and reaction energies for the hydrogen evolution process, hence increasing the CdS surface catalytic performance. These theoretical results complement and reinforce available experimental studies, guiding the rational design of efficient photocatalysts for hydrogen production from H₂S splitting.     

Sulfur vacancy and CdS phase transition synergistically boosting one-dimensional CdS/Cu2S/SiO2 hollow tube for photocatalytic hydrogen evolution

Constructing an efficient photoelectron transfer route to improve carrier separation efficiency is crucial for photocatalytic hydrogen evolution. In this work, CdS/Cu₂S/SiO₂ heterostructure with one-dimensional hollow tube morphology was designed by the solvothermal method using CuO/SiO₂ hollow tube as carrier. The hexagonal phase CdS and sulfur vacancies were adjusted simultaneously by the reduction strategy of NaBH₄ aqueous solution. CdS/CuS/SiO₂ with cubic phase CdS was synthesized in the absence of NaBH₄ aqueous solution. CdS/Cu₂S/SiO₂ was characterized by SEM, TEM, XRD, XPS, SPV and so on. The results showed that hexagonal CdS and sulfur vacancies benefited the separation of photo-generated carriers. As a consequence, the CdS/Cu₂S/SiO₂-10 composite exhibited a high photocatalytic hydrogen production rate (1196.98 μmol/g/h), and its performance almost 7.18 times than that of CdS/CuS/SiO₂. Moreover, CdS/Cu₂S/SiO₂-10 showed an excellent cyclic stability. This was attributed to the strong electron interaction of CdS/Cu₂S/SiO₂ heterostructure and the sulfur vacancy acted as an electron trap, enhancing the separation of photo-induced electrons and holes.     

CdS/CuCo2S4 dots-on-rods boosting charge separation and hydrogen evolution

Herein, we report a new class of CdS/CuCo₂S₄ dots-on-rods nanostructures that exhibit efficient visible-light-induced H₂ evolution from water. The material CuCo₂S₄ nanodots over CdS nanorods are fabricated through controlled loading in a facile hydrothermal process and formed a heterojunction, maximizing the energy conversion, that shows advanced performance in photochemical H₂ evolution (rate: 33.32 mmol g^?1h^?1 and AQY: 13.2% at λ = 420 ± 15 nm) from water. The experimental and theoretical results on physical and chemical properties revealed that the photocatalytic system is positively correlated with the H₂ production rate and suggest that CuCo₂S₄ nanodots in CdS nanorods plays a critical role in relative efficiency of the H₂ generation. The surprisingly high activity was attributed to enhanced charge carriers’ separation and transfer efficiency, confirmed by the kinetic measurements (TAS) and further reinforced from the Kelvin probe force microscopy (KPFM) analysis and theoretical understanding.     

光热对薄膜CdS／Cu2S太阳电池物理参数的影响

研究了光、热和湿气对ＣｄＳ／Ｃｕ２Ｓ电池效率及电池成结、结电容、二极管特性和光谱响应特性的影响。结果表明，对未成结电池光加速成结作用，对成结电池光引起电池性能下降，这种衰降是不可逆过程。     

Photocatalytic decomposition of H2S to produce H2 over CdS nanoparticles formed in HY-zeolite pore

The H₂ production rate from H₂S photocatalytic decomposition under visible light irradiation (λ > 400 nm) over CdS nanoparticules formed in HY-zeolite pore (named CdS/HY) was much higher compared to the commercial bulk CdS. The CdS/HY photocatalyst was characterized by UV–Vis, XRD, FT-IR, N₂ adsorption, SEM and HRTEM. The blue shift from bulk which confirmed CdS nanoparticles located in the pore of HY-Zeolite (named HY). Photocatalytic activity and surface area were enhanced by such structures.     

喷涂法制备混合阳离子钙钛矿太阳电池

采用热基底喷涂法分别制备了FA_0.85MA_0.15PbI₃和(FAPbI₃)_0.85(MAPbBr₃)_0.15两种混合阳离子钙钛矿薄膜,对两种薄膜进行了扫描电镜（SEM）、X-射线衍射（XRD）、紫外-可见光吸收光谱（UV-Vis）测试表征。结果表明,该方法制备的混合阳离子钙钛矿薄膜平整致密,FA_0.85MA_0.15PbI₃结晶性更好,并且吸收带边和吸收强度更大。将两种薄膜组装成平板太阳能电池,对电池的光电性能和稳定性进行了分析。结果表明,FA_0.85MA_0.15PbI₃ PSCs光电转换效率为13.21%,(FAPbI₃)_0.85(MAPbBr₃)_0.15 PSCs光电转换效率为12.08%,并且(FAPbI₃)_0.85(MAPbBr₃)_0.15 PSCs在放置80 d后,性能基本无变化,表明喷涂法制备(FAPbI₃)_0.85(MAPbBr₃)_0.15 PSCs具有较好的稳定性。     

Prickly Ni3S2 nanowires modified CdS nanoparticles for highly enhanced visible-light photocatalytic H2 production

The photocatalytic water splitting strategy is one of the most promising ways to achieve clean and renewable solar-to-hydrogen energy conversion. In this study, a highly enhanced photocatalytic H₂ production system has been achieved, using CdS nanoparticles (NPs) decorated on prickly Ni₃S₂ nanowires (NWs) as the light-driven photocatalyst. The photocatalyst was prepared by a co-precipitated method in which spiky Ni NWs were employed as starting material for prickly Ni₃S₂ NWs. Characterization analysis (XRD, TEM, XPS, etc.) show the high purity of Ni₃S₂/CdS hybrid structures and the well deposition of CdS NPs on prickly Ni₃S₂ NWs. Besides, the as synthesized Ni₃S₂/CdS photocatalyst exhibit reduced photoluminescence peak intensity, which means the Ni₃S₂ NWs functions as electron collector and transporter to quench the photoluminescence of CdS. This prickly Ni₃S₂/CdS nanocomposite demonstrates a 70 times higher H₂ production rate than that of pure CdS and a quantum efficiency of 12.3% at the wavelength of 400 nm in the absence of noble metals. This enhanced H₂ production activity is better than the one of CdS loaded with 0.5 wt% Pt. Our findings highlight the potential application of Ni₃S₂/CdS hybrid structures for visible light photocatalytic hydrogen yielding in the energy conversion field.     

Spectral response of CdS/CdTe solar cells obtained with different S/Cd ratios for the CdS chemical bath

In this work, the influence of the variation of chemical bath thiourea concentration in the solution for depositing CdS layers upon the spectral response of chemical bath deposition (CBD)-CdS/CdTe solar cells is studied. Although changes in the short and long wavelength range for the spectral response of the cells were observed in dependence of the thiourea concentration, no significant changes were observed in the diffusion length of minority carriers in the CdTe layer, as determined from the constant photocurrent method, when the thiourea concentration is increased in the CdS deposition solution.     

The ZnIn2S4/CdS hollow core-shell nanoheterostructure towards enhanced visible light photocatalytic H2 evolution via bimetallic synergism

The ZnIn₂S₄/CdS hollow core-shell nanoheterostructure with bimetallic synergism is synthesized via a hybrid chemical method. As revealed, the ZnIn₂S₄/CdS hollow core-shell nanoheterostructure (ZnIn₂S₄/CdS-3) exhibits remarkable visible light photocatalytic hydrogen evolution (～5209.43 μmol·g^?1·h^?1, AQE of ～20.26%) than that of single CdS (～40 folds) and single ZnIn₂S₄ (～12 folds), and achieves decent photocatalytic stability (average HER performance of ～5056.80 μmol·g^?1·h^?1), which is mainly ascribed to that, the formed ZnIn₂S₄/CdS heterostructure with appropriate potential gradient and Zn/In bimetallic synergism can improve carrier transportation, including increasing carrier transportation, prolonging lifetime and decreasing recombination, the hollow core-shell nanostructure can provide abundant active sites and increase solar efficiency, while can maintain a photocatalytic stability.     

CdS／CdTe－CdS／Cu_2S异质二重结薄膜太阳电池的设计与计算

根据半导体材料的性能参数，考虑光电压Ｖ和耗尽区宽度Ｗ的变化对光电流ＪＬ的影响，较严格地计算了ＣｄＳ／ＣｄＴｅ和ＣｄＳ／Ｃｕ２Ｓ两种异质结单晶薄膜太阳电池的光伏特性曲线。然后在的条件下，对由上述两种异质结构成的二重结太阳电池的ＣｄＴｅ、Ｃｕ２Ｓ厚度进行匹配，计算各种组合下二重结太阳电池的光伏特性曲线。理论证明最佳匹配厚度Ｈｍａｘ约为９．０６μｍ，最大短路电流、开路电压、转换效率分别为１４．２２ｍＡｃｍ－２、１．３Ｖ和１４、６８％。     

Broad spectrum response flower spherical-like composites CQDs@CdIn2S4/CdS modified by CQDs with up-conversion property for photocatalytic degradation and water splitting

A composite material of CQDs@CdIn₂S₄/CdS modified by carbon quantum dots (CQDs) with up-conversion property was prepared by the microwave assisted method. CQDs@CdIn₂S₄/CdS composites consisting of hexagonal phase CdS and cubic phase CdIn₂S₄ show a uniform flower spherical-like morphology and a significant increase in specific surface area. Moreover, the prepared CQDs with up-converted photoluminescence property can convert long wavelength light (λ > 600 nm) into short wavelength light (λ < 600 nm), which can match the light absorption range of the composite CdIn₂S₄/CdS reasonably, broaden its light response range and improve its utilization of sunlight. At the same time, the photocatalytic activity of CQDs@CdIn₂S₄/CdS series composites under different light sources was studied with methyl orange as the model molecule, and 1% CQDs@CdIn₂S₄/CdS was determined as one of the best photocatalytic material. The composite material 1% CQDs@CdIn₂S₄/CdS not only had high photohydrogen production capacity (3177.8 μmol/g, 8 h), but also had a very stable effect on the ultraviolet photocatalytic degradation rate and the final hydrogen evolution yield of photolyzed water after four cycles.     

Solar cells based on CuIn(Se, S)2

In this contribution we report on three- and four source evaporation of CuIn(Se, S)₂ thin films. The existence of secondary phases as well as texture effects are discussed for these thin films. The quaternary system CuIn(Se, S)₂ will be considered regarding incorporation of selenium versus sulphur. Results of heterojunctions completed with (Zn, Cd)S or a composite window consisting of a thin CdS buffer and a highly conductive ZnO window layer will be reported and analyzed. A main feature will be the influence of CuS on the heterojunction and the methods to overcome this problem. Devices with an active area efficiency exceeding 10% could be obtained.     

Solar energy utilization in degradation of 2-chlorophenol by immobilized photosensitizers

The aim of this work was to examine photosensitized oxidation of 2-chlorophenol using solar light. Rose bengal, methylene blue and chlorin e6 were used as sensitizers. They were immobilized in the silane gel and used in the form of a thin film covering glass plates. In some lab-scale experiments xenon arc lamps were used as solar simulators.The influence of various experimental conditions (light intensity, the amount of sensitizer, oxygen concentration) on the rate of 2-chlorophenol degradation was investigated. The obtained results indicate a possibility of the application of solar radiation in the middle latitudes for wastewater treatment. The use of silane gel as a carrier for the sensitizer enables the pollutants elimination at a higher rate than in a homogenous system. The stability and durability of immobilized sensitizers were also studied.     

Preparation and characterization of CuInSe2 and CdS films

The ternary thin film semiconductors CuInSe₂ and Cd(In)S were prepared by co-evaporation of the elements using an electron bombardment heating technique and simple monitoring methods. The films were characterized by energy and wavelength dispersive quantitative compositional analysis, X-ray (powder) diffraction, optical transmittance, SEM surface morphology and electrical measurements. The effects of different composition have have been measured and small hetero-junction solar cells produced.