化学浴法制备CdS薄膜及其光电性能研究

本文用氯化镉、氯化铵、硫脲和氨水的溶液体系采用化学浴沉积法合成CdS薄膜,制备出均匀、致密的CdS薄膜,通过XRD、SEM、EDS、紫外可见吸收光谱等表征手段研究了CdS薄膜的晶体结构,表面形貌,元素比例和光电性能.发现在不同水浴温度下都成功制备了CdS薄膜,其中75℃制备的CdS薄膜最为均匀致密且其XRD衍射峰强度最强,光吸收边在500 nm附近,禁带宽度大约为2.52 eV.这些CdS薄膜的光电响应大,暗态及光照下的电导率分别为1×10-4S·cm-1和1.04×10-2 S · cm-1.用它们制备的CdS/CZTS异质结太阳电池具有明显的光伏效应.     

氨水浓度对化学水浴法制备CdS缓冲层及CZTSe电池性能的影响

主要研究了化学水浴法沉积CdS薄膜中氨水浓度对薄膜材料特性的影响.通过X射线衍射(XRD)、扫描电子显微镜(SEM)和分光光度计(UV-Vis)等测试手段对制备的CdS薄膜的结构和光学特性进行了分析.结果表明:不同的氨水浓度条件下均得到立方相CdS薄膜,薄膜沿(111)面择优取向生长.随着氨水浓度增加时CdS薄膜表面逐渐变得致密光滑,CdS薄膜的透过率增强和带隙变宽.在氨水浓度为0.10 mol/L时制备出材料特性最佳的CdS薄膜,其表面紧凑致密无针孔,颗粒大小均匀,将其应用于CZTSe薄膜太阳电池中的缓冲层材料,得到光电转化效率为3.12;的CZTSe薄膜太阳电池(该电池未经任何后硒化处理工艺).     

竹叶状多孔SnS薄膜的沉积

以硫代乙酰胺、三乙醇胺、氯化亚锡和氨水作反应物,氯化铵作缓冲剂,采用化学浴法在玻璃衬底上沉积SnS薄膜,并用X射线衍射(XRD)、扫描电子显微镜(SEM)等分析手段对样品进行了表征.XRD分析结果表明样品为斜方晶体结构的多晶SnS薄膜.SEM观察结果显示薄膜表面呈竹叶状多孔形貌,此结构有利于增加太阳电池的光吸收.     

水浴温度对CdS薄膜性能的影响

采用化学水浴法,以不同水浴温度在玻璃衬底上沉积CdS薄膜并制备CIGS薄膜太阳能电池,研究了水浴温度对CdS薄膜和CIGS太阳能电池性能的影响.结果表明:水浴温度对CdS薄膜的致密性、沉积速率、透过率和成分比率都有影响.在65-80℃之间制备的CdS薄膜均匀致密且透过率高,可作为CIGS太阳能电池的缓冲层;另外,CdS缓冲层的厚度对CIGS电池的性能影响显著,较薄的CdS缓冲层能够增加CIGS电池在400-500 nm波段对光线的吸收,提高CIGS电池的短路电流.     

CdS纳米晶颗粒薄膜的制备及其光学特性研究

采用化学浴沉积法,以CdCl2·H2O、CS(NH2)2、NH4Cl、NH3·H2O和去离子水作为反应前驱物,在不同的氨水浓度下制备CdS纳米晶颗粒薄膜.通过扫描电镜、X射线衍射、X射线能量色散谱、紫外-可见光透射光谱、椭圆偏振光谱等方法,研究了反应前驱物中氨水浓度对CdS纳米晶颗粒薄膜的表面形貌、晶体结构、S/Cd原子比、光透过率、光学带隙、折射率、消光系数和光学吸收边等物理性能的影响.结果表明:反应前驱物中氨水浓度在0.4～1.0mol/L范围内,可以在衬底上形成均匀致密的CdS纳米晶颗粒薄膜.随着氨水浓度的增加,CdS纳米晶的平均晶粒尺寸逐渐减少,S/Cd原子比逐渐增加,由富Cd型转变为富S型,禁带宽度逐渐增加.在500～1000 nm波段内,折射率的平均值为1.75;消光系数k小于0.07.     

电沉积法制备CdS薄膜及其性能研究

采用电沉积法制备了CdS薄膜.分别用XRD及SEM分析了薄膜的结构和表面形貌.研究了不同温度和不同沉积电压对薄膜表面硫与镉的化学成分比的影响.最佳的沉积电压为2.5～3V之间.制作了ITO/n-CdS/p-SnS/Ag结构的太阳能电池,在100mW/cm2的光强下其开路电压0.2V,短路电流13.2mA/cm2,填充因子0.31,转换效率0.81;.     

硫源和六元瓜环对硫化镉性质的影响

以硫代硫酸钠和硫脲为硫源,氯化镉为镉源,六元瓜环(Q[6])为修饰剂,采用水热法制备Q[6]/CdS复合光催化剂.利用傅里叶变换红外光谱、X射线粉末衍射和扫描电子显微镜对产物进行结构和形貌表征,考察Q[6]和硫源对产物结构和性能的影响.结果表明,硫源对产物形貌和结构都有影响,Q[6]对硫化镉光催化性能有增强作用,15 mg Q[6]/CdS能使50 mL,6 mg/L的次甲基蓝溶液反应200 min时的降解率达到93.0;以上.     

CdS纳米线分级结构薄膜的制备及光催化性能

采用电沉积-溶剂热两步法制备了Cu基CdS纳米线分级结构薄膜.用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、能谱分析仪(EDS)、紫外-可见漫反射光谱(UV-vis-DRS)等对薄膜进行表征,探讨了Cd基CdS纳米线的成核生长机制.结果显示:Cu基Cd微米片阵列与其表面生长的针状CdS纳米线,构筑形成了多孔道的分级结构薄膜,改变溶剂热的时间、温度及硫源浓度,CdS纳米线尺寸呈规律性变化.Cu基CdS薄膜具有较好的光催化活性和稳定性,经5次光催化循环,罗丹明B(RhB)降解率下降不明显.     

乙醇溶液中电沉积CuInSe2(CIS)薄膜过程研究

采用三电极体系,以钼片为工作电极,大面积铂网为辅助电极,饱和甘汞电极(SCE)为参比电极,以氯化铜、氯化铟、亚硒酸为原料,在无水乙醇溶液中,用阴极恒流和恒压两种沉积方法制备出CIS前驱体薄膜,采用XRD和EDAX对制备的薄膜进行了表征,分析了沉积方式、镀液离子浓度、导电盐(LiCl)含量及热处理工艺等因素对薄膜成分及形貌的影响,并对电沉积CIS薄膜的机理进行了初步探讨.在最优条件下所制备的薄膜成分接近标准比且表面致密、均匀.     

水浴温度对化学浴沉积制备的CdxZn1-xS薄膜光电性能的影响

采用氯化镉,氯化锌,硫脲,柠檬酸钠和氨水构成的溶液体系通过化学浴沉积法合成CdxZn1-xS薄膜,采用SEM、EDS、XRD和紫外可见近红外分光光度计等表征手段研究了CdxZn1-xS薄膜的形貌、组分、相结构和光学性能,测试了薄膜的光电流响应曲线进而对薄膜的光电性能进行了分析.结果表明,在65 ～ 85℃水浴温度下均可以制备CdxZn1-xS薄膜,随着水浴温度升高,薄膜中Zn的原子比例相对增加,光学带隙增大;制备的薄膜均显示了明显的光电导现象.75℃制备的薄膜的表面最为平整致密,结晶性最好,光学带隙为2.72 eV,光暗电导比为1.20;光源关闭后电流下降过程最快,关闭10 s后电流下降了约69.39;.     

离子液体对硫化镉粒径和光催化性能调控研究

以氯化镉和硫代乙酰胺为原料,分别以水,离子液以及两者的混合液为溶剂,用超声法成功合成了不同粒径的硫化镉纳米粒子.用XRD,SEM,IR以及UV-Vis等手段对所制备样品的晶型、形貌和光学特性进行了表征;以紫外光为光源、甲基橙为目标降解物评价了硫化镉纳米粒子的光催化活性.结果表明,离子液的引入使硫化镉纳米粒子的粒径明显变小,带隙能量变大,光催化性能测试表明,离子液介质中合成的CdS纳米粒子具有更高的光催化活性.离子液体对比实验还表明,三乙烯四胺型离子液体中合成的硫化镉具有更高的光催化活性.     

化学水浴沉积法制备硫化镉薄膜的微结构和性能

采用化学水浴沉积法在不同氨水用量下制备了Cu(In,Ga)Se₂太阳能电池的缓冲层CdS薄膜,根据化学平衡动力学计算出混合溶液中反应粒子的初始浓度、pH值和离子积,利用台阶仪、扫描电子显微镜(SEM)、X射线衍射仪(XRD)、量子效率测试仪(EQE)和IV测试仪对制备样品的薄膜厚度、表面形貌、晶体结构、量子效率和光电转换效率进行了表征和分析。结果表明:提高氨水用量可以抑制同质反应,促进异质反应,使CdS薄膜晶体结构从立方相向六方相转变,晶粒形状从柳絮状向颗粒状转变,晶粒尺寸逐渐增大,粒径分布更加均匀,薄膜表面更加平整,制备电池的EQE、V_oc、J_sc、FF、R_s等电学参数得到优化,光电转换效率从7.64%提高到13.60%。     

Synthesis and optical properties of MPTMS-capped CdS quantum dots embedded in TiO2 thin films for photonic applications

CdS nanoparticles have been prepared via a colloidal route using 3-mercatopropyltrimethoxysilane as a capping agent. The stability of the particles in solution and embedded in TiO₂ matrices has been followed by optical absorption. Both the size and the size distribution of the particles are well controlled, thus allowing a tunable emission. Raman and photoluminescence spectroscopies have been used to characterize colloidal CdS, TiO₂:CdS solutions and thin films deposited on soda-lime slides. The Z-scan technique has been used to measure the non-linear refractive indices of the solutions and the non-linear absorption coefficients of the thin films.     

A novel sonochemical synthesis and nanostructured assembly of polyvinylpyrrolidone-capped CdS colloidal nanoparticles

Nanoparticles of cadmium sulfide (nano-CdS) have been successfully prepared from an aqueous solution of cadmium chloride and sodium sulfide by a novel sonochemical method. Through adding polyvinylpyrrolidone K30 (PVP) as the dispersant, a yellow translucent colloidal solution of cadmium sulfide which was considerably stable within at least one month was obtained. The characterizations of nanoparticles by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM) and FT-IR spectroscopy showed good properties of small size, high surface area and crystal structure. The size of the prepared nanoparticles was about 3–5 nm according to XRD spectra and TEM images. Poly(diallyldimethylammonium chloride) (PDDA) has been employed to fabricate multilayer films on quartz wafer and indium tin oxide (ITO) electrode in a layer-by-layer manner. Atomic force microscopy (AFM) displayed the dense coverage of the substrate surface by the nanoparticles. UV–vis absorption spectroscopy confirmed the consecutive growth of PDDA/nanoparticles layer pairs. The photoelectrochemical and the electrochemical behaviors of the prepared CdS particle were examined as well.     

Growth and characterization of nanostructured CdS/Polyaniline/CuInSe2 thin films for solar cell applications

In the present paper, we report about synthesis of nanostructured organic–inorganic heterojunction of CdS/Polyaniline/CuInSe₂ thin films by cost effective chemical route at room temperature, for solar cell application. As such obtained thin films are characterized for structural, compositional, morphological, optical and electrical properties by X-ray diffraction (XRD) pattern, energy dispersive X-ray (EDAX) analysis, scanning electron microscopy (SEM), optical absorbance spectra and I–V response respectively. The XRD reveals the polycrystalline nature of the thin films having tetragonal crystal structure and a crystallite size of 19 nm. The presence of observed and expected elements in the EDAX spectra confirms the elemental compositions in CdS/Polyaniline/CuInSe₂ thin films. From SEM images it can be inferred that the surface morphology of the Polyaniline thin films exists like clothing fibers, while CdS/CuInSe₂ shows granular shape particles distributed over the substrate and the SEM of CdS/Polyaniline/CuInSe₂ represents mixing and attachment of circular particles to fiber like structure. The optical absorbance spectra have shown red shift in absorbance strength and energy band gap value of CdS/CuInSe₂ from ~ 1.36 eV to ~ 1.62 eV upon formation of CdS/Polyaniline/CuInSe₂ thin film. The I–V response of CdS/CuInSe₂ and CdS/Polyaniline/CuInSe₂ measured under dark and illumination to 100 mW/cm² light, exhibited the solar characteristics from these graphs and the conversion efficiency calculated is observed to be 0.26 and 0.55% for CdS/CuInSe₂ and CdS/Polyaniline/CuInSe₂ thin films respectively.     

The effect of electron irradiation on electrophysical properties of CdS,CdSe and ZnTe thin films

The effect of electron irradiation on electrophysical properties of CdS, CdSe and ZnTe thin films and CdS-PbTe and CdS-Te heterojunctions were studied. It was found that the effect of irradiation on thin films and devices strongly depend on the electron-irradiation doses and the preparation conditions.     

Investigation into the structure of Langmuir-Blodgett films prepared from salts of acetylenic acids

Langmuir-Blodgett films are prepared from lead, cadmium, and copper salts of carboxylic acids, namely, 23-tetracosynoic acid HC≡C(CH₂)₂₁COOH (with the terminal triple bond) and 2-docosynoic acid CH₃(CH₂)₁₈C≡CCOOH (with the internal triple bond). The structural transformations in the films during polymerization under exposure to UV radiation are investigated using X-ray reflectomertry. It is found that the X-ray reflectograms of the initial films prepared from salts of both acids exhibit no less than four or five pronounced intense Bragg reflections. This suggests that the initial films have good layer ordering. The bilayer periods for all the films are determined, and the influence of the salt type on the bilayer period is analyzed. It is established that, under exposure to UV radiation, the structural transformations in the films prepared from the salts of 23-tetracosynoic acid occur without substantial disturbances and defects, as can be judged from the absence of significant changes in the location and intensity of the Bragg reflections. An increase in the time of irradiation of the films prepared from the salts of 2-docosynoic acid leads to an increase in the bilayer period. This effect is especially pronounced for the lead and copper salts. However, upon long-term exposure to UV radiation, the salts undergo photolysis, the bilayer period decreases, and the structure of the film begins to break down.     

不同形貌TiO2薄膜的可控制备及其光电化学性能研究

采用水热法在FTO(fluorine-doped tin oxide)基底上制备不同形貌的锐钛矿结构TiO₂薄膜。通过不断增大反应前驱物中盐酸浓度,TiO₂薄膜由球状颗粒薄膜逐渐演变生长成大面积高能(001)面裸露的TiO₂纳米片阵列薄膜。通过对形貌演化规律及X射线衍射图谱变化规律进行分析,提出了不同形貌TiO₂薄膜的生长演化机制,并对盐酸在其中的作用进行了说明。为了进一步改善TiO₂薄膜的性能,采用连续离子层吸附反应法对不同形貌的TiO₂薄膜进行CdS量子点敏化。采用紫外可见吸收光谱分析法和三电极体系对复合薄膜的光吸收性能和光电化学(PEC)性能进行了研究,实验数据显示CdS/TiO₂复合薄膜的光电化学性能皆明显优于单纯TiO₂薄膜,而且纳米片阵列薄膜的性能明显优于其他形貌薄膜,说明了大面积高能(001)面裸露的TiO₂纳米片阵列薄膜的性能优越性。     

Laser film thickness modulation and induced small pattern generation

This paper deals with a recently observed effect of laser light on the growth of thin films on a CdS substrate deposited on glass. The possible origins of the phenomenon are analyzed and the experimental apparatus used to observe it is described.