电沉积法制备CdSe薄膜及其光电性能

Preparation and Photoelectric Properties of CdSe Thin Films by the Electrodeposition Method

采用电沉积法制备了硒化镉（CdSe）薄膜,讨论了Cd（NO3）2和H2SeO3摩尔比（n（Cd∶Se））、聚乙烯吡咯烷酮（PVP）浓度、沉积电压和时间等条件对CdSe薄膜光电压的影响,并对样品进行X射线衍射（XRD）、能谱分析（EDS）和扫描电子显微镜（SEM）等表征。结果表明,CdSe薄膜制备最优条件是在二甲基甲酰胺（DMF）体系中,以0.005 5 mol/L PVP、0.036 mol/L Cd（NO3）2、0.054 mol/L H2SeO3混合液为电解液,室温下3.0 V直流电压沉积15 min,可得最高0.3680 V光电压的CdSe薄膜。XRD表征显示,在2θ值为25.354°,42.010°,49.699°,67.083°和76.780°处出现了（111）,（220）,（311）,（331）和（422）五个晶面衍射峰,与立方型CdSe标准衍射卡（PDF 19-0191）峰位相吻合。EDS分析表明,样品中Cd和Se质量分数分别为45.60%和51.65%,原子分数分别为36.84%和59.02%。SEM表征显示,样品中的CdSe呈多层链网结构,链直径尺寸为80300 nm。

CdSe thin films were prepared by the electrodeposition method. The effects of reaction conditions,such as the mole ratio of Cd（NO3）2 and H2SeO3 （n （Cd∶ Se））,the concentration of polyvinylpyrrolidone （PVP） and the deposition voltage and time on the photovoltages of CdSe thin films were discussed. The samples were characterized by the X-ray diffraction （XRD）,energy dispersive spectrometer （EDS） and scanning electron microscopy （SEM）. The experiments comfirm that the optimal preparation condition of CdSe thin films is in the dimethylformamide （DMF） solution of 0. 005 5 mol/L PVP,0. 036 mol/L Cd（NO3）2 and 0. 054 mol/L H2SeO3. At room temperature,the CdSe thin film with the maximum photovoltage of 0. 3680 V is obtained under 3. 0 V direct voltage for 15 min. XRD shows that the diffraction peaks of five crystal planes of （111）, （220）, （311）, （331） and （422） appearing at 2θ of 25. 354°,42. 010°,49. 699°,67. 083° and 76. 780° are consistent with the standard diffraction peaks of cubic CdSe （PDF 19-0191）. EDS indicates that the mass fractions of Cd and Se are 45. 60% and51. 65% and the atomic percentages are 36. 84% and 59. 02%,respectively. SEM reveals that the stucture of CdSe in the samples is multilayer chain network with the chain diameter size range from 80 nm to 300 nm.