Preparation And Property Of CdS Film

Copper indium gallium selenium thin film solar cell(CuIn1-xGaxSe2solar cells, referred to CIGS) is a new kind thin film solar cell developed in the last century. The first CIGS solar cell was produced by pulling method in Bell Labs (CIGS is based on the CIS evolved). From then on CIGS solar cells became the research focus in all over the world and developed quickly. ZnO and CIGS contact directly lead to the conversion efficiency of cell was not high, until1985, R.R.Potter developed the current CIGS the basic structure of solar cells. Adding a layer of CdS film was used as the transition layer between ZnO and CIGS in this kind of cell, so the conversion efficiency of cells improved greatly. Therefore, how to improve the performance of the transition layers is the concern of the majority of scholars. At present, the highest conversion efficiency CIGS colar cell in which the CdS film is the transition layer has reached20.3%,by German solar energy and hydrogen research center to create.CdS was prepared by chemical bath deposition and the magnetron sputtering method in this experiment. Ammonium acetate, cadmium acetate, ammonia and thiourea was used as the main raw materials, and then deposit CdS by the way of spinning on soda-lime glass. Analyzes the influence of the deposition time, deposition temperature, rotating speed and Cd2+concentration on crystalline phase of CdS film, surface morphology, resistance, transmissivity and forbidden band width and so on. In the magnetron sputtering method, we used CdS as the target material and deposited CdS on soda-lime glass. The influence of the sputtering time and sputtering pressure on the crystalline phase structure of CdS film, the crystal cell parameter and the transmissivity, so that we can determine the optimal process parameter.The experimental results show that the change of deposition time, deposition temperature, rotating speed and Cd2+concentration has effect on crystallization degree, transmissivity, surface resistance and the optical band gap value of CdS film by chemical bath deposition. When the deposition time of30min, the deposition temperature of80℃, rotating speed of2r/s, Cd2+concentration of0.001mol/L, the performance of CdS is the best. The change of sputtering time and sputtering pressure will affect the crystallization degree and optical properties of the CdS film by magnetron sputtering. When the sputtering time is20min, working pressure is0.5MPa, the performance of the CdS film is the best.The transmission of the CdS thin film prepared by chemical bath deposition is higer than that prepared by magnetron sputtering, and the transimssion is better when the walvelength below500nm. However, the CdS thin film prepared by chemical bath deposition has lower crystallization.