Preparation Of CdS/CdZnTe Thin Film And Solar Cell By Magnetron Sputtering Method

The CdZnTe material has many advantages such as high absorption coefficient, width band gap and so on. It can be used for the material of the absorption layer of thin film solar cells.In this paper, we use magnetron sputtering method prepare CdZnTe film, CdSe film and Cu film for CdZnTe solar cell, explore influence of the different preparation process on the performance of solar cells.In this paper, we prepare CdS films, CdZnTe films, Cu electrode on the substrate by RF magnetron sputtering to bulid CdZnTe thin film solar cell structure. Using X-ray diffraction (XRD), ultraviolet visible spectrophotometer (UV-VIS), atomic force microscopy (AFM), semiconductor test system and other test equipment on the structure and properties of thin film, study the influence of different process parameters on the performance of solar cells. The results show that:prepared good crystallinity, density, thickness of thin and high optical transmittance of CdS films is helpful to improve the photovoltaic performance of the solar cell, the best process parameters is 40W sputtering power,30min sputtering time and 1.5Pa sputtering pressure; the thickness of the CdZnTe films should be moderate, not only to absorb visible light, and can keep the resistivity is 103Ω·cm, the grain size is large,the best process parameters is 40W sputtering power,30min sputtering time and 1.5Pa sputtering pressure. Combined with the photovoltaic properties of Ⅰ-Ⅴ curve, studied the effect of the film thickness, resistivity, the crystalline quality to cell character. The study found that:the film thickness, resistivity, crystal quality of the CdS layer and CdZnTe layer have a great impact on the efficiency of the cell; good ohmic contact of Cu electrode can improve the photoelectric conversion efficiency of solar cell. Through the simulation method, we study the electronic structure and optical properties of Cd 1-xZnxTe, the underestimation problem of Cd 1-xZnxTe band structure have been solved. The introduction of the U value can not only increase the population of electrons in orbit but also make the electron energy levels split. The intensity of absorption and refractive spectrum peaks increase with the number of peaks decrease.