Research Of Structure And Properties Of CIGS And ZnO Films

Copper-indium-gallium-selenide(CIGS) thin-film solar cells have been attracted more attention because of its high conversion efficiency, high stability, and the forbidden band width can be adjusted. CIGS cells have multi-layer structures which include the back electrode, absorption layer, buffer layer, windows layer and anti-reflection layer. The film quality of each layer will directly affect the CIGS photoelectric conversion efficiency and stability of the cells. The growth temperature has great influence on CIGS film quality which is regarded as the absorption layer of CIGS thin-film solar cells. i-Zn O, which bandgap is 3.3e V, is the ideal material for the windows layer of CIGS cells. The AZO thin films can be used as a transparent electrode because it is lattice match with i-Zn O. Therefore, further research on film preparation technology and new methods of the preparation of thin films is of great significance. This article mainly studies the preparation of absorption layer and window layer of the CIGS cells. The main research content is divided into two parts:(1)Quaternary alloy target material preparation of CIGS thin film. This part mainly studies impact of different growth process on the CIGS thin film. The growth process of CIGS thin film contains the following three parts: grown under normal temperature with annealing, grown under high temperature with annealing and grown under high temperature without annealing. We found that the difference growth process have significant effect on the crystallinity, grain size, surface roughness of CIGS thin film. In the three growth process, the high temperature growth without annealing of CIGS thin film can get large grain size, surface smooth CIGS thin film. Among them, the CIGS thin films which were prepared under 500 ℃ without annealing have the best crystalline quality and optical response.(2) The preparation of i-Zn O and AZO thin film using magnetron sputtering and sol-gel spin coating., The transmittance of i-Zn O films were over 80%,the i-Zn O thin films prepared by magnetron sputtering have larger grain size and smooth surface. The AZO thin films prepared by magnetron sputtering have lower resistivity.When the spin frequency was 11 times, the films had better crystallization. When the spin frequency was less than 7 times. The i-Zn O thin films prepared by sol-gel spin coating have worse quality,transmittance and the light absorption red shift.For the AZO thin filmprepared by magnetron sputtering, the transmittance was over 80% at 0.7 Pa. With the increase of sputtering power, the resistivity of the film was reduced after increase. The resistivity was lowest. With the increase of Al doping amount, the resistivity of the film was reduced after increase. The resistivity was lowest at Al doping amount of 5%.The AZOthin films prepared bysol-gel spin coating have worse quality,transmittance and the light absorption red shift.