The Stady Of CIGS Thin-film Solar Cells: Preparation Process And Properties

As a kind of renewable energy, the solar energy and its effective utilization have drawn much attention. Solar cell material, which is the core of solar power generation, is always a hotspot in the basic research of photovoltaic power generation field. The performance of solar cell material determines the photoelectric conversion efficiency and industria application of solar cells. Besides silicon-based solar cell materials, polycrystalline chalcopyrite Cu(In,Ga)Se2(named as CIGS) thin-film solar cell materials, as absorber layer for high efficiency photovoltaic solar cells, have been well investigated due to the inherent advantages of high absorption coefficient, adjustable bandgap, strong ability to resist radiation, and high stability under high energy irradiation. The preparation processes can deeply affect the preformation of the CIGS thin film. There are sevel kinds of methods to prepare CIGS absorber layer, such as magnetron sputtering, thermal evaporation and so on. In this paper, CIGS thin films were synthesized by two-steps method, i.e., the In-Cu-Ga metal prefabricated layer was deposited by using PLD method, and then was annealed by the selenization(Se)-annealing processes. The best preparation progesses for CIGS thin-film were investigated to obtain excellent comprehensive performance of the solar cells. The main contents of the thesis are as follows:First, the CIGS thin-films were prepared by the PLD method and the post-Se-annealing processes with different preparation conditions. The effect of preparation conditions on the structure, element content, and optical properties of the CIGS samples were well investigated. The result shows that the membrane performance under the immediately annealing 30 mins at 450℃ has the best overall performance.Second, the effect of different order of In-Cu-Ga metal prefabricated layer on the structure, element contents and optical properties of CIGS thin-films were investigated. The experimental results indicate that the CIGS thin film deposited by the order "CuGa/In/CuGa" metal prefabricated layer is suitable for the absorption layer of solar cells..Last, the preparation processes of functional layers in thin film solar cells, including the back contact Mo, the buffer layer CdS, the window layer ZnO and AZO were studied. Based on the above results, CIGS thin-film whole solar cells were produced successfully. The efficiency of CIGS solar cells is 2.5%, which indicates that the new process technology base on PLD method can be used to prepare the CIGS thin-films solar cells.