Crystallization Behavior of Solution-Processed CIGSe Thin Film Semiconductor by Stepwise Annealing Process

Culn(x)Ga(1-x)Se(2) (GIGS) thin films were prepared by a solution-based CuInGa (CIG) precursor-selenization process. First, we investigated the effect of selenization temperature on the formation of polycrystalline CIGS and grain growth. The GIG precursor films were selenized using a two-step process to investigate the reaction of Se and GIG precursors during the formation of GIGS thin films. Depending on the temperature in the 1st step of the selenization process, the GIG precursor forms a different intermediate phase between the single phase to ternary phase such as Cu, Se, Cu Se, In Se, and CuInSe2. In addition, the intermediate phase exerts a significant influence on the final phase obtained after the 2nd step of the selenization process, particularly with regard to characteristics such as polycrystalline structure and grain growth in the GIGS films. The photoelectron conversion efficiency of devices prepared using GIGS thin films was approximately 1.59-2.75%.