SCAPS Simulation on CIGSe Thin Film Solar Cells: Effect of the Defects

CIGSe thin film solar cells have been fascinating in the photovoltaic field due to their potential to get high conversion efficiencies at an attractive cost. The properties of the materials used in solar cells must be optimized to improve the efficiency. Here, SCAPS is utilized to simulate the CIGSe thin film solar cells. First, the material properties (i.e., thickness, bandgap, carrier concentration) of CIGSe, CdS, ZnO, and ZnO:Al are analyzed for the optimization process. The optimized efficiency of 27.32% is achieved for the CIGSe thin film solar cell. Then the effect of defect density and carrier capture cross section in CIGSe, CdS, and CdS/CIGSe interface on the performance of CIGSe thin film solar cell is reviewed. It is found that the higher the defects in the device lower the device’s performance. This decrement in the efficiency is due to the decrease in the diffusion length of charge carriers by enhancing the recombination centers for them, preventing the collection of charge carriers, and finally degrading the device performance. This theoretical study can guide as a roadmap to enhance solar cell performance experimentally.