Simulation analysis of heterojunction ZnO/CdS/Cu(In,Ga)Se2 thin-film solar cells using wxAMPS

Abstract

Solar cells based on Cu(In,Ga)Se2 (CIGS) absorber layers have owned the highest energy conversion efficiency among thin film solar cells and it is reported that the efficiency of CIGS solar cells is above 21% at present. In this paper, the performances of monolayer CIGS thin film solar cells with conventional ZnO/CdS/CIGS structure are calculated by using wxAMPS simulative software. The optimum values of the thicknesses of CdS/CIGS layers and carrier density of CIGS layer have been calculated and it is shown that the performances of solar cells have been improved by optimizing the parameters of solar cells. The temperature dependence of performances for CIGS solar cells has been simulated to guide the fabricated devices to obtain higher efficiency in the different temperature conditions. As a result of calculation, it is shown that excellent performance can be obtained by adjusting the parameters, and that the highest efficiency of solar cell can be achieved under certain conditions, where the thicknesses of ZnO, CdS and CIGS are 100nm, 30nm and 3μm, respectively.