Efficiency enhancement of CIGS solar cell by cubic silicon carbide as prospective buffer layer

Cubic Silicon Carbide (3C-SiC) can be a potential photovoltaic material for thin-film solar cells because of its wide bandgap and non-toxic nature. In this work, we present 3C-SiC as an alternative to the conventional CdS buffer layer and investigate the performance of the proposed 3C-SiC/CIGS cell structure using solar simulator SCAPS-1D. The simulation starts with the optimization of 3C-SiC buffer layer thickness followed by the study of conduction band offsets (CBO) impact on the photovoltaic performance parameters. The highest obtained efficiency is 25.51% (Voc = 0.94 V, Jsc = 31.46 mA/cm2) at CBO, ΔEc = 0.91 eV with the optimized buffer thickness. The linear extrapolation study of Voc as a function of temperature yields the activation energy which tells the existence of interface recombination centres. Next, the inclusion of the acceptor defect state at the 3C-SiC/CIGS interface determines the maximum acceptable defect density of the proposed cell structure. Afterward, the thermal stability through temperature study is performed and compared to the traditional CdS/CIGS structure. The results provided here give few paramount indications that lead to a highly efficient CIGS solar cell with a 3C-SiC buffer layer.