Investigation of Back Surface Field Layer for High Efficiency Ultrathin In2S3 based CIGS Solar Cell

A comprehensive study of a novel structure for In2S3 based CIGS solar cell has been observed. The effects of the absorber layer and temperature with various back surface field (BSF) layers (SnS/SnTe/MoTe2/GeTe) are analyzed with the SCAPS-1D simulator. Performances of the ultrathin CIGS solar cell enhanced with the proposed structure of ZnO:Al/i-ZnO/In2S3/CIGS/BSF/Mo and efficiency reached over 24% with 1000 nm CIGS absorber layer. The cell with SnS BSF layer has obtained 24.41% efficiency but shows less stability with temperature variation. On the other hand, the cell with MoTe2 BSF shows better stability at a higher temperature and reached an efficiency of 24.14%. Besides, the cell with SnTe BSF also suitable for ultrathin In2S3/CIGS, which results in an efficiency of 23.27%. However, the cell with GeTe BSF can give just over 18% efficiency, but it shows greater stability with temperature changes. This study highlights the potential of BSF layer in In2S3/CIGS solar cell enhancing the performance and stability of cells by reducing recombination losses. The incorporation of a 50 nm BSF layer allows further thinning of the absorber layer, reducing material consumption in the fabrication process without sacrificing overall efficiency.