Optimizing Semiconductor-insulator-semiconductor Heterojunction Engineering Performance in a Novel High-efficiency Solar Cell Structure

In this study, we introduce and optimize a novel semiconductor-insulator-semiconductor (SIS) solar cell using SCAPS-1D simulations. The Pt/Si/TiO2/ZnSe/ fluorine-doped tin oxide (FTO), structure employs Pt and FTO as back/front contacts. TiO2 serves as a critical insulating layer between p-Si and n-ZnSe, enhancing electrical isolation while boosting stability and efficiency through reduced recombination and improved charge transport. Results demonstrate TiO2 as an insulating material significantly improves the fill factor (FF) and power conversion efficiency (PCE) of the device, compared to conventional structures. Key optimized parameters include: Si 1300 nm, ZnSe 100 nm, and TiO2 insulating layer to 10 nm; defect densities of 1015 cm−3 for both Si and ZnSe, and 1012 cm−3 for the interfaces. This optimized cell demonstrates the following performance results: a VOC of 0.84 V, a JSC of 42.09 mA cm−2, an FF of 86.42%, and a PCE of 30.65%. These results were achieved under standard test conditions (AM1.5G, temperature of 300 K). Our simulations focus on enhancing electrical parameters, particularly efficiency. This study will provide valuable parameters for any future experimental work on SIS solar cells.