Design and optimization of highly efficient perovskite/homojunction SnS tandem solar cells using SCAPS-1D

Abstract

Double-junction tandem solar cells containing a wide-bandgap top cell and a narrow-bandgap bottom cell have a great potential to outperform current single-junction photovoltaic technologies. However, careful consideration is required in the selection and optimization of both sub-cells to obtain full benefit. In this study, we present numerical simulations of tandem solar cells with tin sulfide (SnS) bottom sub-cells and organic–inorganic lead halide perovskite top sub-cells using SCAPS-1D. The performance of SnS homojunction solar cell optimized by investigation of the p-type and n-type layer thicknesses, doping concentrations, defect densities, and interface defects. Afterward, the perovskite solar cell is optimized in terms of variation in absorber bandgap (1.55–1.75 eV) and thickness (100–800 nm). To properly simulate tandem devices, bottom cells are optically filtered by calculated spectra of perovskite solar cells. Current matching has been done by varying thickness of the perovskite sub-cell with different bandgaps, and the optimized 28.92% efficiency has been revealed for the perovskite/SnS tandem device. This is the first numerical simulation using homojunction SnS as a bottom sub-cell in perovskite tandem solar cells to the best of our knowledge. Results suggest that tin sulfide homojunction solar cells could be a low-cost and environmentally friendly bottom sub-cell for efficient perovskite tandem solar cells.