Modeling and Analysis of KSnI Perovskite Solar Cells Yielding Power Conversion Efficiency of 30.21.

KSnI-based perovskite solar cells have attracted a lot of research interest due their unique electronic, optical, and thermal properties. In this study, we optimized the performance of various lead-free perovskite solar cell structures-specifically, FTO/Al-ZnO/KSnI/rGO/Se, FTO/LiTiO/KSnI/rGO/Se, FTO/ZnO/KSnI/rGO/Se, and FTO/SnO/KSnI/rGO/Se, using the SCAPS-1D simulation tool. The optimization focused on the thicknesses and dopant densities of the rGO, KSnI, Al-ZnO, LiTiO, ZnO, and SnO layers, the thickness of the FTO electrode, as well as the defect density of KSnI. This yielded PCE values of 27.60%, 24.94%, 27.62%, and 30.21% for the FTO/Al-ZnO/KSnI/rGO/Se, FTO/LiTiO/KSnI/rGO/Se, FTO/ZnO/KSnI/rGO/Se, and FTO/SnO/KSnI/rGO/Se perovskite solar cell configurations, respectively. The FTO/SnO/KSnI/rGO/Se device is 7.43% more efficient than the FTO/SnO/3C-SiC/KSnI/NiO/C device, which is currently the highest performing KSnI-based perovskite solar cell in the literature. Thus, our FTO/SnO/KSnI/rGO/Se perovskite solar cell structure is now, by far, the most efficient PSC design. Its best performance is achieved under ideal conditions of a series resistance of 0.5 Ω cm, a shunt resistance of 10 Ω cm, and a temperature of 371 K.