Unlocking the efficiency potential of tin-based perovskite solar cell

As a potential absorber layer for solar cells, tin-based perovskite has drawn interest in photovoltaics. CsSnI₃ is a direct band-gap (~1.3 eV) material belonging to the family of metal halide perovskite. CsSnI₃ has high surface defects, leading to degraded performance. The low power conversion efficiency (PCE) and open circuit voltage (V_oc) losses of the solar cell are a problem. So we report modifying the structure of the solar cell to fix it. We study the perovskite device for enhancing efficiency by lowering interfacial and bulk recombination. The acceptor and donor densities of CsSnI₃ \(/\) $/$ TiO₂ are varied to evaluate the impact on performance. The V_oc losses are fixed by optimising carrier defect density, which effectively allows interface recombination to be regulated. The Fermi level pins near the conduction band, valence band and mid-gap are determined by varying the acceptor and donor defects in CsSnI₃ \(/\) $/$ TiO₂. Additionally, the insertion of ZnO \(/\) $/$ TiO₂ suppresses recombination and enhances the efficiency from 9.43 to 16.26%. The optimised device was compared to the experimental and benchmarked initially to modify the structure. This study provides a detailed investigation to understand the surface mechanisms of the devices and enhance their performance.