Stable lead free perovskite solar cells based on bismuth doped perovskite materials

The inclusion of lead in the Champion perovskite material MAPbI₃ is a detrimental factor in the commercialization of lead based perovskite solar cells. This is mainly due to the toxicity of lead and also due to degradation of MAPbI₃ in ambient condition into hazardous chemicals which are toxic to the environment [1]. Due to these factors, though the Hybrid Organic Inorganic Lead based PSCs exhibit excellent photovoltaic effect and photo conversion efficiency (PCE), yet numerous theoretical and experimental studies have been done to replace lead with suitable elements such as Sn, Ge, Bi etc. This research work focusses on replacing Pb from MAPbI₃, with different wt% of Bi such as 1%, 2%, 4% and 8% and analyzing its effect on the stability and efficiency of the PSC. These solutions of Bi doped perovskite are coated on the FTOs and are fabricated under room ambient condition in the sandwich structure. The results exhibit lower efficiency of Bismuth doped PSCs but it shows remarkable stability comparable to that of MAPbI₃.