Device modeling and performance analysis of an all-inorganic lead-free Ag2BiI5 rudorffite-based solar cell with AgSCN as HTL via GPVDM simulation software

Abstract

The unprecedented photo-electronic conversion efficiency (PCE) of organic–inorganic lead perovskite solar cells (PSCs), over 25% within a span of 10 years, makes them an optimistic solution for sustainable and renewable energy sources. However, issues associated with their toxicity and short lifetime raise public concern for their long-term utility. Therefore, resolving these two problems is urgent for developing sustainable and environmentally friendly PSCs. In this study, a novel configuration of a lead-free light absorbing layer with a rudorffite structure (Ag₂BiI₅) is simulated, using the GPVDM software with TiO₂ and Spiro-OMeTAD as traditional electron and hole transport layers (HTLs). The proposed PSC structure is compared to other published results in the literature. In the meantime, by fitting the current density-voltage characteristic curves of theoretical data and experimental results, the precise photovoltaic parameters of the Ag₂BiI₅ structure are extracted. After optimizing the thickness of the Ag₂BiI₅ and replacing TiO₂ with SnO₂ and Spiro-OMeTAD with new a HTL of AgSCN, a PSC in the form of normal a FTO/SnO₂/Ag₂BiI₅/AgSCN/Ag structure is designed. Further, the effect of the thickness of the AgSCN HTL, defect density of light absorbing layer, operating temperature and metal contacts on the photovoltaic performance of the device are thoroughly evaluated. Under the optimized AgSCN HTL thickness, the best theoretical efficiency of 3.61% is achieved for this normal configuration, which is the highest value reported among rudorffite light absorbing materials-based PSCs.