All-inorganic perovskite photovoltaics for power conversion efficiency of 31

The lead-free perovskite halides emerge as the great alternative for highly efficient and environment friendly photovoltaics due to the inherent optoelectronic properties. In this paper, the numerical study of all-inorganic regular n-i-p structured perovskite photovoltaics using solar cells capacitance simulator (SCAPS-1D) has been performed. The optimised device structure using rGO provided best performance compared to the other hole transport layers (HTLs) like CuI, CuSCN, Cu₂O, NiO, WSe₂, MoO₃ with CsSnI₃ as an active material and TiO₂ as electron transport layer (ETL). Furthermore, WS₂ as an ETL compared to TiO₂, Li-TiO₂, ZnO, Al-ZnO, etc. provided the best performance with rGO as HTL and CsSnI₃ as active material. Therefore, the optimized solar cell structure (FTO/WS₂/CsSnI₃/rGO/Pt) showed best photovoltaic performance with power conversion efficiency (PCE) of 31%, fill factor (FF) of 88.48%, open circuit voltage (V_OC) of 1.15 V, and short circuit current density (J_SC) of 30.47 mA/cm², respectively. Consequently, the effect of variation of temperature, thickness, defect density, doping density of active layer and variation of illumination intensity on the photovoltaic performance of the optimised device are also analysed. Furthermore, this study is also focused on the analysis of photovoltaic parameters for the optimized structure using concept of ideality factor associated with the illumination intensity. Therefore, this analysis suggests a route for further development of all-inorganic, lead-free perovskite photovoltaics experimentally with improved photovoltaic performance.