Inorganic Lead-Free B-γ-CsSnI₃ Perovskite Solar Cells Using Diverse Electron-Transporting Materials: A Simulation...

B-γ-CsSnI₃ perovskite solar cells (PSCs) are simulated employing diverse electron-transporting layers (ETLs, including TiO₂, ZnO, SnO₂, GaN, C₆₀, and PCBM), and a comparative study has been made. Both regular and inverted planar structures are simulated. Effects of the thickness of absorbers and ETLs, doping of ETLs, and interface trap states on the photovoltaic performance are studied to optimize the device structures. The regular structures have larger short-circuit current density (J _sc) than the inverted structures, but the inverted structures have larger fill factor (FF). All of the simulated optimal PSCs have similar open-circuit voltages (V _oc) of ∼0.96 V. The PSCs with TiO₂ ETLs have the best photovoltaic performance, and the optimum structure exhibits the highest efficiency of 20.2% with a V _oc of 0.97 V, J _sc of 29.67 mA/cm², and FF of 0.70. The optimal PSCs with ZnO, GaN, C₆₀, and PCBM ETLs exhibit efficiencies of 17.88, 18.09, 16.71, and 16.59%, respectively. The optimal PSC with SnO₂ ETL exhibits the lowest efficiency of 15.5% in all of the simulated PSCs due to its cliff-like band offset at the SnO₂/CsSnI₃ interface. Furthermore, the increase of interface trap density and capture cross section is found to reduce the photovoltaic performance of PSCs. This work contributes to designing and fabricating CsSnI₃ PSCs.