A Tin-Based Perovskite Solar Cell With an Inverted Hole-Free Transport Layer to Achieve High Energy Conversion Efficiency by SCAPS Device Simulation

Abstract Recently, organic-inorganic halide perovskite solar cells (PSCs) have received extensive research in the field of optoelectronic materials due to their unique optical and electrical properties, especially lead-based PSCs. However, the toxicity and stability of these devices, as well as the expensive hole transport layer (HTL) and other factors inhibit their commercial production. In this work, the non-toxic tin was applied as the battery material, the perovskite solar cell adopts an inverted HTL-free structure, and the one-dimensional solar cell capacitor simulator SCAPS-1D (Solar Cell Capacitance Simulator) was adopted for numerical simulation and found that FTO/CH3 NH3 SnI3 /C60 /Au structure PSCs also showed excellent photovoltaic performance. We studied the influence of the thickness of the absorber layer, the defect density, the doping concentration of different layers, and the thickness of the electron transport layer (ETL) under different directions of illumination on the battery performance. The simulation results show that the optimized inverted HTL-free tin-based PSCs based on C60 are with inspiring performance: a short-circuit current density (JSC ) of 30.1646 mA/cm 2 , open-circuit voltage (VOC ) of 1.0465V, fill factor (FF) of 59.49% and power conversion efficiency (PCE) of 18.78%. We also introduced light from different directions to irradiate PSCs, and the results show that the HTL-free perovskite adopting an inverted structure can retain the light intensity of the irradiated perovskite layer to the greatest extent and exhibit superior performance. Based on the inverted HTL-free tin-based PSCs, we also investigated the performance parameters of ETL batteries with different materials. This work provides new ideas for PSCs development in the future.