Achieving beyond 30% efficiency for hole-transport-layer-free CsSnI₃ perovskite solar cell: a comprehensive simulation study

In recent years, the growing significance of lead-free CsSnI₃ perovskite can be credited to its outstanding optoelectronic properties and environmentally friendly nature. Nevertheless, the photovoltaic potential of CsSnI₃ is limited due to challenges in achieving defect-free device structures. The current study thoroughly analyzed the performance of CsSnI₃-based perovskite solar cells (PSCs) using the SCAPS-1D software. An in-depth investigation was performed on multiple physical parameters, including the thickness of perovskites layer, acceptor density (N_A), operating temperature, defect densities, shunt resistance (R_Sh) and series resistance (R_S). This comprehensive study aimed to identify the optimal device configuration that yields the highest power conversion efficiency (PCE) for the hole-transport-layer (HTL)-free CsSnI₃-based PSCs. The obtained results confirmed that it is crucial to decrease the number of defects (N_t) at the perovskites/electron transport layer (ETL) interface to improve the efficiency of CsSnI₃-based PSCs. The optimized device demonstrated exceptional performance, achieving an open-circuit voltage (V_OC) of 1.12 V, a fill factor (FF) of 85.08%, a short-circuit current density (J_SC) of 33.29 mA cm⁻² and an efficiency of 31.87%. This high efficiency simulated result provide valuable insights into the design of high-performance CsSnI₃-based PSCs, paving the way for potential breakthroughs in cost-effective and eco-friendly solar energy technologies.