High-efficiency and eco-friendly Cs₂SnBr₆-based perovskite solar cells: optimized device architecture and performance analysis via SCAPS-1D simulation

This study aims to develop a sustainable, high-efficiency Cs₂SnBr₆-based perovskite solar cell (PSC) while eliminating the use of hazardous materials. The proposed device architecture Al/FTO/CdS/Cs₂SnBr₆/CBTS/Ni (Device I) demonstrates an enhanced fill factor (FF) and an impressive power conversion efficiency (PCE). Key performance variables like perovskite layer depth, defect density, and the effects of series and shunt resistances are critically evaluated. Comparative analysis of various hole transport layers (HTLs: CBTS, P₃HT, and CuO) and electron transport layers (ETLs: CdS, SnO₂, and ZnSe) identifies CdS and CBTS as the most effective materials for achieving optimal performance. Simulation results obtained using SCAPS-1D reveal that Device I can achieve a short-circuit current density (J_SC) of 33.084 mA/cm², an open-circuit voltage (V_OC) of 1.111 V, an FF of 88.82%, and a PCE of 32.65% under AM 1.5 solar illumination, with a perovskite thickness of 1.0 µm and ETL/HTL thicknesses of 0.05 µm. Devices II and III recorded PCEs of 30.59% and 23.25%, respectively. In addition, quantum efficiency (QE), carrier dynamics, and temperature effects were thoroughly analyzed. Device I demonstrated significant potential for the development of high-efficiency, fully inorganic Cs₂SnBr₆-based PSCs. The findings support the viability of Cs₂SnBr₆ as a sustainable and environmentally friendly material for next-generation solar energy technologies.