Sb2S3 as Hole Transport Layer Material Massively Enhances the Performance and Stability of Tin-Based Perovskite Solar Cell

This study presents a simulation-based analysis of a lead-free perovskite (CH₃NH₃SnI₃) photovoltaic (PV) solar cell, focusing on the replacement of the conventional organic hole transport layer (HTL), Spiro-OMeTAD, with inorganic Sb₂S₃ (antimony trisulfide). The simulation results (using SCAPS-1D) show that the proposed solar cell structure, fluorine-doped tin oxide (FTO)/SrTiO₃/CH₃NH₃SnI₃/Sb₂S₃/Au), achieves considerably improved energy level alignment and stronger interfacial electric fields, effectively suppressing recombination losses. The influence of absorber layer, electron transport layer, and HTL thickness is analyzed with respect to the solar cell performance. In addition, the effect of absorber layer defect density is examined to simulate the proposed solar cell design under as many practical conditions as possible. We also investigate the dark current density–voltage (J–V) behavior for a thermal range of 290–330 K. The simulation results demonstrate notable performance gains corresponding to optimized solar cell design (absorber thickness = 1000 nm, ETL thickness = 150 nm, and HTL thickness = 200 nm)—an increase in open-circuit voltage (V_OC) from 1.11 V to 1.19 V, short-circuit current density (J_SC) from 28.85 mA/cm² to 33.62 mA/cm², and fill factor from 88.5% to 89.5%—yielding massively enhanced power conversion efficiency of 36.5% compared to 28.5%. The proposed solar cell design exhibits a significantly reduced dark current (~10⁻¹⁰ mA/cm² at 0 V) and superior thermal stability, establishing Sb₂S₃ as a nontoxic, stable, and cost-effective HTL for advancing efficient, environmentally sustainable tin-based perovskite solar cells.