<p>Antimony sulfide (Sb₂S₃) is a promising material for solar energy conversion due to its favorable optoelectronic properties and environmental compatibility. In this study, we conduct a comprehensive numerical investigation of Sb₂S₃/CdS/ZnO:Al solar cells using SCAPS-1D software to evaluate the effect of key physical parameters. The impact of absorber thickness, defect densities, and operational temperature on device performance was systematically analyzed. Simulations revealed that the device efficiency improves significantly with increasing absorber thickness up to 1000&#xa0;nm, beyond which the gain becomes marginal. The simulated cell also maintains relatively stable performance across a temperature range of 270–360&#xa0;K, with only a modest efficiency drop attributed to reduced open-circuit voltage. Furthermore, variations in bulk defect concentration and defect type within the Sb₂S₃ layer demonstrate that donor-type defects are particularly detrimental at higher densities. These insights offer valuable guidelines for optimizing Sb₂S₃-based thin-film photovoltaics.</p> Graphical abstract <p></p>