Plasma etching-Induced surface modification and interfacial defect passivation for antimony triselenide thin film solar cells

Sb2Se3 is a promising photovoltaic absorber material due to its high optical absorption coefficient, suitable band gap, and earth-abundant constituent elements. However, the performance of Sb2Se3-based solar cells faces limitations stemming from the suboptimal quality of the Sb2Se3/CdS heterojunction, which suffers from high interfacial recombination loss and low carrier collection efficiency. To address this issue, we employ plasma etching as a simple and effective method to modify the surface of Sb2Se3 thin films, which are prepared using sputtering and post-selenization processes. Our investigation reveals that plasma etching not only increases the surface roughness of Sb2Se3 but also diminishes the presence of the detrimental Sb2O3 impurity phase, leading to improved device performance. As a result, the plasma etched Sb2Se3 devices exhibit improved fill factor and current density and achieve a maximum efficiency of 7.88 %. This study underscores the critical role of surface engineering in enhancing Sb2Se3 solar cells performance and offers a convenient and scalable approach for enhancing the interface quality of such devices.