Superstrate structured Sb${}_2$S${}_3$ thin-film solar cells by magnetron sputtering of Sb and post-sulfurization

Abstract

We report on the fabrication and optimization of semi-transparent antimony sulfide (Sb${}_2$S${}_3$) thin-film solar cells in a superstrate configuration, using RF magnetron sputtering of metallic antimony followed by post-deposition sulfurization. The influence of absorber and buffer layer thicknesses on device performance was systematically studied in FTO/CdS/Sb${}_2$S${}_3$/Spiro-OMeTAD/Au architectures. Optimizing the Sb${}_2$S${}_3$ absorber thickness to 100 nm yielded a champion device with a power conversion efficiency of 2.76\%, short-circuit current density of 14 mA/cm${}^2$, and open-circuit voltage of 650 mV. The devices exhibit up to 20\% transmittance in the 380--740 nm wavelength range, indicating their suitability for indoor and building-integrated photovoltaic applications. Structural and compositional analyses confirmed high-purity Sb${}_2$S${}_3$ (more than 90 at.\%) and improved crystallinity after sulfurization. These results demonstrate the potential of sputtered Sb${}_2$S${}_3$ as a scalable and tunable absorber for emerging transparent thin-film solar technologies and highlight the critical role of thickness optimization and interface control in device performance.