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

TL;DR

This study demonstrates the fabrication of semi-transparent Sb$_2$S$_3$ thin-film solar cells via magnetron sputtering and sulfurization, achieving a 2.76% efficiency with potential for indoor and building-integrated applications.

Contribution

It introduces a scalable sputtering and sulfurization method for high-purity Sb$_2$S$_3$ thin films and optimizes device architecture for improved performance.

Findings

Achieved 2.76% power conversion efficiency.

Demonstrated up to 20% transmittance in visible range.

Optimized absorber thickness to 100 nm.

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.