Fabrication of Sb2S3 thin films by magnetron sputtering and post-sulfurization/selenization for substrate structured solar cells

Antimony sulphide (Sb2S3) as an environment-friendly and cost-efficiently photovoltaic material has drawn tremendous research attentions. To broaden its scope of applications as flexible or tandem devices, Sb2S3 solar cells with substrate structure that are rarely reported and really need further exploration. In this work, an efficient method of magnetron sputtering using Sb2S3 target followed with post-sulfurization or post-selenization heat treatment process has been used to prepare S–Sb2S3 and Se–Sb2S3 thin films, then substrate structured Sb2S3 solar cells with configuration of Mo/Sb2S3/CdS/ITO/Ag were fabricated. The solar cell based on crystalline S–Sb2S3 thin film can achieve power conversion efficiency (PCE) of 0.49%. In contrast, a post-selenization treatment can induce the formation of Sb2(S,Se)3 ternary phase and obtain high-quality thin film with uniform granular crystals. The corresponding substrate structured thin film solar cell shows a significant two times improvement of PCE to 0.95%, also with an increased external quantum efficiency (EQE) value and an extended response region, which can be attributed to the Se–Sb2S3 thin films with lower band gap, better crystallinity and less recombination loss. The combined features of advantageous vacuum preparation process and efficient substrate device structure further demonstrated its attractive application potential in thin film photovoltaic scenarios.