Valorizing Sb ₂ S ₃ Ore through Vapor Transport Deposition and Thiourea Treatment: A “Stone-to-Gold” Strategy for High-Efficiency Thin-Film Photovoltaics

Antimony sulfide (Sb2S3) has demonstrated significant application potential in the photovoltaic industry due to its excellent electrical properties and abundance of antimony ore reserves. China, as the world’s largest holder of antimony resources, possesses substantial reserves. However, these resources remain underexploited in high-tech applications, particularly in the field of photovoltaics. Here, we propose an integrated physicochemical treatment and resource recovery strategy to directly transform crude antimony ore into high-efficiency thin-film solar cells. We first implemented a pretreatment process to remove major silica (SiO2) impurities from the raw ore. Subsequently, a novel in situ self-purification process for Sb2S3 is achieved through vapor transport deposition (VTD), enabling the fabrication of high-purity, large-grain, and highly uniform Sb2S3 thin films. Furthermore, in view of the common sulfur deficiency in the formation process of natural Sb2S3 minerals, which leads to sulfur vacancies in VTD-Sb2S3 films, thiourea (TU) treatment was further developed to effectively compensate for the sulfur content through a hydrothermal reaction. As a result, the power conversion efficiency (PCE) of Sb2S3 thin-film solar cells is significantly enhanced to 4.67%, offering a feasible technical pathway for the photovoltaic utilization of crude antimony ores, contributing to sustainable resource cycling and providing a platform for further development of mineral-based energy materials.