Post-Treatment Strategies Toward High-Quality Sb₂Se₃ Thin Films in Photovoltaic Applications

Antimony selenide (Sb₂Se₃) has attracted increasing attention as a promising photovoltaic absorber due to its superior optoelectronic properties and ample application potential in thin-film solar cells. High-performance Sb₂Se₃ solar cell is closely tied to the quality of Sb₂Se₃ active layer, which requires careful design of the interfacial and bulk defects, as well as crystallinity of the thin films. Postprocessing procedures show great potential to address defect issues and improve the conductivity of solar cells. Therefore, developing efficient and reliable post-treatment techniques is crucial for advancing Sb₂Se₃ solar cell technology. In this review, recent post-treatment methodologies are summarized toward high-quality Sb₂Se₃ thin films, categorizing the strategies into two main types: thermal annealing (TA)-related techniques and TA-free techniques. Furthermore, the effects of these strategies are discussed on Sb₂Se₃ crystal characteristics, including defects, optoelectronic properties, and film morphology, all of which are closely related to device performance. Finally, the critical challenges and perspectives are proposed regarding this new solar cell materials, practical guidelines are also provided for fabricating high-quality Sb₂Se₃ layers for highly efficient Sb₂Se₃ solar cells.