Scalable and efficient Sb₂S₃ thin-film solar cells fabricated by close space sublimation

Antimony sulfide as a cost-effective, low-toxic, and earth-abundant solar cell absorber with the desired bandgap was successfully deposited using a scalable close space sublimation technique. The deposition process can separately control the substrate and source temperature with better engineering of the absorber quality. The device performance can reach 3.8% with the configuration of glass/FTO/CdS/Sb₂S₃/graphite back contact. The defect formation energy and the corresponding transition levels were investigated in detail using theoretical calculations. Our results suggest that Sb₂S₃ exhibits intrinsic p-type owing to S-on-Sb antisites (S_Sb) and the device performance is limited by the S vacancies. The localized conduction characterization at nanoscale shows that the non-cubic Sb₂S₃ has conductive grains and benign grain boundaries. The study of the defects, microstructure, and nanoscale conduction behavior suggests that Sb₂S₃ could be a promising photovoltaic candidate for scalable manufacturing.