LAUSR

Abstract Unavoidable impurities form in Sb2S3 absorber fabricated by conventional chemical bath deposition method which is harmful to the photovoltaic performance of Sb2S3-sensitized solar cells. To obtain high quality Sb2S3 absorber, a two-step template method is introduced to deposit Sb2S3 on mesoporous TiO2 film. This template method is performed by dipping ZnS-coated TiO2 films in a Sb source solution for several minutes. This low temperature method with short operation time allows large area deposition of Sb2S3. Properties of ZnS and Sb2S3 are systematically studied. X-ray photoelectron spectroscopy confirms the absence of impurities. The optimized Sb2S3 device exhibits a power conversion efficiency (PCE) of 3.69%, with an open-circuit voltage of 0.514 V, a short-circuit current-density of 12.14 mA/cm2, and a fill factor of 59.1% under AM 1.5G illumination which is better than the device fabricated by chemical bath deposition. The PCE of our Sb2S3 devices showed an obvious increase after 1–2 months storage which may be caused by reconstruction of the ZnS/Sb2S3 coating fabricated by partial cation exchange.