Template deposition of Sb2S3 for solid-state sensitized solar cells

Unavoidable impurities form in Sb 2 S 3 absorber fabricated by conventional chemical bath deposition method which is harmful to the photovoltaic performance of Sb 2 S 3 -sensitized solar cells. To obtain high quality Sb 2 S 3 absorber, a two-step template method is introduced to deposit Sb 2 S 3 on mesoporous TiO 2 film. This template method is performed by dipping ZnS-coated TiO 2 films in a Sb source solution for several minutes. This low temperature method with short operation time allows large area deposition of Sb 2 S 3 . Properties of ZnS and Sb 2 S 3 are systematically studied. X-ray photoelectron spectroscopy confirms the absence of impurities. The optimized Sb 2 S 3 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/cm 2 , 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 Sb 2 S 3 devices showed an obvious increase after 1–2 months storage which may be caused by reconstruction of the ZnS/Sb 2 S 3 coating fabricated by partial cation exchange.