Spray-coated copper antimony sulfide (CuSbS2) thin film: A novel counter electrode for quantum dot-sensitized solar cells

The catalytic activity and charge transport characteristics of counter electrodes exert a significant impact on the photovoltaic performance of quantum dot-sensitized solar cells (QDSCs). Layered metal chalcogenides have received particular interest owning to their novel electronic properties. In this work, we report for the first time the use of layer-structured copper antimony sulfide (CuSbS2) for serving as the counter electrode materials for QDSCs. The CuSbS2 thin films were fabricated on conducting substrates through spray pyrolysis followed by a sulfuration process. The careful crystal phase and morphology characterizations reveal that as-obtained CuSbS2 thin films display long-range uniformity with flat film surfaces. A CuSbS2 counter electrode-based CdS/CdSe QDSC delivers a considerable power conversion efficiency of 2.15%. In contrast to the conventional noble Pt electrodes, spray-coated CuSbS2 counter electrodes exhibit higher catalytic activity for catalyzing polysulfide electrolyte regeneration. This work offers a promising counter electrode with superior catalytic capability for constructing highly efficient QDSCs.