Efficient SnO2/CdS double electron transport layer for Sb2S3 film solar cell

Abstract Sb2S3 has been proven to be a very promising light absorbing material for photovoltaic applications due to its low cost, high stability, non-toxicity, and abundant elemental storage. Electron transport layer (ETL) is a very crucial factor to the performances of Sb2S3 solar cells. Here we developed a simple chemical solution process method to synthesize SnO2 colloidal and fabricated SnO2 ETL at low-temperature first, and then SnO2/CdS double ETL was prepared by combining SnO2 and CdS. The power conversion efficiency of Sb2S3 solar cell is 5.3% based on the SnO2/CdS double ETL, whereas the device based on CdS ETL only exhibites a PCE of 4.3%. Experimental analyses revealed that the introduction of SnO2 ETL enhanced the grain size of Sb2S3 films and passivated interfacial defects thus enhancing device efficiency. Our results show the potential application of SnO2 in the planar Sb2S3 solar cell.