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

Sb 2 S 3 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 Sb 2 S 3 solar cells. Here we developed a simple chemical solution process method to synthesize SnO 2 colloidal and fabricated SnO 2 ETL at low-temperature first, and then SnO 2 /CdS double ETL was prepared by combining SnO 2 and CdS. The power conversion efficiency of Sb 2 S 3 solar cell is 5.3% based on the SnO 2 /CdS double ETL, whereas the device based on CdS ETL only exhibites a PCE of 4.3%. Experimental analyses revealed that the introduction of SnO 2 ETL enhanced the grain size of Sb 2 S 3 films and passivated interfacial defects thus enhancing device efficiency. Our results show the potential application of SnO 2 in the planar Sb 2 S 3 solar cell.