Progress in Preparation of Electron Transport Layer in Perovskite Solar Cell

Electron transport layer (ETL) plays an important role in improving the performance and stability of perovskite solar cells (PSCs). SnO 2 is a good semiconductor material with high electromigration and wide band gap. TiO 2 has the advantages of superior position of conducting band (CB), long electronic life and low preparation cost, so SnO 2 and TiO 2 are often used in ETL of PSCs. In this paper, the preparation progress of SnO 2 , TiO 2 and SnO 2 /TiO 2 composite ETL is reviewed.