Preparation of tin oxide thin films by liquid phase deposition method and their application to the electron transport layer of perovskite solar cells

Abstract We prepared a tin oxide (SnO 2 ) thin film using liquid phase deposition and used it as the electron transport layer (ETL) of perovskite solar cells. Moreover, the effect of the heat-treatment temperature of SnO 2 on solar cell characteristics was investigated. The conduction band level of SnO 2 decreased with increasing heat-treatment temperature. As a result, the energy levels were better matched at the SnO 2 /perovskite interface with the low heat-treatment temperature of SnO 2 , which led to a more efficient charge transfer from the perovskite layer to the SnO 2 ETL, thus improving its short-circuit current density ( J SC ). Additionally, it was confirmed that the SnO 2 heat-treated at 100 °C showed the highest donor concentration, improved J SC , and a maximum power conversion efficiency of 15.94%.