High performance planar perovskite solar cells based on CH3NH3PbI3-x(SCN)x perovskite film and SnO2 electron transport layer prepared in ambient air with 70% humility

Abstract

In this work, the efficient and stable planar perovskite solar cells (PSCs) based on CH3NH3PbI3-x(SCN)x perovskite layer and low-temperature processed SnO2 electron transport layer (ETL) have been fabricated in ambient air with 70% humility. The maximum processing temperature of the PSCs is only 150 °C. The effect of SnO2 solution concentrations on photoelectronic characteristics of the PSCs has been symmetrically investigated. At the optimized SnO2 concentration, the PSCs based on SnO2 ETL (SnO2-PSCs) achieve the champion power conversion efficiency (PCE) of 16.23% and average PCE of 15.82%, being much higher than that of the reference PSCs based on TiO2 ETL. The higher PCE of SnO2-PSCs can be attributed to the improved carrier transfer and collection, and the suppressed charge recombination. Importantly, the SnO2-PSCs without encapsulation demonstrate an excellent long-term stability. After being stored in ambient air with 70% humidity for 30 days, the PCE of the unsealed SnO2-PSCs decay only 15%. This work presents a simple low-temperature solution method to fabricate efficient and stable PSCs in ambient air with high humidity, which is beneficial for future application of PSCs.