Slow photocharging and reduced hysteresis in low-temperature processed planar perovskite solar cells

Abstract

High efficient organolead trihalide perovskite solar cells typically utilize high temperature processed TiO₂ as the electron transporting layer (ETL). A new method for the preparation of low temperature processed amorphous TiO₂ as the ETL in planar perovskite solar cells is demonstrated. The proposed technique allowed the entire fabrication of perovskite solar cells with power conversion efficiencies as high as 13.7%, to take place at temperatures lower than 150 °C. We revealed that the source of device efficiency lies in the fast and balanced charge transport within the selective contacts as well as the effective charge extraction from the perovskite.