Interface Engineering of Cubic Zinc Metatitanate as an Excellent Electron Transport Material for Stable Perovskite Solar Cells

Perovskite solar cells (PSCs) have experienced considerable development in the past few years. The stability issue has become a focus of research efforts toward their commercial applications. The development and interface engineering of electron transport materials (ETMs) to build up stable interfaces with perovskites has been emerging as a powerful strategy to enhance PSCs' stability. Herein, cubic zinc metatitanate (ZTO) is identified as an excellent ETM with interface engineering treatment of dezincification for fabricating PSCs with much better overall performances than those fabricated from TiO2, a popularly used ETM. The high electron mobility of ZTO helps minimize the hysteresis. Together with the use of CuSCN as inorganic hole transport material and further protecting the PSCs with reduced graphene oxide, the ZTO-based PSCs exhibit remarkable enhancement in stability, retaining 95% of initial power conversion efficiency under AM 1.5 G illumination at 85 degrees C and 85% relative humidity in air for 1000 h at open circuit.