Solution-processed barium hydroxide modified boron-doped ZnO bilayer electron transporting materials: Toward stable perovskite solar cells with high efficiency of over 20.5.

ZnO as an electron transporting material (ETM) in perovskite solar cells has many benefits, including low temperature processability and high mobility. We explore here for the first time, hysteresis-less mesostructured perovskite solar cells with an incredible steady-state efficiency of 20.62% particularly enhancement of the device stability. We anticipated a device structure consisting of a novel fully-solution-processed and low-temperature barium hydroxide hybridized boron-doped ZnO (B:ZnO) bilayer film as electron transport material (ETM). We modify the design of ETMs with reduced trap states density is very crucial to obtain highly stabilized power conversion efficiency (PCE) and adjustable architectures in perovskite solar cells which should produce an impact on emerging highly efficient devices and their future commercialization.