Highly Efficient and Stable Perovskite Solar Cells\nby Interfacial Engineering Using Solution-Processed Polymer Layer

Abstract

Solution-processed organo-lead halide\nperovskite solar cells with\ndeep pinholes in the perovskite layer lead to shunt-current leakage\nin devices. Herein, we report a facile method for improving the performance\nof perovskite solar cells by inserting a solution-processed polymer\nlayer between the perovskite layer and the hole-transporting layer.\nThe photovoltaic conversion efficiency of the perovskite solar cell\nincreased to 18.1% and the stability decreased by only about 5% during\n20 days of exposure in moisture ambient conditions through the incorporation\nof a poly­(methyl methacrylate) (PMMA) polymer layer. The improved\nphotovoltaic performance of devices with a PMMA layer is attributed\nto the reduction of carrier recombination loss from pinholes, boundaries,\nand surface states of perovskite layer. The significant gain generated\nby this simple procedure supports the use of this strategy in further\napplications of thin-film optoelectronic devices.