Benzophosphole Oxide and Sulfide for Thermally Stable Cathode Buffer Layers in Organic Thin‐Film Photovoltaic Devices

Abstract

Don′t touch! Benzophosphole derivatives, which have a high glass transition temperature and resistance to crystallization, are shown to be useful as cathode buffer materials for OPV devices. The benzophosphole-based devices showed an improvement in power conversion efficiency by annealing, which can be ascribed to the decrease in the contact resistance between the buffer layer and the adjoining layers.