Reduced graphene oxide assisted charge separation and serving as transport pathways in planar perovskite photodetector

Abstract

Abstract Graphene derivatives have been intensively investigated as the electron transporting layer and conductive electrodes in perovskite optoelectronic devices. In this work, reduced graphene oxide (RGO) dispersed in nonpolar solvent was achieved by surfactant assisted phase transfer method. The hybrid perovskite/RGO film was prepared by antisolvent treatment. The volume ratio between perovskite and RGO solution is an important parameter that affects the perovskite device performance. The optimal ratio is 1:10 in perovskite photodetector owing to the high photocurrent and on/off ratio. However, lower or larger ratio would result in insufficient charge transfer or short circuit respectively. The spatially and temporally resolved measurements reveal the detailed charge transfer and transport process in the perovskite and RGO blends. RGO coupled with perovskite not only promotes charge transfer, but serves as the transport pathways, resulting in the improved performance of the device.