Polyaniline/Reduced Graphene Oxide Composites for Hole Transporting Layer of High-Performance Inverted Perovskite Solar Cells.

We herein address the optoelectronic properties of polyaniline composite films with graphene oxide and reduced graphene oxide as a hole transport layer in inverted perovskite solar cells. The composite films exhibited enhanced electrical conductivity and suitable energy level matching with CH3NH3PbI3 for efficient hole extraction/transport than the pristine polyaniline film, which thus can deliver improved photovoltaic properties of device. The composite film-based devices exhibited maximum efficiency of 16.61%, which is enhanced by 21.6% from the device with the pristine polyaniline hole transport layer (efficiency = 13.66%). The reduced graphene oxide-based composite film also achieved improved long-term operative stability as compared to the pristine polyaniline-based device, demonstrating a great potential of reduced graphene oxide/polyaniline composite hole transport layer for high performance perovskite solar cells.