▎ 摘　　要

Graphene shows remarkably high mobility, electronic and thermal conductivity, which have been widely incorporated in solar cells as electron transport highway. Herein, graphene is incorporated in TiO2 compact layer as electron transport layer for cesium-containing perovskite (Cs-0.1(CH3NH3)(0.9)PbI3) solar cell. Introducing graphene effectively improves mobility of electron transport layer and reduce the quenching of perovskite photoluminescence, which is correlated with improved electron transport and extraction property. A significant improvement of power conversion efficiency from 11.2% to 15.4% is achieved (37% enhancement) through simply introducing graphene in TiO2 compact layer. The improved efficiency is mainly due to the improved fill factor. This work highlights the roles of graphene in facilitating electron transport and extraction at interface of perovskite and electron transport layer.