▎ 摘　　要

Charge separation in CH3NH3PbI3 (MAPbI(3)) films deposited on a hydrogen doped indium oxide (In2O3:H) photoelectrode was investigated by modulated surface photovoltage (SPV) spectroscopy in a fixed capacitor arrangement. It was found that In2O3:H reproducibly extracts photogenerated-holes from MAPbI(3) films. The oxygen-plasma treatment of the In2O3:H surface is suggested to be a reason for this phenomenon. Introducing graphene interlayer increased charge separation nearly 6 times as compared to that on the In2O3:H/MAPbI(3) interface. Furthermore, it is confirmed by SPV spectroscopy that the defects of the MAPbI(3) interface are passivated by graphene. Published by AIP Publishing.