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  Kumar, S.H.B.V.; Muydinov, R.; Kol'tsova, T.; Erfurt, D.; Steigert, A.; Tolochko, O.; Szyszka, B.: Graphene assisted effective hole-extraction on In₂O₃:H/CH₃NH₃PbI₃ interface: Studied by modulated surface spectroscopy. Applied Physics Letters 112 (2018), p. 011604/1-3

10.1063/1.5017579

Abstract:
Charge separation in CH3NH3PbI3 (MAPbI3) 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 MAPbI3 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/MAPbI3 interface. Furthermore, it is confirmed by SPV spectroscopy that the defects of the MAPbI3 interface are passivated by graphene.