title: Hole selective NiO contact for efficient perovskite solar cells with carbon electrode.
abstract: In this study, we communicate an investigation on efficient CH3NH3PbI3-based solar cells with carbon electrode using mesoporous TiO2 and NiO layers as electron and hole selective contacts. The device possesses an appreciated power conversion efficiency of 14.9% under AM 1.5G illumination. The detailed information can be disclosed with impedance spectroscopy via tuning the interfaces between CH3NH3PbI3 and different charge selective contacts. The results clearly show charge accumulation at the interface of CH3NH3PbI3. The NiO is believed to efficiently accelerate charge extraction to the external circuit. The extracted charge could improve photovoltaic performance by shifting hole Fermi level down, achieving a high device photovoltage. A fast interfacial recombination at the interface of CH3NH3PbI3/electron selective contact layer (mesoporous TiO2), occurring in millisecond domains, is the critical issue for charge carrier recombination loss.
authors: †Michael Grätzel Centre for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P. R. China.|‡Department of Materials Science and Engineering, University of California, Los Angeles, California 90095, United States.
authors: Xiaobao
authors: X
authors: Xu
authors: †Michael Grätzel Centre for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P. R. China.
authors: Zonghao
authors: Z
authors: Liu
authors: †Michael Grätzel Centre for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P. R. China.
authors: Zhixiang
authors: Z
authors: Zuo
authors: †Michael Grätzel Centre for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P. R. China.
authors: Meng
authors: M
authors: Zhang
authors: †Michael Grätzel Centre for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P. R. China.
authors: Zhixin
authors: Z
authors: Zhao
authors: †Michael Grätzel Centre for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P. R. China.
authors: Yan
authors: Y
authors: Shen
authors: ‡Department of Materials Science and Engineering, University of California, Los Angeles, California 90095, United States.
authors: Huanping
authors: H
authors: Zhou
authors: ‡Department of Materials Science and Engineering, University of California, Los Angeles, California 90095, United States.
authors: Qi
authors: Q
authors: Chen
authors: ‡Department of Materials Science and Engineering, University of California, Los Angeles, California 90095, United States.
authors: Yang
authors: Y
authors: Yang
authors: †Michael Grätzel Centre for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P. R. China.
authors: Mingkui
authors: M
authors: Wang
keywords: Perovskite; impedance; interface charge transfer; metal oxide; solar cell