title: Hole-conductor-free perovskite solar cells with carbon counter electrodes based on ZnO nanorod arrays.
abstract: A one dimensional nanostructure array has been considered as a successful charge transport material for perovskite solar cells (PSCs), because of its large internal surface area, superior charge collection efficiency and fast charge transport. Herein we demonstrate a ZnO nanorod (NR) array as the electron collector in a hole-conductor-free PSC with a carbon counter electrode (CE). A relatively low initial power conversion efficiency (PCE) of 5.6% was achieved using a 1 μm long ZnO NR array as an electron collector. However, by introduction of a thin TiO2coating layer on the surface of ZnO via TiCl4treatment, the PCE of the cell has been improved to the highest value of 8.24%. It is revealed that the performance enhancement of the ZnO/TiO2NR based PSCs is largely attributed to the larger surface area, reduced electron combination, and superior electron transport properties.
authors.affiliation: Institute of Nano-science and Technology, Central China Normal University, Wuhan, 430079, China. ywtang@phy.ccnu.edu.cn.
authors.forename: B X
authors.initials: BX
authors.lastname: Wang
authors.affiliation: Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China. hongwei.han@mail.hust.edu.cn.
authors.forename: T F
authors.initials: TF
authors.lastname: Liu
authors.affiliation: Institute of Nano-science and Technology, Central China Normal University, Wuhan, 430079, China. ywtang@phy.ccnu.edu.cn.
authors.forename: Y B
authors.initials: YB
authors.lastname: Zhou
authors.affiliation: Institute of Nano-science and Technology, Central China Normal University, Wuhan, 430079, China. ywtang@phy.ccnu.edu.cn.
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.affiliation: Institute of Nano-science and Technology, Central China Normal University, Wuhan, 430079, China. ywtang@phy.ccnu.edu.cn.
authors.forename: X B
authors.initials: XB
authors.lastname: Yuan
authors.affiliation: Institute of Nano-science and Technology, Central China Normal University, Wuhan, 430079, China. ywtang@phy.ccnu.edu.cn.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Yang
authors.affiliation: Institute of Nano-science and Technology, Central China Normal University, Wuhan, 430079, China. ywtang@phy.ccnu.edu.cn.
authors.forename: W P
authors.initials: WP
authors.lastname: Liu
authors.affiliation: Institute of Nano-science and Technology, Central China Normal University, Wuhan, 430079, China. ywtang@phy.ccnu.edu.cn.
authors.forename: J M
authors.initials: JM
authors.lastname: Wang
authors.affiliation: Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, 430074, China. hongwei.han@mail.hust.edu.cn.
authors.forename: H W
authors.initials: HW
authors.lastname: Han
authors.affiliation: Institute of Nano-science and Technology, Central China Normal University, Wuhan, 430079, China. ywtang@phy.ccnu.edu.cn.
authors.forename: Y W
authors.initials: YW
authors.lastname: Tang