title: Nonreduction-Active Hole-Transporting Layers Enhancing Open-Circuit Voltage and Efficiency of Planar Perovskite Solar Cells.
abstract: Inverted planar perovskite solar cells using poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the hole-transporting layer (HTL) are very attractive because of their low-temperature and easy processing. However, the planar cells with the PEDOT:PSS HTL typically display lower open-circuit voltage (VOC) (about 0.90 V) than that of devices with TiO2-based conventional structure (1.0-1.1 V). The underlying reasons are still not clear. In this work, we report the PEDOT:PSS that is intrinsically p-doped can be chemically reduced by methylamine iodide (MAI) and MAPbI3. The reaction reduces the work function (WF) of PEDOT:PSS, which suppresses the efficient hole collection and yields lower VOC. To overcome this issue, we adopt undoped semiconducting polymers that are intrinsically nonreduction-active (NRA) as the HTL for inverted planar perovskite solar cells. The cells display enhanced VOCfrom 0.88 ± 0.04 V (PEDOT:PSS HTL, reference cells) to 1.02 ± 0.03 V (P3HT HTL) and 1.04 ± 0.03 V (PTB7 and PTB-Th HTL). The power conversion efficiency (PCE) of the devices with these NRA HTL reaches about 17%.
authors.affiliation: Wuhan National Laboratory for Optoelectronics, and School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.|Research Institute of Huazhong University of Science and Technology in Shenzhen , Shenzhen 518057, China.
authors.forename: Tiefeng
authors.initials: T
authors.lastname: Liu
authors.affiliation: Wuhan National Laboratory for Optoelectronics, and School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.|Research Institute of Huazhong University of Science and Technology in Shenzhen , Shenzhen 518057, China.
authors.forename: Fangyuan
authors.initials: F
authors.lastname: Jiang
authors.affiliation: Wuhan National Laboratory for Optoelectronics, and School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Qin
authors.affiliation: Wuhan National Laboratory for Optoelectronics, and School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Meng
authors.affiliation: Wuhan National Laboratory for Optoelectronics, and School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.|Research Institute of Huazhong University of Science and Technology in Shenzhen , Shenzhen 518057, China.
authors.forename: Youyu
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Wuhan National Laboratory for Optoelectronics, and School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Sixing
authors.initials: S
authors.lastname: Xiong
authors.affiliation: Wuhan National Laboratory for Optoelectronics, and School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Tong
authors.affiliation: Wuhan National Laboratory for Optoelectronics, and School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.|Research Institute of Huazhong University of Science and Technology in Shenzhen , Shenzhen 518057, China.
authors.forename: Zaifang
authors.initials: Z
authors.lastname: Li
authors.affiliation: Wuhan National Laboratory for Optoelectronics, and School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Wuhan National Laboratory for Optoelectronics, and School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China.|Research Institute of Huazhong University of Science and Technology in Shenzhen , Shenzhen 518057, China.
authors.forename: Yinhua
authors.initials: Y
authors.lastname: Zhou
keywords: PEDOT:PSS; hole-transporting layers; nonreduction-active; open-circuit voltage; perovskite solar cells