title: Water-Soluble Polymeric Interfacial Material for Planar Perovskite Solar Cells.
abstract: Interfacial materials play a critical role in photoelectric conversion properties as well as the anomalous hysteresis phenomenon of the perovskite solar cells (PSCs). In this article, a water-soluble polythiophene PTEBS was employed as a cathode interfacial material for PSCs. Efficient energy level aligning and improved film morphology were obtained due to an ultrathin coating of PTEBS. Better ohmic contact between the perovskite layer and the cathode also benefits the charge transport and extraction of the device. Moreover, less charge accumulation at the interface weakens the polarization of the perovskite resulting in a relatively quick response of the modified device. The ITO/PTEBS/CH3NH3PbI3/spiro-MeOTAD/Au cells by an all low-temperature process achieved power conversion efficiencies of up to 15.4% without apparent hysteresis effect. Consequently, the utilization of this water-soluble polythiophene is a practical approach for the fabrication of highly efficient, large-area, and low-cost PSCs and compatible with low-temperature solution process, roll-to-roll manufacture, and flexible application.
authors.affiliation: School of Energy Research, Xiang'an Campus, Xiamen University , Xiamen 361100, Fujian China.|Renewable Energy Research Group (RERG), Department of Building Services Engineering, The Hong Kong Polytechnic University , Hong Kong, China.
authors.forename: Lingling
authors.identifier: http://orcid.org/0000-0001-7333-2768
authors.initials: L
authors.lastname: Zheng
authors.affiliation: State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University , Beijing 100871, China.
authors.forename: Yingzhuang
authors.initials: Y
authors.lastname: Ma
authors.affiliation: State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University , Beijing 100871, China.|Co-Innovation Center for Micro/Nano Optoelectronic Materials and Devices, Chongqing University of Arts and Sciences , Yongchuan Chongqing 402160, P.R.China.
authors.forename: Lixin
authors.initials: L
authors.lastname: Xiao
authors.affiliation: School of Energy Research, Xiang'an Campus, Xiamen University , Xiamen 361100, Fujian China.
authors.forename: Fengyan
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Faculty of Science and Technology, Technological and Higher Education Institute of Hong Kong , New Territories, Hong Kong, China.
authors.forename: Yuanhao
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Renewable Energy Research Group (RERG), Department of Building Services Engineering, The Hong Kong Polytechnic University , Hong Kong, China.
authors.forename: Hongxing
authors.initials: H
authors.lastname: Yang
keywords: hysteresis effect; impedance analysis; interfacial materials; planar perovskite solar cells; water-soluble