title: Limiting Perovskite Solar Cell Performance by Heterogeneous Carrier Extraction.
abstract: Although the power conversion efficiency of perovskite solar cells has improved rapidly, a rational path for further improvement remains unclear. The effect of large morphological heterogeneity of polycrystalline perovskite films on their device performance by photoluminescence (PL) microscopy has now been studied. Contrary to the common belief on the deleterious effect of morphological heterogeneity on carrier lifetimes and diffusivities, in neat CH3NH3PbI3(Cl) polycrystalline perovskite films, the local (intra-grain) carrier diffusivities in different grains are all surprisingly high (1.5 to 3.3 cm2s-1; comparable to bulk single-crystals), and the local carrier lifetimes are long (ca. 200 ns) and surprisingly homogenous among grains, and uniform across grain boundary and interior. However, there is a large heterogeneity of carrier extraction efficiency at the perovskite grain-electrode interface. Improving homogeneity at perovskite grain-electrode contacts is thus a promising direction for improving the performance of perovskite thin-film solar cells.
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), 457 ZhongShan Rd., Dalian, 116023, China.
authors.forename: Wenming
authors.initials: W
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), 457 ZhongShan Rd., Dalian, 116023, China.
authors.forename: Rongrong
authors.initials: R
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), 457 ZhongShan Rd., Dalian, 116023, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Leng
authors.affiliation: Department of Chemistry, China University of Petroleum, 66 Changjiang West Rd., Huangdao District, Qingdao, 266580, China.
authors.forename: Junxue
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), 457 ZhongShan Rd., Dalian, 116023, China.
authors.forename: Yajuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), 457 ZhongShan Rd., Dalian, 116023, China.
authors.forename: Chunyi
authors.initials: C
authors.lastname: Zhao
authors.affiliation: Department of Chemistry, China University of Petroleum, 66 Changjiang West Rd., Huangdao District, Qingdao, 266580, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), 457 ZhongShan Rd., Dalian, 116023, China.
authors.forename: Weiqiao
authors.initials: W
authors.lastname: Deng
authors.affiliation: Department of Chemistry, Emory Univeristy, 1515 Dickey Drive, Atlanta, GA, USA. tlian@emory.edu.
authors.forename: Tianquan
authors.initials: T
authors.lastname: Lian
authors.affiliation: State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), 457 ZhongShan Rd., Dalian, 116023, China. sjin@dicp.ac.cn.
authors.forename: Shengye
authors.initials: S
authors.lastname: Jin
keywords: charge carriers; grain boundaries; perovskites; photoluminescence mapping; solar cells