Limiting Perovskite Solar Cell Performance by Heterogeneous Carrier Extraction |
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| Authors: | Dr Wenming Tian Rongrong Cui Dr Jing Leng Junxue Liu Yajuan Li Chunyi Zhao Prof Dr Jun Zhang Prof Dr Weiqiao Deng Prof Dr Tianquan Lian Prof Dr Shengye Jin |
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| Institution: | 1. 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), Dalian, China;2. Department of Chemistry, China University of Petroleum, Qingdao, China;3. Department of Chemistry, Emory Univeristy, Atlanta, GA, USA |
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| 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 cm2 s?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. |
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| Keywords: | charge carriers grain boundaries perovskites photoluminescence mapping solar cells |
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