Controlling Nucleation and Growth of Metal Halide Perovskite Thin Films for High‐Efficiency Perovskite Solar Cells |
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| Authors: | Nobuya Sakai Zhiping Wang Victor M. Burlakov Jongchul Lim David McMeekin Sandeep Pathak Henry J. Snaith |
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| Affiliation: | 1. Department of Physics, University of Oxford, Clarendon Laboratory, Oxford, UK;2. Mathematical Institute, University of Oxford, Andrew Wiles Building, Radcliffe Observatory Quarter, Oxford, UK;3. Center for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India |
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| Abstract: | Metal halide perovskite thin films can be crystallized via a broad range of solution‐based routes. However, the quality of the final films is strongly dependent upon small changes in solution composition and processing parameters. Here, this study demonstrates that a fractional substitution of PbCl2 with PbI2 in the 3CH3NH3I:PbCl2 mixed‐halide starting solution has a profound influence upon the ensuing thin‐film crystallization. The presence of PbI2 in the precursor induces a uniform distribution of regular quadrilateral‐shaped CH3NH3PbI3 perovskite crystals in as‐cast films, which subsequently grow to form pinhole‐free perovskite films with highly crystalline domains. With this new formulation of 3CH3NH3I:0.98PbCl2:0.02PbI2, this study achieves a 19.1% current–voltage measured power conversion efficiency and a 17.2% stabilized power output in regular planar heterojunction solar cells. |
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| Keywords: | lead halide mix nucleation perovskite photovoltaics thin‐film crystallization |
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