Heterojunction‐Depleted Lead‐Free Perovskite Solar Cells with Coarse‐Grained B‐γ‐CsSnI3 Thin Films |
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Authors: | Ning Wang Yuanyuan Zhou Ming‐Gang Ju Hector F Garces Tao Ding Shuping Pang Xiao Cheng Zeng Nitin P Padture Xiao Wei Sun |
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Institution: | 1. Luminous! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore;2. School of Engineering, Brown University, Providence, RI, USA;3. Department of Chemistry, University of Nebraska‐Lincoln, NE, USA;4. Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, P. R. China;5. Department of Electrical and Electronic Engineering, College of Engineering, South University of Science and Technology of China, Shenzhen, P. R. China |
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Abstract: | Perovskite solar cells (PSCs) have been emerging as a breakthrough photovoltaic technology, holding unprecedented promise for low‐cost, high‐efficiency renewable electricity generation. However, potential toxicity associated with the state‐of‐the‐art lead‐containing PSCs has become a major concern. The past research in the development of lead‐free PSCs has met with mixed success. Herein, the promise of coarse‐grained B‐γ‐CsSnI3 perovskite thin films as light absorber for efficient lead‐free PSCs is demonstrated. Thermally‐driven solid‐state coarsening of B‐γ‐CsSnI3 perovskite grains employed here is accompanied by an increase of tin‐vacancy concentration in their crystal structure, as supported by first‐principles calculations. The optimal device architecture for the efficient photovoltaic operation of these B‐γ‐CsSnI3 thin films is identified through exploration of several device architectures. Via modulation of the B‐γ‐CsSnI3 grain coarsening, together with the use of the optimal PSC architecture, planar heterojunction‐depleted B‐γ‐CsSnI3 PSCs with power conversion efficiency up to 3.31% are achieved without the use of any additives. The demonstrated strategies provide guidelines and prospects for developing future high‐performance lead‐free PVs. |
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Keywords: | CsSnI3 lead‐free perovskite solar cells grain coarsening heterojunction‐depleted |
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