Matching Charge Extraction Contact for Wide‐Bandgap Perovskite Solar Cells |
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| Authors: | Yuze Lin Bo Chen Fuwen Zhao Xiaopeng Zheng Yehao Deng Yuchuan Shao Yanjun Fang Yang Bai Chunru Wang Jinsong Huang |
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| Affiliation: | 1. Department of Mechanical and Materials Engineering and Nebraska Center for Materials and Nanoscience, University of Nebraska‐Lincoln, Lincoln, NE, USA;2. Institute of Chemistry, Chinese Academy of Sciences, Beijing, China;3. Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA |
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| Abstract: | Efficient wide‐bandgap (WBG) perovskite solar cells are needed to boost the efficiency of silicon solar cells to beyond Schottky–Queisser limit, but they suffer from a larger open circuit voltage (VOC) deficit than narrower bandgap ones. Here, it is shown that one major limitation of VOC in WBG perovskite solar cells comes from the nonmatched energy levels of charge transport layers. Indene‐C60 bisadduct (ICBA) with higher‐lying lowest‐unoccupied‐molecular‐orbital is needed for WBG perovskite solar cells, while its energy‐disorder needs to be minimized before a larger VOC can be observed. A simple method is applied to reduce the energy disorder by isolating isomer ICBA‐tran3 from the as‐synthesized ICBA‐mixture. WBG perovskite solar cells with ICBA‐tran3 show enhanced VOC by 60 mV, reduced VOC deficit of 0.5 V, and then a record stabilized power conversion efficiency of 18.5%. This work points out the importance of matching the charge transport layers in perovskite solar cells when the perovskites have a different composition and energy levels. |
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| Keywords: | fullerene isomers perovskites solar cells wide bandgap |
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