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Perovskite Bifunctional Device with Improved Electroluminescent and Photovoltaic Performance through Interfacial Energy‐Band Engineering
Author(s) -
Xie Jiangsheng,
Hang Pengjie,
Wang Han,
Zhao Shenghe,
Li Ge,
Fang Yanjun,
Liu Feng,
Guo Xinlu,
Zhu Hepeng,
Lu Xinhui,
Yu Xuegong,
Chan Christopher C. S.,
Wong Kam Sing,
Yang Deren,
Xu Jianbin,
Yan Keyou
Publication year - 2019
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201902543
Subject(s) - materials science , perovskite (structure) , bifunctional , electroluminescence , photovoltaic system , optoelectronics , band gap , halide , nanotechnology , layer (electronics) , chemical engineering , inorganic chemistry , electrical engineering , organic chemistry , chemistry , engineering , catalysis
Currently, photovoltaic/electroluminescent (PV/EL) perovskite bifunctional devices (PBDs) exhibit poor performance due to defects and interfacial misalignment of the energy band. Interfacial energy‐band engineering between the perovskite and hole‐transport layer (HTL) is introduced to reduce energy loss, through adding corrosion‐free 3,3′‐(2,7‐dibromo‐9 H ‐fluorene‐9,9‐diyl) bis( n , n ‐dimethylpropan‐1‐amine) (FN‐Br) into a HTL free of lithium salt. This strategy can turn the n‐type surface of perovskite into p‐type and thus correct the misalignment to form a well‐defined N–I–P heterojunction. The tailored PBD achieves a high PV efficiency of up to 21.54% (certified 20.24%) and 4.3% EL external quantum efficiency. Free of destructive additives, the unencapsulated devices maintain >92% of their initial PV performance for 500 h at maximum power point under standard air mass 1.5G illumination. This strategy can serve as a general guideline to enhance PV and EL performance of perovskite devices while ensuring excellent stability.