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Perovskite‐Derivative Valleytronics
Author(s) -
Liang Jia,
Fang Qiyi,
Wang Hua,
Xu Rui,
Jia Shuai,
Guan Yuxuan,
Ai Qing,
Gao Guanhui,
Guo Hua,
Shen Kaijun,
Wen Xiewen,
Terlier Tanguy,
Wiederrecht Gary P.,
Qian Xiaofeng,
Zhu Hanyu,
Lou Jun
Publication year - 2020
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.202004111
Subject(s) - valleytronics , materials science , perovskite (structure) , halide , optoelectronics , electronics , nanotechnology , engineering physics , physics , condensed matter physics , chemistry , inorganic chemistry , spintronics , crystallography , ferromagnetism
Halide perovskites are revolutionizing the renewable energy sector owing to their high photovoltaic efficiency, low manufacturing cost, and flexibility. Their remarkable mobility and long carrier lifetime are also valuable for information technology, but fundamental challenges like poor stability under an electric field prevent realistic applications of halide perovskites in electronics. Here, it is discovered that valleytronics is a promising route to leverage the advantages of halide perovskites and derivatives for information storage and processing. The synthesized all‐inorganic lead‐free perovskite derivative, Cs 3 Bi 2 I 9 , exhibits strong light–matter interaction and parity‐dependent optically addressable valley degree of freedom. Robust optical helicity in all odd‐layer‐number crystals with inversion symmetry breaking is observed, indicating excitonic coherence extending well beyond 11 layers. The excellent optical and valley properties of Cs 3 Bi 2 I 9 arise from the unique parallel bands, according to first principles calculations. This discovery points to new materials design principles for scalable valleytronic devices and demonstrates the promise of perovskite derivatives beyond energy applications.