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Lead‐Free, Air‐Stable All‐Inorganic Cesium Bismuth Halide Perovskite Nanocrystals
Author(s) -
Yang Bin,
Chen Junsheng,
Hong Feng,
Mao Xin,
Zheng Kaibo,
Yang Songqiu,
Li Yajuan,
Pullerits Tõnu,
Deng Weiqiao,
Han Keli
Publication year - 2017
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201704739
Subject(s) - halide , nanocrystal , perovskite (structure) , passivation , photoluminescence , bismuth , caesium , materials science , chemical engineering , nanotechnology , inorganic chemistry , chemistry , photochemistry , optoelectronics , crystallography , layer (electronics) , engineering , metallurgy
Lead‐based perovskite nanocrystals (NCs) have outstanding optical properties and cheap synthesis conferring them a tremendous potential in the field of optoelectronic devices. However, two critical problems are still unresolved and hindering their commercial applications: one is the fact of being lead‐based and the other is the poor stability. Lead‐free all‐inorganic perovskite Cs 3 Bi 2 X 9 (X=Cl, Br, I) NCs are synthesized with emission wavelength ranging from 400 to 560 nm synthesized by a facile room temperature reaction. The ligand‐free Cs 3 Bi 2 Br 9 NCs exhibit blue emission with photoluminescence quantum efficiency (PLQE) about 0.2 %. The PLQE can be increased to 4.5 % when extra surfactant (oleic acid) is added during the synthesis processes. This improvement stems from passivation of the fast trapping process (2–20 ps). Notably, the trap states can also be passivated under humid conditions, and the NCs exhibited high stability towards air exposure exceeding 30 days.