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Pressure‐Induced Emission Enhancement, Band‐Gap Narrowing, and Metallization of Halide Perovskite Cs 3 Bi 2 I 9
Author(s) -
Zhang Long,
Liu Chunming,
Wang Lingrui,
Liu Cailong,
Wang Kai,
Zou Bo
Publication year - 2018
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201804310
Subject(s) - halide , perovskite (structure) , materials science , band gap , bismuth , semiconductor , exciton , metal , optoelectronics , condensed matter physics , chemistry , inorganic chemistry , crystallography , metallurgy , physics
Low‐toxicity, air‐stable bismuth‐based perovskite materials are attractive substitutes for lead halide perovskites in photovoltaic and optoelectronic devices. The structural, optical, and electrical property changes of zero‐dimensional perovskite Cs 3 Bi 2 I 9 resulting from lattice compression is presented. An emission enhancement under mild pressure is attributed to the increase in exciton binding energy. Unprecedented band gap narrowing originated from Bi−I bond contraction, and the decrease in bridging Bi‐I‐Bi angle enhances metal halide orbital overlap, thereby breaking through the Shockley–Queisser limit under relatively low pressure. Pressure‐induced structural evolutions correlate well with changes in optical properties, and the changes are reversible upon decompression. Considerable resistance reduction implies a semiconductor‐to‐conductor transition at ca. 28 GPa, and the final confirmed metallic character by electrical experiments indicates a wholly new electronic property.