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Visualizing Phase Segregation in Mixed‐Halide Perovskite Single Crystals
Author(s) -
Mao Wenxin,
Hall Christopher R.,
Chesman Anthony S. R.,
Forsyth Craig,
Cheng YiBing,
Duffy Noel W.,
Smith Trevor A.,
Bach Udo
Publication year - 2019
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.201810193
Subject(s) - grain boundary , phase (matter) , halide , perovskite (structure) , crystal (programming language) , chemical physics , materials science , crystallography , monocrystalline silicon , spectroscopy , crystal growth , optoelectronics , chemistry , silicon , physics , inorganic chemistry , microstructure , computer science , organic chemistry , programming language , quantum mechanics
Abstract Mixed organolead halide perovskites (MOHPs), CH 3 NH 3 Pb(Br x I 1− x ) 3 , have been shown to undergo phase segregation into iodide‐rich domains under illumination, which presents a major challenge to their development for photovoltaic and light‐emitting devices. Recent work suggested that phase‐segregated domains are localized at crystal boundaries, driving investigations into the role of edge structure and the growth of larger crystals with reduced surface area. Herein, a method for growing large (30×30×1 μm 3 ) monocrystalline MAPb(Br x I 1− x ) 3 single crystals is presented. The direct visualization of the growth of nanocluster‐like I‐rich domains throughout the entire crystal revealed that grain boundaries are not required for this transformation. Narrowband fluorescence imaging and time‐resolved spectroscopy provided new insight into the nature of the phase‐segregated domains and the collective impact on the optoelectronic properties.