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Mechanistic Insights into Photochemical Reactions on CH 3 NH 3 PbBr 3 Perovskite Nanoparticles from Single‐Particle Photoluminescence Spectroscopy
Author(s) -
Kimura Yuki,
Karimata Izuru,
Kobori Yasuhiro,
Tachikawa Takashi
Publication year - 2019
Publication title -
chemnanomat
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.947
H-Index - 32
ISSN - 2199-692X
DOI - 10.1002/cnma.201800569
Subject(s) - perovskite (structure) , photoluminescence , passivation , nanoparticle , halide , charge carrier , chemical physics , materials science , photochemistry , trapping , chemistry , optoelectronics , nanotechnology , inorganic chemistry , crystallography , ecology , biology , layer (electronics)
Metal halide perovskites have attracted considerable attention in applications such as photovoltaic cells and light‐emitting diodes. The performance and durability of perovskite devices are significantly dependent on the nature of structural defects, but the underlying mechanisms of structure‐related photochemical reactions are not yet fully elucidated. This study demonstrates that the photoluminescence (PL) from individual perovskite nanoparticles (NPs) can be utilized to resolve the different trapping pathways of the photogenerated charges, and hence, obtain a correlation between the pathways. PL deactivation and activation were observed and mainly attributed to nonradiative Auger recombination by the trapped charges and the passivation of surface traps by oxygen, respectively. Single‐particle spectroelectrochemical techniques were further employed to explore the possible origin of the effective charge trap states and the reversibility of redox events under electrical bias. Consequently, this study unravels the complex effects of the structural defects on the charge carrier dynamics in perovskites.