Open AccessUnusual Temperature Dependence of Bandgap in 2D Inorganic Lead‐Halide Perovskite Nanoplatelets
Author(s) -
Yu Shaohua,
Xu Jin,
Shang Xiaoying,
Ma En,
Lin Fulin,
Zheng Wei,
Tu Datao,
Li Renfu,
Chen Xueyuan
Publication year - 2021
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202100084
Subject(s) - band gap , blueshift , materials science , perovskite (structure) , halide , redshift , optoelectronics , nanocrystal , semiconductor , photovoltaics , condensed matter physics , nanotechnology , photoluminescence , physics , chemistry , inorganic chemistry , crystallography , ecology , quantum mechanics , galaxy , photovoltaic system , biology
Understanding the origin of temperature‐dependent bandgap in inorganic lead‐halide perovskites is essential and important for their applications in photovoltaics and optoelectronics. Herein, it is found that the temperature dependence of bandgap in CsPbBr 3 perovskites is variable with material dimensionality. In contrast to the monotonous redshift ordinarily observed in bulk‐like CsPbBr 3 nanocrystals (NCs), the bandgap of 2D CsPbBr 3 nanoplatelets (NPLs) exhibits an initial blueshift then redshift trend with decreasing temperature (290–10 K). The Bose–Einstein two‐oscillator modeling manifests that the blueshift‐redshift crossover of bandgap in the NPLs is attributed to the significantly larger weight of contribution from electron‐optical phonon interaction to the bandgap renormalization in the NPLs than in the NCs. These new findings may gain deep insights into the origin of bandgap shift with temperature for both fundamentals and applications of perovskite semiconductor materials.