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Perovskite Light‐Emitting Diodes with Near Unit Internal Quantum Efficiency at Low Temperatures
Author(s) -
He Yarong,
Yan Jiaxu,
Xu Lei,
Zhang Bangmin,
Cheng Qian,
Cao Yu,
Zhang Ju,
Tao Cong,
Wei Yingqiang,
Wen Kaichuan,
Kuang Zhiyuan,
Chow Gan Moog,
Shen Zexiang,
Peng Qiming,
Huang Wei,
Wang Jianpu
Publication year - 2021
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.202006302
Subject(s) - perovskite (structure) , materials science , quantum efficiency , photoluminescence , diode , light emitting diode , halide , optoelectronics , spontaneous emission , recombination , exciton , non radiative recombination , work (physics) , quantum , condensed matter physics , optics , thermodynamics , semiconductor , physics , inorganic chemistry , crystallography , chemistry , semiconductor materials , laser , biochemistry , gene , quantum mechanics
Room‐temperature‐high‐efficiency light‐emitting diodes based on metal halide perovskite FAPbI 3 are shown to be able to work perfectly at low temperatures. A peak external quantum efficiency (EQE) of 32.8%, corresponding to an internal quantum efficiency of 100%, is achieved at 45 K. Importantly, the devices show almost no degradation after working at a constant current density of 200 mA m −2 for 330 h. The enhanced EQEs at low temperatures result from the increased photoluminescence quantum efficiencies of the perovskite, which is caused by the increased radiative recombination rate. Spectroscopic and calculation results suggest that the phase transitions of the FAPbI 3 play an important role for the enhancement of exciton binding energy, which increases the recombination rate.