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High‐Performance Perovskite Light‐Emitting Diode with Enhanced Operational Stability Using Lithium Halide Passivation
Author(s) -
Wu Tian,
Li Junnan,
Zou Yatao,
Xu Hao,
Wen Kaichuan,
Wan Shanshan,
Bai Sai,
Song Tao,
McLeod John A.,
Duhm Steffen,
Gao Feng,
Sun Baoquan
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201914000
Subject(s) - passivation , perovskite (structure) , halide , light emitting diode , materials science , optoelectronics , diode , lithium (medication) , brightness , chemistry , inorganic chemistry , nanotechnology , optics , layer (electronics) , crystallography , medicine , physics , endocrinology
Defect passivation has been demonstrated to be effective in improving the radiative recombination of charge carriers in perovskites, and consequently, the device performance of the resultant perovskite light‐emitting diodes (LEDs). State‐of‐the‐art useful passivation agents in perovskite LEDs are mostly organic chelating molecules that, however, simultaneously sacrifice the charge‐transport properties and thermal stability of the resultant perovskite emissive layers, thereby deteriorating performance, and especially the operational stability of the devices. We demonstrate that lithium halides can efficiently passivate the defects generated by halide vacancies and reduce trap state density, thereby suppressing ion migration in perovskite films. Efficient green perovskite LEDs based on all‐inorganic CsPbBr 3 perovskite with a peak external quantum efficiency of 16.2 %, as well as a high maximum brightness of 50 270 cd m −2 , are achieved. Moreover, the device shows decent stability even under a brightness of 10 4 cd m −2 . We highlight the universal applicability of defect passivation using lithium halides, which enabled us to improve the efficiency of blue and red perovskite LEDs.