Endowing imidazole derivatives with thermally activated delayed fluorescence and aggregation-induced emission properties for highly efficient non-doped organic light-emitting diodes  

作　　者：Ge Yang You Ran Yimin Wu Minqi Chen Zhengyang Bin Jingsong You 

机构地区：[1]Key Laboratory of Green Chemistry and Technology of Ministry of Education,College of Chemistry,Sichuan University,Chengdu,China

出　　处：《Aggregate》2022年第2期162-168,共7页聚集体（英文）

基　　金：National NSF of China,Grant/Award Numbers:22031007,22005204;Sichuan Science and Technology Program,Grant/Award Numbers:2020YJ0245,2020YJ0302。

摘　　要：The development and enrichment of high-performance organic fluorophores that simultaneously possess thermally activated delayed fluorescence(TADF)and aggregation-induced emission(AIE)properties is going pursued but remains a great challenge due to severe exciton quenching.Herein,a systematical investigation on imidazole moiety has successfully given rise to a series of highly efficient imidazolebased TADF-AIE luminogens for the first time.The attachment of two cyano functionalities on imidazole moiety can significantly increase the electron-withdrawing ability,so as to realize TADF emissions with small singlet-triplet energy gaps(ΔEST)values.Meanwhile,the installation of a steric hindrance group at N1 position of imidazole moiety can twist the geometry between imidazole and phenyl bridge,thus transforming imidazole derivative from an aggregation-caused quenching emitter into an AIE luminogen.Consequently,the non-doped organic light-emitting diodes(OLEDs)utilizing these TADF-AIE luminogens as emitters exhibit outstanding skyblue and green emissions,with external quantum efficiency(EQE)as high as 20.0%and low efficiency roll-off(EQE at 1000 cd m−2,16.1%).These values represent the state-of-the-art performance for all imidazole-based OLED devices,which illustrates the significant potential of imidazole derivatives in assembling high-performance OLEDs.

关 键 词：aggregation-induced emission IMIDAZOLE non-doped OLEDs thermally activated delayed fluorescence 

分 类 号：O62[理学—有机化学]