Crafting host materials for narrowband blue OLEDs with low efficiency roll-off by the medium-ring strategy

作     者：Yuanyuan Bao Anping Luo Jingbo Lan Junjie Liu Zhengyang Bin Jingsong You 

作者机构：Key Laboratory of Green Chemistry and Technology of Ministry of EducationCollege of ChemistrySichuan UniversityChengdu 610064China 

出 版 物：《Science China Chemistry》 (中国科学（化学英文版）)

年 卷 期：2024年第67卷第10期

页      面：3265-3270页

核心收录：

学科分类：080903[工学-微电子学与固体电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：supported by the National Natural Science Foundation of China(22031007 22275127) 

主　　题：host molecule blue organic light-emitting diode low-efficiency roll-off multiple resonance C–H activation 

摘      要：The pursuit of high-performance narrowband blue organic light-emitting diodes(OLEDs)is of paramount importance in both academic research and industrial *** obvious strides have been made in the design of narrowband blue emitters,the development of appropriate host materials has evidently trailed ***,we introduce a medium-ring strategy for crafting host molecules based on the heptagonal tribenzo[b,d,f]azepine(TBA)*** twisted three-dimensional(3D)architecture of the TBA framework not only endows the host molecules with fast hole-transporting pathways but also effectively reduces exciton *** with two TBA units,DTBA,synthesized with ease,demonstrates a huge horizontal orientation factor(Θ//)of 93.5%and a broad emission spectrum for accelerating the energy transfer process in the emitting layer,which contributes to enhancing device *** have fabricated high-performance narrowband blue OLEDs using DTBA as the host,FIrpic as the phosphor sensitizer,and the widely used boron-nitrogen-containing multiple resonance emitter *** devices exhibit a maximum external quantum efficiency(EQEmax)as high as 31.0%with an impressively lowefficiency *** at a high luminance level of 10,000 cd m^(-2),the EQE value remains noteworthy at 20.3%,marking a significant advancement in BCz-BN-based devices.