Narrowband blue emitter based on fused nitrogen/carbonyl combination with external quantum efficiency approaching 30%  

作　　者：Long Chen Jia-Heng Cai You-Jun Yu Yang-Kun Qu Sheng-Yi Yang Sheng-Nan Zou Rui-Hong Liu Dong-Ying Zhou Liang-Sheng Liao Zuo-Quan Jiang 

机构地区：[1]Institute of Functional Nano&Soft Materials(FUNSOM),Jiangsu Key Laboratory for Carbon-Based Functional Materials&Devices,Soochow University,Suzhou 215123,China [2]Macao Institute of Materials Science and Engineering,Macao University of Science and Technology,Macao 999078,China

出　　处：《Science China Chemistry》2024年第1期351-359,共9页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(51873139,22175124,62175171,61961160731);the Natural Science Foundation of Jiangsu Province of China(BK20220057);the Suzhou Science and Technology Plan Project(SYG202010);supported by the Suzhou Key Laboratory of Functional Nano&Soft Materials;the Collaborative Innovation Center of Suzhou Nano Science&Technology;the 111 Project;the Joint International Research Laboratory of Carbon-Based Functional Materials and Devices。

摘　　要：Multi-resonance thermally activated delayed fluorescence(MR-TADF)emitters can enable narrowband emission with high color purity and electroluminescence efficiency.Nitrogen/carbonyl(N/C=O)system is receiving increasing attention while the nitrogen/boron(N/B)system has been widely studied.Donor decoration is an effective approach for N/B type MR-TADF system but always leads to broadening and red-shifting of the emission band in N/C=O MR-TADF system.We attribute these unfavorable phenomena to the formation of intramolecular charge transfer between the MR-core and peripheral donors.To address this issue,we have developed a new strategy by decorating DMQAO(a fused N/C=O MR-core)with a triazine acceptor and a neutral terphenyl group to construct MTDMQAO and MBDMQAO,respectively.The introduction of the triazine acceptor not only realizes efficient narrowband emission in MTDMQAO,but also accelerates the reverse intersystem crossing process through enhanced spin-orbital coupling.As a result,MTDMQAO exhibits a significantly higher external quantum efficiency of 29.4%compared to the referent emitters,validating the rationality of our derivation strategy.This study highlights the potential of the N/C=O system for MR-TADF emitters and provides important insights for understanding the difference between N/B and N/C=O systems.

关 键 词：carbonyl group NARROWBAND acceptor decoration thermally activated delayed fluorescence OLEDS 

分 类 号：TN873[电子电信—信息与通信工程]