Highly efficient through-space charge transfer TADF molecule employed in TADF-and TADF-sensitized organic light-emitting diodes  

作　　者：Jiasen Zhang Deli Li Wei Li Yujie Wu Xilin Mu Chunyu Liu Kaibo Fang Ziyi Ge 

机构地区：[1]Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices,Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences,Ningbo 315201,China [2]Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China [3]State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices,South China University of Technology,Guangzhou 510640,China

出　　处：《Science China Chemistry》2024年第4期1270-1276,共7页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(U21A20331,51773212,81903743,52003088);the Distinguished Young Scholars(21925506);the Ningbo Key Scientific and Technological Project(2022Z124,2022Z119)。

摘　　要：The inception and harnessing of excitons are paramount for the electroluminescence performance of organic light-emitting devices(OLEDs).Through-space charge transfer(TSCT)via intramolecular interaction has proved to be one of the most potent techniques employed to achieve 100% internal quantum efficiency.However,molecular strategies utilized to comprehensively enhance the electroluminescent performance of TSCT emitters regarding improving the photoluminescence quantum yield(PLQY)and elevating the light out-coupling efficiency remain arduous.To surmount this challenge,we deliberately designed and synthesized a proof-of-concept TSCT emitter called CzO-TRZ by incorporating an extra carbazole donor into spiroheterocyclic architecture.The introduction of rigid spiral fragments can immensely boost the horizontal orientation dipole ratio and establish an extra through-bond charge transfer(TBCT)radiative decay channel.As a result,a very high PLQY of 98.7%,fast kRISCof 2.2×10^(5)s^(-1)and high k_(r)^(s) of 2.2×10^(7)s^(-1),and an ultrahigh horizontal dipolar ratio of 90%were concurrently achieved for Cz O-TRZ blended films.Furthermore,corresponding thermally activated delayed fluorescence(TADF)-and TADF-sensitized fluorescence(TSF)-OLEDs based on CzO-TRZ demonstrated external quantum efficiencies(EQEs)of 33.4% and 30.3%,respectively,highlighting its versatile applications as both an emitter and sensitized host.

关 键 词：organic electronics organic light-emitting diodes polycyclic aromatic hydrocarbons multiple-resonance 

分 类 号：TN383.1[电子电信—物理电子学]