A modular approach to efficient thermally activated delayed fluorescence from metal-perturbed intraligand charge-transfer excited state of Au(Ⅰ)complexes  

作　　者：Jian-Gong Yang Xingyu Feng Guohua Xie Nengquan Li Jiayu Li Xiu-Fang Song Ming-De Li Jingling Zhang Xiaoyong Chang Kai Li 

机构地区：[1]Shenzhen Key Laboratory of New Information Display and Storage Materials,Guangdong Provincial Key Laboratory of New Energy Materials Service Safety,College of Materials Science and Engineering,Shenzhen University,Shenzhen 518055,China [2]Hubei Key Laboratory of Biomass Fibers and Eco-dyeing&Finishing,Department of Chemistry and Chemical Engineering,Wuhan Textile University,Wuhan 430200,China [3]The Institute of Flexible Electronics(Future Technologies),Xiamen University,Xiamen 361005,China [4]Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province,Department of Chemistry,Shantou University,Shantou 515031,China [5]Department of Chemistry,Southern University of Science and Technology,Shenzhen 518055,China

出　　处：《Science China Chemistry》2024年第12期4149-4157,共9页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(22322505,22271196,22301226);the Shenzhen Science and Technology Program(ZDSYS20210623091813040);support from the Department of Science and Technology of Guangdong Province(2019QN01C617)。

摘　　要：The efficient harvesting of triplet excitons is crucial to the realization of high-performance organic light-emitting diodes(OLEDs).Herein,we show that coordination of donor-acceptor(D-A)type molecules to a metal atom in a monodentate fashion can lead to thermally activated delayed fluorescence(TADF)emissions with wide color tunability only through varying the noncoordinating acceptor moiety.A panel of TADF gold(Ⅰ)complexes with emission maxima(λmax)of 545–645 nm from metal perturbed intraligand charge-transfer(MPICT)excited states have been developed.Synergetic effects of heavy atom-induced spin-orbit coupling(SOC),steric-induced donor-acceptor twisting and suppressed intramolecular motions lead to high emission efficiencies of 65%-85%in doped films with delayed fluorescence lifetime of as short as 2.0μs.Transient absorption spectroscopic studies on selected complexes determined the kISCto be 6.5×10^(9)s^(-1).Theoretical calculations confirmed the participation of minor d orbital into the lowest excited state,which led to an SOC value of 5.19 cm^(-1)between the lowest-lying singlet and triplet excited states.The yellow to deep red solution-processed OLEDs based on the new gold(Ⅰ)complexes incorporated with various D-A ligands demonstrated promising performances.This study validates a modular design for TADF metal complexes,which will broaden the choices of metal centers and allow for facile color tuning via simple ligand synthesis.

关 键 词：gold(Ⅰ)complex OLED thermally activated delayed fluorescence(TADF) MPICT 

分 类 号：O641.4[理学—物理化学]