Deciphering TADF Mechanisms in Metal-Free Organic Emitters BrA-HBI:Utilizing Optimally Tuned Range-Separated Functionals for Insight  

作　　者：Chunyue Yu Hang Yin Jie Guo Wentian Zhang Ying Shi 于春悦;尹航;郭婕;张闻天;石英(Institute of Atomic and Molecular Physics,Jilin University,Changchun 130012,China)

机构地区：[1]Institute of Atomic and Molecular Physics,Jilin University,Changchun 130012,China

出　　处：《Chinese Physics Letters》2024年第9期28-37,共10页中国物理快报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.12174149)。

摘　　要：Metal-free organic emitters,characterized by their thermally activated delayed fluorescence(TADF)properties,offer considerable promise for the creation of highly efficient organic light-emitting diodes(OLEDs).Recently,Shao et al.presented a novel excited state intramolecular proton transfer(ESIPT)system BrA-HBI,demonstrating an emission quantum yield of up to 50%[Adv.Funct.Mater.32,2201256(2022)].However,many open issues cannot be answered solely by experimental means only and require detailed theoretical investigations.For instance,what causes the activation of TADF from the Keto^(*) tautomer and leads to fluorescence quenching in the Enol^(*)form?Herein,we provide a theoretical investigation on the TADF mechanism of the BrA-HBI molecule by optimally tuned range-separated functionals.Our findings reveal that ESIPT occurs in the BrA-HBI molecule.Moreover,we have disclosed the reason for the fluorescence quenching of the Enol^(*)form and determined that the T_(2)state plays a dominant role in the TADF phenomenon.In addition,double hybrid density functionals method was utilized to verify the reliability of optimally tuned range separation functionals on the calculation of the TADF mechanism in BrA-HBI.These findings not only provide a theoretical reference for development of highly efficient organic light-emitting diodes,but also demonstrate the effectiveness of the optimally tuned range-separated functionals in predicting the luminescence properties of TADF molecules.

关 键 词：optimal finding SEPARATED 

分 类 号：TN383.1[电子电信—物理电子学] TB34[一般工业技术—材料科学与工程]