Luminescent properties of thermally activated delayed fluorescence molecule with intramolecular π-π interaction between donor and acceptor  

作　　者：蔡磊 范建忠 孔祥朋 蔺丽丽 王传奎 

机构地区：[1]Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics,Shandong Normal University

出　　处：《Chinese Physics B》2017年第11期544-549,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.11374195 and 21403133);Taishan Scholar Project of Shandong Normal University,China;the Promotive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province,China(Grant No.BS2014cl001);the China Postdoctoral Science Foundation(Grant No.2014M560571)

摘　　要：Influence of intramolecular π-π interaction on the luminescent properties of thermally activated delayed fluorescence（TADF） molecule（3, 5-bis（3,6-di-tert-butyl-9 H-carbazol-9-yl）-phenyl）（pyridin-4-yl） methanone（DTCBPY） is theoretically studied by using the density functional theory（DFT） and time-dependent density functional theory（TD-DFT）.Four conformations（named as A, B, C, and D） of the DTCBPY can be found by relax scanning, and the configuration C corresponds to the luminescent molecule detected experimentally. Besides, we calculate the proportion of each conformation by Boltzmann distribution, high configuration ratios（44% and 52%） can be found for C and D. Moreover, C and D are found to exist with an intramolecular π-π interaction between one donor and the acceptor; the intramolecular interaction brings a smaller Huang-Rhys factor and reduced reorganization energy. Our work presents a rational explanation for the experimental results and demonstrates the importance of the intramolecular π-π interaction to the photophysical properties of TADF molecules.Influence of intramolecular π-π interaction on the luminescent properties of thermally activated delayed fluorescence（TADF） molecule（3, 5-bis（3,6-di-tert-butyl-9 H-carbazol-9-yl）-phenyl）（pyridin-4-yl） methanone（DTCBPY） is theoretically studied by using the density functional theory（DFT） and time-dependent density functional theory（TD-DFT）.Four conformations（named as A, B, C, and D） of the DTCBPY can be found by relax scanning, and the configuration C corresponds to the luminescent molecule detected experimentally. Besides, we calculate the proportion of each conformation by Boltzmann distribution, high configuration ratios（44% and 52%） can be found for C and D. Moreover, C and D are found to exist with an intramolecular π-π interaction between one donor and the acceptor; the intramolecular interaction brings a smaller Huang-Rhys factor and reduced reorganization energy. Our work presents a rational explanation for the experimental results and demonstrates the importance of the intramolecular π-π interaction to the photophysical properties of TADF molecules.

关 键 词：thermally activated delayed fluorescence intramolecular π-π interaction Huang-Rhys factor and reorganization energy aggregation induced enhanced emission 

分 类 号：TN383.1[电子电信—物理电子学]