文献类型：期刊文献

英文题名：Triazolo[1,5- a]pyridine-Based Host Materials for Green Phosphorescent and Delayed-Fluorescence OLEDs with Low Efficiency Roll-Off

作者：Song, Wenxuan[1]; Chen, Yi[1]; Xu, Qihao[1]; Mu, Haichuan[2]; Cao, Jingjing[3]; Huang, Jinhai[4]; Su, Jianhua[1]

机构：[1] Key Laboratory for Advanced Materials, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, China; [2] Department of Physics, School of Science, East China University of Science and Technology, Shanghai, 200237, China; [3] State Key Laboratory of Applied Organic Chemistry [SKLAOC], College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China; [4] Shanghai Taoe Chemical Technology Co., Ltd, Shanghai, 200030, China

年份：2018

卷号：10

期号：29

起止页码：24689

外文期刊名：ACS Applied Materials and Interfaces

收录：EI(收录号：20182805543144)

语种：英文

外文关键词：Glass transition - Efficiency - Hole mobility - Fluorescence - Sound insulating materials - Synthesis (chemical) - Polycyclic aromatic hydrocarbons - Phosphorescence - Pyridine

摘要：Herein, a series of universal bipolar host materials, 9,9′-([1,2,4]triazolo[1,5-a]pyridine-2,6-diylbis(4,1-phenylene))bis(9H-carbazole) (TP26Cz1), 3-(2-(4-(9H-carbazol-9-yl)phenyl)-[1,2,4]triazolo[1,5-a] pyridine-6-yl)-9-phenyl-9H-carbazole (TP26Cz2), 9,9′-([1,2,4]triazolo[1,5-a]pyridine-2,7-diylbis(4,1-phenylene))bis(9H-carbazole) (TP27Cz1), and 3-(2-(4-(9H-carbazol-9-yl)phenyl)-[1,2,4]triazolo[1,5-a]pyridin-7-yl)-9-phenyl-9H-carbazole (TP27Cz2), using [1,2,4]triazolo[1,5-a]pyridine (TP) as electron-transporting moiety and carbazole as hole-transporting moiety, were designed and synthesized. All four compounds possess remarkable carrier-transporting properties and excellent thermal stability with high glass-transition temperature (Tg) in the range of 136-144 °C. The hole- and electron-transporting abilities could be regulated by adjusting the linkage mode between the carbazole and TP units, and balanced charge-transporting properties were realized in TP26Cz2 and TP27Cz2. The phosphorescent and thermally activated delayed-fluorescence (TADF) organic light-emitting diodes (OLEDs) based on these host materials exhibit superior performance with high efficiency and low roll-off. For example, TP26Cz2-hosted phosphorescent OLED (PhOLED) exhibits the maximum external quantum efficiency (ηext) of 25.6%, and at the high luminance of 5000 cd m-2, the ηext still remained at 25.2%. TP27Cz1-hosted TADF device exhibits the maximum ηext of 15.5% and only dropped to 15.4% at the luminance of 1000 cd m-2. Moreover, the influence of linking mode of carbazole unit and TP units in these hosts on their photophysical and carrier-transporting properties as well as the electroluminescence (EL) performance of devices was discussed. ? 2018 American Chemical Society.