Thermally activated delayed fluorescence carbazole-triazine dendrimer with bulky substituents  

作　　者：Hiroki Ikebe Kohei Nakao Eri Hisamura Minori Furukori Yasuo Nakayama Takuya Hosokai Minlang Yang Guanting Liu Takuma Yasuda Ken Albrecht 

机构地区：[1]Interdisciplinary Graduate School of Engineering Sciences,Kyushu University,Fukuoka,Japan [2]Institute for Materials Chemistry and Engineering,Kyushu University,Kasuga,Japan [3]Department of Pure and Applied Chemistry,Graduate School of Science and Technology,Tokyo University of Science,Noda,Chiba,Japan [4]National Metrology Institute of Japan(NMIJ),National Institute of Advanced Industrial Science and Technology(AIST),Tsukuba,Ibaraki,Japan [5]Institute for Advanced Study,Kyushu University,Nishi-ku,Fukuoka,Japan

出　　处：《Aggregate》2024年第1期236-243,共8页聚集体（英文）

基　　金：Ministry of Education,Culture,Sports,Science and Technology,Grant/Award Number:ARIM/JPMXP1222JI0040;Japan Society for the Promotion of Science,Grant/Award Numbers:KAKENHI/JP20KK0316,KAKENHI/JP21H05405,KAKENHI/JP22H02055,KAKENHI/JP23H02026,KAKENHI/JP23H03966,KAKENHI/JP20H02801。

摘　　要：Carbazole-triazine dendrimers with a bulky terminal substituent were synthesized,and the thermally activated delayed fluorescence(TADF)property was investigated.Compared to unsubstituted carbazole dendrimers,dendrimers with bulky terminal substituents showed comparable to better photoluminescence quantum yields(PLQY)in neat films.Phenylfluorene(PF)-substituted dendrimers showed the highest PLQY of 81%,a smallΔEst of 0.06 eV,and the fastest reverse intersystem crossing(RISC)rate of∼1×10^(5 )s^(−1) compared to other dendrimers.Phosphorescence measurements of dendrimers and dendrons(fragments)indicate that the close proximity of the triplet energy of phenylfluorene-substituted carbazole dendrons(^(3)LE)to that of phenylfluorene-substituted dendrimers(^(1)CT,^(3)CT)contributes to RISC promotion and improves TADF efficiency.Terminal modification fine-tunes the energy level and suppresses intermolecular interactions,and this study provides a guideline for designing efficient solution-processable and non-doped TADF materials.

关 键 词：DENDRIMER OLED TADF 1 INTRODUCTION Thermally activated delayed materials which are inexpensive and highly efficient alternatives to fluorescent 

分 类 号：O62[理学—有机化学]