通过调节交联空穴传输材料三线态能级实现溶液法制备高效的热活化延迟荧光有机电致发光二极管  

Suppressing triplet exciton quenching by regulating the triplet energy of crosslinkable hole transport materials for efficient solution-processed TADF OLEDs

作　　者：燕逸飞 张飞 刘红丽 李祥高 王世荣 Yifei Yan;Fei Zhang;Hongli Liu;Xianggao Li;Shirong Wang(School of Chemical Engineering and Technology,Tianjin University,Tianjin 300350,China;Collaborative Innovation Center of Chemical Science and Engineering(Tianjin),Tianjin 300072,China)

机构地区：[1]School of Chemical Engineering and Technology,Tianjin University,Tianjin 300350,China [2]Collaborative Innovation Center of Chemical Science and Engineering(Tianjin),Tianjin 300072,China

出　　处：《Science China Materials》2023年第1期291-299,共9页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(52173180);the Key Research and Development Project of Tianjin(19ZXNCGX00020);the S&T Program of Hebei Province(20311401D)。

摘　　要：具有高三线态能级的交联空穴传输材料能够平衡发光层载流子的复合并有效抑制三线态激子的猝灭,对制备高性能溶液法有机电致发光二极管具有重要意义.本文设计合成了两种具有不同母核的新型交联空穴传输材料,V-p-DBT和V-p-DBF.与已报道的交联空穴传输材料V-p-TPD相比,二苯并噻吩和二苯并呋喃母核的引入增加了分子的扭转角,使两种化合物具有更高的三线态能级,分别为2.57和2.64 e V.通过瞬态荧光光谱证明它们能够有效地抑制三线态激子的猝灭.交联的空穴传输层表现出优异的抗溶剂能力和溶液工艺所需的理化性质.其中,基于V-p-DBF的绿色热活化延迟荧光有机发光二极管获得了79.94 cd A-1的最大电流效率和24.35%的最大外量子效率.这项工作为实现溶液法制备的有机电致发光二极管提供了一种新的分子设计策略.Crosslinkable hole transport materials(HTMs)with high triplet energies would have a balance of carrier injection into the emitting material layer,suppressing the triplet exciton quenching and resulting in high-performance solution-processed organic light-emitting diode(OLED)devices.Two novel crosslinkable HTMs with different central units,N~2,N~8di-p-tolyl-N~2,N~8-bis(4-vinylphenyl)dibenzo[b,d]thiophene-2,8-diamine(V-p-DBT)and N~2,N~8-di-p-tolyl-N~2,N~8-bis(4-vinylphenyl)dibenzo[b,d]furan-2,8-diamine(V-p-DBF),were designed and synthesized.The use of dibenzothiophene and dibenzofuran units increases the torsion angle compared with the commonly used N,N’-di-p-tolyl-N,N’-bis(4-vinylphenyl)-[1,1’-biphenyl]-4,4’-diamine(V-p-TPD),leading to high triplet energies of 2.57 and 2.64 eV,respectively.The triplet energies of V-p-DBT and V-p-DBF effectively suppress triplet exciton quenching.Furthermore,the crosslinked HTM layer showed excellent solvent-resistant abilities and high thermal stability.An outstanding maximum current efficiency(CEmax)of 79.94 cd A-1and maximum external quantum efficiency(EQEmax)of 24.35%were obtained by V-p-DBF-based green thermally activated delayed fluorescent(TADF)OLEDs.This work provides a new molecular design strategy for achieving efficient solution-processed TADF OLEDs.

关 键 词：有机电致发光二极管 空穴传输材料 有机发光二极管 热活化延迟荧光 外量子效率 空穴传输层 有效抑制 发光层 

分 类 号：TN383.1[电子电信—物理电子学]