具有聚集诱导发光性质的热活化延迟荧光材料综述  

A Review on Thermally Activated Delayed Fluorescent Material with Aggregation-induced Emission Property

作　　者：赵思宇 张祥 卢伶 张义 赵青华[1] ZHAO Siyu;ZHANG Xiang;LU Ling;ZHANG Yi;ZHAO Qinghua(The Key Laboratory for Functional Materials of Fujian Higher Education,Colledge of Materials Science&Engineering,Huaqiao University,Xiamen 361021,China;High&New Technology Research Center,Henan Academy of Sciences,Zhengzhou 450002)

机构地区：[1]华侨大学材料科学与工程学院,福建省高校功能材料重点实验室,厦门361021 [2]河南省科学院高新技术研究中心,郑州450002

出　　处：《材料导报》2020年第17期17155-17167,共13页Materials Reports

基　　金：国家自然科学基金(51202073);福建省自然科学基金面上项目(2016J01233);福建省石墨烯粉末及复合材料研究中心建设项目(2017H2001);华侨大学研究生科研创新基金资助项目。

摘　　要：有机发光二极管(Organic light-emitting diode,OLED)近些年来受到了广泛的关注。在众多有机电致发光材料中,热激活延迟荧光(Thermally activated delayed fluorescent,TADF)材料能够同时利用单线态和三线态激子发光,获取100%的理论内量子效率,因此被认为是有机电致发光材料中第三代材料的代表。然而,TADF材料同样存在聚集淬灭效应(Aggregation-caused quenching,ACQ),因此会导致发光效率降低。由于聚集诱导发光(Aggregation-induced emission,AIE)能够在一定程度上减弱淬灭效应,从而使发光效率得到提高,因此,大量具有AIE性质的TADF材料不断被报道。本文简要介绍了OLED材料的发展历程,阐述了TADF、TTA、HLCT的相关机理、AIE效应的机理及TADF材料的设计原则等,重点介绍了以羰基、二苯砜、三嗪以及其他类型吸电子基团为受体单元,建立的具有AIE性质的TADF材料及器件的研究进展。在具有AIE性质的TADF材料设计中,基于苯酮的分子设计大多是采用不对称结构,这不仅能使分子的AIE特性显著,而且有利于分子刚性的增强,从而使分子的单线态和三线态能极差(ΔE ST)值减小。另外,与苯酮基团相比,苯砜结构能够产生较大的扭转角,更易于形成AIE材料;与前两者相比,三嗪本身存在多个能与电子供体结合的接枝点,这使得分子内的偏转角和能级更易于调控。最后,文章展望了具有AIE性质的TADF材料的发展前景,以期为未来设计新型TADF材料提供有意义的理论指导。Organic light-emitting diodes(OLEDs)have attracted much attention in recent years.Among organic electroluminescent materials,thermally activated delayed fluorescent(TADF)materials,which could harvest both singlet and triplet excitons to afford internal quantumn efficiencies of 100%,are emerging as one of the third-generation organic electroluminescent materials.However,TADF materials have to suffer from aggregation-caused quenching(ACQ)effect,which results in reduced luminance efficiencies.Aggregation-induced emission(AIE)materials have excellent emission efficiencies by suppressing concentration quenching.Therefore,a few of TADF materials with AIE characters have been reported.In this review,the research progress of OLED materials,the related mechanisms of TADF,TTA,HLCT and AIE,the design principles of TADF materials are briefly introduced.The paper specially focuses on the outputs of works on the photophysical performance improvement of TADF materials with AIE effect and relevant devices,in which carbonyl,diphenyl sulfone,triazine and other representative electron withdrawing groups are utilized as electron acceptors.In design concept of TADF materials with benzophenone substituents,asymmetric structures are adopted to construct TADF materials,which can enhance AIE characteristics of the molecules,and also reduceΔE ST values due to increased rigidity of the molecular.Compared with phenylsulfone groups considered as acceptors for TADF materials can form a larger torsion angle,which is more inclined to form AIE properties.Moreover,triazine units in TADF materials provide multiple grafting points for the combination with electron donors,and consequently,facilitate the adjustment of intramolecular deflection angle and energy level.The paper ends with a prospective discussion on the future trend of TADF materials with AIE properties,which is expected to provide a meaningful theoretical guidance for the design this type of novel materials.

关 键 词：聚集诱导发光(AIE) 热活化延迟荧光(TADF) 效率 有机发光二极管(OLED) 非掺杂 

分 类 号：O625[理学—有机化学]