摘要
具有分子间电荷转移激发态特性的激基复合物(Exciplex)体系,由于前线分子轨道的分离特性--最高占有轨道(Highest occupied molecular orbital,HOMO)集中分布于给体分子上,最低空轨道(Lowest unoccupied molecular orbital,LUMO)集中分布于受体分子上,因此具有极小的单线态-三线态能级差(ΔE_(st))以及热活化延迟荧光(Thermally activated delayed fluorescence,TADF)特性。因此,激基复合物体系的理论内量子效率可以达到100%。由于构建激基复合物体系的给体分子具有空穴传输特性,受体分子具有电子传输特性,因此,激基复合物体系具有平衡的载流子迁移特性,这使得激基复合物体系在作为发光层材料以及混合主体材料制备电致发光器件时具有平衡载流子迁移、扩大激子复合区域、提高器件效率以及降低效率滚降的优势。本文将讨论和总结基于激基复合物激发态体系的电致发光材料与器件基本原理、设计思路以及近期的研究进展。
Exciplex,characterized by intermolecular charge-transfer excited state,possesses tiny energy splitting between the first singlet state and triplet state and thus thermally activated delayed fluorescence(TADF)property,which is caused by the separated distribution of frontier molecular orbitals.The highest occupied molecular orbital(HOMO)mainly locates at the donor molecule and the lowest unoccupied molecular orbital(LUMO)mainly locates at the acceptor molecule.As a result,exciplex can achieve 100%internal quantum efficiency theoretically like intramolecular charge-transfer TADF materials.Moreover,the donor molecule usually is hole-transporting material and the acceptor molecule is electron-transporting material,which contributes to balanced carrier injection.And the electroluminescent devices based on exciplex systems as emitting layer or mixed hosts exhibit balanced carrier injection,enlarged exciton recombination region,improved efficiency and suppressed efficiency roll-off.In this mini review,ultimate principle,design strategy and recent research progress of electroluminescent materials and devices based on exciplex excited state will be discussed and summarized.
作者
梁宝炎
庄旭鸣
宋小贤
梁洁
毕海
王悦
LIANG Baoyan;ZHUANG Xuming;SONG Xiaoxian;LIANG Jie;BI Hai;WANG Yue(Jihua Laboratory,Foshan 528000,China;Jihua Hengye(Foshan)Electronic Materials Co.,Ltd.,Foshan 528000,China;Engineering Research Center of Organic and Polymer Optoelectronic Materials,Ministry of Education,Jilin University,Changchun 130012,China)
出处
《发光学报》
EI
CAS
CSCD
北大核心
2023年第1期61-76,共16页
Chinese Journal of Luminescence
基金
广东省基础与应用基础研究基金(2020A1515110979)
季华实验室(X201231XF200)
佛山市科技创新团队项目(1920001000128)。
关键词
激基复合物
热活化延迟荧光
有机电致发光材料与器件
exciplex
thermally activated delayed fluorescence
electroluminescent materials and devices
