<br>用于高效溶液加工 OLED 的 HLCT 型受体分子激基复合物系统，可抑制效率滚降,Advanced Materials

当前位置： X-MOL 学术 › Adv. Mater. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

用于高效溶液加工 OLED 的 HLCT 型受体分子激基复合物系统，可抑制效率滚降
Advanced Materials ( IF 27.4 ) Pub Date : 2024-02-05 , DOI: 10.1002/adma.202313656
Yixiao Yin ₁ , Xiaoyi Lai ₁ , Qian Ma ₂ , Huili Ma ₂ , Weiguo Zhu ₁ , Jun Yeob Lee _{3,

4} , Yafei Wang ₁

Affiliation

由于最低单线态和三线态激发态 (Δ E _ST ) 之间的能量差异较小，激基复合物系统是热激活延迟荧光 (TADF) 分子的有希望的候选者。然而，使用激基复合物系统在溶液处理的有机发光二极管（OLED）中实现高效率和低外量子效率（EQE）滚降仍然是一项艰巨的挑战。本研究设计并合成了两种具有螺骨架的(HLCT)型异构体2- ^t Bu spo Cz-TRZ和10- ^t Bu spo Cz-TRZ作为激基复合物的受体，其中叔丁基螺芴吲哚被认为是作为供体，三嗪单元作为受体。 2- ^t Bu spo Cz-TRZ:TAPC 和 10- ^t Bu spo Cz-TRZ:TAPC 激基复合物观察到绿色激发复合物发射，表明具有 35 ± 5 meV 的非常小的 Δ E _ST的独特 TADF 特征。通过使用基于 HLCT 受体的 TADF 激基复合物系统作为发射器，可溶液加工的 OLED 实现了 20.8% 的最大外量子效率 (EQE _max )。此外，使用基于HLCT的激基复合物作为磷光体基质的可溶液加工磷光器件获得了> 25％的高EQE _max和非常低的效率滚降（在1000 cd m ^-2下约为3.5％）。这项研究为可溶液加工 OLED 中有效 TADF 分子和主体基质设计受体激基复合物分子的新策略铺平了道路。

"点击查看英文标题和摘要"

HLCT-Type Acceptor Molecule-Based Exciplex System for Highly Efficient Solution-Processable OLEDs with Suppressed Efficiency Roll-Offs

Exciplex systems are promising candidates for thermally activated delayed fluorescence (TADF) molecules because of the small energy difference between the lowest singlet and triplet excited states (ΔE_ST). However, realizing high-efficiency and low-external-quantum-efficiency (EQE) roll-off in solution-processed organic light-emitting diodes (OLEDs) using an exciplex system remains a formidable challenge. In this study, two (HLCT)-type isomers with a spiro skeleton, 2-^tBuspoCz-TRZ and 10-^tBuspoCz-TRZ, are designed and synthesized as acceptors of exciplexes, where tert-butylspirofluorene indole is regarded as a donor and the triazine unit as an acceptor. Green exciplex emissions are observed for the 2-^tBuspoCz-TRZ:TAPC and 10-^tBuspoCz-TRZ:TAPC exciplexes, indicating distinct TADF characteristics with a very small ΔE_ST of 35 ± 5 meV. By using the TADF exciplex system based on the HLCT acceptor as an emitter, solution-processable OLEDs achieve a maximum external quantum efficiency (EQE_max) of 20.8%. Furthermore, a high EQE_max > 25% with a very low-efficiency roll-off (≈3.5% at 1000 cd m⁻²) is obtained for solution-processable phosphorescent devices using HLCT-based exciplexes as the host matrix of phosphors. This study paves the way for a novel strategy for designing acceptor exciplex molecules for effective TADF molecules and host matrices in solution-processable OLEDs.

更新日期：2024-02-05

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南