Deng Sheng-Lin, Chen Yi-Kuan, Lei Jian, Jayakumar Jayachandran, Ko Chang-Lun, Hung Wen-Yi, Wu Tien-Lin, Cheng Chien-Hong
Department of Chemistry, National Tsing Hua University, Hsinchu 300044, Taiwan.
Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
ACS Appl Mater Interfaces. 2023 Jul 19;15(28):33819-33828. doi: 10.1021/acsami.3c05243. Epub 2023 Jul 7.
The strategy of acceptor modification is a powerful technique for tuning the emission color of thermally activated delayed fluorescence (TADF) emitters. In this study, we have successfully designed and synthesized three TADF emitters with donor-acceptor (D-A) structures using a 4-(diphenylamino)-2,6-dimethylphenyl (TPAm) donor and various pyridine-3,5-dicarbonitrile (PC) acceptor units. As a result, three compounds named TPAmbPPC, TPAm2NPC, and TPAmCPPC exhibited greenish-yellow to orange-red emissions with high photoluminescent quantum yields (76-100%) in thin films. Remarkably, a greenish-yellow device based on TPAmbPPC and TPAm2NPC showed a high maximum external quantum efficiency (EQE) of 39.1 and 39.0%, respectively. Furthermore, benefiting from the suitable steric hindrance between the acceptor and donor, the nondoped organic light-emitting diodes (OLEDs) based on TPAmbPPC demonstrated an exceptional EQE of 21.6%, indicating its promising potential as an efficient emitter for the application of OLED applications. Furthermore, orange-red OLED devices based on TPAmCPPC exhibited a high EQE of 26.2%, a CE of 50.1 cd A, and a PE of 52.4 lm W.
受体修饰策略是一种用于调节热激活延迟荧光（TADF）发光体发射颜色的强大技术。在本研究中，我们使用4-（二苯胺基）-2,6-二甲基苯基（TPAm）供体和各种吡啶-3,5-二甲腈（PC）受体单元，成功设计并合成了三种具有供体-受体（D-A）结构的TADF发光体。结果，三种名为TPAmbPPC、TPAm2NPC和TPAmCPPC的化合物在薄膜中呈现出绿黄色至橙红色发射，具有高光致发光量子产率（76-100%）。值得注意的是，基于TPAmbPPC和TPAm2NPC的绿黄色器件分别显示出39.1%和39.0%的高最大外量子效率（EQE）。此外，得益于受体和供体之间合适的空间位阻，基于TPAmbPPC的非掺杂有机发光二极管（OLED）表现出21.6%的优异EQE，表明其作为OLED应用的高效发光体具有广阔的应用前景。此外，基于TPAmCPPC的橙红色OLED器件表现出26.2%的高EQE、50.1 cd A的电流效率（CE）和52.4 lm W的功率效率（PE）。
