基于二苯甲腈取代的二吡啶并[3,2-a:2',3'-c]吩嗪受体的高效红色热激活延迟荧光发射体

Efficient Red Thermally Activated Delayed Fluorescence Emitters Based on a Dibenzonitrile-Substituted Dipyrido[3,2-a:2',3'-c]phenazine Acceptor.

作者信息

He Lin, Zeng Xuan, Ning Weimin, Ying Ao, Luo Yunbai, Gong Shaolong

机构信息

Department of Chemistry, Hubei Key Laboratory on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan 430072, China.

出版信息

Molecules. 2021 Apr 22;26(9):2427. doi: 10.3390/molecules26092427.

How to construct efficient red-emitting thermally activated delayed fluorescence (TADF) materials is a challenging task in the field of organic light-emitting diodes (OLEDs). Herein, an electron acceptor moiety, 3,6-DCNB-DPPZ, with high rigidity and strong acceptor strength was designed by introducing two cyanobenzene groups into the 3,6-positions of a dipyrido[3,2-a:2',3'-c]phenazine unit. A red-emitting compound, 3,6_R, has been designed and synthesized by combining the rigid acceptor unit with two triphenylamine donors. Due to high molecular rigidity and strong intramolecular charge transfer characteristic in donor-acceptor-donor skeleton, 3,6_R exhibited a red emission with a high photoluminescence quantum yield of 86% and distinct TADF nature with short delayed fluorescence lifetime of about 1 microsecond. Accordingly, the OLED using 3,6_R as the guest emitter gained a high external quantum efficiency of 12.0% in the red region with an electroluminescence peak of 619 nm and favorable Commission Internationale de l'Eclairage coordinates of (0.62, 0.38).

如何构建高效的红色热激活延迟荧光（TADF）材料是有机发光二极管（OLED）领域一项具有挑战性的任务。在此，通过将两个氰基苯基团引入二吡啶并[3,2-a:2',3'-c]吩嗪单元的3,6位，设计了一种具有高刚性和强受体强度的电子受体部分3,6-DCNB-DPPZ。通过将刚性受体单元与两个三苯胺供体相结合，设计并合成了一种红色发光化合物3,6_R。由于供体-受体-供体骨架中具有高分子刚性和强分子内电荷转移特性，3,6_R呈现出红色发射，光致发光量子产率高达86%，并且具有明显的TADF性质，延迟荧光寿命约为1微秒。因此，以3,6_R作为客体发射体的OLED在红色区域获得了12.0%的高外量子效率，电致发光峰值为619nm，国际照明委员会（CIE）坐标为（0.62, 0.38），表现良好。