Yan Zhi-Ping, Yuan Li, Zhang Yuan, Mao Meng-Xi, Liao Xiang-Ji, Ni Hua-Xiu, Wang Zhi-Heng, An Zhongfu, Zheng You-Xuan, Zuo Jing-Lin
State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China.
Jihua Laboratory, No.28 Island Ring South Road, Foshan, 528200, P. R. China.
Adv Mater. 2022 Sep;34(36):e2204253. doi: 10.1002/adma.202204253. Epub 2022 Aug 7.
The realization of luminescent materials with narrowband and circularly polarized luminescence (CPL) is of great significance for the development of future optical and photonic devices. Herein, through a steric-hindrance-assisted dual-core strategy, two pairs of chiral dual-core multiple resonance thermally activated delayed fluorescence (MR-TADF) materials (R/S-DOBN and R/S-DOBNT) are directly constructed by the bonding of two organoboron MR-TADF monocores (SOBN and SOBNT) with carbazole/3,6-di-tert-butyl-9H-carbazole and phenol derivative as donors, realizing obvious CPL and narrowband emissions. Furthermore, the dual-core effect in the prepared R/S-DOBN and R/S-DOBNT increases the transition oscillator strength two times more than that of a monocore structure, while maintaining the ultrapure blue emissions peaking at 453 and 459 nm with a narrower full-width at half-maximum of 21 nm through reorganization energy reduction. The circularly polarized organic light-emitting diodes based on the enantiomers exhibit ultrapure blue emission with Commission Internationale de L'Eclairage (CIE) coordinates of (0.14, 0.10) and (0.13, 0.12), high maximum external quantum efficiencies of 23.9% and 25.6%, and obvious circularly polarized electroluminescence with dissymmetry factors (|g |) ≈ 10 .
实现具有窄带和圆偏振发光（CPL）的发光材料对于未来光学和光子器件的发展具有重要意义。在此，通过空间位阻辅助双核策略，以咔唑/3,6-二叔丁基-9H-咔唑和酚衍生物为供体，将两个有机硼多重共振热激活延迟荧光（MR-TADF）单核（SOBN和SOBNT）与咔唑/3,6-二叔丁基-9H-咔唑和酚衍生物键合，直接构建了两对手性双核多重共振热激活延迟荧光（MR-TADF）材料（R/S-DOBN和R/S-DOBNT），实现了明显的CPL和窄带发射。此外，所制备的R/S-DOBN和R/S-DOBNT中的双核效应使跃迁振子强度比单核结构增加了两倍以上，同时通过降低重组能保持了在453和459 nm处峰值的超纯蓝光发射，半高宽更窄，为21 nm。基于对映体的圆偏振有机发光二极管表现出超纯蓝光发射，国际照明委员会（CIE）坐标为（0.14, 0.10）和（0.13, 0.12），最大外量子效率高达23.9%和25.6%，并且具有明显的圆偏振电致发光，不对称因子（|g|）≈10 。
