Luo Xu-Feng, Song Shi-Quan, Ni Hua-Xiu, Ma Huili, Yang Dezhi, Ma Dongge, 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.
Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Nanjing Tech University, Nanjing, 211816, P. R. China.
Angew Chem Int Ed Engl. 2022 Oct 10;61(41):e202209984. doi: 10.1002/anie.202209984. Epub 2022 Sep 2.
Herein, we report two multiple-resonance thermally activated delayed fluorescence emitters (VTCzBN and TCz-VTCzBN) based on indolo[3,2,1-jk]carbazole unit and boron-nitrogen skeletons, whose emissions peaking at 496 and 521 nm with full width at half maximum of 34 and 29 nm, respectively. Meanwhile, fast rate constants of reverse intersystem crossing of above 10 s are obtained due to small singlet-triplet energy gaps and large spin-orbital coupling values. Notably, planar molecular structures along the transition dipole moment direction endow them with high horizontal emitting dipole ratios of up to 94 %. Consequently, the corresponding organic light-emitting diodes (OLEDs) show the maximum external quantum efficiencies of 31.7 % and 32.2 %, respectively. Particularly, OLED with TCz-VTCzBN display ultra-pure green emission with Commission Internationale de l'Eclairage coordinates of (0.22, 0.71), consistent with the green display standard of the National Television System Committee.
在此，我们报道了两种基于吲哚并[3,2,1-jk]咔唑单元和硼氮骨架的多共振热激活延迟荧光发射体（VTCzBN和TCz-VTCzBN），其发射峰分别位于496和521 nm处，半高宽分别为34和29 nm。同时，由于单重态-三重态能隙小和自旋-轨道耦合值大，获得了高于10 s的快速反向系间窜越速率常数。值得注意的是，沿跃迁偶极矩方向的平面分子结构赋予它们高达94%的高横向发射偶极比。因此，相应的有机发光二极管（OLED）分别显示出31.7%和32.2%的最大外量子效率。特别地，具有TCz-VTCzBN的OLED显示出超纯绿色发射，国际照明委员会坐标为(0.22, 0.71)，符合国家电视系统委员会的绿色显示标准。
