Li Jie, Gong Heqi, Zhang Jincheng, Liu Hui, Tao Li, Wang Yanqing, Guo Qiang
College of Optoelectronic Engineering, Chengdu University of Information Technology, Chengdu 610225, China.
College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China.
Molecules. 2021 Sep 13;26(18):5568. doi: 10.3390/molecules26185568.
The realization of a deep-blue-emitting exciplex system is a herculean task in the field of organic light-emitting diodes (OLEDs) on account of a large red-shifted and broadened exciplex emission spectrum in comparison to those of the corresponding single compounds. Herein, 2,5,8-tris(di(4-fluorophenyl)amine)-1,3,4,6,7,9,9b-heptaazaphenalene (HAP-3FDPA) was designed as an electron acceptor by integrating three bis(4-fluorophenyl)amine groups into a heptazine core, while 1,3-di(9-carbazol-9-yl)benzene (mCP) possessing two electron-donating carbazole moieties was chosen as the electron donor. Excitingly, the exciplex system of 8 % HAP-3FDPA:mCP exhibited deep-blue emission and a high photoluminescence quantum yield of 53.2%. More importantly, an OLED containing this exciplex system as an emitting layer showed deep-blue emission with Commission Internationale de l'Eclairage coordinates of (0.16, 0.12), a peak luminance of 15,148 cd m, and a rather high maximum external quantum efficiency of 10.2% along with a low roll-off. This study not only reports an efficient exciplex-based deep-blue emitter but also presents a feasible pathway to construct highly efficient deep-blue OLEDs based on exciplex systems.
由于与相应单一化合物相比，激基复合物发射光谱存在较大红移且变宽，因此在有机发光二极管（OLED）领域实现深蓝色发射激基复合物体系是一项艰巨的任务。在此，通过将三个双（4-氟苯基）胺基团整合到七嗪核中，设计了2,5,8-三（双（4-氟苯基）胺）-1,3,4,6,7,9,9b-七氮杂菲（HAP-3FDPA）作为电子受体，而选择具有两个供电子咔唑基团的1,3-二（9-咔唑-9-基）苯（mCP）作为电子供体。令人兴奋的是，8% HAP-3FDPA:mCP的激基复合物体系呈现出深蓝色发射，光致发光量子产率高达53.2%。更重要的是，以该激基复合物体系作为发光层的OLED呈现出深蓝色发射，国际照明委员会坐标为（0.16, 0.12），峰值亮度为15148 cd m，最大外量子效率相当高，为10.2%，且滚降较低。这项研究不仅报道了一种基于激基复合物的高效深蓝色发光体，还为构建基于激基复合物体系的高效深蓝色OLED提供了一条可行途径。
