Multifunctional electron-transporting indolizine derivatives for highly efficient blue fluorescence, orange phosphorescence host and two-color based white OLEDs
作者:Jing Wan、Cai-Jun Zheng、Man-Keung Fung、Xiao-Ke Liu、Chun-Sing Lee、Xiao-Hong Zhang
DOI:10.1039/c2jm14904d
日期:——
In this work, derivatives of indolizine are first used as electron-transporting host materials for hybrid fluorescence/phosphorescence white organic light-emitting devices (F/P-WOLED). Of the indolizine derivatives, a blue fluorescent material BPPI (3-(4,4′-biphenyl)-2-diphenylindolizine) was found to have: (1) blue emission with high quantum yields, (2) good morphological and thermal stabilities, (3) electron-transporting properties, and (4) a sufficiently high triplet energy level to act as a host for red or yellow-orange phosphorescent dopants. The multifunctional BPPI enables adaptation of several simplified device configurations. For example, a non-doped blue fluorescent device exhibits good performance with an external quantum efficiency of 3.16% and Commission Internationale de l'Eclairage coordinates of (0.15, 0.07). A high-performance orange phosphorescent device was found to have a high current efficiency of 23.9 cd A−1. Using BPPI, we also demonstrate a F/P-WOLED with a simplified structure, stable emissions and respectable performance (current and external quantum efficiencies of 17.8 cd A−1 and 10.7%, respectively).
在该研究中,吲哚啉衍生物首次被用作混合荧光/磷光白色有机发光器件(F/P-WOLED)中的电子传输主体材料。在吲哚啉衍生物中,蓝色荧光材料BPPI(3-(4,4'-联苯)-2-二苯基吲哚啉)被发现具有以下特点:(1) 高量子产率的蓝色发光,(2) 良好的形态和热稳定性,(3) 电子传输性质,以及 (4) 足够高的三重能级,可作为红色或黄橙色磷光掺杂剂的主体。多功能BPPI使得几种简化的器件结构得以适应。例如,非掺杂的蓝色荧光器件表现出良好的性能,其外部量子效率为3.16%,国际照明委员会坐标为(0.15,0.07)。高性能橙色磷光器件的电流效率高达23.9 cd A^-1。使用BPPI,我们还展示了一种简化结构、稳定发光且性能可观的F/P-WOLED(电流和外部量子效率分别为17.8 cd A^-1和10.7%)。