利用荧光材料PT-01, PT-86, PT-05作为黄色荧光客体,蓝色荧光客体以及荧光母体制备了一种基于连续性掺杂结构的全荧光白光有机电致发光器件.其发光层为主体/客体薄层/主体/客体薄层···交替蒸镀的重复单元.通过优化发光层中主体的厚度并检测发光层中单线态激子的分布,将黄、蓝两种客体染料生长在发光层中适当的位置,得到了高效且光谱稳定的全荧光白光器件.其最大电流效率为11.2 cd/A,亮度在159-20590 cd/m2范围内色坐标仅有(±0.004,±0.005)的改变.基于这种连续性掺杂结构制备的器件,其性能不但可以达到传统主-客体共掺结构所制备的器件的性能,而且具有较高的可重复性,更适合产业化大批量生产.
Highly efficient all fluorescent white organic light-emitting devices (WOLED) have been fabricated by means of sequential dop-ing. Fluorescent materials PT-01, PT-86 and PT-05 serve as the yellow guest, blue guest and fluorescent host, respectively. The emission layer consists of a few repeating cells, which are made of sequentially evaporated host and guest layers. From the analyses of the singlet exciton distribution and the influences of the thickness of the host layer, PT-86 and PT-01 are evaporated at the proper locations in the emission layer (EML), yielding a high efficiency and stable all fluorescent WOLEDs. The maximum current efficiency of the WOLED is 11.2 cd/A. In addition, the emission color of this WOLED is fairly stable, consistent with the Commission Inter-national de L’Eclairage coordinates, only showing changes (±0.004, ±0.005) when luminance increasing from 159 cd/m2 to 20590 cd/m2 . The devices based on the method of sequential doping not only have the similar performance compared with that fabricated by co-evaporation doping, but also have higher repeatability, which makes them appropriate for mass-production.