荧光/磷光混合型白光有机发光二极管的研究

Studies of fluorescence/phosphorescence hybrid white organic light-emitting diodes

白光有机发光二极管(white organic light-emitting diodes,WOLEDs)在全色显示、固态照明以及背光源等领域有巨大的应用前景,其研究备受关注.其中,荧光/磷光混合型WOLEDs因兼具荧光材料的长寿命和磷光材料的高效率,被认为是目前最有希望实现照明应用的器件结构.荧光/磷光混合型WOLEDs最重要的问题是要解决荧光材料的单线态激子和磷光材料的三线态激子的协同发光.为了避免单线态激子和三线态激子的相互猝灭问题,必须设计有效的器件结构.本文以两种不同三线态能级的蓝光荧光材料为研究对象,介绍了不同高性能荧光/磷光混合型WOLEDs的结构设计与性能.研究表明,载流子传输平衡的高效结构设计和激子分布宽范围内的有效调控是实现高性能荧光/磷光混合型WOLEDs的关键.

White organic light-emitting diodes （WOLEDs） have attracted more and more attention due to their wide applications in full-color displays, solid-state lighting sources and backlight sources. Amongst, fluorescence/ hosphorescence hybrid WOLEDs are considered as promising device structures in lighting application because of the long lifetime of fluorescence materials and the high efficiency of phosphorescence materials. For fluorescence/ hosphorescence hybrid WOLEDs, it is very important to resolve the synergic emission from the singlet excitons of fluorescence materials to the triplet excitons of phosphorescence materials. The design of effective device structures is necessary to avoid the quench between the singlet excitons and triplet excitons. In this paper, we introduced the structure design and performances of fluorescence/phosphorescence hybrid WOLEDs with different structures based on two blue fluorescence materials with different triplet levels. It is experimentally demonstrated that the high effective structure design with charge carrier transport balance and the effective control of exciton distribution in a wide range are keys in realizing high performance fluorescence/phosphorescence hybrid WOLEDs.