新型叠层白光器件的结构设计及其对器件性能的影响

White Organic light-emitting devices (WOLEDs) have great potential in the applications of green lighting project, and its optimal structure design is tandem structure. But low power efficiency is one of the bottlenecks of tandem OLEDs. So how to improve the structure design of tandem WOLEDs from the perspective of devices physics to achieve higher power efficiency and better working stablity are the key to WOLEDs. In this proposal, we will study the performance improvement of tandem WOLEDs based on p-i-n structure, thermal excitation delay fluorescence (TADF) and exciplex mechanism from two aspects: charge generation unit (CGU) and electroluminescent unit (ELU). On the one hand we will design CGU structure with double n-type doping material layer and double p-type doping layer based on the study of p-i-n structure, which enables effective generation, efficient transmission and injection of electrons and holes in CGU of tandem WOLEDs. On the other hand we will design blue fluorescent ELU and orange phosphorescent ELU based on the study of TADF and exciplex mechanism respectively, which will improve the utilization rate of triplet exciton energy and reduce the workong voltage of the device. The high power efficiency and high stability of tandem WOLEDs will eventually be achievable. The proposed studies would provide theory reference for the development of green lighting technology, which will promote the development of high performance organic solid-state lighting technology.

白光有机电致发光技术(WOLEDs)是实现绿色照明最具前景的应用技术之一。叠层结构是WOLEDs最理想的器件结构，但功率效率低是其瓶颈之一。如何从器件物理角度改进叠层白光器件的结构设计，提高功率效率和工作稳定性是WOLEDs的关键。本项目拟研究p-i-n结构，热激发延迟荧光(TADF)和激基复合物(exciplex)机制，改进电荷产生单元(CGU)和电致发光单元(ELU)的结构设计，提升叠层白光器件的性能。基于p-i-n结构研究，将设计具有双n型掺杂层和双p型掺杂层的CGU，实现载流子的有效产生、高效传输及向两侧ELU的高效注入；基于TADF和exciplex机制研究，将分别构建蓝色荧光ELU和橙色磷光ELU，提高三线态激子能量利用率，降低工作电压，实现高效、高稳定性、低功耗的叠层白光器件。本项目的研究将为绿色照明技术的发展提供参考，促进我国具有自主知识产权的高性能有机固态光源技术的发展。

白光有机电致发光技术（WOLEDs）是实现绿色照明最具前景的应用技术之一。叠层结构是WOLEDs最理想的器件结构，但功率效率低是其瓶颈之一。本项目主要从器件物理角度改进叠层白光器件的结构设计，研究影响和提高器件性能的因素和方法。重要研究结果：1) 设计了有机光伏型（OPV）的电荷产生层C60/CuPc，实现器件电流效率的提升；2) 利用掺杂功能层提升电荷的传输特性，通过优化掺杂比例参数实现了器件工作电压的降低；3) 基于数理方程的导纳波谱法测量了材料的载流子迁移率，发现空穴传输材料具有电子缺陷态的特点；4) 设计了杂化多层结构的阴极修饰层，提升了器件阴极电子的注入效率；5) 基于“热点效应”，仅利用外力因素对倒置器件进行界面修饰，有效地提升器件的性能。