全磷光单一高分子白光材料的设计合成与性能研究

Different from traditional all-fluorescent and fluorescent/phosphorescent hybrid single white-emitting polymers (SWPs) which can not completely utilize the excitons in the electroluminescent process, all-phosphorescent SWPs can harvest all the singlet and triplet excitons and thus can achieve theoretically 100% internal quantum efficiency, which makes it a promising approach to enhance the efficiency of SWPs. In view of the high driving voltage that has been the bottleneck in improving the power efficiency of all-phosphorescent SWPs, this proposal aims at developing all-phosphorescent SWPs with low driving voltages and high power efficiencies through simultaneously grafting blue and yellow phosphorescent dopants into the sidechain of poly(arylene phosphine oxide) hosts. By coordinately regulating triplet energy level of the mainchain and HOMO level of the sidechain, as well as adjusting the energy levels of dopants to match with the host, this proposal is expected to reduce the driving voltages of SWPs and boost their power efficiencies to be comparable with fluorescent lamps (higher than 40 lm/W). We believe that, this study will provide innovative solutions for developing low-cost white OLED materials with independent intellectual property rights and push forward the development of the white OLED field.

不同于传统全荧光型以及荧光/磷光混合型单一高分子白光材料面临激子利用不充分的问题，全磷光型单一高分子白光材料的所有发光单元均可以利用单线态和三线态激子，具有高达100%的理论内量子效率，为提升单一高分子白光材料的器件性能提供了创新机遇。针对驱动电压偏高是制约全磷光单一高分子白光材料功率效率大幅提升的瓶颈问题，本申请旨在采用具有双极特性的芳基氧膦高分子作为主体材料，在侧链同时接枝蓝光和黄光磷光掺杂剂的方法，发展具有低电压特性和高功率效率的全磷光单一高分子白光材料。通过主链三线态能级和侧链HOMO能级的协同调控以及磷光掺杂剂与主体的能级匹配，降低单一高分子白光器件的驱动电压，实现功率效率突破40 lm/W，达到荧光灯的效率水平，为发展具有自主产权的低成本溶液加工型白光OLED材料提供源头创新的解决方案，形成对本领域发展具有推动意义和引领作用的创新性成果。

全磷光单一高分子白光材料的所有发光单元均可以利用单线态和三线态激子，能够实现100%的理论内量子效率，为提升单一高分子白光材料的器件性能提供了新途径。针对驱动电压偏高是制约其功率效率提升的瓶颈问题，本项目通过发展高三线态高分子主体材料以及调控主体与磷光掺杂剂的能级结构，提出了降低器件驱动电压和提升功率效率的实施途径，开发出功率效率为52.1 lm/W的全磷光单一高分子白光材料，实现了单一高分子白光材料器件效率的突破，圆满完成了项目原初制定的计划任务目标。（1）在主链三线态能级调控方面，发展了适用于蓝光磷光染料的高三线态聚芳醚主体材料，阐明了主链三线态能级对磷光能量回传过程的影响规律；（2）在侧链HOMO能级调控方面，开发出与阳极功函相匹配的高HOMO聚芳醚主体，建立了其能级结构与注入/传输特性和器件驱动电压与功率效率的内在关联；（3）在磷光掺杂剂方面，发展了含有不同磷光掺杂剂的全磷光单一高分子白光材料，通过磷光掺杂剂与高分子主体材料的能级匹配消除空穴散射效应和空穴注入势垒，实现了器件驱动电压降低和功率效率提升。项目执行期间，发表学术论文5篇，获权中国发明专利1项，负责人获中科院青年创新促进会“优秀会员”奖励。