高迁移率聚集诱导发光分子的设计合成、组装及其光电性能研究

Multifunctional organic semiconductors with high mobility and strong solid-state luminescence are the basis of optoelectronic integration, which is essential for the developments of organic light-emitting transistors and organic electrically pumped lasers. Organic semiconductors with excellent charge transport properties generally require tight molecular packing and strong intermolecular interactions, but are prone to generate exciton/energy levels tend to non-radiative transitions, ie, aggregation-induced fluorescence quenching（ACQ）. Therefore, how to achieve high mobility and strong solid-state luminescence at the same time has become a scientific problem to be solved in the field of organic optoelectronics. In view of the fact that the fluorescence of aggregated-induced luminogens (AIEgens) greatly enhance in the aggregated state, it has the natural advantage of becoming high mobility emissive semiconductors. Based on the comprehensive literature and the applicant's preliminary work, AIEgens with excellent charge transport properties are designed through two strategies: 1) linking the aggregation-induced luminescent fragments to the π conjugated units, and 2) introducing specific functional groups for weak intermolecular interactions (like hydrogen bonding, etc.) into the π conjugated units to enhance the aggregated-induced emission. The molecular morphology，molecular packing and aggregated structure were further optimized via fine tuning the molecular periphery and suitable molecular assembly methods. High mobility AIEgens with compact packing and orderly arrangement and their integrated optoelectronic applications are expected be obtained. More importantly, the relationship between molecular structure, aggregates structure and optoelectronic properties will be systematically studied and give insights into the design of the novel multifunctional semiconductors. The efficient strategy for design and synthesis of high mobility AIEgens will be summarized and offer references for the future design of optoelectronic molecules.

兼具高迁移率和强固态发光的多功能有机半导体是光电集成的基础，对于有机发光晶体管、有机电泵激光的发展至关重要。电荷传输性能优异的有机半导体通常要求分子堆积紧密有序，分子间相互作用强，但易于产生非辐射跃迁的激子/能级，猝灭荧光。如何同时实现高迁移率和强固态发光，成为有机光电领域亟待解决的科学难题。鉴于聚集诱导发光分子在聚集态下荧光大大增强，具有实现高迁移率强固态发光的天然优势，本项目综合文献和申请人前期工作基础，通过两种策略设计高迁移率聚集诱导发光分子：1)聚集诱导发光片段与π共轭单元键联，2) π共轭单元上引入弱相互作用基团促进分子聚集诱导发光。进一步通过精细调控分子外围修饰基团，优化分子聚集态结构，获得堆积紧密、排列有序的高迁移率聚集诱导发光分子，实现光电集成器件应用。系统研究分子结构、聚集态结构和光电性能的关系，总结出高迁移率聚集诱导发光分子设计策略，为有机光电材料的设计合成提供参考。

如何同时实现高迁移率和强聚集态发光，是有机光电领域一大科学难题：电荷传输性能优异的有机半导体通常要求材料内部分子堆积紧密有序、分子间相互作用较强，但较强的分子间相互作用易于产生非辐射跃迁的激子/能级，猝灭荧光。在本项目执行期间，我们以高迁移率聚集诱导发光分子的设计合成为目标，围绕蒽衍生物体系、吡嗪[2,3-g]喹喔啉体系、反式二噻吩乙烯体系进行系统研究，设计合成了TBU-DNA、DTPAA、PQ-4FP、PQ-4ClP等高迁移率发光有机半导体分子，并深入探究了分子堆积对于有机半导体光电性能的影响；构筑了高性能发光场效应晶体管、光控晶体管，实现了高迁移率发光有机半导体材料的光电集成器件应用。此外，我们也通过调节分子末端取代基的极性来调节有机半导体的激子动力学行为，进而调控有机半导体光稳/光敏性质。项目执行期内，发表SCI学术论文9篇，申请发明专利1项。