具有给体-受体空间位阻效应的近红外延迟荧光材料的分子设计、合成及性能研究

Two classes of the donor (D)-acceptor (A)-based type thermal activation delayed fluorescence (TADF) molecules with the frameworks of D-A-D’ and D-A-A’ will be designed and synthesized. Through introducing steric hindrance groups, changing the structures of donor or acceptor units and the construction framework, we can study the influence of the quantity，steric configuration and molecular building mode of donor and acceptor structures on photo-electronic properties of their resulting thermal activation delayed fluorescence (TADF) molecules. The molecular building rule of the high-efficiency near-infrared-emitting small molecules will be revealed. Furthermore, the independent innovated near-infrared-emitting small molecules and their organic light-emitting devices (OLEDs) with high performance will be obtained. This project is available to enrich and develop the near-infrared-emitting materials. It has an important theoretical and realistic significance for solving the key issues in the near-infrared-emitting OLEDs, such as low luminescent efficiency and radiance intensity, further promoting the application of TADF molecules in the near-infrared-emitting devices.

设计合成具有D-A-D’和D-A-A’两类框架结构的D-A型近红外延迟荧光电致发光材料。通过引入能够对给/受体单元间产生较大二面角的位阻基团，改变给/受体的结构以及构建方式，研究D-A型分子中的给/受体结构，数量，空间构型及构建方式的改变对D-A型近红外延迟荧光电致发光材料光电性能的影响，揭示D-A型近红外延迟荧光材料的分子结构与器件发光性能的关系，阐明高效发光的D-A型近红外延迟荧光材料的分子设计规律及发光机理，解决近红外有机电致发光器件发光效率低、淬灭严重等关键问题，促进近红外电致发光材料的发展及其在近红外有机电致发光器件的应用。

针对近红外电致发光材料种类较少，器件发光效率不高等关键科学问题，在本项目的支持下，项目负责人通过多种策略设计并合成了近红外电致荧光材料和电致磷光材料，并进一步表征了这些材料的分子结构，研究了它们的电学、热学、光物理以及电致发光等性能。开发的材料最大外量子效率可达15%，电致发光波长为725 nm，是迄今为止发光波长超过720 nm的最大外量子效率值。通过多种设计策略，本项目为设计高效、稳定近红外电致发光材料及其器件提供一定的理论依据。