高三线态杂多环芳烃类电子传输材料及其器件研究

Electron-transporting materials based on fused-ring aromatic hydrocarbons derivatives have been widely used in organic light-emitting diodes (OLEDs), possessing large electron-transporting mobilities (μe) and high stabilities but poor exciton confinement abilities due to their low triplet energy. In previous research, the applicant has demonstrated that, by encapsulating the anthracene core with large sterically inert groups, the exciton confinement ability of the anthracene derivatives can be improved as ETMs. But this strategy also enlarges the intermolecular distance of ETMs, unfavorable for large μe. In this project, the applicant proposes a new strategy to solve this problem, that is developing ETMs in which hetero-atom embedded polycyclic aromatic hydrocarbons (hetero-PAH) act as electron-transporting cores. On one hand, hetero-PAHs maintain the large planar structure for large μe; on the other hand, the existence of hetero-atoms promotes the triplet energy and the electron affinity, facilitating exciton confinement and electron injection. To promote the ETM performances, the hetero-PAH units, the side groups and their connection strategy will be optimized according to the theoretical calculation results. The relationships between molecular structures and properties will be analyzed, and the factors that limit the simultaneous existence of high μe（>10-3 cm2/Vs）, good exciton confinement and long-term stability will be studied. By adopting highly efficient ETMs and optimizing the emitting layers, OLEDs devices will be fabricated for high efficiencies and long lifetimes under high brightness. The relationships between the molecular properties and device performances will also be analyzed，providing theoretical basis for developing better performed ETMs.

稠环芳烃衍生物类电子传输材料（ETMs）被广泛应用于有机发光二极管（OLED）中，具有高电子迁移率（μe）及高稳定性，但受限于低的三线态（T1）能级，激子阻挡能力差。前期工作中，申请人证明采用惰性大位阻基团包覆的策略可提升蒽衍生物的激子阻挡能力，但该方法同时增大了分子间距，降低了μe。本项目中，申请人提出采用高T1能级的杂多环芳烃作为传输母核构筑ETMs的策略。一方面，杂多环芳烃保持了大平面结构有助于实现高μe；另一方面，引入杂原子可提升T1能级和电子亲和能，促进激子阻挡和电子注入。拟结合量化计算，优化杂多环芳烃母核，侧链以及键连方式来提升材料性能；分析材料构效关系，力争突破高μe（>10-3 cm2/Vs），优异激子阻挡性能以及高稳定性之间的相互制约因素。选择理想的ETMs，优化器件发光层，制备高亮度下高效稳定的OLED器件，探索材料性质与器件性能的关系，为设计更高效ETMs奠定基础。