基于热活化延迟荧光（TADF）机制的有机发光二极管（OLED）技术在使用纯有机发光材料的条件下仍能实现高的器件效率，这类技术可以降低制作成本，更有利于商业化应用。然而，受限于窄能隙材料非辐射跃迁显著的问题，红光-近红外TADF材料很难实现高效的激子利用，导致器件无法获得高效率和低效率滚降等科学问题。本项目针对以上问题，拟重点开展以下三个方面的工作：（1）从引入平面刚性的基团组建红光-近红外分子出发，发展具有小单-三重态能级差和高荧光量子产率的红光-近红外TADF材料；（2）通过研究平面刚性基团不同连接方式对分子偶极取向的影响，获得高水平偶极取向因子的红光-近红外TADF材料；（3）在精选发光材料和优化器件结构的基础上研制出高效率、低效率滚降的红光-近红外OLED器件。以上研究可为发展高取向性、高效TADF特性的红光-近红外材料和高效率、低效率滚降的OLED器件提供理论依据和技术支持。

Organic light-emitting diode (OLED) based on thermally activated delayed fluorescence (TADF) can achieve high-efficiency with only pure organic materials, which not only reduce production costs but also facilitate commercial application. However, some critical scientific issues still exist in this novel OLED technology, it is difficult for red to near-infrared TADF materials to achieve highly efficient exciton utilization, because their photoluminescence efficiencies tend to decrease with the increase of emission wavelength according to the energy gap law, which results in low external quantum efficiencies and serious efficiency roll-offs in the devices. Aiming at these issues, this project is mainly focus on the following three aspects: (1) developing red to near-infrared TADF materials with small singlet-triplet energy gap and high fluorescence quantum yield based on planar rigid groups; (2) obtaining red to near-infrared TADF materials with high horizontal dipole orientation factor via adjusting the connection mode of the planar rigid groups; (3) realizing high-efficiencies and low-efficiency roll-offs red-near-infrared OLED devices by well-selecting emitters and optimizing device structures. The project will provide a theoretical basis and technical support for developing highly efficiencies red to near-infrared TADF materials and devices.