Progress on Blue-Emitting Hot Exciton Materials
Mingbing Lian, Zecong Ye, Yingxiao Mu, Dehua Hu, Yuan Liu, Hao‐Li Zhang, Shaomin Ji, Yanping Huo
Abstract
In hot exciton materials, the excitons from the high-lying triplet state (Tn, n≥2) can be efficiently converted into the singlet state (Sm, m≥1) via reverse intersystem crossing (RISC) process due to the staggered energy level arrangement, which maximizes the use of the triplet exciton and theoretically achieves a maximum internal quantum efficiency (IQE) of 100%.Hot exciton materials not only break the exciton utilization limitation of traditional fluorescent materials and triplet-triplet annihilation materials, but also overcome the serious efficiency roll-off of thermally activated delayed fluorescent (TADF) materials at high current density, exhibiting unique advantages in the electroluminescence.Blue light has long been the short board of the organic photoelectric full-color display.Compared with the phosphorescent and TADF materials with unsatisfying color purity and inferior stability, hot exciton materials can achieve higher-quality emission in blue devices, exhibiting excellent performance even in the deep-blue region.In this review, the representative blue-emitting hot exciton materials reported recently are summarized, the light-emitting mechanism and design strategy are elaborated, and a full vision of its development is made Keywords hot exciton; blue emitter; organic electroluminesence; organic light-emitting diodes 有机发光二极管(organic light emitting diodes, OLE-Ds)是全固态自发光的载流子注入型发光器件, 由于轻 质、超薄、宽视角、低功耗、高亮度和对比度以及柔性 显示等优点, 被誉为"梦幻显示器" [1][2] .典型的 OLED