The efficiency of pure blue organic light-emitting diodes (OLEDs) still needs to be improved, which is limited by the utilization of the forbidden transition triplet excitons and low light-out-coupling efficiency in devices. Herein, two blue emitters were developed through combining multiple diphenylamine (DPA) donors with an oxygen-bridged boron (DBA) or triphenyl triazine (TRZ) acceptor. Notably, a narrow-band deep blue emission with a peak of 423 nm and a full-width at half-maximum (FWHM) of 34 nm is realized for the boron-based emitter in toluene solution. Thanks to their multiple charge transfer (CT) channels and high orientated disk-like structure, high radiative transition rates ($k_r$ > 10⁸ s⁻¹) and high horizontal emitting dipole ratios (Θ > 80%) can be realized simultaneously. Meanwhile, the introduction of the peripheral DPA units can also provide multiple localized triplet (³LE) states for spin up-conversion of forbidden transition triplet excitons. Owing to the effective up-conversion of triplet excitons and high light-out-coupling efficiency, maximum external quantum efficiency of more than 10% is achieved for the boron emitter-based pure blue OLEDs with a Commission Internationale de l’Eclairage (CIE) coordinates of (0.14, 0.08).

纯蓝色有机发光二极管（OLED）的效率仍有待提高，这受到器件中禁跃三​​重态激子的利用和低光耦合效率的限制。在此，通过将多个二苯胺 (DPA) 供体与氧桥硼 (DBA) 或三苯基三嗪 (TRZ) 受体结合，开发了两种蓝色发射体。值得注意的是，硼基发射体在甲苯溶液中实现了窄带深蓝色发射，峰值为 423 nm，半峰全宽 (FWHM) 为 34 nm。由于它们的多个电荷转移 (CT) 通道和高定向盘状结构，高辐射跃迁率 (${克}_r$> 10 ⁸ s ^-1 ) 和高水平发射偶极子比 (Θ > 80%) 可以同时实现。同时，外围 DPA 单元的引入还可以为禁止跃迁三重态激子的自旋上转换提供多个局域化三重态 ( ³ LE) 态。由于三重态激子的有效上转换和高光耦合效率，基于国际照明委员会 (CIE) 的基于硼发射体的纯蓝色 OLED 实现了超过 10% 的最大外部量子效率(0.14, 0.08) 的坐标。