Riley Charlotte, Cho Hwan-Hee, Brannan Alexander C, Le Phuoc Nguyen, Linnolahti Mikko, Greenham Neil C, Romanov Alexander S
Department of Chemistry, The University of Manchester, Manchester, UK.
Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge, UK.
Commun Chem. 2024 Dec 19;7(1):298. doi: 10.1038/s42004-024-01377-y.
Energy-efficient and deep-blue organic light-emitting diode (OLED) with long operating stability remains a key challenge to enable a disruptive change in OLED display and lighting technology. Part of the challenge is associated with a very narrow choice of the robust host materials having over 3 eV triplet energy level to facilitate efficient deep-blue emission and deliver excellent performance in the OLED device. Here we show the molecular design of new 1,3,5-oxadiazines (NON)-host materials with high triplet energy over 3.2 eV, enabling deep-blue OLED devices with a peak external quantum efficiency of 21%. A series of NON-host materials are prepared by the condensation of substituted arylhydrazines and cyclohexylcarbaldehyde in a 2:3 ratio. This straightforward "one-pot" procedure enables the formation of indoline-containing derivatives with three fused heterocyclic rings and two stereogenic centres. All materials emit UV-fluorescence in the range of 315-338 nm while possessing highly desirable characteristics for application in deep-blue OLED devices: good thermal stability, a wide energy gap (3.9 eV), a high triplet energy level of (3.3 eV), and excellent volatility during sublimation.
具有长工作稳定性的高能效深蓝色有机发光二极管（OLED）仍然是实现OLED显示和照明技术颠覆性变革的关键挑战。部分挑战在于，用于促进高效深蓝色发射并在OLED器件中实现优异性能的具有超过3 eV三重态能级的稳健主体材料的选择非常有限。在此，我们展示了新型1,3,5 - 恶二嗪（NON）主体材料的分子设计，其三重态能量超过3.2 eV，可实现峰值外量子效率为21%的深蓝色OLED器件。一系列NON主体材料通过取代芳基肼与环己基甲醛以2:3的比例缩合制备。这种简单的“一锅法”程序能够形成具有三个稠合杂环和两个立体中心的含二氢吲哚衍生物。所有材料在315 - 338 nm范围内发射紫外荧光，同时具有在深蓝色OLED器件中应用所需的高度理想特性：良好的热稳定性、宽能隙（3.9 eV）、高三重态能级（3.3 eV）以及升华过程中优异的挥发性。
