Efficient Deep-Blue Electroluminescence Employing Heptazine-Based Thermally Activated Delayed Fluorescence

Photonics

Li Tao¹  Jie Li¹  Jincheng Zhang¹  Heqi Gong¹  Qiang Guo¹  Yanqing Wang² 

[1] College of Optoelectronic Engineering, Chengdu University of Information Technology, Chengdu 610225, China;College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China;

关键词: organic light-emitting diode;    thermally activated delayed fluorescence;    heptazine;    deep blue emitter;    electroluminescence;   

DOI  :  10.3390/photonics8080293

来源: DOAJ

【 摘 要 】

We report an efficient deep-blue organic light-emitting diode (OLED) based on a heptazine-based thermally activated delayed fluorescent (TADF) emitter, 2,5,8-tris(diphenylamine)-tri-s-triazine (HAP-3DPA). The deep-blue-emitting compound, HAP-3DPA, was designed and synthesized by combining the relatively rigid electron-accepting heptazine core with three electron-donating diphenylamine units. Due to the rigid molecular structure and intramolecular charge transfer characteristics, HAP-3DPA in solid state presented a high photoluminescence quantum yield of 67.0% and obvious TADF nature with a short delayed fluorescent lifetime of 1.1 μs. Most importantly, an OLED incorporating HAP-3DPA exhibited deep-blue emission with Commission Internationale de l’Eclairage (CIE) coordinates of (0.16, 0.13), a peak luminance of 10,523 cd/m⁻², and a rather high external quantum efficiency of 12.5% without any light out-coupling enhancement. This finding not only reports an efficient deep-blue TADF molecule, but also presents a feasible pathway to construct high-performance deep-blue emitters and devices based on the heptazine skeleton.

【 授权许可】

Unknown