Bipyridyl substituted triazoles as hole-blocking and electron-transporting materials for organic light-emitting devices

• Published in: Organic electronics Vol. 9; no. 1; pp. 77 - 84
• Main Authors: Ichikawa, Musubu, Fujimoto, Soichi, Miyazawa, Yuta, Koyama, Toshiki, Yokoyama, Norimasa, Miki, Tetsuzo, Taniguchi, Yoshio
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-02-2008; Elsevier
• Subjects: Amorphous material; Applied sciences; Electroluminescent device; Electron transporting; Electronics; Exact sciences and technology; Hole blocking; Mobility; OLED; Optoelectronic devices; Phosphorescent device; Pyridine; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Triazole; 85.60.Jb; Amorphous material; Triazole; Phosphorescent device; Hole blocking; Pyridine; 73.61.Ph; Electroluminescent device; Mobility; OLED; Electron transporting; 72.80.Le; Amorphous material; Hole blocking; Electron transporting; Triazole; Electroluminescent device; OLED; Phosphorescent device; Mobility; Pyridine; Aluminium; Electroluminescence; Quantum yield; Light emitting device; Organic light emitting diodes; Optoelectronic device; Electron mobility; 72.80.Le; 73.61.Ph; 85.60.Jb; Phosphorescence; Bilayers; Organic electronics
• ISSN: 1566-1199; 1878-5530
• DOI: 10.1016/j.orgel.2007.09.002

We have demonstrated bipyridyl substituted triazole derivatives (Bpy-TAZs) as an electron-transporting material for organic light-emitting devices (OLEDs). Substitution of triazole with bipyridyl is a good way to improve electron-transporting ability of triazoles with keeping good hole-blocking ability, which is a useful property of triazole derivatives. A Bpy-TAZ has high electron mobility of above 10−4cm2/Vs. Moreover, by employing one of Bpy-TAZs as a hole-blocking and electron-transporting material for phosphorescent OLEDs, lower operation voltage was achieved with keeping the same external quantum efficiency of electroluminescence (almost 10%) as compared with the conventional hole-blocking and electron-transporting bilayer consisting of bathocuproine and tris (8-hydroxyquinolinato) aluminum.