Undoped, red organic light-emitting diodes based on a N,N,N’,N’-tetraphenylbenzidine (TPD) derivative as red emitter with a triphenylamine derivative as hole-transporting layer

• Published in: Dyes and pigments Vol. 84; no. 2; pp. 203 - 207
• Main Authors: Cao, Xingbo, Wen, Yugeng, Guo, Yunlong, Yu, Gui, Liu, Yunqi, Yang, Lian-Ming
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2010
• Subjects: Brightness; Hole-transporting layer; Luminous efficiency; OLEDs; Red fluorescent material; Tetraphenylbenzidine derivative; Tetraphenylbenzidine derivative; OLEDs; Brightness; Red fluorescent material; Luminous efficiency; Hole-transporting layer
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2009.08.003

A novel dicyanovinyl-functionalized N,N,N’,N’-tetraphenylbenzidine (TPD) derivative, N,N’-bis[4-(1,1-dicyanovinyl)phenyl]- N,N’-bis(4-fluorophenyl)benzidine and a novel triphenylamine-based derivative, 4,4′,4″-tris{[di( p-tolyl)amino]phenyl}triphenylamine were synthesized and employed as red molecular emitter and hole-transporting layer, respectively, in an undoped organic light-emitting diode devices. The device based on the TPD-FCN emitter and DBTPA hole-transporting material, which was fabricated in a facile non-doped configuration, achieved maximum luminance of 3400 cd m −2 at a driven voltage of 17.5 V and maximum luminous efficiency of 3.04 cd A −1. Interestingly, the device reached a brightness of 1399 cd m −2 and luminous efficiency of 2.85 cd A −1 at the low current density of 20 mA cm −2.