Organic Light-Emitting Devices Consisting of A/-Triarylamine-Based Hole Injecting/Transporting Materials

摘要

A series of N-triarylamine-based derivatives such as 4,4"' -bislN-(l-naphthyl)-N-phenyl-amino]biphenyl (a-NPD), l,3,5-tris[4-(3-methylphenyl(phenyl)amino) phenyUbenzene (m-MTDAPB) and l,3,5-tris-(4-[l-naphthyl(phenyl)amino]phenyll-benzene (1-TNAPB) were synthesized and characterized. Specially, 1-TNAPB was synthesized with high yield in 1 hr. The hole injecting/transporting properties of these materials were investigated by using double-layered organic light-emitting diodes (OLEDs) with the configuration of ITO/N-triarylamine/Alq3/LiF/Al, in which Alq_3 was used as an emitting and electron transporting layer. A comparative study on EL performance of OLEDs fabricated with N-triarylamines as the hole injecting I transporting layer revealed that better results were observed in OLED with m-MTDAPB and alpha-NPD, respectively. OLED with m-MTDAPB (20nm thickness) showed maximum luminescence of 15,970cd/m~2 at 10V and turn-on voltage of 4 V. On the other hand, alpha-NPD (50 nm thickness) exhibited maximum luminescence of 17,650 cd/m~2 at 17 V and turn-on voltage of7V.