Carbazole/Indole-Substituted Bianthracene Derivatives for Blue Organic Light Emitting Diodes

Abstract

As an effort to search efficient blue emitters for OLEDs, we synthesized two blue fluorescent materials based on carbazole- and indole-substituted bianthracene. To investigate their electroluminescent (EL) properties, multilayered OLEDs with the following sequence; indium-tin-oxide (ITO)/N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB) (50 nm)/Blue emitting materials (30 nm)/bathophenanthroline (Bphen) (30 nm)/8-hydroxyquinolinolate-lithium (Liq) (2 nm)/Al (100 nm) were fabricated using these materials as emitters. Particularly, a device using 9-(4-(10-(10-(4-(9H-carbazol-9-yl)phenyl)anthracen-9-yl)anthracen-9-yl)phenyl)-9H-carbazole exhibited the efficient blue emission with a luminous efficiency, a power efficiency, an external quantum efficiency, and CIE coordinates of 2.49 cd/A, 1.07 lm/W, 2.30% at 20 mA/cm(2), and (0.15, 0.12) at 8.0 V, respectively. This study demonstrates that arylamine-substituted bianthracene derivatives have the excellent properties for blue emitting materials for OLEDs.