Fabrication of Blue Organic Light-Emitting Diodes Based on Indeno-Phenanthrene/Triphenylene Amine Derivatives

Among the three primary colors, blue-emitting materials are limited by the wide energy band gap. In this study, we designed and synthesized emitting materials based on indeno-phenanthrene/ triphenylene derivatives. Organic light emitting-diodes (OLEDs) using these materials were fabricated in the following sequence; ITO/N,N'-diphenyl-N,N'-(2-napthyl)-(1,1'-phenyl)-4,4'-diamine (NPB) (500 Å)/Blue materials (30 nm)/4,7-diphenyl-1,10-phenanthroline (BPhen) (30 nm)/lithium quinolate (Liq) (20 Å)/Al (1000 Å). All the devices showed efficient blue emission. Particularly, a device using 10,10-dimethyl-N,N-diphenyl-10H-indeno[1,2-b]triphenylen-12-amine as an emitter exhibited luminous efficiency, power efficiency, and external quantum efficiency of 3.62 cd/A, 1.83 lm/W, 2.82% at 20 mA/cm², respectively, with Commission Internationale d'Énclairage (CIE) coordinates of (0.16, 0.15) at 6.0 V.