Studies on Organic Light Emitting Diodes Using Phenanthroline Derivatives as Emitters

Abstract

In this study, we designed and synthesized blue emitting materials based on 1, 10-phenanthroline derivatives. OLED devices using these materials were fabricated in the following sequence; indium-tin-oxide (ITO) (180 nm)/N,N'-diphenyl-N,N'-(2-napthyl)-(1,1'-phenyl)-4,4'-diamine (NPB) (50 nm)/Tris(4-carbazoyl-9-ylphenyl)amine (TCTA) (10 nm)/Blue materials (20 nm)/2,2',2 ''-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi) (30 nm)/lithium quinolate (Liq) (2 nm)/Al (100 nm). Particularly, a device using 2-(4-(9,9-dimethylacridin-10(9H)-yl) phenyl)-1-phenyl-1H-imidazo[4,5-f][1,10] phenanthroline as a blue emitter showed the maximum values of luminous efficiency, power efficiency, and external quantum efficiency of 1.45 cd/A, 1.52 lm/W, 0.99%, respectively with the Commission Internationale d'Enclairage (CIE) (x, y) coordinates of (0.16, 0.14) at 8.0 V.