Synthesis of Benzo[g]quinoline Derivatives and Their Electroluminescent Properties.

Two fluorescent benzo[g]quinoline derivatives were synthesized via Friedländer synthesis. Multilayered OLEDs using benzo[g]quinoline derivatives as the emitters showed unexpected emissions by electroplexes. Particularly, a device using 2-(naphthalen-3-yl)-4-phenylbenzo[g]quinoline as an emitting material exhibited efficient emission with a luminous efficiency, a power efficiency, an external quantum efficiency, and CIE coordinates of 3.58 cd/A, 1.11 lm/W, 1.08% at 20 mA/cm², and (0.36, 0.56) at 1,000 cd/m², respectively.

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.

Highly Efficient Blue Organic Light-Emitting Diodes Based on Diarylamine-Substituted Pyrene Derivatives.

In this study, we designed and synthesized three blue fluorescence materials based on diarylamine-substituted pyrene derivatives. Organic Light Emitting-Diodes devices using these materials were fabricated in the following sequence; ITO/2-TNATA (300 Å)/NPB (200 Å)/α,ß-ADN: 10 wt% blue materials 1-3 (300 Å)/DNAB (300 Å)/Liq (20 Å)/Al (1000 Å). All devices showed highly efficient blue emissions. Particularly, a device using materials (3) shown highly efficient blue emission with luminous efficiency of 8.94 cd/A, power efficiency of 4.40 lm/W, external quantum efficiency of 6.62% at 20 mA/cm², respectively, and the CIE coordinates of (0.16, 0.23) at 6.0 V.

Naphthalene Derivatives End-Capped with 2-(Diphenylamino)-9,9-Diethylfluorenes for Blue Organic Light-Emitting Diodes.

To investigate the electroluminescent (EL) properties of fluorescent materials based on fluorene-substituted naphthalene, 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)/4,7-diphenyl-1,10-phenanthroline (Bphen) (30 nm)/lithium quinolate (Liq) (2 nm)/Al (100 nm) were fabricated using these materials as emitters. These devices exhibited blue emissions. Particularly, a device using 7-(1-(1-(2-(diphenylamino)-9,9-diethyl-9H-fluoren-7- yl)naphthalen-4-yl)naphthalen-4-yl)-9,9-diethyl-N,N-diphenyl-9H-fluoren-2-amine as a blue emitting material exhibited blue emission with a luminous efficiency, a power efficiency, an external quantum efficiency, and CIE coordinates of 2.79 cd/A, 1.19 lm/W, 2.30% at 1,000 cd/m2, and (0.14, 0.12) at 8.0 V, respectively. This study demonstrates that 2-(Diphenylamino)-9,9-diethylfluorenes endcapped naphthalene derivatives have the excellent properties for blue emitting materials for OLEDs.