Efficient Organic Light-Emitting Diodes Based on Indeno-Type Polyaromatic Hydrocarbons.

To develop the efficient emitters for organic light-emitting diode (OLED), three indeno-type polyaromatic hydrocarbons materials were designed and synthesized through Buchwald-Hartwig amination. 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)/Emitting materials (1-3) (30 nm)/4,7-diphenyl-1,10-phenanthroline (BPhen) (30 nm)/lithium quinolate (Liq) (2 nm)/Al (100 nm). All devices showed the efficient emissions. In particular, a device using 8,8-dimethyl-N,N-diphenyl-8H-indeno[2,1-b]fluoranthen-6-amine (2) as efficient emitter showed luminous efficiency, power efficiency, and external quantum efficiency of 8.35 cd/A, 5.70 lm/W, 2.37% at 20 mA/cm², respectively, with Commission Internationale d'Énclairage (CIE) coordinates of (0.37, 0.59) at 6.0 V.

Platinum(II) Complexes Based on Phenylbenzoazole-Derived Ligands for Phosphorescent Organic Light-Emitting Diodes.

Phosphorescent Pt(II) complexes based on phenylbenzoazole ligands were synthesized and their photophysical properties were investigated for OLEDs. Multilayered OLEDs devices using these complexes as emitters showed the efficient emissions, which are very sensitive to the structural and photophysical properties of Pt(II) complexes. In particularly, a device C using Pt(II) complex 2 based on phenylbenzoazole ligand as the dopant exhibited efficient emission with a luminous efficiency, a power efficiency, an external quantum efficiency, and CIE coordinates of 8.03 cd/A, 2.79 lm/W, 4.84% at 20 mA/cm², and (0.63, 0.35) at 10.0 V, respectively.

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.

Highly Efficient Organic Light-Emitting Diodes Based on Naphthoanthracene Derivatives Containing Different Arylamines.

Herein, we designed and synthesized emitting materials based on naphthoanthracene with the different arylamino-substituents. Organic Light Emitting-Diodes (OLEDs) devices 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)/Emitters (400 Å)/Alumium quinolate (Alq3) (150 Å)/lithium quinolate (Liq) (20 Å)/Al (1000 Å). All devices showed efficient emissions. In particular, a device using 4-((5,5-dimethyl-9-phenyl-5H-naphtho[3,2,1-de]anthracen-3-yl)(phenyl)amino)benzonitrile as an emitter exhibited the luminous efficiency, power efficiency, and external quantum efficiency of 9.15 cd/A, 6.36 lm/W, 2.72% at 20 mA/cm², respectively, with the Commission Internationale d'Énclairage (CIE) coordinates of (0.30, 0.62) at 6.0 V.

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.

Synthesis and Electroluminescent Properties of Quinoline-Substituted Anthracene Derivatives for Organic Light-Emitting Diodes.

In this study, two anthracene derivatives with quinoline moieties were synthesized. To investigate their electroluminescent (EL) properties, multilayered OLEDs with the following sequence; indiumtin-oxide (ITO)/N, N'-di(1-naphthyl)-N, N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB) (20 nm)/Blue emitting materials (30 nm)/bathophenanthroline (Bphen) (30 nm)/lithium quinolate (Liq) (2 nm)/Al (100 nm) were fabricated using these materials as emitters. Two devices exhibited EL in blue to sky-blue regions. Especially, a device using 2,3-diphenyl-6-(10-(naphthalen-7-yl)anthracen-9-yl)quinoline (1) as an emitting material exhibited blue emission with a luminous efficiency, a power efficiency, an external quantum efficiency, and Commission International de L'Eclairage (CIE) coordinates of 1.01 cd/A, 0.43 lm/W, 0.80% at 20 mA/cm2, and (0.17, 0.22) at 6.0 V, respectively.