Organic Electroluminescent Device

• US 20090128011A1
• Filed: 10/10/2006
• Published: 05/21/2009
• Est. Priority Date: 10/31/2005
• Status: Active Grant

• Current Assignee: Nippon Steel & Sumikin Chemical Co., Ltd. (Nippon Steel Corporation)
• Original Assignee: Nippon Steel Chemical Company Limited (Nippon Steel Corporation)
• Inventors: Henzan, Natsumi, Miyazaki, Hiroshi
• Granted Patent: US 8,119,257 B2
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/10 Non-macromolecular compounds
• CPC Class Codes: C09K 2211/1011 Condensed systems
• CPC Class Codes: C09K 2211/1014 bridged by heteroatoms, e.g. N, P, Si or B
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/1037 with sulfur
• CPC Class Codes: C09K 2211/186 of the light metals other than alkali metals and alkaline earth metals, i.e. Be, Al or Mg
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/361 Polynuclear complexes, i.e. complexes comprising two or more metal centers
• CPC Class Codes: H10K 85/40 Organosilicon compounds, e.g. TIPS pentacene
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

Disclosed is an organic electroluminescent device (organic EL device) utilizing phosphorescence which is improved in luminous efficiency and sufficiently secured of driving stability. The organic EL device comprises an anode 2, organic layers containing a hole-transporting layer 4, a light-emitting layer 5, and an electron-transporting layer 6, and a cathode 7 piled one upon another on a substrate 1, the hole-transporting layer is disposed between the light-emitting layer and the anode, the electron-transporting layer is disposed between the light-emitting layer and the cathode, and the light-emitting layer comprises an organic Al complex represented by the following general formula (I) as a host material and an organic Ir complex represented by the following general formula (II) as a guest material. In formula (I), L is ArO—, ArCOO—, Ar₃SiO—, Ar₃GeO—, or Ar₂AlO—.

Claims

1. An organic electroluminescent device comprising an anode, organic layers containing a hole-transporting layer, a light-emitting layer, and an electron-transporting layer, and a cathode piled one upon another on a substrate with the hole-transporting layer disposed between the light-emitting layer and the anode and the electron-transporting layer disposed between the light-emitting layer and the cathode wherein the light-emitting layer comprises an organic metal complex represented by the following general formula (I) as a host material and an organic metal complex represented by general formula (II) as a guest material:

in general formula (I), each of R₁ to R₆ is independently a hydrogen atom, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an alkoxy group, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted aromatic heterocyclic group and L is a monovalent group represented by the following general formula (1), (2), (3), or (4)

wherein each of Ar₁ to Ar₅ is independently a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, Z is silicon or germanium, and R₁ to R₆ are as defined above;

in general formula (II),

wherein, each of R₇ to R₁₄ is independently a hydrogen atom, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an alkoxy group, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted hereocyclic group.

2. An organic electroluminescent device as described in claim 1 wherein a hole-injecting layer is disposed between the anode and the hole-transporting layer.

3. An organic electroluminescent device as described in claim 1 wherein an electron-injecting layer is disposed between the cathode and the electron-transporting layer.

4. An organic electroluminescent device as described in claim 2 wherein an electron-injecting layer is disposed between the cathode and the electron-transporting layer.