Organic electroluminescent device and display using same

• US 8,007,924 B2
• Filed: 06/16/2004
• Issued: 08/30/2011
• Est. Priority Date: 07/02/2003
• Status: Active Grant

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Kosan Company Limited
• Inventors: Fukuoka, Kenichi, Hosokawa, Chishio
• Primary Examiner(s): Shosho; Callie
• Assistant Examiner(s): Wilson; Michael H
• Application Number:
  US10/562,124
• Publication Number:
  US 20070007882A1
• Time in Patent Office: 2,631 Days
• Field of Search: 428/690, 428/917, 313/504, 313/506, 257/40, 257/E51.044
• US Class Current: 428/690
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/611 Charge transfer complexes
• CPC Class Codes: H10K 85/626 containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene
• CPC Class Codes: H10K 85/631 Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine
• CPC Class Codes: H10K 85/655 comprising only sulfur as heteroatom
• CPC Class Codes: H10K 85/6565 Oxadiazole compounds
• CPC Class Codes: H10K 85/657 Polycyclic condensed heteroaromatic hydrocarbons
• CPC Class Codes: Y10T 428/24818 Knitted, with particular or differential bond sites or intersections

Abstract

An organic electroluminescent device including: at least two or more emitting layers (4), (8) between an anode (10) and a cathode (2), and an intermediate electrode layer (6) being interposed between emitting layers (4), (8), the intermediate electrode layer (6) being a single layer or a multilayer structure of a plurality of layers, at least one of the layers (6) including a semiconductive material having a resistivity of 0.001 to 10,000 Ω·cm. The device and a display using the same have a high efficiency and long life time.

Claims

1. An organic electroluminescent device comprising:

at least two or more emitting layers between an anode and a cathode, and

an intermediate electrode layer being interposed between emitting layers,

the intermediate electrode layer being a single layer or a multilayer structure, at least one of the layers comprising a semiconductive material and at least one of the layers comprising a donor that is an alkali metal and/or an alkaline earth metal,

the semiconductive material comprising an acceptor that is at least one conductive oxide comprising a transition metal selected from the group consisting of NbO_X, LaO_x, NdO_x, SmO_x, EuO_x, MoO_x, WO_x, OsO_x, IrO_x and PtO_x, wherein x is 0.2 to 5;

wherein the acceptor is the main constituent of the intermediate electrode layer and the ratio of donor to acceptor in the intermediate electrode layer is between 2;

98 to 20;

80 by weight.

2. A display comprising a screen comprising the organic electroluminescent device according to claim 1.

3. The organic electroluminescent device according to claim 1, wherein the conductive oxide is MoO_x.

4. The organic electroluminescent device according to claim 1, wherein the conductive oxide is MoO_x, x is 2 to 3, and the donor is Cs.

5. The organic electroluminescent device according to claim 1, further comprising an electron injecting layer on the anode side of the intermediate layer, wherein the electron injecting layer comprises an alkali metal compound or a reducing dopant.

6. The organic electroluminescent device according to claim 1, wherein the intermediate electrode layer has a resistivity between 0.001 and 10,000 Ω

·

cm.

7. The organic electroluminescent device according to claim 1, wherein the intermediate electrode layer has a resistivity between 0.01 and 100 Ω

·

cm.

8. An organic electroluminescent device comprising:

at least two or more emitting layers between an anode and a cathode, and

an intermediate electrode layer being interposed between emitting layers,

the intermediate electrode layer being a single layer or a multilayer structure, at least one of the layers comprising a semiconductive material and at least one of the layers comprising a donor that is an alkali metal and/or an alkaline earth metal, and

the semiconductive material comprising MoO_x, wherein x is 0.2 to 5.