Organic electroluminescent device

• US 6,445,126 B1
• Filed: 06/25/1999
• Issued: 09/03/2002
• Est. Priority Date: 08/13/1998
• Status: Expired due to Fees

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Onitsuka, Osamu, Arai, Michio
• Primary Examiner(s): Day, Michael H.
• Assistant Examiner(s): ZIMMERMAN, GLENN D
• Application Number:
  US09/339,878
• Time in Patent Office: 1,166 Days
• Field of Search: 313/504, 313/506, 313/509, 257/86, 257/94, 257/103, 257/40
• US Class Current: 313/504
• CPC Class Codes: H05B 33/22 characterised by the chemical or physical composition or the arrangement of auxiliary dielectric or reflective layers
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/171 Electron injection layers

Abstract

An organic EL device has a hole injecting electrode (2), an electron injecting electrode (6), an organic layer participating in a light emitting function disposed between the electrodes. The organic layer includes a light emitting layer (4) comprising a conjugated polymer. The device further includes an inorganic insulative hole injecting layer (3) or an inorganic insulative electron injecting layer (5). The device can take advantage of both organic and inorganic materials, and has an improved efficiency, an extended effective life, and a low cost.

Claims

1. An organic electroluminescent device comprising a hole injecting electrode,

an electron injecting electrode,

an organic layer participating in a light emitting function disposed between the electrodes, said organic layer including a light emitting layer comprising a conjugated polymer, and

an inorganic insulative hole injecting layer disposed between the light emitting layer and the hole injecting electrode, wherein said inorganic insulative hole injecting layer contains as a main component an oxide represented by the formula:

2. The device of claim 1 wherein said inorganic insulative hole injecting layer contains an element having a work function of 4.5 to 5.5 eV in addition to the main component.

3. The device of claim 1, wherein the electron injecting electrode has a thickness of about 1 to about 500 nm.

4. The device of claim 1, wherein the electron injection electrode further comprises an auxiliary or protective electrode.

5. The device of claim 1, wherein said conjugated polymer is a poly(4,4′

-diphenylene vinylene)polymer.

6. The device of claim 1, wherein said conjugated polymer is a poly(1,4-phenylene diphenyl vinylene)polymer.

7. The device of claim 1, wherein said conjugated polymer is a poly(3-alkylthiophene)polymer.

8. The device of claim 1, wherein said conjugated polymer is a poly(3-alkylpyrrole)polymer.

9. The device of claim 1, wherein said conjugated polymer is a poly(2,5-dialkoxy-p-phenylene vinylene)polymer.

10. The device of claim 1, wherein said conjugated polymer is a poly(phenylacetylene)polymer.

11. An organic electroluminescent device comprising

a hole injecting electrode,

an electron injecting electrode,

an organic layer participating in a light emitting function disposed between the electrodes, said organic layer including a light emitting layer comprising a conjugated polymer, and

an inorganic insulative electron injecting layer disposed between the light emitting layer and the electron injecting electrode, wherein said inorganic insulative electron injecting layer contains a metal oxide having an electron affinity of up to 3.5 eV as a main component and at least one member selected from the group consisting of oxides, nitrides and carbides of silicon and germanium.

12. The device of claim 11, further comprising an inorganic insulative hole injecting layer disposed between the light emitting layer and the hole injecting electrode.

13. The device of claim 11, wherein the electron injecting electrode has a thickness of about 1 to about 500 nm.

14. The device of claim 11, wherein the electron injection electrode further comprises an auxiliary or protective electrode.

15. The device of claim 11, wherein said conjugated polymer is a poly(4,4′

-diphenylene vinylene)polymer.

16. The device of claim 11, wherein said conjugated polymer is a poly(1,4-phenylene diphenyl vinylene)polymer.

17. The device of claim 11, wherein said conjugated polymer is a poly(3-alkylthiophene)polymer.

18. The device of claim 11, wherein said conjugated polymer is a poly(3-alkylpyrrole)polymer.

19. The device of claim 11, wherein said conjugated polymer is a poly(2,5-dialkoxy-p-phenylene vinylene)polymer.

20. The device of claim 11, wherein said conjugated polymer is a poly(phenylacetylene)polymer.