Organic electroluminescent device

• US 5,719,467 A
• Filed: 07/27/1995
• Issued: 02/17/1998
• Est. Priority Date: 07/27/1995
• Status: Expired due to Term

• Current Assignee: InnoLux Corporation
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Antoniadis, Homer, Roitman, Daniel B., Miller, Jeffrey N.
• Primary Examiner(s): Patel, Ashok
• Application Number:
  US08/508,020
• Time in Patent Office: 936 Days
• Field of Search: 313/506, 313/502, 313/501, 313/503, 313/504, 428/917, 428/690, 315/169.3
• US Class Current: 313/506
• 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: H05B 33/26 characterised by the composition or arrangement of the conductive material used as an electrode
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/81 Anodes

Abstract

An organic electroluminescent device with a conducting polymer layer beneath the hole transport layer. A conducting polymer layer of doped polyaniline (PANI) is spin-cast onto an indium-tin oxide (ITO) anode coating on a glass substrate. Then a hole transport layer, for example TPD or another aromatic tertiary amine, is vapor-deposited onto the conducting polymer layer, followed by an electron transport layer and a cathode. Polyester may be blended into the PANI before spin-casting and then removed by a selective solvent after the spincasting, leaving a microporous layer of PANI on the anode. The conducting polymer layer may instead be made of a π-conjugated oxidized polymer or of TPD dispersed in a polymer binder that is doped with an electron-withdrawing compound. An additional layer of copper-phthalocyanine, or of TPD in a polymer binder, may be disposed between the conducting polymer layer and the hole transport layer. The conducting polymer layer may serve as the anode, in which case the ITO is omitted.

Claims

1. An organic electroluminescent device comprising:

an anode on the substrate,

a first hole transport layer fabricated of an aromatic tertiary amine adjacent the anode,

an electron transport layer adjacent the first hole transport layer,

a cathode adjacent the electron transport layer, and

a conductive polymer layer between the anode and the hole transport layer.

2. The organic electroluminescent device of claim 1 wherein the conductive polymer layer comprises doped polyaniline.

3. The organic electroluminescent device of claim 2 wherein the polyaniline comprises a microporous film.

4. The organic electroluminescent device of claim 2 and further comprising a second hole transport layer fabricated of an aromatic tertiary amine dispersed in a polymer binder between the conducting polymer layer and the first hole transport layer.

5. The organic electroluminescent device of claim 4 wherein the second hole transport layer comprises N,N'"'"'-diphenyl-N-N'"'"'-bis(3-methylphenyl)-1,1'"'"'-biphenyl-4,4'"'"'-diamine "TPD", and wherein the polymer binder comprises polystyrene.

6. The organic electroluminescent device of claim 2 wherein the doped polyaniline comprises polyaniline doped with camphor-sulfonic acid.

7. The organic electroluminescent device of claim 2 wherein the doped polyaniline comprises polyaniline that has been doped by being oxidized through Lewis acid chemistry.

8. The organic electroluminescent device of claim 2 wherein the doped polyaniline comprises polyaniline that has been doped by being protonated through an acid-base chemistry.

9. The organic electroluminescent device of claim 1 wherein the conductive polymer layer comprises π

-conjugated oxidized polymer.

10. The organic electroluminescent device of claim 9 wherein the π

-conjugated oxidized polymer comprises poly "MEH-PPV") doped with an electron-withdrawing compound.

11. The organic electroluminescent device of claim 10 wherein the electron-withdrawing compound is selected from the group comprising FeCl₃, SbCl₅ and AsF₅.

12. The organic electroluminescent device of claim 1 wherein the conductive polymer layer comprises:

a polymer binder doped with an electron-withdrawing compound; and

a hole-transporting compound dispersed in the polymer binder.

13. The organic electroluminescent device of claim 12 wherein the hole-transporting compound comprises an aromatic tertiary amine.

14. The organic electroluminescent device of claim 12 wherein the hole-transporting compound comprises N,N'"'"'-diphenyl-N-N'"'"'-bis(3-methylphenyl)-1,1'"'"'-biphenyl-4,4'"'"'-diamine "TPD").

15. The organic electroluminescent device of claim 12 wherein the polymer binder is selected from the group comprising polycarbonates and polystyrenes.

16. The organic electroluminescent device of claim 12 wherein the electron-withdrawing compound is selected from the group comprising FeCl₃, SbCl₅, and AsF₅.

17. The organic electroluminescent device of claim 1 and further comprising a second hole transport layer of copper-phthalocyanine between the conducting polymer layer and the first hole transport layer.

22. An organic electroluminescent device as in claim 1 wherein the aromatic tertiary amine comprises N,N'"'"'-diphenyl-N-N'"'"'-bis(3-methylphenyl)-1,1'"'"'-biphenyl-4,4'"'"'-diamine ("TPD").

23. An organic electroluminescent device as in claim 2 wherein the aromatic tertiary amine comprises N,N'"'"'-diphenyl-N-N'"'"'-bis(3-methylphenyl)-1,1'"'"'-biphenyl-4,4'"'"'-diamine "TPD").

24. An organic electroluminescent device as in claim 9 wherein the aromatic tertiary amine comprises N,N'"'"'-diphenyl-N-N'"'"'-bis(3-methylphenyl)-1,1'"'"'-biphenyl-4,4'"'"'-diamine "TPD").

25. An organic electroluminescent device as in claim 12 wherein the aromatic tertiary amine comprises N,N'"'"'-diphenyl-N-N'"'"'-bis(3-methylphenyl)-1,1'"'"'-biphenyl-4,4'"'"'-diamine "TPD").

26. An organic electroluminescent device as in claim 17 wherein the aromatic tertiary amine comprises N,N'"'"'-diphenyl-N-N'"'"'-bis(3-methylphenyl)-1,1'"'"'-biphenyl-4,4'"'"'-diamine "TPD").

18. An organic electroluminescent device comprising:

a glass substrate;

a conductive polymer layer formed on the glass substrate to define an anode;

an organic hole-transport layer fabricated of an aromatic tertiary amine on the anode;

an organic electron-transport layer on the hole-transport layer; and

a cathode on the electron-transport layer.

19. An organic electroluminescent device as in claim 18 wherein the conductive polymer layer comprises polyaniline doped with camphor-sulfonic acid.

20. An organic electroluminescent device as in claim 18 wherein the conductive polymer layer comprises a π

-conjugated oxidized polymer.

21. An organic electroluminescent device as in claim 18 wherein the conductive polymer layer comprises:

a polymer binder doped with an electron-withdrawing compound; and

a hole-transporting compound dispersed in the polymer binder.

27. An organic electroluminescent device as in claim 18 wherein the aromatic tertiary amine comprises N,N'"'"'-diphenyl-N-N'"'"'-bis(3-methylphenyl)-1,1'"'"'-biphenyl-4,4'"'"'-diamine "TPD").