Stacked oled structure

• US 20060261731A1
• Filed: 05/20/2005
• Published: 11/23/2006
• Est. Priority Date: 05/20/2005
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Aziz, Hany, Coggan, Jennifer A.
• Granted Patent: US 7,750,561 B2
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths

Abstract

A stacked OLED device comprises a plurality of individual OLEDs in a vertical stacked arrangement separated by intermediate electrodes, wherein at least one of the individual OLEDs includes a light emitting region or zone comprising a mixed region; the mixed region comprising a mixture of a hole transport material, an electron transport material, and optionally a dopant.

Claims

1. A stacked organic light emitting device comprising:

a substrate;

a first electrode;

a second electrode;

a plurality of luminescent regions disposed between the first and second electrodes; and

an intermediate electrode disposed between successive luminescent regions,

wherein at least one of the plurality of luminescent regions comprises a mixed region, the mixed region comprising a mixture of a first material and a second material, and optionally a dopant, at least one of the first material, second material, and dopant being an emitter, and wherein the said first and second materials have different electron and hole transport capacities.

2. The stacked organic light emitting device of claim 1, wherein said first and said second materials are independently selected from hole transport materials, electron transport materials and bipolar transport materials.

3. The stacked organic light emitting device of claim 2, wherein said first material is a hole transport material and said second material is an electron transport material or a bipolar transport material.

4. The stacked organic light emitting device of claim 2, wherein said first material is an electron transport material and said second material is a hole transport material or a bipolar transport material.

5. The stacked organic light emitting device of claim 2, wherein said first material is a hole transport material and said second material is an electron transport material.

6. The stacked organic light emitting device according to claim 1, wherein the mixed region further comprises a dopant.

7. The stacked organic light emitting device according to claim 1, wherein each of the plurality of luminescent regions emits a different emission color.

8. The stacked organic light emitting device according to claim 1, wherein at least one of the plurality of luminescent regions emits an emission color different from an emission color emitted from at least one of the other luminescent regions.

9. The stacked organic light emitting device according to claim 1, wherein each of the plurality of luminescent regions emits the same emission color.

10. The stacked organic light emitting device according to claim 1, wherein at least a luminescent region comprising a mixed region further comprises a charge transport zone adjacent one of the first electrode, the second electrode, and the intermediate electrode.

11. The stacked organic light emitting device according to claim 1, wherein at least one of a luminescent region comprising a mixed region comprises the mixed region disposed between a first charge transport zone and a second charge transport zone.

12. The stacked organic light emitting device according to claim 1, wherein a mixed region comprises from about 5 to about 95 volume percent of the first material and from about 5 to about 95 volume percent of the second material.

13. The stacked organic light emitting device according to claim 12, wherein a mixed region further comprises a dopant in an amount of from about 0.01 to about 25 volume percent.

14. A display device comprising the stacked organic light emitting device of claim 1.

15. A stacked organic light emitting device comprising:

a first electrode;

a second electrode;

a plurality of luminescent regions disposed between the first and second electrodes; and

an intermediate electrode disposed between successive luminescent regions,

wherein at least one of the plurality of luminescent regions comprises a first charge transport zone, a second charge transport zone, and a mixed region disposed between the first and second charge transport zones, the mixed region comprising a mixture of a first material and a second material, and optionally a dopant, at least one of the first material, second material, and dopant being an emitter, and wherein the said first and second materials have different electron and hole transport capacities.

16. The stacked organic light emitting device of claim 15, wherein said first and said second materials are independently selected from hole transport materials, electron transport materials and bipolar transport materials.

17. The stacked organic light emitting device of claim 16, wherein said first material is a hole transport material and said second material is an electron transport material or a bipolar transport material.

18. The stacked organic light emitting device of claim 16, wherein said first material is an electron transport material and said second material is a hole transport material or a bipolar transport material.

19. The stacked organic light emitting device of claim 16, wherein said first material is a hole transport material and said second material is an electron transport material.

20. The stacked organic light emitting device according to claim 15, wherein the mixed region further comprises a dopant.

21. The stacked organic light emitting device according to claim 15, wherein each of the plurality of luminescent regions emits a different color.

22. The stacked organic light emitting device according to claim 15, wherein each of the plurality of luminescent regions emits the same emission color.

23. The stacked organic light emitting device according to claim 15, wherein an intermediate electrode comprises a first surface in contact with a charge transport zone of a first luminescent region, and a second surface in contact with a charge transport surface of a second luminescent region, each of the charge transport zones contacting the first and second surfaces of the intermediate electrode having the same charge transporting function.

24. The stacked organic light emitting device according to claim 15, wherein the intermediate electrode is a single layer capable of injecting a single type of charge into an adjacent charge transport zone.

25. The stacked organic light emitting device according to claim 15, wherein an intermediate electrode is a multi-layer configuration comprising a first layer adjacent a charge transport zone of a first luminescent region, and a second layer adjacent a charge transport zone of a second luminescent region, the first and second layers of the intermediate electrode comprising a charge injecting material capable of injecting an appropriate charge type to the adjacent charge transport zone.

26. The stacked organic light emitting device according to claim 15, wherein each of the plurality of light emitting regions comprises a first charge transport zone, a second charge transport zone, and a mixed region disposed between the first and second charge transport zones, the mixed region comprising a mixture of a first material and a second material, and optionally a dopant, at least one of the first material, second material, and dopant being an emitter, and wherein the said first and second materials have different electron and hole transport capacities.

27. The stacked organic light emitting device according to claim 15, wherein the first electrode is an anode and the second electrode is a cathode.

28. The stacked organic light emitting device according to claim 15, wherein the first electrode is a cathode and the second electrode is an anode.

29. The stacked organic light emitting device according to claim 15, wherein each of the first and second electrodes is an anode.

30. The stacked organic light emitting device according to claim 15, wherein each of the first and second electrodes is a cathode.

31. The stacked organic light emitting device according to claim 15, wherein an intermediate electrode comprises a first surface contacting a hole transport zone of a first luminescent region and a second surface contacting an electron transport zone of a second luminescent region.

32. The stacked organic light emitting device according to claim 31, wherein the intermediate electrode contacting a hole transport zone of a first luminescent region and an electron transport zone of a second luminescent region comprise a first layer adjacent the hole transport zone of the first luminescent region and a second layer adjacent the electron transport zone of the second luminescent region, the first layer comprising a hole injecting material, and the second layer comprising an electron injecting material.

33. The stacked organic light emitting device according to claim 15, wherein a mixed region comprises from about 5 to about 95 volume percent of the first material and from about 5 to about 95 volume percent of the second transport material.

34. The stacked organic light emitting device according to claim 33, wherein a mixed region further comprises a dopant in an amount in an amount from about 0.01 to about 25 volume percent.

35. A display device comprising the stacked organic light emitting device of claim 15.

36. A stacked organic light emitting device comprising:

an optional substrate;

a first electrode;

a second electrode;

a plurality of luminescent regions disposed between the first and second electrodes; and

an intermediate electrode disposed between successive luminescent regions,

wherein at least one of the plurality of luminescent regions comprises a mixed region, the mixed region comprising a mixture of a first material and a second material, and optionally a dopant, at least one of the first material, second material, and dopant being an emitter, and wherein the said first and second materials have different electron and hole transport capacities; and

,

wherein at least one of the one or more intermediate electrodes is a metal-organic mixed layer electrode comprising a first charge injecting layer, a second charge injecting layer, and a metal-organic mixed layer disposed between the first and second charge injecting layers.

37. The stacked organic light emitting device according to claim 36, wherein the first and second charge injecting layers of the metal-organic mixed layer electrode are independently selected from the group consisting of a hole injecting layer and an electron injecting layer.

38. The stacked organic light emitting device according to claim 36, wherein the metal-organic mixed layer of the metal-organic mixed layer electrode independently comprises a metal material in an amount of from about 5 to about 95 percent by volume and an organic material in an amount of from about 5 to about 95 percent by volume.

39. The stacked organic light emitting device according to claim 36, wherein the metal-organic mixed layer of the metal-organic mixed layer electrode comprises a metal material in an amount of from about 5 to about 30 percent by volume and an organic material in an amount of from about 95 to about 70 percent by volume.

40. The stacked organic light emitting device according to claim 36, wherein the first charge injecting layer is an electron injecting layer and the second charge injecting layer is a hole injecting layer.