Organic light emitting devices with an emissive region having emissive and non-emissive layers and method of making

• US 7,776,456 B2
• Filed: 12/03/2004
• Issued: 08/17/2010
• Est. Priority Date: 12/03/2004
• Status: Active Grant

• Current Assignee: Universal Display Corporation
• Original Assignee: Universal Display Corporation
• Inventors: D'Andrade, Brian, Zhou, Theodore
• Primary Examiner(s): GARRETT, DAWN L
• Application Number:
  US11/002,260
• Publication Number:
  US 20060121309A1
• Time in Patent Office: 2,083 Days
• Field of Search: 428/690, 428/917, 313/504, 313/506
• US Class Current: 428/690
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: Y10S 428/917 Electroluminescent
• CPC Class Codes: Y10T 428/24851 Intermediate layer is discontinuous or differential
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree

Abstract

The present invention provides an OLED with an emissive region comprising a plurality of sets of organic layers, each set comprising a non-continuous emissive layer and a neat non-emissive layer. The present invention also provides an OLED with an emissive region comprising a plurality of sets of organic layers, each set comprising an emissive layer and a neat non-emissive layer, wherein the energy gaps of the emissive layer and the non-emissive layer are not nested. The present invention also provides a method for making OLEDs by depositing on a substrate an anode, a plurality of sets of organic layers, each set comprising an emissive layer and a non-emissive layer wherein each layer is deposited sequentially, and a cathode.

Claims

1. An organic light emitting device, comprising:

(a) an anode;

(b) a cathode;

(c) a plurality of sets of organic layers disposed between the anode and the cathode, each set comprising;

a non-continuous emissive layer of an emissive material without a host material which comprises spaces that are empty or occupied by molecules of another layer; and

a neat non-emissive layer adjacent to and in physical contact with the non-continuous emissive layer,

wherein the plurality of sets of organic layers are disposed in a manner such that the non-continuous emissive layers form a series of planar regions separated from each other by the neat non-emissive layers.

2. The device of claim 1, wherein each set consists of one non-continuous emissive layer and one neat non-emissive layer, such that the plurality of sets of organic layers comprises alternating non-continuous emissive layers and neat non-emissive layers.

3. The device of claim 1, wherein each non-continuous emissive layer includes the same organic emissive material.

4. The device of claim 1, wherein each neat non-emissive layer includes the same organic non-emissive material.

5. The device of claim 1, wherein the plurality of sets comprises 2 to 10 sets of organic layers.

6. The device of claim 1, wherein the plurality of sets comprises more than 10 sets of organic layers.

7. The device of claim 1, wherein each non-continuous emissive layer has a thickness of less than about 1 Å

.

8. The device of claim 1, wherein each non-continuous emissive layer has an island structure.

9. The device of claim 1, wherein each non-continuous emissive layer has a mesh structure.

10. The device of claim 1, wherein each neat non-emissive layer has a thickness of about 10 to about 100 Å

.

11. The device of claim 1, wherein each non-continuous emissive layer comprises a small molecule organic phosphorescent emissive material.

12. The device of claim 1, wherein each non-continuous emissive layer consists essentially of Ir(ppy)₃.

13. The device of claim 1, wherein each neat non-emissive layer consists essentially of CBP.

14. The device of claim 1, further comprising a hole transport layer disposed between the anode and the plurality of sets of organic layers.

15. The device of claim 1, further comprising an electron transport layer disposed between the plurality of sets of organic layers and the cathode.

16. The device of claim 1, wherein the non-continuous emissive layers are the only layers that emit light when an operating voltage is applied across the device.

17. The device of claim 1, wherein the device comprises:

(a) an anode;

(b) a layer consisting essentially of CuPc;

(c) a layer consisting essentially of NPD;

(d) a repeated set of organic layers alternating between a neat layer consisting essentially of CBP and a non-continuous layer consisting essentially of Ir(ppy)₃,

(e) a layer consisting essentially of BAlq,

(f) a layer consisting essentially of Alq, and

(g) a cathode, disposed, in that order, over a substrate.

18. The device of claim 1, wherein at least one organic layer in the plurality of sets of organic layers is deposited by organic vapor phase deposition.

19. The device of claim 1, wherein at least one organic layer in the plurality of sets of organic layers is deposited by vacuum thermal evaporation.

20. The device of claim 1, wherein all layers are deposited by the same process.

40. The device of claim 1, wherein each non-continuous emissive layer has a thickness less than the size of a single molecule of the emissive material, wherein said thickness is calculated by the total thickness of the plurality of sets of organic layers multiplied by the volume percent of the emissive material.

41. The device of claim 1, wherein each non-continuous emissive layer consists essentially of the emissive material.

42. The device of claim 1, wherein each non-continuous emissive layer consists essentially of a single emissive material.

43. The device of claim 1, wherein each non-continuous emissive layer consists essentially of the emissive material and a non-emissive material from an adjacent non-emissive layer.

21. An organic light emitting device, comprising:

(a) an anode;

(b) a cathode;

(c) a plurality of sets of organic layers disposed between the anode and the cathode, each set comprising an emissive layer of an emissive material without a host material and a neat non-emissive layer, wherein said emissive layer is a non-continuous emissive layer which comprises spaces that are empty or occupied by molecules of another layer, wherein the plurality of sets of organic layers are disposed in a manner such that the non-continuous emissive layers form a series of planar regions separated from each other by the neat non-emissive layers, and wherein the energy gaps of the emissive layer and the non-emissive layer are not nested.

22. The device of claim 21, wherein the energy gaps of the emissive layer and the non-emissive layer partially overlap.

23. The device of claim 22, wherein the highest occupied molecular orbital level of the emissive layer is higher than the highest occupied molecular orbital level of the non-emissive layer, and the lowest unoccupied molecular orbital level of the emissive layer is higher than the lowest unoccupied molecular orbital level of the non-emissive layer.

25. The device of claim 21, wherein each non-continuous emissive layer has a mesh structure.

24. The device of clam 21, wherein each non-continuous emissive layer has an island structure.

26. An organic light emitting device, comprising:

(a) an anode;

(b) a cathode;

(c) a plurality of sets of organic layers disposed between the anode and the cathode, each set comprising an emissive layer and a neat non-emissive layer, wherein the energy gaps of the emissive layer and the non-emissive layer are not nested, wherein the energy gaps of the emissive layer and the non-emissive layer partially overlap, wherein each emissive layer is continuous and wherein said emissive layer is formed by an emissive material without a host material, and wherein the plurality of sets of organic layers are disposed in a manner such that the emissive layers form a series of planar regions separated from each other by the neat non-emissive layers.

27. The device of claim 26, wherein each emissive layer has a thickness of at least one monolayer.

28. An organic light emitting device, comprising:

(a) an anode;

(b) a cathode;

(c) a plurality of sets of organic layers disposed between the anode and the cathode, each set comprising a layer of a first organic material and a neat layer of a second organic material, wherein said layer of said first organic material is a non-continuous layer which comprises spaces that are empty or occupied by molecules of another layer, wherein the plurality of sets of organic layers are disposed in a manner such that the layers of the first organic material form a series of planar regions separated from each other by the neat layers of the second organic material, and wherein the energy gaps of the first organic material and the second organic material are not nested.

29. The device of claim 28, wherein the energy gaps of the first organic material and the second organic material partially overlap.

30. The device of claim 28, wherein the highest occupied molecular orbital level of the first organic material is higher than the highest occupied molecular orbital level of the second organic material, and the lowest unoccupied molecular orbital level of the first organic material is higher than the lowest unoccupied molecular orbital level of the second organic material.

31. An organic light emitting device, comprising:

(a) an anode;

(b) a cathode;

(c) a plurality of sets of organic layers disposed between the anode and the cathode, each set comprising a layer of a first organic material and a layer of a second organic material, wherein said layer of said first organic material is a non-continuous layer which comprises spaces that are empty or occupied by molecules of another layer, wherein the plurality of sets of organic layers are disposed in a manner such that the layers of the first organic material form a series of planar regions separated from each other by the layers of the second organic material, and wherein the layer of the first organic material has a thickness of less than about 1 Å

, and the layer of the second organic material has a thickness of about 10 to about 100 Å

.

32. A method comprising:

(a) depositing an anode over a substrate;

(b) depositing a plurality of sets of organic layers over the anode, each set comprising a non-continuous emissive layer of an emissive material without a host material and a neat non-emissive layer, wherein each layer is deposited sequentially, wherein said non-continuous emissive layer comprises spaces that are empty or occupied by molecules of another layer, and wherein the plurality of sets of organic layers are disposed in a manner such that the non-continuous emissive layers form a series of planar regions separated from each other by the neat non-emissive layers; and

(c) depositing a cathode over the plurality of sets of organic layers.

33. The method of claim 32, wherein depositing comprises organic vapor phase deposition.

34. The method of claim 32, wherein depositing comprises vacuum thermal evaporation.

35. A method comprising:

(a) depositing an anode over a substrate;

(b) depositing a plurality of sets of organic layers over the anode, each set comprising an emissive layer of an emissive material without a host material and a neat non-emissive layer, wherein the energy gaps of the emissive layer and the non-emissive layer are not nested, wherein said emissive layer is a non-continuous emissive layer which comprises spaces that are empty or occupied by molecules of another layer, wherein each layer is deposited sequentially, and wherein the plurality of sets of organic layers are disposed in a manner such that the non-continuous emissive layers form a series of planar regions separated from each other by the neat non-emissive layers; and

(c) depositing a cathode over the plurality of sets of organic layers.

36. The method of claim 35, wherein depositing comprises organic vapor phase deposition.

37. The method of claim 35, wherein depositing comprises vacuum thermal evaporation.

38. An organic light emitting device made by the process comprising:

(a) depositing an anode over a substrate;

(b) depositing a plurality of sets of organic layers over the anode, each set comprising a non-continuous emissive layer of an emissive material without a host material and a neat non-emissive layer, wherein said emissive layer is a non-continuous emissive layer which comprises spaces that are empty or occupied by molecules of another layer, wherein the plurality of sets of organic layers are disposed in a manner such that the non-continuous emissive layers form a series of planar regions separated from each other by the neat non-emissive layers, and wherein each layer is deposited sequentially and in physical contact with the other layer in the set; and

(c) depositing a cathode over the plurality of sets of organic layers.

39. An organic light emitting device made by the process comprising:

(a) depositing an anode over a substrate;

(b) depositing a plurality of sets of organic layers over the anode, each set comprising an emissive layer of an emissive material without a host material and a neat non-emissive layer, wherein the energy gaps of the emissive layer and the non-emissive layer are not nested, wherein said emissive layer is a non-continuous emissive layer which comprises spaces that are empty or occupied by molecules of another layer, wherein each layer is deposited sequentially, and wherein the plurality of sets of organic layers are disposed in a manner such that the non-continuous emissive layers form a series of planar regions separated from each other by the neat non-emissive layers; and

(c) depositing a cathode over the plurality of sets of organic layers.