Organometallic compounds having host and dopant functionalities

• US 20080280163A1
• Filed: 05/10/2007
• Published: 11/13/2008
• Est. Priority Date: 05/10/2007
• Status: Active Grant

• Current Assignee: Universal Display Corporation
• Original Assignee: Universal Display Corporation
• Inventors: Kwong, Raymond, Xia, Chuanjun, Brooks, Jason
• Granted Patent: US 7,993,763 B2
• Time in Patent Office: Days
• US Class Current: 428/704
• CPC Class Codes: C07F 15/0033 Iridium compounds
• CPC Class Codes: C08G 2261/312 Non-condensed aromatic systems, e.g. benzene
• CPC Class Codes: C08G 61/10 only aromatic carbon atoms, e.g. polyphenylenes
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1011 Condensed systems
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/185 of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 85/141 comprising aliphatic or olefinic chains, e.g. poly N-vinylcarbazol, PVC or PTFE
• CPC Class Codes: H10K 85/151 Copolymers
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/633 comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom
• CPC Class Codes: H10K 85/6572 comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole
• CPC Class Codes: H10K 85/731 Liquid crystalline materials
• CPC Class Codes: H10K 85/791 Starburst compounds
• CPC Class Codes: Y02E 10/549 Organic PV cells

Abstract

Organometallic compounds comprising an emissive core and one or more poly-phenylene branches linked to the emissive core. Host moieties are provided as pendant groups on the branches. In some cases, the poly-phenylene chain is linked in meta configuration to reduce π-conjugation in the chain. Suitable host moieties for use in the organometallic compound include those that contain carbazole or triphenylene structures. The quantity and types of host moieties on the organometallic compound may be varied to tune the molecular weight ratio of the host moieties relative to the emissive core. In some cases, the organometallic compound is sufficiently soluble in organic solvents to permit solution processing. Also provided are organic electronic devices comprising organometallic compounds of the present invention and methods for making an organic electronic device using organometallic compounds of the present invention.

Claims

1. An organometallic compound comprising one or more branches linked to an emissive core as represented by the formula:

2. The organometallic compound of claim 1, wherein each phenyl unit within the chain is linked to the adjacent phenyl units in meta configuration.

3. The organometallic compound of claim 1, wherein the emissive core is represented by the formula:

4. The organometallic compound of claim 3, wherein the structure A-B is:

5. The organometallic compound of claim 3, wherein ring A is a quinoline or isoquinoline and ring B is a phenyl.

6. The organometallic compound of claim 5, wherein variable “

q”

is 2 and L is acetylacetonate or a derivative of acetylacetonate.

7. The organometallic compound of claim 6, wherein one of the branches is linked to L.

8. The organometallic compound of claim 1, wherein each R_H independently has 3 to 6 rings.

9. The organometallic compound of claim 1, wherein each R_H is independently selected from the group consisting of:

carbazole, triphenylene, phenanthrene, phenanthroline, and derivatives thereof.

10. The organometallic compound of claim 1, wherein each variable “

x”

is independently in the range of 2 to 7.

11. The organometallic compound of claim 1, wherein the poly-phenylene chain in each branch contains 4 to 14 phenyl units.

12. The organometallic compound of claim 1, wherein the molecular weight of the emissive core is from 15% to 100% of the sum of the molecular weights of all the branches with host moieties R_H.

13. The organometallic compound of claim 1, wherein the molecular weight of the emissive core is from 0 to 30% of the sum of the molecular weights of all the branches with host moieties R_H.

14. The organometallic compound of claim 1, wherein the organometallic compound has a solubility of at least 0.01 g in 10 ml of an organic solvent.

15. The organometallic compound of claim 1, wherein the metal atom is iridium.

16. The organometallic compound of claim 1, wherein the host moieties R_H are selected from Group X or derivatives thereof having alkyl group, heteroalkyl group, aryl group, or heteroaryl group substitutions at any position on any of the rings in the host moieties, wherein Group X consists of:

17. The organometallic compound of claim 1, wherein the host moieties R_H are selected from Group X, Group Y, Group Z, or derivatives thereof having alkyl group, heteroalkyl group, aryl group, or heteroaryl group substitutions at any position on any of the rings in the host moieties,

wherein Group X consists of:

18. The organometallic compound of claim 1, wherein the organometallic compound is selected from the group consisting of:

19. An organic electronic device comprising:

an anode;

a cathode; and

a first organic layer disposed between the anode and the cathode, wherein the first organic layer comprises an organometallic compound having the formula;

20. The device of claim 19, wherein the first organic layer is an electroluminescent layer.

21. The device of claim 20, wherein the first organic layer further comprises a host material that is separate and distinct from the organometallic compound.

22. The device of claim 19, wherein the device is an organic light-emitting diode.

23. The device of claim 19, wherein the first organic layer is formed by solution processing.

24. The device of claim 19, further comprising a second organic layer disposed between the first organic layer and the anode, wherein the second organic layer comprises a hole injection material.

25. The device of claim 24, further comprising a third organic layer disposed between the second organic layer and the first organic layer, wherein the third organic layer comprises a hole transport material.

26. The device of claim 25, further comprising a fourth organic layer disposed between the first organic layer and the cathode, wherein the fourth organic layer comprises an electron transport material.

27. The device of claim 26, further comprising a fifth organic layer disposed between the fourth organic layer and the cathode, wherein the fifth organic layer comprises an electron transport material.

28. A method for making an organic electronic device, comprising:

providing a first electrode disposed on a substrate;

forming a first organic layer over the first electrode, wherein the first organic layer comprises an organometallic compound; and

forming a second electrode disposed over the first organic layer,

wherein the organometallic compound has the formula;

29. The method of claim 28, wherein forming the first organic layer comprises depositing the organometallic compound by solution processing.

30. The method of claim 28, further comprising forming a second organic layer over the first electrode such that the second organic layer is disposed between the first organic layer and the first electrode.

31. The method of claim 30, wherein forming the second organic layer comprises depositing by solution processing.

32. The method of claim 30, wherein the second organic layer comprises a hole injection material.

33. The method of claim 31, further comprising cross-linking the second organic layer.

34. The method of claim 30, further comprising forming a third organic layer over the second organic layer such that the third organic layer is disposed between the second organic layer and the first organic layer, wherein the third organic layer comprises a hole transport material.

35. The method of claim 34, wherein forming the third organic layer comprises depositing by solution processing.

36. The method of claim 35, further comprising cross-linking the third organic layer.

37. The method of claim 34, further comprising depositing a fourth organic layer over the first organic layer such that the fourth organic layer is disposed between the first organic layer and the cathode, wherein the fourth organic layer comprises an electron transport material.

38. The method of claim 37, wherein the fourth organic layer is deposited by vacuum thermal evaporation.

39. The method of claim 37, further comprising depositing a fifth organic layer over the fourth organic layer such that the fifth organic layer is disposed between the fourth organic layer and the cathode, wherein the fifth organic layer comprises an electron transport material.