Organometallic complexes as phosphorescent emitters in organic LEDS

• US 7,291,406 B2
• Filed: 09/22/2005
• Issued: 11/06/2007
• Est. Priority Date: 03/23/1999
• Status: Expired due to Term

• Current Assignee: The Trustees of Princeton University (Princeton University), University of Southern California
• Original Assignee: The Trustees of Princeton University (Princeton University), University of Southern California
• Inventors: Burrows, Paul E., Baldo, Marc A., Forrest, Stephen R., Abdel-Razzaq, Feras, Lamansky, Sergey, Thompson, Mark E., Kwong, Raymond, Murphy, Drew, Djurovic, Peter
• Primary Examiner(s): YAMNITZKY, MARIE ROSE
• Application Number:
  US11/233,605
• Publication Number:
  US 20060029829A1
• Time in Patent Office: 775 Days
• Field of Search: None
• US Class Current: 428/690
• CPC Class Codes: C07D 209/86 with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to carbon atoms of the ring system
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1014 bridged by heteroatoms, e.g. N, P, Si or B
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/1033 with oxygen
• CPC Class Codes: C09K 2211/1037 with sulfur
• CPC Class Codes: C09K 2211/1092 containing sulfur as the only heteroatom
• CPC Class Codes: C09K 2211/185 of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd
• CPC Class Codes: C09K 2211/186 of the light metals other than alkali metals and alkaline earth metals, i.e. Be, Al or Mg
• CPC Class Codes: C09K 2211/188 of other metals not provided for in one of the previous groups
• 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: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 2102/103 comprising indium oxides, e.g. ITO
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/18 Carrier blocking layers
• CPC Class Codes: H10K 85/146 poly N-vinylcarbazol; Derivatives thereof
• CPC Class Codes: H10K 85/30 Coordination compounds
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/346 : comprising platinum
• CPC Class Codes: H10K 85/348 : comprising osmium
• CPC Class Codes: H10K 85/631 : Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine
• CPC Class Codes: H10K 85/633 : comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom
• CPC Class Codes: H10K 85/649 : Aromatic compounds comprising a hetero atom
• CPC Class Codes: H10K 85/653 : comprising only oxygen as heteroatom
• CPC Class Codes: H10K 85/654 : comprising only nitrogen as heteroatom H10K85/652 takes precedence
• CPC Class Codes: H10K 85/655 : comprising only sulfur as heteroatom
• CPC Class Codes: H10K 85/657 : Polycyclic condensed heteroaromatic hydrocarbons
• CPC Class Codes: H10K 85/6572 : comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole
• CPC Class Codes: Y10S 428/917 : Electroluminescent

Abstract

Organic light emitting devices are described wherein the emissive layer comprises a host material containing an emissive molecule, which molecule is adapted to luminesce when a voltage is applied across the heterostructure, and the emissive molecule is selected from the group of phosphorescent organometallic complexes, including cyclometallated platinum, iridium and osmium complexes. The organic light emitting devices optionally contain an exciton blocking layer. Furthermore, improved electroluminescent efficiency in organic light emitting devices is obtained with an emitter layer comprising organometallic complexes of transition metals of formula L₂MX, wherein L and X are distinct bidentate ligands. Compounds of this formula can be synthesized more facilely than in previous approaches and synthetic options allow insertion of fluorescent molecules into a phosphorescent complex, ligands to fine tune the color of emission, and ligands to trap carriers.

Claims

1. An organic light emitting device, comprising an anode, a cathode and an emissive layer, wherein

the emissive layer is located between the anode and the cathode, and the emissive layer comprises a host and a dopant, the dopant comprising:

a phosphorescent organometallic compound of formula L₂MX, LL′

MX, LL′

L″

M, L₃M, or LMXX′

, wherein L, L′

, L″

, X, and X′

are inequivalent, bidentate ligands, and M is a metal that forms octahedral complexes, wherein

L, L′

, and L″

are monoanionic bidentate ligands coordinated to M through an sp² hybridized carbon and a heteroatom.

2. The organic light emitting device of claim 1, wherein the host is a compound of formula

3. The organic light emitting device of claim 1, wherein the host is a compound of formula

4. The organic light emitting device of claim 1, wherein the host is a compound of formula

5. The organic light emitting device of claim 1, wherein the host is a compound of formula

6. The organic light emitting device of claim 1, wherein the host is a compound of formula

7. An organic light emitting device, comprising an anode, a cathode, and an emissive layer;

wherein the emissive layer is located between the anode and the cathode, and the emissive layer comprises a phosphorescent organometallic compound of formula L₂MX, LL′

MX, LL′

L″

M, L₃M, or LMXX′

, wherein

L, L′

, L″

, X, and X′

are inequivalent, bidentate ligands, and M is a metal that forms octahedral complexes;

wherein

L, L′

, and L″

are monoanionic bidentate ligands coordinated to M through an sp² hybridized carbon and a heteroatom; and

L, L′

, and L″

are selected from the group consisting of a 2-((1-naphthyl)benzoxazole), a (2-phenylbenzoxazole), a (2-phenylbenzothiazole), a (7,8-benzoquinoline), a coumarin, a phenylpyridine, a benzothienylpyridine, a 3-methoxy-2-phenylpyridine, a thienylpyridine, a tolylpyridine, a phenylimine, a vinylpyridine, an arylquinoline, a pyridylnaphthalene, a pyridylpyrrole, a pyridylimidazole and a phenylindole;

or

the X ligand is selected from the group consisting of an acetylacetonate, a hexafluoroacetylacetonate, a salicylidene, a picolinate, a 8-hydroxyquinolinate, and substituted or unsubstituted ligand selected from the group consisting of an aminoacid, a salicylaldehyde, an acetylacetonate, and a substituted or unsubstituted ligand derived from the structure;

8. The organic light emitting device of claim 7, wherein L is a 2-((1-naphthyl)benzoxazole).

9. The organic light emitting device of claim 7, wherein L is a (2-phenylbenzoxazole).

10. The organic light emitting device of claim 7, wherein L is a (2-phenylbenzothiazole).

11. The organic light emitting device of claim 7, wherein L is a (7,8-benzoquinoline).

12. The organic light emitting device of claim 7, wherein L is a coumarin.

13. The organic light emitting device of claim 7, wherein L is a phenylpyridine.

14. The organic light emitting device of claim 7, wherein L is a benzothienylpyridine.

15. The organic light emitting device of claim 7, wherein L is a 3-methoxy-2-phenylpyridine.

16. The organic light emitting device of claim 7, wherein L is a thienylpyridine.

17. The organic light emitting device of claim 7, wherein L is a tolylpyridine.

18. The organic light emitting device of claim 7, wherein L is a phenylimine.

19. The organic light emitting device of claim 7, wherein L is a vinylpyridine.

20. The organic light emitting device of claim 7, wherein L is an aryiquinoline.

21. The organic light emitting device of claim 7, wherein L is a pyridylnaphthalene.

22. The organic light emitting device of claim 7, wherein L is a pyridylpyrrole.

23. The organic light emitting device of claim 7, wherein L is a pyridylimidazole.

24. The organic light emitting device of claim 7, wherein L is a phenylindole.

25. The organic light emitting device of claim 7, wherein, when X is present, X is an acetylacetonate.

26. The organic light emitting device of claim 7, wherein, when X is present, X is a hexafluoroacetylacetonate.

27. The organic light emitting device of claim 7, wherein, when X is present, X is a salicylidene.

28. The organic light emitting device of claim 7, wherein, when X is present, X is a picolinate.

29. The organic light emitting device of claim 7, wherein, when X is present, X is a 8-hydroxyquinolinate.

30. The organic light emitting device of claim 7, wherein, when X is present, X is an aminoacid.

31. The organic light emitting device of claim 7, wherein, when X is present, X is a salicylaldehyde.

32. The organic light emitting device of claim 7, wherein, when X is present, X is a substituted or unsubstituted ligand derived from the structure:

33. An organic light emitting device comprising an anode, a cathode, and an emissive layer, wherein the emissive layer is located between the anode and the cathode, and the emissive layer comprises a phosphorescent organometallic compound of formula L2MX, LL′

MX, LL′

L″

M, or LMXX′

, wherein L, L′

, L″

, X, and X′

are inequivalent, bidentate ligands and M is a metal that forms octahedral complexes, wherein L, L′

, L″

are monoanionic bidentate ligands coordinated to M through an sp2 hybridized carbon and a heteroatom, and the X ligand is emissive.

45. The organic light emitting device of claim 33, wherein the L ligand is an unsubstituted arylquinoline, having the structure:

46. The organic light emitting device of claim 33, wherein the L ligand is a substituted aryiquinoline, having the structure:

34. An organic light emitting device comprising an anode, a cathode and an emissive layer, wherein the emissive layer is located between the anode and the cathode, the emissive layer consisting essentially of a phosphorescent organometallic compound of formula L₂MX, LL′

MX, LL′

L″

M, L₃M, or LMXX′

, wherein L, L′

, L″

, X, and X′

are inequivalent, bidentate ligands and M is a metal that forms octahedral complexes, wherein L, L′

, and L″

are monoanionic bidentate ligands coordinated to M through an sp² hybridized carbon and a heteroatom.

35. An organic light emitting device comprising an anode, a cathode, and an emissive layer, wherein the emissive layer is located between the anode and the cathode, the emissive layer comprises a phosphorescent organometallic compound of formula L2MX, LL′

MX, LL′

L″

M, L₃M, or LMXX′ and

, optionally, a host, wherein L, L′

, L″

,X, and X′

are inequivalent, bidentate ligands, and M is a metal that forms octahedral complexes, wherein L is a monoanionic bidentate ligand coordinated to M through an sp² hybridized carbon and a heteroatom.

36. An organic light emitting device comprising:

an anode,

a cathode, and

an emissive layer, wherein

the emissive layer is located between the anode and the cathode, and

the emissive layer comprises a phosphorescent organometallic compound of formula L₂MX, LL′

MX, LL′

L″

M, L₃M, or LMXX′

, wherein

L, L′

, L″

, X, and X′

are inequivalent, bidentate ligands, and

M is a metal that forms octahedral complexes, wherein

L, L′

, and L″

are monoanionic bidentate ligands coordinated to M through an sp² hybridized carbon and a heteroatom, and wherein

the organic light emitting device emits light when a carrier injected into the emissive layer is trapped on a ligand of a molecule of the phosphorescent organometallic compound, and recombines with an opposite carrier from the molecule or from an adjacent molecule.

37. The organic light emitting device of claim 36, wherein the trapped carrier is a hole, and the ligand on which the hole is trapped is an X or X′

ligand.

38. An organic light emitting device, comprising:

an anode, a cathode, and an emissive layer, the emissive layer located between the anode and the cathode, wherein the emissive layer comprises a host and a dopant, wherein the dopant is a cyclometallated phosphorescent organometallic compound, comprising a cyclometallated ring, having a carbon-metal bond.

39. The organic light emitting device of claim 38, wherein the cyclometallated phosphorescent organometallic compound is of formula L₂MX, LL′

MX, LL′

L″

M, L₃M, or LMXX′

, wherein L, L′

, L″

, X, and X′

are inequivalent, bidentate ligands, and M is a metal that forms octahedral complexes, and L, L′

, and L″

are monoanionic bidentate ligands coordinated to M through an sp² hybridized carbon and a heteroatom.

40. The organic light emitting device of claim 38, wherein the host is a compound of formula

41. The organic light emitting device of claim 38, wherein the host is a compound of formula

42. The organic light emitting device of claim 38, wherein the host is a compound of formula

43. The organic light emitting device of claim 38, wherein the host is a compound of formula

44. The organic light emitting device of claim 38, wherein the host is a compound of formula