Organometallic complexes as phosphorescent emitters in organic LEDs

• US 7,001,536 B2
• Filed: 06/16/2004
• Issued: 02/21/2006
• 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:
  US10/870,788
• Publication Number:
  US 20040262576A1
• Time in Patent Office: 615 Days
• Field of Search: 544/4, 544/64, 544/225, 546/4, 546/10, 548/103, 548/402, 549/3, 549/209, 252/301.16, 428/917
• US Class Current: 252/301.16
• 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. A composition comprising a compound of formula L₂MX, wherein L and X are inequivalent monoanionic bidentate ligands, M is a metal that forms octahedral complexes, and the L ligands are coordinated to M through an sp² hybridized carbon and a heteroatom, wherein M is selected from the group consisting of the transition metals of the third row of the transition series of the periodic table.

2. The composition of claim 1 wherein the heteroatoms of the L ligands are in a trans configuration.

3. The composition of claim 1 wherein the heteroatom of the L ligand is nitrogen.

4. The composition of claim 1 wherein the X ligand is an O—

O ligand.

5. The composition of claim 1 wherein the X ligand is an N—

O ligand.

6. The composition of claim 1 wherein M comprises Pt.

7. The composition of claim 1 wherein M comprises Ir.

8. The composition of claim 1 wherein the ring comprising the metal M, the sp² hybridized carbon and the heteroatom consists of five atoms.

9. The composition of claim 1 wherein the ring comprising the metal M, the sp² hybridized carbon and the heteroatom consists of six atoms.

10. The composition of claim 1 wherein L is 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, and a tolylpyridine.

11. The composition of claim 1 wherein the X ligand is selected from the group consisting of an acetylacetonate, a hexafluoroacetylacetonate, a salicylidene, a picolinate, and a 8-hydroxyquinolinate.

12. The composition of claim 1 wherein the L ligand is a substituted or unsubstituted ligand selected from the group consisting of a phenylimine, a vinylpyridine, an arylquinoline, a pyridylnaphthalene, a pyridylpyrrole, a pyridylimidazole and a phenylindole.

13. The composition of claim 1 wherein the X ligand is a 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:

14. The composition of claim 1 wherein the L ligand comprises a substituted or unsubstituted arylquinoline.

15. The composition of claim 14 wherein the X ligand comprises an acetylacetonate.

16. The composition of claim 14 wherein the L ligand is an unsubstituted arylquinoline having the structure:

17. The composition of claim 16 wherein the X ligand comprises an acetylacetonate.

18. The composition of claim 14 wherein the L ligand is a substituted arylquinoline comprising the structure:

19. The composition of claim 18 wherein the X ligand comprises an acetylacetonate.

20. A composition comprising a compound of formula LL′

L″

M, wherein L, L′ and

L″

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

L″

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

21. The composition of claim 20 wherein the heteroatom of the L, L′

and L″

ligands is nitrogen.

22. The composition of claim 20 wherein M is selected from the group consisting of the transition metals of the third row of the transition series of the periodic table.

23. The composition of claim 20 wherein M comprises Pt.

24. The composition of claim 20 wherein M comprises Ir.

25. A composition comprising a compound of formula LL′

MX, wherein L, L′ and

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

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

26. The composition of claim 25 wherein the hetero atom of the L and the L′

ligands is nitrogen.

27. The composition of claim 25 wherein M is selected from the group consisting of the transition metals of the third row of the transition series of the periodic table.

28. The composition of claim 25 wherein M comprises Pt.

29. The composition of claim 25 wherein M comprises Ir.

30. The composition of claim 25 wherein the X ligand is an O—

O ligand.

31. The composition of claim 25 wherein the X ligand is an N—

O ligand.

32. A composition comprising a compound of formula LMXX′

, wherein L, X and X′

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

33. The composition of claim 32 wherein the heteroatom of the L ligand is nitrogen.

34. The composition of claim 32 wherein M is selected from the group consisting of the transition metals of the third row of the transition series of the periodic table.

35. The composition of claim 32 wherein M comprises Pt.

36. The composition of claim 32 wherein M comprises Ir.

37. The composition of claim 32 wherein the X ligand is an O—

O ligand.

38. The composition of claim 32 wherein the X′

ligand is an N—

O ligand.