OLEDs doped with phosphorescent compounds

• US 20050008897A1
• Filed: 08/06/2004
• Published: 01/13/2005
• Est. Priority Date: 12/01/1997
• Status: Active Grant

• Current Assignee: Andrei Shoustikov, Mark Thompson, Paul E. Burrows, Scott Sibley, Stephen R. Forrest, Yujian You
• Original Assignee: Andrei Shoustikov, Mark Thompson, Paul E. Burrows, Scott Sibley, Stephen R. Forrest, Yujian You
• Inventors: Burrows, Paul E., Forrest, Stephen R., Sibley, Scott, Thompson, Mark E., You, Yujian, Shoustikov, Andrei
• Granted Patent: US 7,488,542 B2
• Time in Patent Office: Days
• US Class Current: 428/690
• CPC Class Codes: C07D 487/22 in which the condensed system contains four or more hetero rings
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/10 Non-macromolecular compounds
• CPC Class Codes: C09K 2211/1003 Carbocyclic compounds
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1018 Heterocyclic compounds
• 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 2211/1074 containing more than three nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/18 Metal complexes
• 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: 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: H05B 33/28 of translucent electrodes
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 2102/103 comprising indium oxides, e.g. ITO
• CPC Class Codes: H10K 2102/3031 Two-side emission, e.g. transparent OLEDs [TOLED]
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 59/80524 : Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 85/30 : Coordination compounds
• CPC Class Codes: H10K 85/324 : comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/341 : Transition metal complexes, e.g. Ru(II)polypyridine complexes H10K85/331 takes precedence
• CPC Class Codes: H10K 85/346 : comprising platinum
• CPC Class Codes: H10K 85/621 : Aromatic anhydride or imide compounds, e.g. perylene tetra-carboxylic dianhydride or perylene tetracarboxylic di-imide
• CPC Class Codes: H10K 85/654 : comprising only nitrogen as heteroatom H10K85/652 takes precedence
• CPC Class Codes: Y10S 428/917 : Electroluminescent
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree

Abstract

Organic light emitting devices are disclosed which are comprised of a heterostructure for producing electroluminescence wherein the heterostructure is comprised of an emissive layer containing a phosphorescent dopant compound. For example, the phosphorescent dopant compound may be comprised of platinum octaethylporphine (PtOEP), which is a compound having the chemical structure with the formula:

Claims

1-20. -20. (canceled).

21. A light emitting device comprising an anode, an organic compound film, and a cathode, the organic compound film comprising:

a hole transporting layer containing a hole transporting material; and

an electron transporting layer in contact with the hole transporting layer and containing an electron transporting material,

wherein a light emitting material capable of emitting light from a triplet excited state is added in the electron transporting layer.

22. A light emitting device according to claim 21, wherein an energy difference between a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level in the hole transporting material is larger than that between a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level in the electron transporting material.

23. A light emitting device according to claim 21, wherein an absorption spectrum of the hole transporting material and a light emission spectrum of the electron transporting material do not overlap each other.

24. A light emitting device according to claim 21, wherein an absorption spectrum of the hole transporting material is on a shorter-wavelength side of a light emission spectrum of the electron transporting material.

25. A light emitting device according to claim 21, wherein both a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level of the light emitting material are in an energy gap between a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level of the electron transporting material.

26. A light emitting device according to claim 21, wherein an ionization potential of the hole transporting material is equal to or larger than that of an ionization potential of the light emitting material.

27. A light emitting device according to claim 21, wherein an absolute value of a lowest unoccupied molecular orbit level of the hole transporting material is smaller by 0.2 eV or more than that of a lowest unoccupied molecular orbit level of the electron transporting material.

28. A light emitting device according to claim 21, wherein an ionization potential of the hole transporting material is equal to or larger than that of ionization potential of the light emitting material, and an absolute value of a lowest unoccupied molecular orbit level of the hole transporting material is smaller by 0.2 eV or more than that of a lowest unoccupied molecular orbit level of the electron transporting material.

29. A light emitting device according to claim 21, wherein used as the hole transporting material is one selected from the group consisting of 4,4′

,4″

-tris(N-carbazole)triphenylamine, 4,4′

-bis[N,N-bis(3-methylphenyl)-amino]-diphenylmethane, 1,3,5-tris[N,N-bis(2-methylphenyl)-amino]-benzene, 1,3,5-tris[N,N-bis(3-methylphenyl)-amino]-benzene, and 1,3,5-tris[N,N-bis(4-methylphenyl)-amino]-benzene.

30. A light emitting device according to claim 21, wherein used as the electron transporting material is one selected from the group consisting of 2,2′

,2″

-(1,3,5-benzenetriyl)tris-[1-phenyl-1H-benzoimidazole], lithiumtetra(2-(2-hydroxyphenyl)benzooxazolatoboron, bis(2-(2-hydroxyphenyl)benzooxazolato)(triphenylsilanolato)aluminum, bis(2-(2-hydroxyphenyl)benzothiazolato)(triphenylsilanolato)aluminum, 2-(2-hydroxyphenyl)benzooxazolatolithium, (2-(2-hydroxyphenyl)benzooxazolato)-diphenylboron, tris(8-quinolinolato)-aluminum, bis(2-methyl-8-quinolinolato) (triphenylsilanolato)aluminum, bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum, lithiumtetra(2-methyl-8-hydroxy-quinolinato)boron, (2-methyl-8-quinolinolato)-diphenylboron, and bis(2-methyl-8-quinolinolato) aluminiumhydroxide.

31. A light emitting device comprising an anode, an organic compound film, and a cathode, the organic compound film comprising:

a hole injection layer in contact with the anode; and

a hole transporting layer containing a hole transporting material;

an electron transporting layer in contact with the hole transporting layer and containing an electron transporting material,

wherein a light emitting material capable of emitting light from a triplet excited state is added in the electron transporting layer.

32. A light emitting device according to claim 31, wherein an energy difference between a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level in the hole transporting material is larger than that between a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level in the electron transporting material.

33. A light emitting device according to claim 31, wherein an absorption spectrum of the hole transporting material and a light emission spectrum of the electron transporting material do not overlap each other.

34. A light emitting device according to claim 31, wherein an absorption spectrum of the hole transporting material is on a shorter-wavelength side of a light emission spectrum of the electron transporting material.

35. A light emitting device according to claim 31, wherein both a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level of the light emitting material are in an energy gap between a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level of the electron transporting material.

36. A light emitting device according to claim 31, wherein an ionization potential of the hole transporting material is equal to or larger than that of an ionization potential of the light emitting material.

37. A light emitting device according to claim 31, wherein an absolute value of a lowest unoccupied molecular orbit level of the hole transporting material is smaller by 0.2 eV or more than that of a lowest unoccupied molecular orbit level of the electron transporting material.

38. A light emitting device according to claim 31, wherein an ionization potential of the hole transporting material is equal to or larger than that of ionization potential of the light emitting material, and an absolute value of a lowest unoccupied molecular orbit level of the hole transporting material is smaller by 0.2 eV or more than that of a lowest unoccupied molecular orbit level of the electron transporting material.

39. A light emitting device according to claim 31, wherein used as the hole transporting material is one selected from the group consisting of 4,4′

,4″

-tris(N-carbazole)triphenylamine, 4,4′

-bis[N,N-bis(3-methylphenyl)-amino]-diphenylmethane, 1,3,5-tris[N,N-bis(2-methylphenyl)-amino]-benzene, 1,3,5-tris[N,N-bis(3-methylphenyl)-amino]-benzene, and 1,3,5-tris[N,N-bis(4-methylphenyl)-amino]-benzene.

40. A light emitting device according to claim 31, wherein used as the electron transporting material is one selected from the group consisting of 2,2′

,2″

-(1,3,5-benzenetriyl)tris-[1-phenyl-1H-benzoimidazole], lithiumtetra(2-(2-hydroxyphenyl)benzooxazolatoboron, bis(2-(2-hydroxyphenyl)benzooxazolato)(triphenylsilanolato)aluminum, bis(2-(2-hydroxyphenyl)benzothiazolato)(triphenylsilanolato)aluminum, 2-(2-hydroxyphenyl)benzooxazolatolithium, (2-(2-hydroxyphenyl)benzooxazolato)-diphenylboron, tris(8-quinolinolato)-aluminum, bis(2-methyl-8-quinolinolato)(triphenylsilanolato)aluminum, bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum, lithiumtetra(2-methyl-8-hydroxy-quinolinato)boron, (2-methyl-8-quinolinolato)-diphenylboron, and bis(2-methyl-8-quinolinolato) aluminiumhydroxide.

41. A light emitting device comprising an anode, an organic compound film, and a cathode, the organic compound film comprising:

a hole transporting layer containing a hole transporting material;

an electron transporting layer in contact with the hole transporting layer and containing an electron transporting material; and

an electron injection layer in contact with the cathode;

wherein a light emitting material capable of emitting light from a triplet excited state is added in the electron transporting layer.

42. A light emitting device according to claim 41, wherein an energy difference between a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level in the hole transporting material is larger than that between a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level in the electron transporting material.

43. A light emitting device according to claim 41, wherein an absorption spectrum of the hole transporting material and a light emission spectrum of the electron transporting material do not overlap each other.

44. A light emitting device according to claim 41, wherein an absorption spectrum of the hole transporting material is on a shorter-wavelength side of a light mission spectrum of the electron transporting material.

45. A light emitting device according to claim 41, wherein both a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level of the light emitting material are in an energy gap between a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level of the electron transporting material.

46. A light emitting device according to claim 41, wherein an ionization potential of the hole transporting material is equal to or larger than that of an ionization potential of the light emitting material.

47. A light emitting device according to claim 41, wherein an absolute value of a lowest unoccupied molecular orbit level of the hole transporting material is smaller by 0.2 eV or more than that of a lowest unoccupied molecular orbit level of the electron transporting material.

48. A light emitting device according to claim 41, wherein an ionization potential of the hole transporting material is equal to or larger than that of ionization potential of the light emitting material, and an absolute value of a lowest unoccupied molecular orbit level of the hole transporting material is smaller by 0.2 eV or more than that of a lowest unoccupied molecular orbit level of the electron transporting material.

49. A light emitting device according to claim 41, wherein used as the hole transporting material is one selected from the group consisting of 4,4′

,4″

-tris(N-carbazole)triphenylamine, 4,4′

-bis[N,N-bis(3-methylphenyl)-amino]-diphenylmethane, 1,3,5-tris[N,N-bis(2-methylphenyl)-amino]-benzene, 1,3,5-tris[N,N-bis(3-methylphenyl)-amino]-benzene, and 1,3,5-tris[N,N-bis(4-methylphenyl)-amino]-benzene.

50. A light emitting device according to claim 41, wherein used as the electron transporting material is one selected from the group consisting of 2,2′

,2′

-(1,3,5-benzenetriyl)tris-[1-phenyl-1H-benzoimidazole], lithiumtetra(2-(2-hydroxyphenyl)benzooxazolatoboron, bis(2-(2-hydroxyphenyl)benzooxazolato)(triphenylsilanolato)aluminum, bis(2-(2-hydroxyphenyl)benzothiazolato)(triphenylsilanolato)aluminum, 2-(2-hydroxyphenyl)benzooxazolatolithium, (2-(2-hydroxyphenyl)benzooxazolato)-diphenylboron, tris(8-quinolinolato)-aluminum, bis(2-methyl-8-quinolinolato)(triphenylsilanolato)aluminum, bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum, lithiumtetra(2-methyl-8-hydroxy-quinolinato)boron, (2-methyl-8-quinolinolato)-diphenylboron, and bis(2-methyl-8-quinolinolato) aluminiumhydroxide.

51. A light emitting device comprising an anode, an organic compound film, and a cathode, the organic compound film comprising:

a hole injection layer in contact with the anode;

a hole transporting layer containing a hole transporting material;

an electron transporting layer in contact with the hole transporting layer and containing an electron transporting material; and

an electron injection layer in contact with the cathode,

wherein a light emitting material capable of emitting light from a triplet excited state is added in the electron transporting layer.

52. A light emitting device according to claim 51, wherein an energy difference between a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level in the hole transporting material is larger than that between a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level in the electron transporting material.

53. A light emitting device according to claim 51, wherein an absorption spectrum of the hole transporting material and a light emission spectrum of the electron transporting material do not overlap each other.

54. A light emitting device according to claim 51, wherein an absorption spectrum of the hole transporting material is on a shorter-wavelength side of a light emission spectrum of the electron transporting material.

55. A light emitting device according to claim 51, wherein both a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level of the light emitting material are in an energy gap between a highest occupied molecular orbit level and a lowest unoccupied molecular orbit level of the electron transporting material.

56. A light emitting device according to claim 51, wherein an ionization potential of the hole transporting material is equal to or larger than that of an ionization potential of the light emitting material.

57. A light emitting device according to claim 51, wherein an absolute value of a lowest unoccupied molecular orbit level of the hole transporting material is smaller by 0.2 eV or more than that of a lowest unoccupied molecular orbit level of the electron transporting material.

58. A light emitting device according to claim 51, wherein an ionization potential of the hole transporting material is equal to or larger than that of ionization potential of the light emitting material, and an absolute value of a lowest unoccupied molecular orbit level of the hole transporting material is smaller by 0.2 eV or more than that of a lowest unoccupied molecular orbit level of the electron transporting material.

59. A light emitting device according to claim 51, wherein used as the hole transporting material is one selected from the group consisting of 4,4′

,4″

-tris(N-carbazole)triphenylamine, 4,4′

-bis[N,N-bis(3-methylphenyl)-amino]-diphenylmethane, 1,3,5-tris[N,N-bis(2-methylphenyl)-amino]-benzene, 1,3,5-tris[N,N-bis(3-methylphenyl)-amino]-benzene, and 1,3,5-tris[N,N-bis(4-methylphenyl)-amino]-benzene.

60. A light emitting device according to claim 51, wherein used as the electron transporting material is one selected from the group consisting of 2,2′

,2″

-(1,3,5-benzenetriyl)tris-[1-phenyl-1H-benzoimidazole], lithiumtetra(2-(2-hydroxyphenyl)benzooxazolatoboron, bis(2-(2-hydroxyphenyl)benzooxazolato)(triphenylsilanolato)aluminum, bis(2-(2-hydroxyphenyl)benzothiazolato)(triphenylsilanolato)aluminum, 2-(2-hydroxyphenyl)benzooxazolatolithium, (2-(2-hydroxyphenyl)benzooxazolato)-diphenylboron, tris(8-quinolinolato)-aluminum, bis(2-methyl-8-quinolinolato)(triphenylsilanolato)aluminum, bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum, lithiumtetra(2-methyl-8-hydroxy-quinolinato)boron, (2-methyl-8-quinolinolato)-diphenylboron, and bis(2-methyl-8-quinolinolato) aluminiumhydroxide.