White OLED having multiple white electroluminescence units

• US 20060040132A1
• Filed: 08/20/2004
• Published: 02/23/2006
• Est. Priority Date: 08/20/2004
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Eastman Kodak Company
• Inventors: Hatwar, Tukaram K., Liao, Liang-Sheng, Tang, Ching W., Klubek, Kevin P.
• Granted Patent: US 7,273,663 B2
• Time in Patent Office: Days
• US Class Current: 428/690
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: Y10S 428/917 Electroluminescent
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree

Abstract

A tandem white OLED device includes an anode, a cathode, and a plurality of organic electroluminescence units disposed between the anode and the cathode, wherein each organic electroluminescence unit includes at least one light-emitting layer, and wherein each organic electroluminescence unit emits white light. The device also includes an intermediate connector disposed between each adjacent organic electroluminescence unit, wherein the intermediate connector includes at least two different layers, and wherein the intermediate connector has no direct connection to an external power source.

Claims

1. A tandem white OLED device comprising:

a) an anode;

b) a cathode;

c) a plurality of organic electroluminescence units disposed between the anode and the cathode, wherein each organic electroluminescence unit includes at least one light-emitting layer, and wherein each organic electroluminescence unit emits white light; and

d) an intermediate connector disposed between each adjacent organic electroluminescence unit, wherein the intermediate connector includes at least two different layers, and wherein the intermediate connector has no direct connection to an external power source.

2. The tandem white OLED device of claim 1 wherein each organic electroluminescence unit includes at least three light-emitting layers, and wherein each of the light-emitting layers has a different color of emission.

3. The tandem white OLED device of claim 1 wherein each organic electroluminescence unit includes at least two light-emitting layers, and wherein each of the light-emitting layers has a different color of emission.

4. The tandem white OLED device of claim 1 wherein each organic electroluminescence unit includes at least one light-emitting layer.

5. The tandem white OLED device of claim 1 wherein each of the organic electroluminescence units can have the same or different layer structures provided that each electroluminescence unit produces white light.

6. The tandem white OLED device of claim 1 wherein each intermediate connector includes at least an n-type doped organic layer disposed adjacent to the electron-transporting layer of the preceding organic electroluminescence unit and a p-type doped organic layer disposed over the n-type doped organic layer.

7. The tandem white OLED device of claim 6 wherein each intermediate connector includes a metal compound layer disposed between the n-type organic layer and the p-type organic layer.

8. The tandem white OLED device of claim 6 wherein each intermediate connector includes a high work function metal layer disposed between the n-type organic layer and the p-type organic layer.

9. The tandem white OLED device of claim 1 wherein each intermediate connector has a sheet resistance of higher than 100 kΩ

per square including at least an n-type doped organic layer disposed adjacent to the electron-transporting layer of the preceding organic electroluminescence unit and a metal compound layer disposed over the n-type doped organic layer.

10. The tandem white OLED device of claim 9 wherein each intermediate connector includes a high work function metal layer disposed between the n-type organic layer and the metal compound layer.

11. The tandem white OLED device of claim 1 wherein each intermediate connector has a sheet resistance of higher than 100 kΩ

per square including at least a low work function metal layer disposed adjacent to the electron-transporting layer of the preceding organic electroluminescence unit and a metal compound layer disposed over the low work function metal layer.

12. The tandem white OLED device of claim 11 wherein each intermediate connector includes a high work function metal layer disposed between the low work function metal layer and the metal compound layer.

13. The tandem white OLED device of claim 1 wherein each intermediate connector has a sheet resistance of higher than 100 kΩ

per square including at least an n-type inorganic semiconductor layer disposed adjacent to the electron-transporting layer in the organic electroluminescence unit and a metal compound layer disposed over the n-type inorganic semiconductor layer.

14. The tandem white OLED device of claim 13 wherein each intermediate connector includes a high work function metal layer disposed between the n-type inorganic semiconductor layer and the metal compound layer.

15. The tandem white OLED device of claim 1 wherein each of the intermediate connectors can have the same or different layer structures.

16. The tandem white OLED device of claim 6 wherein the n-type doped organic layer contains at least one organic host material and at least one n-type dopant, wherein the organic host material is capable of supporting electron transport.

17. The tandem white OLED device of claim 16 wherein the organic host material includes metal chelated oxinoid compounds, butadiene derivatives, heterocyclic optical brighteners, triazines, hydroxyquinoline derivatives, benzazole derivatives, phenanthroline derivatives, or silole derivatives, or combinations thereof.

18. The tandem white OLED device of claim 16 wherein the organic host material includes tris(8-hydroxyquinoline)aluminum (Alq), 4,7-diphenyl-1,10-phenanthroline (Bphen), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), or 2,2′

-1,3,5-triazine] (TRAZ), or combinations thereof.

19. The tandem white OLED device of claim 16 wherein the

n-type dopant includes alkali metals, alkali metal compounds, alkaline earth metals, or alkaline earth metal compounds, or combinations thereof.

20. The tandem white OLED device of claim 16 wherein the

n-type dopant includes Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce, Nd, Sm, Eu, Tb, Dy, or Yb, or combinations thereof.

21. The tandem white OLED device of claim 6 wherein the

p-type doped organic layer contains at least one organic host material and at least one p-type dopant, wherein the organic host material is capable of supporting hole transport.

22. The tandem white OLED device of claim 21 wherein the organic host material includes aromatic tertiary amines having at least one trivalent nitrogen atom that is bonded only to carbon atoms, at least one of which is a member of an aromatic ring.

23. The tandem white OLED device of claim 21 wherein the organic host material includes N,N′

-di(naphthalene-1-yl)-N,N′

-diphenyl-benzidine (NPB), N,N′

-diphenyl-N,N′

-bis(3-methylphenyl)-1,1-biphenyl-4,4′

-diamine (TPD), N,N,N′

,N′

-tetranaphthyl-benzidine (TNB), 4,4′

,4″

-tris(N-3-metylphenyl-N-phenyl-amino)-triphenylamine (m-MTDATA), 4,4′

,4″

-tris(N,N-diphenyl-amino)-triphenylamine (TDATA), or dihydrophenazine compounds, or combinations thereof.

24. The tandem white OLED device of claim 21 wherein the

p-type dopant includes oxidizing agents capable of forming a charge transfer complex with the host material.

25. The tandem white OLED device of claim 21 wherein the

p-type dopant includes iodine, FeCl₃, FeF₃, SbCl₅, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F₄-TCNQ), or other derivatives of 7,7,8,8-tetra-cyanoquinodimethane (TCNQ), or combinations thereof.

26. The tandem white OLED device of claim 7 wherein the metal compound layer includes MoO₃, NiMoO₄, CuMoO₄, WO₃, ZnTe, Al₄C₃, AlF₃, B₂S₃, CuS, GaP, InP, or SnTe.

27. The tandem white OLED device of claim 8 wherein the high work function metal layer includes Ti, Zr, Ti, Nb, Ta, Cr, Mo, W, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Al, In, or Sn, or combinations thereof.

28. The tandem white OLED device of claim 9 wherein the

n-type doped organic layer contains at least one organic host material and at least one n-type dopant, wherein the organic host material is capable of supporting electron transport.

29. The tandem white OLED device of claim 28 wherein the organic host material includes metal chelated oxinoid compounds, 8-hydroxy-quinoline derivatives, butadiene derivatives, heterocyclic optical brighteners, triazines, benzazoles, phenanthroline derivatives, or silole derivatives, or combinations thereof.

30. The tandem white OLED device of claim 28 wherein the organic host material includes tris(8-hydroxyquinoline)aluminum (Alq), 4,7-diphenyl-1,10-phenanthroline (Bphen), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), or 2,2′

-1,3,5-triazine] (TRAZ), or combinations thereof.

31. The tandem white OLED device of claim 28 wherein the

n-type dopant includes alkali metals, alkali metal compounds, alkaline earth metals, or alkaline earth metal compounds, or combinations thereof.

32. The tandem white OLED device of claim 28 wherein the

n-type dopant includes Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce, Nd, Sm, Eu, Tb, Dy, or Yb, or combinations thereof.

33. The tandem white OLED device of claim 9 wherein the metal compound layer includes MoO₃, NiMoO₄, CuMoO₄, WO₃, ZnTe, Al₄C₃, AlF₃, B₂S₃, CuS, GaP, InP, or SnTe.

34. The tandem white OLED device of claim 10 wherein the high work function metal layer includes Ti, Zr, Ti, Nb, Ta, Cr, Mo, W, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Al, In, or Sn, or combinations thereof.

35. The tandem white OLED device of claim 11 wherein the low work function layer includes Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce, Nd, Sm, Eu, Tb, Dy, or Yb, or combinations thereof.

36. The tandem white OLED device of claim 11 wherein the metal compound layer includes MoO₃, NiMoO₄, CuMoO₄, WO₃, ZnTe, Al₄C₃, AlF₃, B₂S₃, CuS, GaP, InP, or SnTe.

37. The tandem white OLED device of claim 12 wherein the high work function metal layer includes Ti, Zr, Ti, Nb, Ta, Cr, Mo, W, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Al, In, or Sn, or combinations thereof.

38. The tandem white OLED device of claim 13 wherein the

n-type inorganic semiconductor layer includes ZnSe, ZnS, ZnSSe, SnSe, SnS, SnSSe, LaCuO₃, or La₄Ru₆O₁₉.

39. The tandem white OLED device of claim 13 wherein the metal compound layer includes MoO₃, NiMoO₄, CuMoO₄, WO₃, ZnTe, Al₄C₃, AlF₃, B₂S₃, CuS, GaP, InP, or SnTe.

40. The tandem white OLED device of claim 14 wherein the high work function metal layer includes Ti, Zr, Ti, Nb, Ta, Cr, Mo, W, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Al, In, or Sn, or combinations thereof.

41. The tandem white OLED device of claim 1 wherein the thickness of each light-emitting layer in the electroluminescence EL unit is in the range of from 5 nm to 50 nm.

42. The tandem white OLED device of claim 1 wherein the thickness of each layer in the intermediate connector is in the range of from 0.1 nm to 150 nm.

43. The tandem white OLED device of claim 7 wherein the thickness of the metal compound layer in the intermediate connector is in the range of from 0.5 nm to 20 nm.

44. The tandem white OLED device of claim 8 wherein the thickness of the high work function metal layer in the intermediate connector is in the range of from 0.1 nm to 5.0 nm.

45. The tandem white OLED device of claim 9 wherein the thickness of the metal compound layer in the intermediate connector is in the range of from 0.5 nm to 20 nm.

46. The tandem white OLED device of claim 10 wherein the thickness of the high work function metal layer in the intermediate connector is in the range of from 0.1 nm to 5.0 nm.

47. The tandem white OLED device of claim 11 wherein the thickness of the low work function metal layer in the intermediate connector is in the range of from 0.1 nm to 10 nm.

48. The tandem white OLED device of claim 11 wherein the thickness of the metal compound layer in the intermediate connector is in the range of from 0.5 nm to 20 nm.

49. The tandem white OLED device of claim 12 wherein the thickness of the high work function metal layer in the intermediate connector is in the range of from 0.1 nm to 5.0 nm.

50. The tandem white OLED device of claim 13 wherein the thickness of the n-type inorganic semiconductor layer in the intermediate connector is in the range of from 0.5 nm to 20 nm.

51. The tandem white OLED device of claim 13 wherein the thickness of the metal compound layer in the intermediate connector is in the range of from 0.5 nm to 20 nm.

52. The tandem white OLED device of claim 14 wherein the thickness of the high work function metal layer in the intermediate connector is in the range of from 0.1 nm to 5.0 nm.

53. The tandem white OLED device of claim 1 wherein the intermediate connector has at least 75% optical transmission in the visible region of the spectrum.

54. The tandem white OLED device of claim 1 wherein the intermediate connector is produced by thermal evaporation, electron beam evaporation, ion sputtering technique, or spin coating.

55. A tandem white OLED device comprising:

a) an anode;

b) a cathode;

c) a plurality of organic electroluminescence units disposed between the anode and the cathode, wherein each organic electroluminescence unit includes at least one light-emitting layer, and wherein each organic electroluminescence unit emits white light; and

d) an intermediate connector disposed between each adjacent organic electroluminescence unit, wherein the intermediate connector contains two different organic layers, and wherein the intermediate connector has no direct connection to an external power source.

56. The tandem white OLED device of claim 55 wherein each organic electroluminescence unit includes at least three light-emitting layers, and wherein each of the light-emitting layers has a different color of emission.

57. The tandem white OLED device of claim 55 wherein each organic electroluminescence unit includes at least two light-emitting layers, and wherein each of the light-emitting layers has a different color of emission.

58. The tandem white OLED device of claim 55 wherein each organic electroluminescence unit includes at least one light-emitting layer.

59. The tandem white OLED device of claim 55 wherein each of the organic electroluminescence units can have the same or different layer structures provided that each electroluminescence unit produces white light.

60. The tandem white OLED device of claim 55 wherein each intermediate connector includes at least an n-type doped organic layer disposed adjacent to the electron-transporting layer of the preceding organic electro-luminescence unit and a p-type doped organic layer disposed over the n-type doped organic layer.

61. The tandem white OLED device of claim 60 wherein each intermediate connector includes a metal compound layer disposed between an n-type doped organic layer and a p-type doped organic layer.

62. The tandem white OLED device of claim 60 wherein each intermediate connector includes a high work function metal layer disposed between an n-type doped organic layer and a p-type doped organic layer.

63. The tandem white OLED device of claim 55 wherein each of the intermediate connectors can have the same or different layer structures.

64. The tandem white OLED device of claim 60 wherein the

n-type doped organic layer contains at least one organic host material and at least one n-type dopant, wherein the organic host material is capable of supporting electron transport.

65. The tandem white OLED device of claim 64 wherein the organic host material includes metal chelated oxinoid compounds, butadiene derivatives, heterocyclic optical brighteners, triazines, hydroxyquinoline derivatives, benzazole derivatives, phenanthroline derivatives, or silole derivatives, or combinations thereof.

66. The tandem white OLED device of claim 64 wherein the organic host material includes tris(8-hydroxyquinoline)aluminum (Alq), 4,7-diphenyl-1,10-phenanthroline (Bphen), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), or 2,2′

-[1,1′

-biphenyl]diylbis[4,6-(p-tolyl)-1,3,5-triazine] (TRAZ), or combinations thereof.

67. The tandem white OLED device of claim 64 wherein the

n-type dopant includes alkali metals, alkali metal compounds, alkaline earth metals, or alkaline earth metal compounds, or combinations thereof.

68. The tandem white OLED device of claim 64 wherein the

n-type dopant includes Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce, Nd, Sm, Eu, Tb, Dy, or Yb, or combinations thereof.

69. The tandem white OLED device of claim 60 wherein the

p-type doped organic layer contains at least one organic host material and at least one p-type dopant, wherein the organic host material is capable of supporting hole transport.

70. The tandem white OLED device of claim 69 wherein the organic host material includes aromatic tertiary amines having at least one trivalent nitrogen atom that is bonded only to carbon atoms, at least one of which is a member of an aromatic ring.

71. The tandem white OLED device of claim 69 wherein the organic host material includes N,N′

-di(naphthalene-1-yl)-N,N′

-diphenyl-benzidine (NPB), N,N′

-diphenyl-N,N′

-bis(3-methylphenyl)-1,1-biphenyl-4,4′

-diamine (TPD), N,N,N′

,N′

-tetranaphthyl-benzidine (TNB), 4,4′

,4″

-tris(N-3-metylphenyl-N-phenyl-amino)-triphenylamine (m-MTDATA), 4,4′

,4″

-tris(N,N-diphenyl-amino)-triphenylamine (TDATA), or dihydrophenazine compounds, or combinations thereof.

72. The tandem white OLED device of claim 69 wherein the

p-type dopant includes oxidizing agents capable of forming a charge transfer complex with the host material.

73. The tandem white OLED device of claim 69 wherein the

p-type dopant includes iodine, FeCl₃, FeF₃, SbCl₅, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F₄-TCNQ), or other derivatives of 7,7,8,8-tetracyanoquinodimethane (TCNQ), or combinations thereof.

74. The tandem white OLED device of claim 61 wherein the metal compound layer includes MoO₃, NiMoO₄, CuMoO₄, WO₃, ZnTe, Al₄C₃, AlF₃, B₂S₃, CuS, GaP, InP, or SnTe.

75. The tandem white OLED device of claim 62 wherein the high work function metal layer includes Ti, Zr, Ti, Nb, Ta, Cr, Mo, W, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Al, In, or Sn, or combinations thereof.

76. The tandem white OLED device of claim 55 wherein the thickness of each light-emitting layer in the electroluminescence EL unit is in the range of from 5 nm to 50 nm.

77. The tandem white OLED device of claim 55 wherein the thickness of each layer in the intermediate connector is in the range of from 0.1 nm to 150 nm.

78. The tandem white OLED device of claim 61 wherein the thickness of the metal compound layer in the intermediate connector is in the range of from 0.5 nm to 20 nm.

79. The tandem white OLED device of claim 62 wherein the thickness of the high work function metal layer in the intermediate connector is in the range of from 0.1 nm to 5.0 nm.

80. The tandem white OLED device of claim 55 wherein the intermediate connector has at least 75% optical transmission in the visible region of the spectrum.

81. The tandem white OLED device of claim 55 wherein the intermediate connector is produced by thermal evaporation, electron beam evaporation, ion sputtering technique, or spin coating.