Method of fabricating transparent contacts for organic devices

• US 6,596,134 B2
• Filed: 12/21/1999
• Issued: 07/22/2003
• Est. Priority Date: 12/13/1994
• Status: Expired due to Fees

• Current Assignee: The Trustees of Princeton University (Princeton University)
• Original Assignee: The Trustees of Princeton University (Princeton University)
• Inventors: Burrows, Paul E., Thompson, Mark E., Gu, Gong, Forrest, Stephen R., Bulovic, Vladimir
• Primary Examiner(s): Ryan, Patrick
• Assistant Examiner(s): ANTHONY, JULIAN
• Application Number:
  US09/468,986
• Publication Number:
  US 20020153243A1
• Time in Patent Office: 1,309 Days
• Field of Search: 204/192.26, 204/192.27, 204/192.28, 204/192.29, 427/585, 427/68, 427/69, 427/70, 427/75, 427/78, 427/525, 427/529, 427/531, 427/255.6
• US Class Current: 204/192.29
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: G09F 9/335 being organic light emitting diodes [OLED]
• CPC Class Codes: H01L 2224/24145 the bodies being stacked
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01021 Scandium [Sc]
• CPC Class Codes: H01L 2924/01068 Erbium [Er]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/12044 OLED
• 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 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/14 Carrier transporting layers
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 50/8423 Metallic sealing arrangements
• CPC Class Codes: H10K 50/8426 Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 85/10 Organic polymers or oligomers
• CPC Class Codes: H10K 85/111 comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
• CPC Class Codes: H10K 85/113 : Heteroaromatic compounds comprising sulfur or selene, e.g. polythiophene
• CPC Class Codes: H10K 85/114 : Poly-phenylenevinylene; Derivatives thereof
• CPC Class Codes: H10K 85/146 : poly N-vinylcarbazol; Derivatives thereof
• CPC Class Codes: H10K 85/30 : Coordination compounds
• CPC Class Codes: H10K 85/322 : comprising boron
• 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 85/60 : Organic compounds having low molecular weight H10K85/10 - H10K85/50 take precedence
• CPC Class Codes: H10K 85/611 : Charge transfer complexes
• CPC Class Codes: H10K 85/631 : Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine

Abstract

A multicolor organic light emitting device employs vertically stacked layers of double heterostructure devices which are fabricated from organic compounds. The vertical stacked structure is formed on a glass base having a transparent coating of ITO or similar metal to provide a substrate. Deposited on the substrate is the vertical stacked arrangement of three double heterostructure devices, each fabricated from a suitable organic material. Stacking is implemented such that the double heterostructure with the longest wavelength is on the top of the stack. This constitutes the device emitting red light on the top with the device having the shortest wavelength, namely, the device emitting blue light, on the bottom of the stack. Located between the red and blue device structures is the green device structure. The devices are configured as stacked to provide a staircase profile whereby each device is separated from the other by a thin transparent conductive contact layer to enable light emanating from each of the devices to pass through the semitransparent contacts and through the lower device structures while further enabling each of the devices to receive a selective bias. The devices are substantially transparent when de-energized, making them useful for heads-up display applications.

Claims

1. A method of fabricating an organic light emitting device structure, comprising:

obtaining a substrate coated with a first electrically conductive layer, wherein the first electrically conductive layer has a positive polarity;

fabricating a transparent organic light emitting device over said first electrically conductive layer;

depositing a transparent electrically conductive metal layer having a thickness less than about 100 angstroms over the transparent organic light emitting device; and

depositing a second electrically conductive layer over the transparent electrically conductive metal layer, wherein the second electrically conductive layer hasd a negative polarity, and wherein the second electrically conductive layer is selected from the group consisting of a transparent electrically conductive oxide layer and a transparent electrically conductive polymer layer.

2. The method of claim 1 wherein the second electrically conductive layer comprises a transparent electrically conductive oxide layer.

3. The method of claim 1 wherein the second electrically conductive layer comprises indium tin oxide.

4. The method of claim 3 wherein the step of depositing said indium tin oxide over the transparent electrically conductive metal layer comprises:

(1) forming a protective cap layer comprising indium tin oxide over said transparent electrically conductive metal layer using a non-destructive growth rate; and

then

(2) increasing the growth rate for depositing indium tin oxide on said protective cap layer.

5. The method of claim 4 wherein said protective cap layer has a thickness of about 50 to about 100 angstroms.

6. The method of claim 3 wherein the substrate is transparent.

7. The method of claim 3 wherein the substrate is rigid.

8. The method of claim 3 wherein the first electrically conductive layer is transparent.

9. The method of claim 3 wherein the first electrically conductive layer comprises indium tin oxide.

10. The method of claim 3 wherein the first electrically conductive layer comprises a reflective metal layer.

11. The method of claim 3 wherein the obtaining step comprises coating said substrate with said first electrically conductive layer.

12. The method of claim 1 wherein the transparent electrically conductive metal layer comprises magnesium.

13. The method of claim 12 wherein the transparent electrically conductive metal layer further comprises silver.

14. A method of fabricating an organic light emitting device structure, comprising:

obtaining a substrate coated with a first electrically conductive layer, wherein the first electrically conductive layer has a positive polarity;

fabricating a transparent organic light emitting device over said first electrically conductive layer;

depositing a transparent electrically conductive metal layer having a thickness less than about 100 angstroms over the transparent organic light emitting device, wherein the transparent electrically conductive metal layer comprises magnesium and silver; and

depositing an indium tin oxide layer over the transparent electrically conductive metal layer, wherein the indium tin oxide layer has a negative polarity.

15. The method of claim 14 wherein the step of depositing said indium tin oxide layer over the transparent electrically conductive metal layer comprises:

(1) forming a protective cap layer comprising indium tin oxide over said transparent electrically conductive metal layer using a non-destructive growth rate; and

then

(2) increasing the growth rate for depositing indium tin oxide on said protective cap layer.

16. The method of claim 15 wherein said protective cap layer has a thickness of about 50 to about 100 angstroms.

17. The method of claim 15 wherein the substrate is transparent.

18. The method of claim 15 wherein the substrate is rigid.

19. The method of claim 15 wherein the first electrically conductive layer comprises indium tin oxide.

20. The method of claim 15 wherein the first electrically conductive layer comprises a reflective metal layer.

21. The method of claim 15 wherein the obtaining step comprises coating said substrate with said first electrically conductive layer.

22. The method of claim 14 wherein the first electrically conductive layer is transparent.

23. A method of fabricating an organic light emitting device structure, comprising:

obtaining a substrate coated with a first electrically conductive layer, wherein the first electrically conductive layer has a positive polarity;

depositing a hole transporting layer over the first electrically conductive layer;

depositing an electron transporting layer over the hole transporting layer;

depositing a transparent electrically conductive metal layer over the electron transporting layer, wherein the metal has a work function less than about 4 eV; and

depositing a second electrically conductive layer over the transparent electrically conductive metal layer, wherein the second electrically conductive layer has a negative polarity, and wherein the second electrically conductive layer is selected from the group consisting of a transparent electrically conductive oxide layer and a transparent electrically conductive polymer layer.

24. The method of claim 23 wherein the method further comprises the step of depositing an emission layer over the hole transporting layer and then depositing the electron transporting layer over the emission layer.

25. The method of claim 23 wherein the second electrically conductive layer comprises a transparent electrically conductive oxide layer.

26. The method of claim 23 wherein the second electrically conductive layer comprises indium tin oxide.

27. The method of claim 26 wherein the step of depositing the indium tin oxide over the transparent electrically conductive metal layer comprises:

(1) forming a protective cap layer comprising indium tin oxide over the transparent electrically conductive metal layer using a non-destructive growth rate; and

then

(2) increasing the growth rate for depositing indium tin oxide on the protective cap layer.

28. The method of claim 27 wherein the protective cap layer has a thickness of about 50 to about 100 angstroms.

29. The method of claim 26 wherein the substrate is transparent.

30. The method of claim 26 wherein the substrate is rigid.

31. The method of claim 26 wherein the first electrically conductive layer is transparent.

32. The method of claim 26 wherein the first electrically conductive layer comprises indium tin oxide.

33. The method of claim 26 wherein the first electrically conductive layer comprises a metal layer.

34. The method of claim 26 wherein the obtaining step comprises coating said substrate with said first electrically conductive layer.

35. The method of claim 23 wherein the transparent electrically conductive metal layer comprises magnesium.

36. The method of claim 35 wherein the transparent electrically conductive metal layer further comprises silver.

37. The method of claim 26 wherein the transparent electrically conductive metal layer has a thickness less than 100 angstroms.

38. A method of fabricating an organic light emitting device structure, comprising:

obtaining a substrate coated with a first electrically conductive layer, wherein the first electrically conductive layer has a positive polarity;

depositing a hole transporting layer over the first electrically conductive layer;

depositing an electron transporting layer over the hole transporting layer;

depositing a layer comprising magnesium and silver over the electron transporting layer; and

depositing an indium tin oxide layer over the layer comprising magnesium and silver, wherein the indium tin oxide layer has a negative polarity.

39. The method of claim 38 wherein the method further comprises the step of depositing an emission layer over the hole transporting layer and then depositing the electron transporting layer over the emission layer.

40. The method of claim 38 wherein the step of depositing the indium tin oxide layer over the transparent electrically conductive metal layer comprises:

(1) forming a protective cap layer comprising indium tin oxide over the transparent electrically conductive metal layer using a non-destructive growth rate; and

then

(2) increasing the growth rate for depositing indium tin oxide on the protective cap layer.

41. The method of claim 40 wherein the protective cap layer has a thickness of about 50 to about 100 angstroms.

42. The method of claim 38 wherein the substrate is transparent.

43. The method of claim 38 wherein the substrate is rigid.

44. The method of claim 38 wherein the first electrically conductive layer is transparent.

45. The method of claim 38 wherein the first electrically conductive layer comprises indium tin oxide.

46. The method of claim 38 wherein the first electrically conductive layer comprises a metal layer.

47. The method of claim 38 wherein the obtaining step comprises coating said substrate with said first electrically conductive layer.

48. The method of claim 38 wherein the layer comprising magnesium and silver has a thickness less than 100 angstroms.

49. A method of fabricating an organic light emitting device structure, comprising:

obtaining a substrate coated with a first electrically conductive layer, wherein the first electrically conductive layer has a positive polarity;

depositing a hole transporting layer over the first electrically conductive layer;

depositing an electron transporting layer over the hole transporting layer;

depositing a transparent electrically conductive metal layer over the electron transporting layer, wherein the transparent electrically conductive metal layer has a thickness less than about 100 angstroms; and

depositing a second electrically conductive layer over the transparent electrically conductive metal layer, wherein the second electrically conductive layer has a negative polarity, and wherein the second electrically conductive layer is selected from the group consisting of a transparent electrically conductive oxide layer and a transparent electrically conductive polymer layer.

50. The method of claim 49 wherein the method further comprises the step of depositing an emission layer over the hole transporting layer and then depositing the electron transporting layer over the emission layer.

51. The method of claim 49 wherein the second electrically conductive layer comprises a transparent electrically conductive oxide layer.

52. The method of claim 49 wherein the second electrically conductive layer comprises indium tin oxide.

53. The method of claim 52 wherein the step of depositing the indium tin oxide over the transparent electrically conductive metal layer comprises:

(1) forming a protective cap layer comprising indium tin oxide over the transparent electrically conductive metal layer using a non-destructive growth rate; and

then

(2) increasing the growth rate for depositing indium tin oxide on the protective cap layer.

54. The method of claim 53 wherein the protective cap layer has a thickness of about 50 to about 100 angstroms.

55. The method of claim 49 wherein the transparent electrically conductive metal layer comprises magnesium.

56. The method of claim 55 wherein the transparent electrically conductive metal layer further comprises silver.

57. The method of claim 49 wherein the substrate is transparent.

58. The method of claim 49 wherein the substrate is rigid.

59. The method of claim 49 wherein the first electrically conductive layer is transparent.

60. The method of claim 49 wherein the first electrically conductive layer comprises indium tin oxide.

61. The method of claim 49 wherein the first electrically conductive layer comprises a metal layer.

62. The method of claim 49 wherein the obtaining step comprises coating said substrate with said first electrically conductive layer.

63. A method of fabricating an organic light emitting device structure, comprising:

obtaining a substrate coated with a first electrically conductive layer, wherein the first electrically conductive layer has a positive polarity;

fabricating a transparent organic light emitting device over said first electrically conductive layer;

depositing an electrically conductive metal layer having a thickness of 50 to 400 angstroms over the transparent organic light emitting device; and

depositing a transparent electrically conductive oxide layer over the electrically conductive metal layer, wherein the transparant electrically conductive oxide layer has a negative polarity.

64. The method of claim 63 wherein the transparent electrically conductive oxide layer comprises indium tin oxide.

65. The method of claim 63 wherein the step of depositing said indium tin oxide over the electrically conductive metal layer comprises:

(1) forming a protective cap layer comprising indium tin oxide over said electrically conductive metal layer using a non-destructive growth rate; and

then

(2) increasing the growth rate for depositing indium tin oxide on said protective cap layer.

66. The method of claim 65 wherein said protective cap layer has a thickness of about 50 to about 100 angstroms.

67. The method of claim 63 wherein said electrically conductive metal layer has a thickness of about 50 to about 100 angstroms.

68. The method of claim 63 wherein the electrically conductive metal layer comprises magnesium.

69. The method of claim 68 wherein the electrically conductive metal layer further comprises silver.

70. The method of claim 63 wherein the substrate is transparent.

71. The method of claim 63 wherein the substrate is rigid.

72. The method of claim 63 wherein the first electrically conductive layer is transparent.

73. The method of claim 63 wherein the first electrically conductive layer comprises indium tin oxide.

74. The method of claim 63 wherein the first electrically conductive layer comprises a reflective metal layer.

75. The method of claim 63 wherein the obtaining step comprises coating said substrate with said first electrically conductive layer.

76. A method of fabricating an organic light emitting device structure, comprising:

obtaining a substrate coated with a first electrically conductive layer, wherein the first electrically conductive layer has a positive polarity;

depositing a hole transporting layer over the first electrically conductive layer;

depositing an electron transporting layer over the hole transporting layer;

depositing an electrically conductive metal layer having a thickness of 50 to 400 angstroms over the electron transporting layer; and

depositing a transparent electrically conductive oxide layer over the electrically conductive metal layer, wherein the transparent electrically conductive oxide layer has a negative polarity.

77. The method of claim 76 wherein the method further comprises the step of depositing an emission layer over the hole transporting layer and then depositing the electron transporting layer over the emission layer.

78. The method of claim 76 wherein the transparent electrically conductive oxide layer comprises indium tin oxide.

79. The method of claim 76 wherein the step of depositing said indium tin oxide over the electrically conductive metal layer comprises:

(1) forming a protective cap layer comprising indium tin oxide over said electrically conductive metal layer using a non-destructive growth rate; and

then

(2) increasing the growth rate for depositing indium tin oxide on said protective cap layer.

80. The method of claim 79 wherein said protective cap layer has a thickness of about 50 to about 100 angstroms.

81. The method of claim 76 wherein said electrically conductive metal layer has a thickness of about 50 to about 100 angstroms.

82. The method of claim 76 wherein the electrically conductive metal layer comprises magnesium.

83. The method of claim 82 wherein the electrically conductive metal layer further comprises silver.

84. The method of claim 76 wherein the substrate is transparent.

85. The method of claim 76 wherein the substrate is rigid.

86. The method of claim 76 wherein the first electrically conductive layer is transparent.

87. The method of claim 76 wherein the first electrically conductive layer comprises indium tin oxide.

88. The method of claim 76 wherein the first electrically conductive layer comprises a reflective metal layer.

89. The method of claim 76 wherein the obtaining step comprises coating said substrate with said first electrically conductive layer.