Method of repairing a light-emitting device, and method of manufacturing a light -emitting device

• US 20020181276A1
• Filed: 05/30/2002
• Published: 12/05/2002
• Est. Priority Date: 06/01/2001
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Granted Patent: US 6,777,249 B2
• Time in Patent Office: Days
• US Class Current: 365/175
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0809 Several active elements per pixel in active matrix panels
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2310/0256 with the purpose of reversing the voltage across a light emitting or modulating element within a pixel
• CPC Class Codes: G09G 2310/061 for resetting or blanking
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2330/08 Fault-tolerant or redundant circuits, or circuits in which repair of defects is prepared
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• CPC Class Codes: G09G 3/3216 using a passive matrix
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: H10K 50/80 Constructional details
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 59/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/8052 Cathodes
• CPC Class Codes: H10K 71/861 Repairing

Abstract

A method of repairing a light-emitting device capable of performing high quality image display even if pinholes are formed when forming an organic compound layer is provided. Device contamination can be prevented during repair. By applying a reverse bias voltage to an organic light emitting element during fixed periods of time, the electric current flowing in the EL element during application of the reverse bias voltage is reduced. Further, by forming a cathode so as to contain as little as possible of the high mobility ions Li and Na, contamination of the device when the reverse bias is applied can be prevented. It is preferable to use AlMg and MgAg for this type of cathode.

Claims

1. A method of repairing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therebetween, wherein a concentration of at least one of Li and Na contained in the cathode is 1×

10¹⁸ atoms/cm³ or less,

the method comprising;

applying a reverse bias voltage between the anode and the cathode.

2. A method of repairing a light-emitting device according to claim 1, wherein the cathode is an alloy containing at least one selected from the group consisting of Be, Mg, Ca, Sr and Ba.

3. A method of repairing a light-emitting device according to claim 1, wherein the cathode is an alloy containing magnesium.

4. A method of repairing a light-emitting device according to claim 1, wherein the cathode is one selected from the group consisting of AlMg, MgAg and MgAgAl.

5. A method of repairing a light-emitting device according to claim 1, wherein the reverse bias voltage is applied during fixed periods of time.

6. A method of repairing a light-emitting device according to claim 1, wherein the reverse bias voltage is gradually increased during the application until it settles within ±

15% of the height at which an avalanche current begins to flow within the organic compound layer.

7. A method of repairing a light-emitting device according to claim 1, wherein the organic light emitting elements are arranged in a matrix shape, and a thin film transistor is connected to each of the organic light emitting elements.

8. A method of repairing a light-emitting device according to claim 1, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.

9. A method of repairing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therebetween, wherein a concentration of at least one of Li and Na contained in the cathode is 1×

10¹⁸ atoms/cm³ or less,

the repairing method comprising;

applying a reverse bias voltage between the anode and the cathode, thereby making an electric current flow in portions at which the anode and the cathode are electrically short-circuited, causing the short-circuited portions to emit heat, and making the portions that emit heat into higher resistance portions, or insulating portions.

10. A method of repairing a light-emitting device according to claim 9, wherein the cathode is an alloy containing at least one selected from the group consisting of Be, Mg, Ca, Sr and Ba.

11. A method of repairing a light-emitting device according to claim 9, wherein the cathode is an alloy containing magnesium.

12. A method of repairing a light-emitting device according to claim 9, wherein the cathode is one selected from the group consisting of AlMg, MgAg and MgAgAl.

13. A method of repairing a light-emitting device according to claim 9, wherein the reverse bias voltage is applied during fixed periods of time.

14. A method of repairing a light-emitting device according to claim 9, wherein the reverse bias voltage is gradually increased during the application until it settles within ±

15% of the height at which an avalanche current begins to flow within the organic compound layer.

15. A method of repairing a light-emitting device according to claim 9, wherein the organic light emitting elements are arranged in a matrix shape, and a thin film transistor is connected to each of the organic light emitting elements.

16. A method of repairing a light-emitting device according to claim 9, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.

18. A method of repairing a light-emitting device according to claim 17, wherein the cathode is an alloy containing at least one selected from the group consisting of Be, Mg, Ca, Sr and Ba.

19. A method of repairing a light-emitting device according to claim 17, wherein the cathode is an alloy containing magnesium.

20. A method of repairing a light-emitting device according to claim 17, wherein the cathode is one selected from the group consisting of AlMg, MgAg and MgAgAl.

21. A method of repairing a light-emitting device according to claim 17, wherein the reverse bias voltage is applied during fixed periods of time.

22. A method of repairing a light-emitting device according to claim 17, wherein the reverse bias voltage is gradually increased during the application until it settles within ±

15% of the height at which an avalanche current begins to flow within the organic compound layer.

23. A method of repairing a light-emitting device according to claim 17, wherein the organic light emitting elements are arranged in a matrix shape, and a thin film transistor is connected to each of the organic light emitting elements.

24. A method of repairing a light-emitting device according to claim 17, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.

26. A method of repairing a light-emitting device according to claim 25, wherein there is the electrical current flowing in portions at which the anode and the cathode are in electrical contact, causing heat to be emitted, and making the portions that emit heat into higher resistance portions, or insulating portions.

27. A Method of repairing a light-emitting device according to claim 25, wherein the cathode is an alloy containing at least one selected from the group consisting of Be, Mg, Ca, Sr and Ba.

28. A method of repairing a light-emitting device according to claim 25, wherein the cathode is an alloy containing magnesium.

29. A method of repairing a light-emitting device according to claim 25, wherein the cathode is one selected from the group consisting of AlMg, MgAg and MgAgAl.

30. A method of repairing a light-emitting device according to claim 25, wherein the reverse bias voltage is applied during fixed periods of time.

31. A method of repairing a light-emitting device according to claim 25, wherein the reverse bias voltage is gradually increased during the application until it settles within ±

15% of the height at which an avalanche current begins to flow within the organic compound layer.

32. A method of repairing a light-emitting device according to claim 25, wherein the organic light emitting elements are arranged in a matrix shape, and a thin film transistor is connected to each of the organic light emitting elements.

33. A method of repairing a light-emitting device according to claim 25, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.

35. A method of repairing a light-emitting device according to claim 34, wherein there is the electrical current flowing in portions at which the layer on the light emitting layer and the layer under the light emitting layer are in electrical contact, causing heat to be emitted, and making the portions that emit heat into higher resistance portions, or insulating portions.

36. A method of repairing a light-emitting device according to claim 34, wherein the cathode is an alloy containing at least one selected from the group consisting of Be, Mg, Ca, Sr and Ba.

37. A method of repairing a light-emitting device according to claim 34, wherein the cathode is an alloy containing magnesium.

38. A method of repairing a light-emitting device according to claim 34, wherein the cathode is one selected from the group consisting of AlMg, MgAg and MgAgAl.

39. A method of repairing a light-emitting device according to claim 34, wherein the reverse bias voltage is applied during fixed periods of time.

40. A method of repairing a light-emitting device according to claim 34, wherein the reverse bias voltage is gradually increased during the application until it settles within ±

15% of the height at which an avalanche current begins to flow within the organic compound layer.

41. A method of repairing a light-emitting device according to claim 34, wherein the organic light emitting elements are arranged in a matrix shape, and a thin film transistor is connected to each of the organic light emitting elements.

42. A method of repairing a light-emitting device according to claim 34, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.

17. A method of repairing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therebetween, wherein a concentration of at least one of Li and Na contained in the cathode is 1×

10¹⁸ atoms/cm³ or less, and wherein the organic compound layer comprises a hole injecting layer, a hole transporting layer, an electron injecting layer, an electron transporting layer, and a light emitting layer,

the repairing method comprising;

applying a reverse bias voltage between the anode and the cathode, thereby making an electric current flow in portions at which a layer on the light emitting layer and a layer under the light emitting layer are electrically short-circuited, causing the short-circuited portions to emit heat, and making the portions that emit heat into higher resistance portions, or insulating portions.

25. A method of repairing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therebetween, wherein a concentration of at least one of Li and Na contained in the cathode is 1×

10¹⁸ atoms/cm³ or less,

the repairing method comprising;

applying a reverse bias voltage between the anode and the cathode, thereby causing an electric current to flow in portions at which the anode and the cathode are in electrical contact.

34. A method of repairing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therebetween, wherein a concentration of at least one of Li and Na contained in the cathode is 1×

10¹⁸ atoms/cm³ or less, and wherein the organic compound layer comprises a hole injecting layer, a hole transporting layer, an electron injecting layer, an electron transporting layer, and a light emitting layer,

the repairing method comprising;

applying a reverse bias voltage between the anode and the cathode, thereby causing an electric current to flow in portions at which a layer on the light emitting layer and a layer under the light emitting layer are in electrical contact.

43. A method of repairing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therbetween, wherein the cathode contains Mg, and at least one of Al and Ag,

the repairing method comprising:

applying a reverse bias voltage between the anode and the cathode.

44. A method of repairing a light-emitting device according to claim 43, wherein a concentration of at least one of Li and Na contained in the cathode is 1×

10¹⁸ atoms/cm³ or less.

45. A method of repairing a light-emitting device according to claim 43, wherein an amount of Mg contained in the cathode is 1×

10²⁰ atoms/cm³ or more.

46. A method of repairing a light-emitting device according to claim 43, wherein the reverse bias voltage is applied during fixed periods of time.

47. A method of repairing a light-emitting device according to claim 43, wherein the reverse bias voltage is gradually increased during the application until it settles within ±

15% of the height at which an avalanche current begins to flow within the organic compound layer.

48. A method of repairing a light-emitting device according to claim 43, wherein the organic light emitting elements are arranged in a matrix shape, and a thin film transistor is connected to each of the organic light emitting elements.

49. A method of repairing a light-emitting device according to claim 43, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.

50. A method of repairing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therebetween, wherein the cathode contains Mg, and at least one of Al and Ag,

the repairing method comprising:

applying a reverse bias voltage between the anode and the cathode, thereby causing an electric current to flow in portions at which the anode and the cathode are electrically short-circuited, and causing the short-circuited portions to emit heat; and

making the portions that emit heat into higher resistance portions, or insulating portions.

51. A method of repairing a light-emitting device according to claim 50, wherein a concentration of at least one of Li and Na contained in the cathode is 1×

10¹⁸ atoms/cm³ or less.

52. A method of repairing a light-emitting device according to claim 50, wherein an amount of Mg contained in the cathode is 1×

10²⁰ atoms/cm³ or more.

53. A method of repairing a light-emitting device according to claim 50, wherein the reverse bias voltage is applied during fixed periods of time.

54. A method of repairing a light-emitting device according to claim 50, wherein the reverse bias voltage is gradually increased during the application until it settles within ±

15% of the height at which an avalanche current begins to flow within the organic compound layer.

55. A method of repairing a light-emitting device according to claim 50, wherein the organic light emitting elements are arranged in a matrix shape, and a thin film transistor is connected to each of the organic light emitting elements.

56. A method of repairing a light-emitting device according to claim 50, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.

58. A method of repairing a light-emitting device according to claim 57, wherein a concentration of at least one of Li and Na contained in the cathode is 1×

10¹⁸ atoms/cm³ or less.

59. A method of repairing a light-emitting device according to claim 57, wherein an amount of Mg contained in the cathode is 1×

10²⁰ atoms/cm³ or more.

60. A method of repairing a light-emitting device according to claim 57, wherein the reverse bias voltage is applied during fixed periods of time.

61. A method of repairing a light-emitting device according to claim 57, wherein the reverse bias voltage is gradually increased during the application until it settles within ±

15% of the height at which an avalanche current begins to flow within the organic compound layer.

62. A method of repairing a light-emitting device according to claim 57, wherein the organic light emitting elements are arranged in a matrix shape, and a thin film transistor is connected to each of the organic light emitting elements.

63. A method of repairing a light-emitting device according to claim 57, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.

57. A method of repairing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therebetween, wherein the cathode contains Mg, and at least one of Al and Ag, and

wherein the organic compound layer comprises a hole injecting layer, a hole transporting layer, an electron injecting layer, an electron transporting layer, and a light emitting layer;

the repairing method comprising;

applying a reverse bias voltage between the anode and the cathode, thereby making an electric current flow in portions at which a layer on the light emitting layer and a layer under the light emitting layer are electrically short-circuited, and causing the short-circuited portions to emit heat; and

making the portions that emit heat into higher resistance portions, or insulating portions.

64. A method of repairing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therebetween, wherein the cathode contains Mg, and at least one of Al and Ag,

the repairing method comprising:

applying a reverse bias voltage between the anode and the cathode, thereby causing an electric current to flow in portions at which the anode and the cathode are in electrical contact.

65. A method of repairing a light-emitting device according to claim 64, wherein there is the electrical current flowing in portions at which the anode and the cathode are in electrical contact, causing heat to be emitted, and making the portions that emit heat into higher resistance portions, or insulating portions.

66. A method of repairing a light-emitting device according to claim 64, wherein a concentration of at least one of Li and Na contained in the cathode is 1×

10¹⁸ atoms/cm³ or less.

67. A method of repairing a light-emitting device according to claim 64, wherein an amount of Mg contained in the cathode is 1×

10²⁰ atoms/cm³ or more.

68. A method of repairing a light-emitting device according to claim 64, wherein the reverse bias voltage is applied during fixed periods of time.

69. A method of repairing a light-emitting device according to claim 64, wherein the reverse bias voltage is gradually increased during the application until it settles within ±

15% of the height at which an avalanche current begins to flow within the organic compound layer.

70. A method of repairing a light-emitting device according to claim 64, wherein the organic light emitting elements are arranged in a matrix shape, and a thin film transistor is connected to each of the organic light emitting elements.

71. A method of repairing a light-emitting device according to claim 64, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.

72. A method of repairing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therebetween, wherein the cathode contains Mg, and at least one of Al and Ag, and

wherein the organic compound layer comprises a hole injecting layer, a hole transporting layer, an electron injecting layer, an electron transporting layer, and a light emitting layer,

the repairing method comprising:

applying a reverse bias voltage between the anode and the cathode, thereby causing an electric current to flow in portions at which the layer on the light emitting layer and the layer under the light emitting layer are in electrical contact.

73. A method of repairing a light-emitting device according to claim 72, wherein there is the electrical current flowing in portions at which the layer on the light emitting layer and the layer under the light emitting layer are in electrical contact, causing heat to be emitted, and making the portions that emit heat into higher resistance portions, or insulating portions.

74. A method of repairing a light-emitting device according to claim 72, wherein a concentration of at least one of Li and Na contained in the cathode is 1×

10¹⁸ atoms/cm³ or less.

75. A method of repairing a light-emitting device according to claim 72, wherein an amount of Mg contained in the cathode is 1×

10²⁰ atoms/cm³ or more.

76. A method of repairing a light-emitting device according to claim 72, wherein the reverse bias voltage is applied during fixed periods of time.

77. A method of repairing a light-emitting device according to claim 72, wherein the reverse bias voltage is gradually increased during the application until it settles within ±

15% of the height at which an avalanche current begins to flow within the organic compound layer.

78. A method of repairing a light-emitting device according to claim 72, wherein the organic light emitting elements are arranged in a matrix shape, and a thin film transistor is connected to each of the organic light emitting elements.

79. A method of repairing a light-emitting device according to claim 72, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.

80. A method of manufacturing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therbetween, comprising:

forming the cathode so that a concentration of at least one of Li and Na contained therein is 1×

10¹⁸ atoms/cm³ or less; and

applying a reverse bias voltage between the anode and the cathode.

81. A method of manufacturing a light-emitting device according to claim 80, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.

82. A method of manufacturing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therebetween, comprising:

forming the cathode so that a concentration of at least one of Li and Na contained in the cathode is 1×

10¹⁸ atoms/cm³ or less; and

applying a reverse bias voltage between the anode and the cathode, thereby making an electric current flow in portions at which the anode and the cathode are electrically short-circuited, causing the short-circuited portions to emit heat, and making the portions that emit heat into higher resistance portions, or insulating portions.

83. A method of manufacturing a light-emitting device according to claim 82, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.

84. A method of manufacturing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therebetween, comprising:

forming the cathode from an alloy containing Mg and at least one of Al and Ag; and

applying a reverse bias voltage between the anode and the cathode.

85. A method of manufacturing a light-emitting device according to claim 84, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.

86. A method of manufacturing a light-emitting device comprising an organic light emitting element having an anode, a cathode, and an organic compound layer interposed therebetween, comprising:

forming the cathode from an alloy containing Mg and at least one of Al and Ag; and

applying a reverse bias voltage between the anode and the cathode, thereby making an electric current flow in portions at which the anode and the cathode are electrically short-circuited, causing the short-circuited portions to emit heat, and making the portions that emit heat into higher resistance portions, or insulating portions.

87. A method of manufacturing a light-emitting device according to claim 86, wherein the light-emitting device is incorporated in at least one selected from the group consisting of a display device, digital camera, a personal computer, a mobile computer, an image reproducing device, a goggle-type display, a video camera, and a portable telephone.