Display device and method for manufacturing thereof

• US 7,199,516 B2
• Filed: 01/16/2003
• Issued: 04/03/2007
• Est. Priority Date: 01/25/2002
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Seo, Satoshi, Yamazaki, Shunpei
• Primary Examiner(s): Guharay; Karabi
• Application Number:
  US10/345,745
• Publication Number:
  US 20030227253A1
• Time in Patent Office: 1,538 Days
• Field of Search: 313/504, 313/506, 313/509, 313/500, 313/505
• US Class Current: 313/504
• CPC Class Codes: H05B 33/10 Apparatus or processes specially adapted to the manufacture of electroluminescent light sources
• CPC Class Codes: H10K 50/155 comprising dopants
• CPC Class Codes: H10K 50/165 comprising dopants
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/171 Electron injection layers
• CPC Class Codes: H10K 50/805 Electrodes
• 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 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/173 comprising banks or shadow masks

Abstract

It is a problem to provide an electric apparatus less in consumption power and long in life by the manufacture using the display device.

An insulating bank 103a is provided in a form surrounding the pixel portions 110a on first electrodes 102a over a substrate. The entire surface is applied, by a wet scheme(method), with an organic conductive film 104. The organic conductive film 104 has a thickness form of T2>T1>T3 under the influence of the insulating bank 103. Accordingly, the portion T3 has an increased resistance in a lateral direction, making possible to prevent against crosstalk. Due to a conductive polymer as a buffer layer 104, a display device can be provided which is low in drive voltage. Furthermore, because the portion T2 is increased in thickness, the electric-field concentration is relaxed at and around the pixel portion. This makes it possible to prevent the organic light-emitting element from deteriorating at around the pixel.

Claims

1. A display device having a plurality of pixels arranged in a matrix form, comprising:

a substrate;

insulating banks formed over the substrate;

a first electrode formed over the substrate and between the insulating banks;

a conductive polymer film covering surfaces of the insulating banks and formed over the first electrode;

an organic thin film containing an organic compound capable of causing electroluminescence formed over the conductive polymer film and between the insulating banks; and

a second electrode formed over the organic thin film,

wherein the conductive polymer film formed in a vicinity of a top edge of the insulating bank has a first thickness, and the conductive polymer film formed in a vicinity of a center of the first electrode between the insulating banks has a second thickness, and

wherein the second thickness is thicker than the first thickness.

2. A display device according to claim 1, wherein the conductive polymer film is a polymer having π

-conjugated system added with an acceptor or a donor.

3. A polymer having π

-conjugated system added with an acceptor or a donor according to claim 2, wherein the polymer having π

-conjugated system added with an acceptor or a donor is at least one selected from group consisting of PEDOT/PSS and PAni/PSS.

4. A display device according to claim 1, wherein the conductive polymer film is a film formed by a wet method.

5. A display device according to claim 4, wherein the wet method is a spin coat process, an ink jet process or a spray process.

6. A display device according to claim 1, wherein the conductive polymer film has a conductivity of 10⁻

6 S/cm or higher and 10<sup>−

2</sup> S/cm or lower.

7. A display device according to claim 1, wherein the insulating bank has a taper form gradually smaller toward the above of the substrate.

8. A display device according to claim 7, wherein the taper form has a taper angle of 60 degrees or greater and 80 degrees or smaller.

9. A display device according to claim 1, wherein the insulating bank has a curved surface form having at least one center of a radius of curvature at the substrate side to an edge line of the insulating bank.

10. A display device according to claim 1, wherein the edge line of the insulating bank is a curved surface form having no inflection point.

11. A display device according to claim 1, wherein the insulating bank has a curved surface form having at least one center of a radius of curvature at the substrate side to an edge line of the insulating bank and at least one center of a radius of curvature at the opposite side of the substrate side to an edge line of the insulating bank.

12. A display device according to claim 1, wherein the edge line of the insulating bank is a curved surface form having at least one inflection point.

13. A display device according to claim 1, wherein the display device further includes a data signal line, a scanning signal line and a nonlinear element connected to the data signal line, the scanning signal line and the first electrode.

14. A display device according to claim 13, wherein the nonlinear element is formed by a combination of a mutually connected thin film transistor and capacitor or a combination of a thin film transistor and a parasitic capacitor to the thin film transistor.

15. A display device according to claim 1, wherein the substrate and the first electrode have a transparency for a visible portion of light.

16. A display device according claim 1, wherein the second electrode has a transparency for a visible portion of light.

17. An electronic device having said display device according to claim 1, wherein said electronic device is selected from the group consisting of an OLED display device, a video camera, a digital camera, a mobile computer, a personal computer, a mobile phone, and an audio playback device.

18. A display device according to claim 1, wherein the a conductive polymer film is a polymer having π

-conjugated system.

19. A polymer having π

-conjugated system according to claim 18, wherein the polymer having π

-conjugated system is at least one selected from group consisting of PEDOT, PAni, polypyrol, polyphenylene derivative, polythiophene derivative, and poly(paraphenylenevinylene).

20. A display device according to claim 1, wherein the insulating banks have a form protruding above and cover at least one edge of a surface of the first electrode formed over the substrate.

21. A method for manufacturing a display device having a plurality of pixels arranged in a matrix form, comprising:

a step of forming insulating banks over a substrate;

a patterning step of forming a first electrode over the substrate and between the insulating banks;

a step of forming a conductive polymer film over the first electrode to cover surfaces of the insulating banks;

a step of forming an organic thin film containing an organic compound capable of causing electroluminescence over the conductive polymer film and between the insulating banks; and

a step of forming a second electrode over the organic thin film,

wherein the conductive polymer film formed in a vicinity of a top edge of the insulating bank has a first thickness, and the conductive polymer film formed in a vicinity of a center of the first electrode between the insulating banks has a second thickness, and

wherein the second thickness is thicker than the first thickness.

22. A method for manufacturing a display device according to claim 21, wherein the step of providing the conductive polymer film is by a wet method.

23. A method for manufacturing a display device according to claim 22, wherein the wet method is a process to spray-apply, spin-apply or ink-jet-apply a material solution or a material dispersion liquid for the conductive polymer film.

24. A method for manufacturing a display device according to claim 21, wherein the patterning step includes a step to form a data signal line, a scanning signal line and a nonlinear element connected to the data signal line, the scanning signal line and the first electrode.

25. A method for manufacturing a display device according to claim 24, wherein the nonlinear element is formed by a combination of a mutually connected thin film transistor and capacitor or a combination of a thin film transistor and a parasitic capacitor to the thin film transistor.

26. A method for manufacturing a display device according to claim 21, wherein the insulating banks have a form protruding above and cover at least one edge of a surface of the first electrode formed over the substrate.

27. A display device having a plurality of pixels arranged in a matrix form, comprising:

a substrate;

insulating banks formed over the substrate;

a first electrode formed over the substrate and between the insulating banks;

a conductive polymer film formed over the first electrode and on at least top surfaces of the insulating banks;

an organic thin film containing an organic compound capable of causing electroluminescence formed over the conductive polymer film and between the insulating banks; and

a second electrode formed over the organic thin film,

wherein top surfaces of the insulating banks are not covered with the organic thin film containing an organic compound capable of causing electroluminescence,

wherein the conductive polymer film formed in a vicinity of a top edge of the insulating bank has a first thickness, and the conductive polymer film formed in a vicinity of a center of the first electrode between the insulating banks has a second thickness, and

wherein the second thickness is thicker than the first thickness.

28. An electronic device having said display device according to claim 27, wherein said electronic device is selected from the group consisting of an OLED display device, a video camera, a digital camera, a mobile computer, a personal computer, a mobile phone, and an audio playback device.

29. A display device according to claim 27, wherein the a conductive polymer film is a polymer having π

-conjugated system added with an acceptor or a donor.

30. A polymer having π

-conjugated system added with an acceptor or a donor according to claim 29, wherein the polymer having π

-conjugated system added with an acceptor or a donor is at least one selected from group consisting of PEDOT/PSS and PAni/PSS.

31. A display device according to claim 27, wherein the conductive polymer film has a conductivity of 10⁻

6 S/cm or higher and 10^{31 2} S/cm or lower.

32. A display device according to claim 27, wherein the insulating bank has a taper form gradually smaller toward the above of the substrate.

33. A display device according to claim 32, wherein the taper form has a taper angle of 60 degrees or greater and 80 degrees or smaller.

34. A display device according to claim 27, wherein the insulating bank has a curved surface form having at least one center of a radius of curvature at the substrate side to an edge line of the insulating bank.

35. A display device according to claim 27, wherein the edge line of the insulating bank is a curved surface form having no inflection point.

36. A display device according to claim 27, wherein the insulating bank has a curved surface form having at least one center of a radius of curvature at the substrate side to an edge line of the insulating bank and at least one center of a radius of curvature at the opposite side of the substrate side to an edge line of the insulating bank.

37. A display device according to claim 27, wherein the edge line of the insulating bank is a curved surface form having at least one inflection point.

38. A display device according to claim 27, wherein the display device further includes a data signal line, a scanning signal line and a nonlinear element connected to the data signal line, the scanning signal line and the first electrode.

39. A display device according to claim 38, wherein the nonlinear element is formed by a combination of a mutually connected thin film transistor and capacitor or a combination of a thin film transistor and a parasitic capacitor to the thin film transistor.

40. A display device according to claim 27, wherein the substrate and the first electrode have a transparency for a visible portion of light.

41. A display device according claim 27, wherein the second electrode has a transparency for a visible portion of light.

42. A display device according to claim 27, wherein the conductive polymer film is a polymer having π

-conjugated system.

43. A polymer having π

-conjugated system according to claim 42, wherein the polymer having π

-conjugated system is at least one selected from group consisting of PEDOT, PAni, polypyrol, polyphenylene derivative, polythiophene derivative, and poly(paraphenylenevinylene).

44. A display device according to claim 27, wherein the insulating banks have a form protruding above and cover at least one edge of a surface of the first electrode formed over the substrate.

45. A display device having a plurality of pixels arranged in a matrix form, comprising:

a substrate;

tapered insulating banks formed over the substrate;

a first electrodes formed over the substrate and between the tapered insulating banks;

a conductive polymer film covering surfaces of the tapered insulating banks and formed over the first electrode;

an organic thin film containing an organic compound capable of causing electroluminescence formed over the conductive polymer film and between the tapered insulating banks; and

a second electrode formed over the organic thin film,

wherein the conductive polymer film formed in a vicinity of a top edge of the insulating bank has a first thickness, and the conductive polymer film formed in a vicinity of a center of the first electrode between the insulating banks has a second thickness, and

wherein the second thickness is thicker than the first thickness.

46. A display device according to claim 45, wherein the conductive polymer film is a polymer having π

-conjugated system added with an acceptor or a donor.

47. A polymer having π

-conjugated system added with an acceptor or a donor according to claim 46, wherein the polymer having π

-conjugated system added with an acceptor or a donor is at least one selected from group consisting of PEDOT/PSS and PAni/PSS.

48. A display device according to claim 45, wherein the conductive polymer film is a polymer having π

-conjugated system.

49. A polymer having π

-conjugated system according to claim 48, wherein the polymer having π

-conjugated system is at least one selected from group consisting of PEDOT, PAni, polypyrol, polyphenylene derivative, polythiophene derivative, and poly(paraphenylenevinylene).

50. A display device according to claim 45, wherein the conductive polymer film has a conductivity of 10⁻

6 S/cm or higher and 10<sup>−

2</sup> S/cm or lower.

51. A display device according to claim 45, wherein the tapered insulating banks have a form protruding above and cover at least one edge of a surface of the first electrode formed over the substrate.

52. A display device according to claim 45, wherein the tapered insulating bank has a taper form gradually smaller toward the above of the substrate.

53. A display device according to claim 52, wherein the taper form has a taper angle of 60 degrees or greater and 80 degrees or smaller.

54. A display device according to claim 45, wherein the tapered insulating bank has a curved surface form having at least one center of a radius of curvature at the substrate side to an edge line of the tapered insulating bank.

55. A display device according to claim 45, wherein the edge line of the tapered insulating bank is a curved surface form having no inflection point.

56. A display device according to claim 45, wherein the tapered insulating bank has a curved surface form having at least one center of a radius of curvature at the substrate side to an edge line of the tapered insulating bank and at least one center of a radius of curvature at the opposite side of the substrate side to an edge line of the tapered insulating bank.

57. A display device according to claim 45, wherein the edge line of the tapered insulating bank is a curved surface form having at least one inflection point.

58. A display device according to claim 45, wherein the display device further includes a data signal line, a scanning signal line and a nonlinear element connected to the data signal line, the scanning signal line and the first electrode.

59. A display device according to claim 58, wherein the nonlinear element is formed by a combination of a mutually connected thin film transistor and capacitor or a combination of a thin film transistor and a parasitic capacitor to the thin film transistor.

60. A display device according to claim 45, wherein the substrate and the first electrode have a transparency for a visible portion of light.

61. A display device according claim 45, wherein the second electrode has a transparency for a visible portion of light.

62. An electronic device having said display device according to claim 45, wherein said electronic device is selected from the group consisting of an OLED display device, a video camera, a digital camera, a mobile computer, a personal computer, a mobile phone, and an audio playback device.

63. A display device having a plurality of pixels arranged in a matrix form, comprising:

a substrate;

tapered insulating banks formed over the substrate;

a first electrode formed over the substrate and between the tapered insulating banks;

a conductive polymer film formed over the first electrode and over at least top surfaces of the insulating banks;

an organic thin film containing an organic compound capable of causing electroluminescence formed over the conductive polymer film and between the tapered insulating banks; and

a second electrode formed over the organic thin film,

wherein top surfaces of the insulating banks are not covered with the organic thin film containing an organic compound capable of causing electroluminescence,

wherein the conductive polymer film formed in a vicinity of a top edge of the insulating bank has a first thickness, and the conductive polymer film formed in a vicinity of a center of the first electrode between the insulating banks has a second thickness, and

wherein the second thickness is thicker than the first thickness.

64. A display device according to claim 63, wherein the conductive polymer film is a polymer having π

-conjugated system added with an acceptor or a donor.

65. A polymer having π

-conjugated system added with an acceptor or a donor according to claim 64, wherein the polymer having π

-conjugated system added with an acceptor or a donor is at least one selected from group consisting of PEDOT/PSS and PAnifPSS.

66. A display device according to claim 63, wherein the conductive polymer film is a polymer having π

-conjugated system.

67. A polymer having π

-conjugated system according to claim 66, wherein the polymer having π

-conjugated system is at least one selected from group consisting of PEDOT, PAni, polypyrol, polyphenylene derivative, polythiophene derivative, and poly(paraphenylenevinylene).

68. A display device according to claim 63, wherein the conductive polymer film has a conductivity of 10⁻

6 S/cm or higher and 10<sup>−

2</sup> S/cm or lower.

69. A display device according to claim 63, wherein the tapered insulating banks have a form protruding above and cover at least one edge of a surface of the first electrode formed over the substrate.

70. A display device according to claim 63, wherein the tapered insulating bank has a taper form gradually smaller toward the above of the substrate.

71. A display device according to claim 63, wherein the taper form has a taper angle of 60 degrees or greater and 80 degrees or smaller.

72. A display device according to claim 63, wherein the tapered insulating bank has a curved surface form having at least one center of a radius of curvature at the substrate side to an edge line of the tapered insulating bank.

73. A display device according to claim 63, wherein the edge line of the tapered insulating bank is a curved surface form having no inflection point.

74. A display device according to claim 63, wherein the tapered insulating bank has a curved surface form having at least one center of a radius of curvature at the substrate side to an edge line of the tapered insulating bank and at least one center of a radius of curvature at the opposite side of the substrate side to an edge line of the tapered insulating bank.

75. A display device according to claim 63, wherein the edge line of the tapered insulating bank is a curved surface form having at least one inflection point.

76. A display device according to claim 63, wherein the display device further includes a data signal line, a scanning signal line and a nonlinear element connected to the data signal line, the scanning signal line and the first electrode.

77. A display device according to claim 76, wherein the nonlinear element is formed by a combination of a mutually connected thin film transistor and capacitor or a combination of a thin film transistor and a parasitic capacitor to the thin film transistor.

78. A display device according to claim 63, wherein the substrate and the first electrode have a transparency for a visible portion of light.

79. A display device according claim 63, wherein the second electrode has a transparency for a visible portion of light.

80. An electronic device having said display device according to claim 63, wherein said electronic device is selected from the group consisting of an OLED display device, a video camera, a digital camera, a mobile computer, a personal computer, a mobile phone, and an audio playback device.