Light emitting device and method for manufacturing the same

• US 20060163597A1
• Filed: 12/27/2005
• Published: 07/27/2006
• Est. Priority Date: 12/28/2004
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Arai, Yasuyuki, Noda, Takeshi, Sakakura, Masayuki, Tachimura, Yuko
• Granted Patent: US 8,633,473 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H10K 2102/351 Thickness
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 59/8791 Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

It is an object of the present invention to provide a high-contrast light-emitting device without using a polarization plate. In particular, it is an object of the present invention to make contrast control simpler for a light-emitting device provided with a color filter. A light-emitting device according to the present invention has a feature of having a structure for reducing reflection of light from a light-emitting later at a reflective electrode, and further, has a feature of absorbing wavelengths other than the light by a color filter to enhance the contrast. Accordingly, contrast control can be performed in consideration of only a luminescence component from the light-emitting layer, and is thus made simpler.

Claims

1. A light-emitting device comprising:

a first electrode;

a light emitting layer adjacent to the first electrode;

a second electrode adjacent to the light emitting layer with the light emitting layer interposed between the first and second electrodes;

a color filter adjacent to the second electrode with the second electrode interposed between the light emitting layer and the color filter,

wherein reflection of an emission wavelength from the light-emitting element at the first electrode is reduced due to optimize a thickness of the light emitting layer, and

wherein the color filter comprises a material that has a high transmittance with respect to the emission wavelength from the light-emitting element.

8. The light-emitting device according to claim 1, wherein Anti-Reflection treatment coating is performed to a substrate that is opposed to a substrate over which the light-emitting element is provided.

15. The light-emitting device according to claim 1, wherein the first electrode comprises a reflective material.

22. The light-emitting device according to claim 1, wherein the second electrode comprises a light-transmitting material.

2. A light-emitting device comprising:

a first electrode;

a light emitting layer adjacent to the first electrode;

a second electrode adjacent to the light emitting layer with the light emitting layer interposed between the first and second electrodes;

a color filter adjacent to the second electrode with the second electrode interposed between the light emitting layer and the color filter,

wherein any one layer of the electroluminescent layer has a thickness that reduces reflection of an emission wavelength from the light-emitting element at the first electrode, and

wherein the color filter comprises a material that has a high transmittance with respect to the emission wavelength from the light-emitting element.

9. The light-emitting device according to claim 2, wherein Anti-Reflection treatment coating is performed to a substrate that is opposed to a substrate over which the light-emitting element is provided.

16. The light-emitting device according to claim 2, wherein the first electrode comprises a reflective material.

23. The light-emitting device according to claim 2, wherein the second electrode comprises a light-transmitting material.

3. A light-emitting device comprising:

a first electrode;

a light emitting layer adjacent to the first electrode;

a second electrode adjacent to the light emitting layer with the light emitting layer interposed between the first and second electrodes;

a color filter adjacent to the second electrode with the second electrode interposed between the light emitting layer and the color filter,

wherein a reflectance of light emitted from said light emitting layer at the first electrode is 10% or less.

10. The light-emitting device according to claim 3, wherein Anti-Reflection treatment coating is performed to a substrate that is opposed to a substrate over which the light-emitting element is provided.

17. The light-emitting device according to claim 3, wherein the first electrode comprises a reflective material.

24. The light-emitting device according to claim 3, wherein the second electrode comprises a light-transmitting material.

4. A light-emitting device comprising:

a first electrode;

a light emitting layer adjacent to the first electrode;

a second electrode adjacent to the light emitting layer with the light emitting layer interposed between the first and second electrodes;

a color filter adjacent to the second electrode with the second electrode interposed between the light emitting layer and the color filter,

wherein a reflectance of light emitted from said light emitting layer at the first electrode is 10% or less, and wherein visible light having at least peak wavelength passes through the color filter.

11. The light-emitting device according to claim 4, wherein Anti-Reflection treatment coating is performed to a substrate that is opposed to a substrate over which the light-emitting element is provided.

18. The light-emitting device according to claim 4, wherein the first electrode comprises a reflective material.

25. The light-emitting device according to claim 4, wherein the second electrode comprises a light-transmitting material.

5. A light-emitting device comprising:

a first electrode;

a light emitting layer adjacent to the first electrode;

a second electrode adjacent to the light emitting layer with the light emitting layer interposed between the first and second electrodes;

a color filter adjacent to the second electrode with the second electrode interposed between the light emitting layer and the color filter,

wherein a reflectance of light emitted from said light emitting layer at the first electrode is 10% or less,

wherein visible light having at least peak wavelength passes through the color filter, and

wherein the light emitting layer emits monochromatic light.

12. The light-emitting device according to claim 5, wherein Anti-Reflection treatment coating is performed to a substrate that is opposed to a substrate over which the light-emitting element is provided.

19. The light-emitting device according to claim 5, wherein the first electrode comprises a reflective material.

26. The light-emitting device according to claim 5, wherein the second electrode comprises a light-transmitting material.

6. A light-emitting device comprising:

a first electrode;

a electroluminescent layer adjacent to the first electrode;

a second electrode adjacent to the light emitting layer with the light emitting layer interposed between the first and second electrodes;

a color filter adjacent to the second electrode with the second electrode interposed between the light emitting layer and the color filter,

wherein the electroluminescent layer having the layer including a metal oxide,

wherein the layer including a metal oxide a thickness that 10% or less reflectance of an emission wavelength from the electroluminescent layer at the first electrode,

wherein visible light having at least peak wavelength passes through the color filter, and

wherein the light-emitting element emits monochromatic light.

7. The light-emitting device according to claim 6, wherein the metal oxide selected from the group consisting of a vanadium oxide, a molybdenum oxide, a niobium oxide, a rhenium oxide, a tungsten oxide, a ruthenium oxide, a titanium oxide, a chromium oxide, a zirconium oxide, a hafnium oxide, and a tantalum oxide.

13. The light-emitting device according to claim 6, wherein Anti-Reflection treatment coating is performed to a substrate that is opposed to a substrate over which the light-emitting element is provided.

14. The light-emitting device according to claim 7, wherein Anti-Reflection treatment coating is performed to a substrate that is opposed to a substrate over which the light-emitting element is provided.

20. The light-emitting device according to claim 6, wherein the first electrode comprises a reflective material.

21. The light-emitting device according to claim 7, wherein the first electrode comprises a reflective material.

27. The light-emitting device according to claim 6, wherein the second electrode comprises a light-transmitting material.

28. The light-emitting device according to claim 7, wherein the second electrode comprises a light-transmitting material.

29. A method for manufacturing a light-emitting device comprising,

wherein the light-emitting device comprises:

a first electrode;

a second electrode provided to be opposed to the first electrode;

an electroluminescent layer provided between the first electrode and the second electrode;

a light-emitting element comprising the first electrode, the second electrode, and the electroluminescent layer; and

a color filter through which light from the light-emitting element is transmitted,

wherein any one layer of the electroluminescent layer is formed to have a thickness that reduces reflection of an emission wavelength from the light-emitting element at the first electrode, and

wherein the color filter is formed to have a high transmittance with respect to the emission wavelength from the light-emitting element.

35. The method according to claim 29, wherein the layer of the electroluminescent layer is formed by using a layer including a metal oxide selected from the group consisting of a vanadium oxide, a molybdenum oxide, a niobium oxide, a rhenium oxide, a tungsten oxide, a ruthenium oxide, a titanium oxide, a chromium oxide, a zirconium oxide, a hafnium oxide, and a tantalum oxide.

38. The method according to claim 29, wherein the first electrode is formed by using a reflective material.

44. The method according to claim 29, wherein the second electrode is formed by using a light-transmitting material.

30. A method for manufacturing a light-emitting device comprising,

wherein the light-emitting device comprises:

a first electrode;

a second electrode provided to be opposed to the first electrode;

an electroluminescent layer provided between the first electrode and the second electrode;

a light-emitting element comprising the first electrode, the second electrode, and the electroluminescent layer; and

a color filter through which light from the light-emitting element is transmitted,

wherein the light-emitting element emits monochromatic light,

wherein any one layer of the electroluminescent layer is formed to have a thickness that reduces reflection of an emission wavelength of a luminescent color from the monochromatic light-emitting element at the first electrode, and

wherein the color filter is formed to have a high transmittance with respect to the emission wavelength from the monochromatic light-emitting element.

36. The method according to claim 30, wherein the layer of the electroluminescent layer is formed by using a layer including a metal oxide selected from the group consisting of a vanadium oxide, a molybdenum oxide, a niobium oxide, a rhenium oxide, a tungsten oxide, a ruthenium oxide, a titanium oxide, a chromium oxide, a zirconium oxide, a hafnium oxide, and a tantalum oxide.

39. The method according to claim 30, wherein the first electrode is formed by using a reflective material.

45. The method according to claim 30, wherein the second electrode is formed by using a light-transmitting material.

31. A method for manufacturing a light-emitting device comprising,

forming a first electrode;

forming a light emitting layer over the first electrode;

forming a second electrode over the light emitting layer;

forming a color filter at the second electrode side, and

wherein a reflectance of light emitted from said light emitting layer at the first electrode is 10% or less.

40. The method according to claim 31, wherein the first electrode is formed by using a reflective material.

46. The method according to claim 31, wherein the second electrode is formed by using a light-transmitting material.

32. A method for manufacturing a light-emitting device comprising,

forming a first electrode;

forming a light emitting layer over the first electrode;

forming a second electrode over the light emitting layer;

forming a color filter at the second electrode side, and

wherein a reflectance of light emitted from said light emitting layer at the first electrode is 10% or less, and

wherein visible light having at least peak wavelength passes through the color filter.

41. The method according to claim 32, wherein the first electrode is formed by using a reflective material.

47. The method according to claim 32, wherein the second electrode is formed by using a light-transmitting material.

33. A method for manufacturing a light-emitting device comprising, forming a first electrode;

forming a light emitting layer over the first electrode;

forming a second electrode over the light emitting layer;

forming a color filter at the second electrode side, and

wherein a reflectance of light emitted from said light emitting layer at the first electrode is 10% or less,

wherein visible light having at least peak wavelength passes through the color filter, and

wherein the light emitting layer emits monochromatic light.

42. The method according to claim 33, wherein the first electrode is formed by using a reflective material.

48. The method according to claim 33, wherein the second electrode is formed by using a light-transmitting material.

34. A method for manufacturing a light-emitting device comprising,

forming a first electrode;

forming a electroluminescent layer having a light emitting layer and a layer including a metal oxide over the first electrode;

forming a second electrode over the light emitting layer;

forming a color filter at the second electrode side, and

wherein the layer including a metal oxide is formed so that a reflectance of light emitted from said light emitting layer at the first electrode is 10% or less,

wherein visible light having at least peak wavelength passes through the color filter, and

wherein the light emitting layer emits monochromatic light.

37. The method according to claim 34, wherein the layer of the electroluminescent layer is formed by using a layer including a metal oxide selected from the group consisting of a vanadium oxide, a molybdenum oxide, a niobium oxide, a rhenium oxide, a tungsten oxide, a ruthenium oxide, a titanium oxide, a chromium oxide, a zirconium oxide, a hafnium oxide, and a tantalum oxide.

43. The method according to claim 34, wherein the first electrode is formed by using a reflective material.

49. The method according to claim 34, wherein the second electrode is formed by using a light-transmitting material.