Light emitting device

• US 20040012331A1
• Filed: 04/04/2003
• Published: 01/22/2004
• Est. Priority Date: 04/05/2002
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kuwabara, Hideaki, Yamazaki, Shunpei
• Granted Patent: US 7,038,374 B2
• Time in Patent Office: Days
• US Class Current: 313/506
• CPC Class Codes: H10K 50/87 Arrangements for heating or cooling
• CPC Class Codes: H10K 59/8794 Arrangements for heating and cooling
• CPC Class Codes: H10K 85/146 poly N-vinylcarbazol; Derivatives thereof
• CPC Class Codes: H10K 85/60 Organic compounds having low molecular weight H10K85/10 - H10K85/50 take precedence
• CPC Class Codes: H10K 85/649 Aromatic compounds comprising a hetero atom
• CPC Class Codes: H10K 85/6565 Oxadiazole compounds

Abstract

When a light emitting element is actuated to allow the light emission, the generation of Joule heat occurs, leading to the decomposition or crystallization of an organic compound to cause the degradation of the light emitting device. Therefore, a light emitting element of the present invention is provided for effecting removing or decreasing the generation of heat. In the present invention, between two electrodes, layers having organic compounds and carbon-based thin films are alternatively laminated one after another for stepping down the driving voltage in the light emitting element using the tunnel effect. In addition, a carbon-based thin film is placed on a film containing an organic compound, so that it prevents the electric filed from being locally concentrated and also prevents the generation of short-circuit between the anode and the cathode.

Claims

1. A light emitting device comprising a plurality of light emitting elements over a substrate having an insulating surface, wherein each of the light emitting elements comprises:

a first electrode;

a first layer comprising an organic compound provided over the first electrode;

a first carbon-based thin film formed over the first layer;

a second layer comprising an organic compound formed over the first carbon-based thin film;

a second carbon-based thin film over the second layer;

a third layer comprising an organic compound formed over the second carbon-based thin film;

a third carbon-based thin film over the third layer;

a fourth layer comprising an organic compound formed over the third carbon-based thin layer;

a fifth organic layer comprising an organic compound formed over the fourth layer; and

a second electrode provided over the fifth layer comprising an organic layer.

5. A light emitting device according to claim 1, each of the carbon-based thin films is a diamond like carbon film or an amorphous carbon film.

11. A light emitting device according to claim 1, wherein the first layer comprising the organic compound or the fifth layer comprising the organic compound is a layer of transporting or injecting a hole, or a layer of transporting or injecting an electron.

15. A light emitting device according to claim 1, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates red illumination, a material that generates green illumination, or material that generates blue illumination.

20. A light emitting device according to claim 1, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates white illumination, and is combined with a color filter mounted over a sealing member.

25. A light emitting device according to claim 1, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates monochroic illumination, and is combined with a color changing layer or a coloring layer provided over the sealing member.

30. An electronic device having the light emitting device according to claim 1, wherein said electronic device is selected from the group consisting of a video camera, a digital camera, a goggles-type display, a car navigation system, a personal computer, a DVD player, an electronic game machine, or a portable information terminal.

2. A light emitting device comprising a plurality of light emitting elements over a substrate having an insulating layer, wherein each of the light emitting elements comprises:

a first electrode;

a first layer comprising an organic compound provided over the first electrode;

a second layer comprising an organic compound formed over the first layer;

a first carbon-based thin film formed over the second layer;

a third layer comprising an organic compound formed over the first carbon-based thin film;

a second carbon-based thin film formed over the third layer;

a fourth layer comprising an organic compound formed over the second carbon-based thin film;

a third carbon-based thin film formed over the fourth layer;

a fifth layer comprising the organic compound formed over the third carbon-based thin film; and

a second electrode provided over the fifth layer.

6. A light emitting device according to claim 2, each of the carbon-based thin films is a diamond like carbon film or an amorphous carbon film.

12. A light emitting device according to claim 2, wherein the first layer comprising the organic compound or the fifth layer comprising the organic compound is a layer of transporting or injecting a hole, or a layer of transporting or injecting an electron.

16. A light emitting device according to claim 2, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates red illumination, a material that generates green illumination, or material that generates blue illumination.

19. A light emitting device according to claim 6, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates red illumination, a material that generates green illumination, or material that generates blue illumination.

21. A light emitting device according to claim 2, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates white illumination, and is combined with a color filter mounted over a sealing member.

24. A light emitting device according to claim 6, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates white illumination, and is combined with a color filter mounted over a sealing member.

26. A light emitting device according to claim 2, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates monochroic illumination, and is combined with a color changing layer or a coloring layer provided over the sealing member.

29. A light emitting device according to claim 6, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates monochroic illumination, and is combined with a color changing layer or a coloring layer provided over the sealing member.

31. A light emitting device according to claim 2, wherein said electronic device is selected from the group consisting of a video camera, a digital camera, a goggles-type display, a car navigation system, a personal computer, a DVD player, an electronic game machine, or a portable information terminal.

34. A light emitting device according to claim 6, wherein the light emitting device is a video camera, a digital camera, a goggles-type display, a car navigation system, a personal computer, a DVD player, an electronic game machine, or a portable information terminal.

3. A light emitting device comprising a plurality of light emitting elements over a substrate having an insulating layer, wherein each of the light emitting elements comprises:

a first electrode;

a first layer comprising an organic compound provided over the first electrode;

a first carbon-based thin film formed over the first layer;

a second layer comprising an organic compound formed over the first carbon-based thin film;

a second carbon-based thin film formed over the second layer;

a third layer comprising an organic compound formed over the second carbon-based thin film;

a third carbon-based thin film formed over the third layer;

a fourth layer comprising an organic compound formed over the third carbon-based thin film;

a fourth carbon-based thin film formed over the fourth layer;

a fifth layer comprising an organic compound formed over the fourth carbon-based thin film; and

a second electrode provided over the fifth layer.

7. A light emitting device according to claim 3, each of the carbon-based thin films is a diamond like carbon film or an amorphous carbon film.

13. A light emitting device according to claim 3, wherein the first layer comprising the organic compound or the fifth layer comprising the organic compound is a layer of transporting or injecting a hole, or a layer of transporting or injecting an electron.

17. A light emitting device according to claim 3, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates red illumination, a material that generates green illumination, or material that generates blue illumination.

22. A light emitting device according to claim 3, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates white illumination, and is combined with a color filter mounted over a sealing member.

27. A light emitting device according to claim 3, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates monochroic illumination, and is combined with a color changing layer or a coloring layer provided over the sealing member.

32. A light emitting device according to claim 3, wherein said electronic device is selected from the group consisting of a video camera, a digital camera, a goggles-type display, a car navigation system, a personal computer, a DVD player, an electronic game machine, or a portable information terminal.

4. A light emitting device comprising a plurality of light emitting elements over a substrate having an insulating layer, wherein each of the light emitting elements comprises:

a first electrode;

a first layer comprising an organic compound provided over the first electrode;

a second layer comprising an organic compound formed over the first layer;

a first carbon-based thin film formed over the second layer;

a third layer comprising an organic compound formed over the first carbon-based thin film;

a second carbon-based thin film formed over the third layer;

a fourth layer comprising an organic compound formed over the second carbon-based thin layer;

a fifth layer comprising an organic compound formed over the fourth layer; and

a second electrode provided over the fifth layer.

8. A light emitting device according to claim 4, each of the carbon-based thin films is a diamond like carbon film or an amorphous carbon film.

14. A light emitting device according to claim 4, wherein the first layer comprising the organic compound or the fifth layer comprising the organic compound is a layer of transporting or injecting a hole, or a layer of transporting or injecting an electron.

18. A light emitting device according to claim 4, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates red illumination, a material that generates green illumination, or material that generates blue illumination.

23. A light emitting device according to claim 4, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates white illumination, and is combined with a color filter mounted over a sealing member.

28. A light emitting device according to claim 4, wherein the second layer comprising the organic compound, the third layer comprising the organic compound, or the forth layer comprising the forth organic compound comprises a material that generates monochroic illumination, and is combined with a color changing layer or a coloring layer provided over the sealing member.

33. A light emitting device according to claim 4, wherein the light emitting device is a video camera, a digital camera, a goggles-type display, a car navigation system, a personal computer, a DVD player, an electronic game machine, or a portable information terminal.

9. A light emitting device comprising a plurality of light emitting elements over a substrate having an insulating layer, wherein each of the light emitting elements comprises:

a first electrode;

a first layer comprising an organic compound provided over the first electrode;

a first conductive thin film comprising an organic material over the first layer;

a second layer comprising an organic compound over the first conductive thin film;

a second conductive thin film comprising an organic material over the second layer;

a third layer comprising an organic compound over the second conductive thin film;

a third conductive thin film comprising an organic material over the third layer;

a fourth layer comprising an organic compound over the third conductive thin film;

a fifth layer comprising an organic compound over the fourth layer; and

a second electrode provided over the fifth layer.

10. A light emitting device according to claim 9, wherein each of the conductive thin films comprising the organic materials is PEDOT.