Electronic Appliance and Light-Emitting Device

• US 20090251052A1
• Filed: 04/15/2009
• Published: 10/08/2009
• Est. Priority Date: 12/06/2004
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kawakami, Takahiro, Ikeda, Hisao, Sakata, Junichiro
• Granted Patent: US 7,999,460 B2
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1011 Condensed systems
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/1033 with oxygen
• CPC Class Codes: C09K 2211/1044 containing two nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/185 of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd
• CPC Class Codes: C09K 2211/188 of other metals not provided for in one of the previous groups
• CPC Class Codes: H10K 2102/3031 Two-side emission, e.g. transparent OLEDs [TOLED]
• CPC Class Codes: H10K 2102/331 Nanoparticles used in non-emissive layers, e.g. in packaging layer
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/171 Electron injection layers
• CPC Class Codes: H10K 59/10 OLED displays
• CPC Class Codes: H10K 59/173 comprising banks or shadow masks
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/351 comprising more than three subpixels, e.g. red-green-blue-white [RGBW]
• CPC Class Codes: H10K 59/353 characterised by the geometrical arrangement of the RGB subpixels
• CPC Class Codes: H10K 71/841 Applying alternating current [AC] during manufacturing or treatment
• CPC Class Codes: Y10S 428/917 : Electroluminescent

Abstract

An EL element having a novel structure is provided, which is suitable for AC drive. A light-emitting element of the invention is provided with material layers (material layers each having approximately symmetric I-V characteristics with respect to the zero point in a graph having the abscissa axis showing current values and the ordinate axis showing voltage values) between a first electrode and a layer including an organic compound and between the layer including the organic compound and a second electrode respectively. Specifically, each of the material layers is a composite layer including a metal oxide and an organic compound.

Claims

1-10. -10. (canceled)

11. A light-emitting device comprising:

a first electrode;

a first composite layer formed over the first electrode, the first composite layer including a first metal oxide and a first organic compound;

a light emitting layer comprising an organic material formed over the first composite layer;

a second composite layer formed over the light emitting layer, the second composite layer including a second metal oxide and a second organic compound;

a second electrode formed over the second composite layer; and

a power source for applying an AC voltage between the first electrode and the second electrode.

12. The light-emitting device according to claim 11,

wherein the first composite layer has symmetric current-voltage characteristics with respect to the zero point in a graph having the abscissa axis showing current values and the ordinate axis showing voltage values;

and

wherein the second composite layer has the same current-voltage characteristic as the first composite layer.

13. The light-emitting device according to claim 11, wherein the first metal oxide and the second metal oxide are the same material, and the first organic compound and the second organic compound are the same material.

14. The light-emitting device according to claim 11, wherein the light-emitting device is of a passive matrix type.

22. The light-emitting device according to claim 11, wherein the first metal oxide and the second metal oxide are one or more of molybdenum oxide, tungsten oxide and rhenium oxide.

23. The light-emitting device according to claim 11, wherein the first composite layer and the second composite layer have both a hole injection property and an electron injection property.

24. The light-emitting device according to claim 11, wherein the first composite layer and the second composite layer have both a hole transport property and an electron transport property.

25. The light-emitting device according to claim 11, wherein the light-emitting device is a lighting device.

26. The light-emitting device according to claim 11, further comprising a sealing substrate provided with a drying agent.

15. A driving method of a light-emitting device including a first electrode, a first composite layer formed over the first electrode, a light emitting layer comprising an organic material formed over the first composite layer, a second composite layer formed over the light emitting layer, and a second electrode formed over the second composite layer wherein the first composite layer includes a first metal oxide and a first organic compound and the second composite layer includes a second metal oxide and a second organic compound, the driving method comprising the step of:

applying an AC voltage between the first electrode and the second electrode of the light-emitting device.

16. The driving method of a light-emitting device according to claim 15,

wherein the first composite layer has symmetric current-voltage characteristics with respect to the zero point in a graph having the abscissa axis showing current values and the ordinate axis showing voltage values;

and

wherein the second composite layer has the same current-voltage characteristic as the first composite layer.

17. The driving method of a light-emitting device according to claim 15, wherein the first metal oxide and the second metal oxide are the same material, and the first organic compound and the second organic compound are the same material.

18. The driving method of a light-emitting device according to claim 15, wherein the light-emitting device is of a passive matrix type.

27. The driving method according to claim 15, wherein the first metal oxide and the second metal oxide are one or more of molybdenum oxide, tungsten oxide and rhenium oxide.

28. The driving method according to claim 15, wherein the first composite layer and the second composite layer have both a hole injection property and an electron injection property.

29. The driving method according to claim 15, wherein the first composite layer and the second composite layer have both a hole transport property and an electron transport property.

30. The driving method according to claim 15, wherein the light-emitting device is a lighting device.

31. The light-emitting device according to claim 15, further comprising a sealing substrate provided with a drying agent.

19. A light-emitting device comprising:

a first electrode disposed in a stripe form;

a first composite layer formed over the first electrode, the first composite layer including a first metal oxide and a first organic compound;

a light emitting layer comprising an organic material formed over the first composite layer;

a second composite layer formed over the light emitting layer, the second composite layer including a second metal oxide and a second organic compound;

a second electrode formed over the second composite layer, the second electrode being disposed in a stripe form perpendicular to the first electrode; and

a power source for applying an AC voltage between the first electrode and the second electrode,

wherein the first electrode is formed using a light-reflective conductive material; and

wherein the second electrode is formed using a light-transmissive conductive material.

20. The light-emitting device according to claim 19,

wherein the first composite layer has symmetric current-voltage characteristics with respect to the zero point in a graph having the abscissa axis showing current values and the ordinate axis showing voltage values;

and

wherein the second composite layer has the same current-voltage characteristic as the first composite layer.

21. The light-emitting device according to claim 19, wherein the first metal oxide and the second metal oxide are the same material, and the first organic compound and the second organic compound are the same material.

32. The light-emitting device according to claim 19, wherein the first metal oxide and the second metal oxide are one or more of molybdenum oxide, tungsten oxide and rhenium oxide.

33. The light-emitting device according to claim 19, wherein the first composite layer and the second composite layer have both a hole injection property and an electron injection property.

34. The light-emitting device according to claim 19, wherein the first composite layer and the second composite layer have both a hole transport property and an electron transport property.

35. The light-emitting device according to claim 19, wherein the light-emitting device is a lighting device.

36. The light-emitting device according to claim 19, further comprising a sealing substrate provided with a drying agent.