Light emitting element and producing method thereof, and display device and lighting device using the same

• US 6,910,933 B1
• Filed: 10/05/2000
• Issued: 06/28/2005
• Est. Priority Date: 10/05/1999
• Status: Expired due to Term

• Current Assignee: JOLED Inc.
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Sato, Tetsuya, Matsuo, Mikiko, Sugiura, Hisanori, Hisada, Hitoshi
• Primary Examiner(s): Santiago, Mariceli
• Application Number:
  US09/857,424
• Time in Patent Office: 1,727 Days
• Field of Search: 313/502, 313/503, 313/504, 313/506, 313/509, 428/690, 427/66
• US Class Current: 445/24
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/14 Carrier transporting layers
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/171 Electron injection layers
• CPC Class Codes: H10K 59/17 Passive-matrix OLED displays
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 71/13 using printing techniques, e.g. ink-jet printing or screen printing

Abstract

An organic light-emitting device 10 has the constitution in which an emission region 3 between an anode 2 and a cathode 4 is laminated on a substrate 1. The emission region 3 includes polymer 3A, luminous molecules 3G which are material contributable to emission, and charge transport material 3F.

The luminous molecules 3G and the charge transport material 3F are high in concentration at a side close to the cathode 4 and low in concentration at a side close to the anode 2 in a layer thickness direction of the emission region 3. The organic light-emitting device can be formed by luminous material, or luminous material and charge transport material being penetrated into polymer, or polymer in which charge transport material is dispersed, thus providing highly improved luminous efficiency and at the same time facilitating the patterning.

Claims

1. A light-emitting device, comprising:

an anode and a cathode having an emission region therebetween,

wherein the emission region comprises material contributable to emission and a medium for containing the material, wherein the material contributable to the emission has a substantially successive distribution of concentration from the anode side of the emission region toward the cathode side thereof, and

wherein a part of the emission region that exhibits a maximum concentration of the material contributable to the emission is away from the anode and the cathode.

2. The light-emitting device as set forth in claim 1, wherein the emission region further comprises charge transport material.

3. The light-emitting device as set forth in claim 2, wherein the charge transport material has a substantially successive distribution of concentration from the anode side of the emission region toward the cathode side thereof.

4. The light-emitting device as set forth in claim 1, wherein the emission region comprises, at the side of the emission region near the anode or the cathode, a region where the material contributable to the emission is not present.

5. A lighting device comprising in combination therewith the light-emitting device as set forth in claim 1.

6. A light-emitting device, comprising:

an anode and a cathode having a charge transport region therebetween,

wherein the charge transport region comprises charge transport material and a medium for containing the charge transport material wherein the charge transport material has a substantially successive distribution of concentration from the cathode side of the charge transport region toward the anode side thereof, and

wherein a part of the charge transport region that exhibits a maximum concentration of the charge transport material is away from the anode and the cathode.

7. The light-emitting device as set forth in claim 6, wherein the charge transport region comprises, at the side of the emission region near the anode or the cathode, a region where the charge transport material is not present.

8. A light-emitting device, comprising:

an anode and a cathode having an emission region therebetween,

wherein the emission region comprises material contributable to emission and a medium for containing the material, and

wherein the material contributable to the emission has a distribution of concentration that reduces substantially successively in a direction parallel to a surface of the cathode and a surface of the anode from a substantially center of the emission region toward a periphery thereof.

9. The light-emitting device as set forth in claim 8, wherein said material contributable to emission is a plurality of materials contributable to emission adjacently arranged in a direction parallel to a surface of the cathode and a surface of the anode, wherein each of the plurality of materials contributable to emission is different in luminous color from others of said plurality of materials.

10. The light-emitting device as set forth in claim 8, wherein the emission region further comprises charge transport material.

11. The light-emitting device as set forth in claim 10, wherein the charge transport material has a distribution of concentration that reduces in the direction parallel to the surface of the cathode and the surface of the anode from the substantially center of the emission region toward the periphery thereof.

12. The light-emitting device as set forth in claim 11, wherein the charge transport material has a substantially successive distribution of concentration from the cathode side of the emission region toward the anode side thereof.

13. The light-emitting device as set forth in claim 8, wherein the material contributable to the emission has a substantially successive distribution of concentration from the cathode side of the emission region toward the anode side thereof.

14. The light-emitting device as set forth in claim 8, wherein the emission region includes a region where the material contributable to the emission is not present.

15. The light-emitting device as set forth in claim 8, wherein the medium for containing the material contributable to the emission has charge transport capabilities.

16. The light-emitting device as set forth in claim 8, wherein the medium for containing the material contributable to the emission comprises organic material.

17. The light-emitting device as set forth in claim 8, wherein the medium comprises a polymer.

18. A display comprising in combination therewith the light-emitting device as set forth in claim 8.

19. A method of producing a light-emitting device having an emission region between an anode and a cathode, the method comprising:

locating a medium on the anode or the cathode;

and containing material contributable to emission and charge transport material in the medium;

wherein said containing comprises penetrating the material contributable to the emission and the charge transport material into the medium, so that said materials are contained in the medium.

20. A method of producing a light-emitting device having an emission region between an anode and a cathode, the method comprising:

locating a medium on the anode or the cathode;

and containing material contributable to emission and charge transport material in the medium;

wherein said containing comprises bringing a solution comprising the material contributable to the emission and the charge transport material dissolved in solvent into contact with the medium, so that the materials are penetrated into the medium.

25. A display comprising in combination therewith the light-emitting device as set forth in claim 20.

21. A light-emitting device, comprising:

an anode and a cathode having an emission region therebetween,

wherein the emission region comprises material contributable to emission and a medium comprising organic material for containing the material,

wherein at least one of an anode side of the emission region and a cathode side thereof is porous, and

wherein the material contributable to emission is collected and included in a surface of the emission region which is porous.

22. The light-emitting device as set forth in claim 21, wherein charge transport material is included in a surface of the emission region which is porous.

23. The light-emitting device as set forth in claim 21, wherein a leveled layer comprising charge transport material is located on a surface of the emission region which is porous.

24. The light-emitting device as set forth in claim 21, wherein the emission region comprises a polymer.

26. A lighting device comprising in combination therewith the light-emitting device as set forth in claim 21.

27. A light-emitting device, comprising:

an anode and a cathode having an emission region therebetween,

wherein the emission region comprises material contributable to emission and a medium comprising organic material for containing the material,

wherein at least one of an anode side of the emission region and a cathode side thereof is porous, and

wherein the material contributable to emission is collected and included in a region in the vicinity of a surface of the emission region which is porous.

28. A light-emitting device, comprising:

an anode and a cathode having a charge transport region therebetween,

wherein the charge transport region comprises material contributable to emission and a medium comprising organic material for containing the material, and

wherein at least one of an anode side of the charge transport region and a cathode side thereof is porous.

29. The light-emitting device as set forth in claim 28, wherein the charge transport region is a hole transport region.

30. The light-emitting device as set forth in claim 28, wherein the charge transport region is an electron transport region.

31. A light-emitting device, comprising:

an anode and a cathode having an emission region therebetween,

wherein the emission region comprises material contributable to emission and a medium comprising organic material for containing the material,

wherein at least one of an anode side of the emission region and a cathode side thereof is a roughened side, and

wherein the material contributable to emission is collected and included in a surface of the roughened emission region.

32. The light-emitting device as set forth in claim 31, wherein a leveled layer comprising charge transport material is provided on a roughened surface of the emission region.

33. The light-emitting device as set forth in claim 31, wherein the emission region comprises a polymer.

34. A light-emitting device, comprising:

an anode and a cathode having an emission region therebetween,

wherein the emission region comprises material contributable to emission and a medium comprising organic material for containing the material,

wherein at least one of an anode side of the emission region and a cathode side thereof is a roughened side, and

wherein the material contributable to emission is collected and included in a region in the vicinity of a roughened surface of the emission region.

35. A light-emitting device, comprising:

an anode and a cathode having a charge transport region therebetween,

wherein the charge transport region comprises material contributable to emission and a medium comprising organic material for containing the material, and

wherein at least one of an anode side of the charge transport region and a cathode side thereof is a roughened side.

36. The light-emitting device as set forth in claim 35, wherein the charge transport region is a hole transport region.

37. The light-emitting device as set forth in claim 35, wherein the charge transport region is an electron transport region.

38. A method of producing a light-emitting device having an emission region between an anode and a cathode, the method comprising:

locating a medium comprising organic material on the anode or the cathode; and

making at least a part of the medium comprising organic material porous.

39. A method of producing a light-emitting device having an emission region between an anode and a cathode, the method comprising:

locating a medium comprising organic material on the anode or the cathode;

making at least one of an anode side of the medium comprising organic material and a cathode side thereof porous; and

locating material contributable to emission on a porous surface of the medium comprising organic material, so that the emission region is formed by the medium and the material contributable to the emission.

40. The method of producing a light-emitting device as set forth in claim 39, further comprising locating charge transport material on a porous surface of the emission region.

41. The method of producing a light-emitting device as set forth in claim 39, further comprising forming a leveled layer comprising charge transport material on the emission region.

42. The method of producing a light-emitting device as set forth in claim 39, comprising locating a medium containing material soluble in a specified solvent, and eluting the soluble material from the solvent to thereby make the medium porous.

43. A method of producing a light-emitting device having an emission region between an anode and a cathode, the method comprising:

locating a medium comprising organic material on the anode or the cathode;

making at least one of an anode side of the medium comprising organic material and a cathode side thereof porous;

containing material contributable to emission in a region in the vicinity of a porous surface of the medium comprising organic material, so that the emission region is formed by the medium and the material contributable to the emission; and

locating charge transport material on a porous surface of the medium.

44. A method of producing a light-emitting device having an emission region between an anode and a cathode, the method comprising:

locating a medium comprising organic material on the anode or the cathode; and

roughening a part of the medium comprising organic material.

45. A method of producing a light-emitting device having an emission region between an anode and a cathode, the method comprising:

locating a medium comprising organic material on the anode or the cathode;

roughening at least one of an anode side of the medium comprising organic material and a cathode side thereof; and

locating material contributable to emission on a roughened surface of the medium comprising organic material, so that the emission region is formed by the medium and the material contributable to the emission.

46. The method of producing a light-emitting device as set forth in claim 45, further comprising forming a leveled layer comprising charge transport material on the emission region.

47. The method of producing a light-emitting device as set forth in claim 45, comprising roughening the emission region by dry etching.

48. A method of producing a light-emitting device having an emission region between an anode and a cathode, the method comprising:

locating a medium comprising organic material on the anode or the cathode;

roughening at least one of an anode side of the medium comprising organic material and a cathode side thereof; and

containing material contributable to emission in a region in the vicinity of a roughened surface of the medium comprising organic material, so that the emission region is formed by the medium and the material contributable to the emission.