Organic electroluminescent device

• US 8,154,193 B2
• Filed: 10/30/2007
• Issued: 04/10/2012
• Est. Priority Date: 08/09/2002
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Tsutsui, Tetsuo
• Primary Examiner(s): Patel, Ashok
• Application Number:
  US11/928,036
• Publication Number:
  US 20080150420A1
• Time in Patent Office: 1,624 Days
• Field of Search: None
• US Class Current: 313/504
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/13 comprising stacked EL layers within one EL unit
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/18 Carrier blocking layers
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 71/841 Applying alternating current [AC] during manufacturing or treatment
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

An organic electroluminescence device of the present invention adapts a new concept in its configuration to improve its efficiency in addition to obtain a high reliability and good yielding. The organic electroluminescent device having an electroluminescent film containing an organic material capable of causing an electroluminescence and being arranged between a first electrode and a second electrode, includes: a carrier generation layer, which is a floating electrode, is embodied in the electroluminescent film; an insulting film between the first electrode and the electroluminescent film, and an insulating film between the second electrode and the electroluminescent film, wherein the organic electroluminescent device is driven by an alternating current bias.

Claims

1. An organic electroluminescent device comprising:

a first electrode;

a second electrode; and

an electroluminescent film containing an organic compound capable of causing an electroluminescence and being provided between the first electrode and the second electrode,

wherein a carrier generation layer is embodied in the electroluminescent film, the carrier generation layer being a floating electrode,

wherein a first insulating film is provided between the first electrode and the electroluminescent film,

wherein a second insulating film is provided between the second electrode and the electroluminescent film,

wherein the carrier generation layer comprises a conductive film, a first electron injection region on the conductive film, a second electron injection region under the conductive film,

wherein the conductive film is in contact with the first and second electron injection regions.

2. The organic electroluminescent device according to claim 1,

wherein the electroluminescent film comprises a layer having bipolar property.

3. The organic electroluminescent device according to claim 1,

wherein the organic electroluminescent device is configured to be driven by an alternating current bias.

4. The organic electroluminescent device according to claim 3,

wherein a waveform of the alternating current bias is selected from a sine wave, a square wave, and a triangle wave.

5. The organic electroluminescent device according to claim 1,

wherein the carrier generation layer has an electric conductivity of 10¹⁰ S/m or more.

6. The organic electroluminescent device according to claim 1,

wherein a drive frequency of the organic electroluminescent device is in a range of 1 to 100 kHz.

7. The organic electroluminescent device according to claim 1,

wherein the first and second electron injection regions are cluster-like.

8. The organic electroluminescent device according to claim 1,

wherein parts of top and upper surfaces of the conductive film are in contact with the electroluminescent film.

9. The organic electroluminescent device according to claim 1, wherein the first and second electron injection regions comprise one selected from the group consisting of Al:

Li, Ca, and LiF.

10. The organic electroluminescent device according to claim 1, wherein the first and second insulating films prevent a carrier injection from the first and second electrodes to the electroluminescent film, respectively.

11. A display device comprising the organic electroluminescent device according to claim 1.

12. An organic electroluminescent device comprising:

a first electrode;

a second electrode; and

an electroluminescent film containing an organic compound capable of causing an electroluminescence and being provided between the first electrode and the second electrode,

wherein a carrier generation layer is embodied in the electroluminescent film, the carrier generation layer being a floating electrode,

wherein a first insulating film is provided between the first electrode and the electroluminescent film,

wherein a second insulating film is provided between the second electrode and the electroluminescent film, and

wherein the carrier generation layer comprises a conductive film, a first hole injection region on the conductive film, a second hole injection region under the conductive film,

wherein the conductive film is in contact with the first and second hole injection regions.

13. The organic electroluminescent device according to claim 12, wherein the electroluminescent film comprises a layer having bipolar property.

14. The organic electroluminescent device according to claim 12, wherein the organic electroluminescent device is configured to be driven by an alternating current bias.

15. The organic electroluminescent device according to claim 14, wherein a waveform of the alternating current bias is selected from a sine wave, a square wave, and a triangle wave.

16. The organic electroluminescent device according to claim 12, wherein the carrier generation layer has an electric conductivity of 10⁻

10 S/m or more.

17. The organic electroluminescent device according to claim 12, wherein a drive frequency of the organic electroluminescent device is in a range of 1 to 100 kHz.

18. The organic electroluminescent device according to claim 12, wherein the first and second hole injection regions are cluster-like.

19. The organic electroluminescent device according to claim 16, wherein parts of top and upper surfaces of the conductive film are in contact with the electroluminescent film.

20. The organic electroluminescent device according to claim 12, wherein the first and second hole injection regions comprise one selected from the group consisting of Au and ITO.

21. The organic electroluminescent device according to claim 12, wherein the first and second insulating films prevent a carrier injection from the first and second electrodes to the electroluminescent film, respectively.

22. A display device comprising the organic electroluminescent device according to claim 12.

23. A lighting comprising an organic electroluminescent device:

the organic electroluminescent device comprising;

a first electrode;

a second electrode; and

an electroluminescent film containing an organic compound capable of causing an electroluminescence and being provided between the first electrode and the second electrode,

wherein a carrier generation layer is embodied in the electroluminescent film, the carrier generation layer being a floating electrode,

wherein a first insulating film is provided between the first electrode and the electroluminescent film,

wherein a second insulating film is provided between the second electrode and the electroluminescent film, and

wherein the carrier generation layer comprises a conductive film, a first electron injection region on the conductive film, a second electron injection region under the conductive film,

wherein the conductive film is in contact with the first and second electron injection regions.

24. The lighting according to claim 23, wherein the electroluminescent film comprises a layer having bipolar property.

25. The lighting according to claim 23, wherein the organic electroluminescent device is configured to be driven by an alternating current bias.

26. The lighting according to claim 25, wherein a waveform of the alternating current bias is selected from a sine wave, a square wave, and a triangle wave.

27. The lighting according to claim 23, wherein the carrier generation layer has an electric conductivity of 10⁻

10 S/m or more.

28. The lighting according to claim 23, wherein a drive frequency of the organic electroluminescent device is in a range of 1 to 100 kHz.

29. The lighting according to claim 23, wherein the first and second electro injection regions are cluster-like.

30. The lighting according to claim 23, wherein parts of top and upper surfaces of the conductive film are in contact with the electroluminescent film.

31. The lighting according to claim 23, wherein the first and second electron injection regions comprise one selected from the group consisting of Al:

Li, Ca, and LiF.

32. The lighting according to claim 23, wherein the first and second insulating films prevent a carrier injection from the first and second electrodes to the electroluminescent film, respectively.

33. The lighting according to claim 23, wherein the lighting is configured to emit white light.

34. A lighting comprising an organic electroluminescent device:

the organic electroluminescent device comprising;

a first electrode;

a second electrode; and

an electroluminescent film containing an organic compound capable of causing an electroluminescence and being provided between the first electrode and the second electrode,

wherein a carrier generation layer is embodied in the electroluminescent film, the carrier generation layer being a floating electrode,

wherein a first insulating film is provided between the first electrode and the electroluminescent film,

wherein a second insulating film is provided between the second electrode and the electroluminescent, and

wherein the carrier generation layer comprises a conductive film, a first hole injection region on the conductive film, a second hole injection region under the conductive film, wherein the conductive film is in contact with the first and second hole injection regions.

35. The lighting according to claim 34, wherein the electroluminescent film comprises a layer having bipolar property.

36. The lighting according to claim 34, wherein the organic electroluminescent device is configured to be driven by an alternating current bias.

37. The lighting according to claim 36, wherein a waveform of the alternating current bias is selected from a sine wave, a square wave, and a triangle wave.

38. The lighting according to claim 34, wherein the carrier generation layer has an electric conductivity of 10⁻

10 S/m or more.

39. The lighting according to claim 34, wherein a drive frequency of the organic electroluminescent device is in a range of 1 to 100 kHz.

40. The lighting according to claim 34, wherein the first and second hole injection regions are cluster-like.

41. The lighting according to claim 34, wherein parts of top and upper surfaces of the conductive film are in contact with the electroluminescent film.

42. The lighting according to claim 34, wherein the first and second hole injection regions comprise one selected from the group consisting of Au and ITO.

43. The lighting according to claim 34, wherein the first and second insulating films prevent a carrier injection from the first and second electrodes to the electroluminescent film, respectively.

44. The lighting according to claim 34, wherein the lighting is configured to emit white light.