Organic electroluminescent device

• US 10,217,967 B2
• Filed: 05/30/2018
• Issued: 02/26/2019
• Est. Priority Date: 03/26/2002
• Status: Expired due to Term

• Current Assignee: Junji Kido, Mitsubishi Heavy Industries, Ltd., ROHM Co., Ltd.
• Original Assignee: Junji Kido, Mitsubishi Heavy Industries, Ltd., ROHM Co., Ltd.
• Inventors: Kido, Junji, Matsumoto, Toshio
• Primary Examiner(s): Luu, Chuong A
• Application Number:
  US15/993,493
• Publication Number:
  US 20180351134A1
• Time in Patent Office: 272 Days
• Field of Search: 257 40
• CPC Class Codes: C07C 211/58 Naphthylamines; N-substituted derivatives thereof
• CPC Class Codes: C07C 211/61 with at least one of the condensed ring systems formed by three or more rings
• CPC Class Codes: C07C 2603/18 Fluorenes; Hydrogenated fluorenes
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1003 Carbocyclic compounds
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1011 Condensed systems
• CPC Class Codes: C09K 2211/1014 bridged by heteroatoms, e.g. N, P, Si or B
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/131 with spacer layers between the electroluminescent layers
• CPC Class Codes: H10K 50/15 Hole transporting layers
• CPC Class Codes: H10K 50/16 Electron transporting layers
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/171 Electron injection layers
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/865 comprising light absorbing layers, e.g. light-blocking layers
• CPC Class Codes: H10K 59/875 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 71/00 : Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 71/40 : Thermal treatment, e.g. annealing in the presence of a solvent vapour
• CPC Class Codes: H10K 85/60 : Organic compounds having low molecular weight H10K85/10 - H10K85/50 take precedence
• CPC Class Codes: H10K 85/624 : containing six or more rings
• CPC Class Codes: H10K 85/626 : containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene
• CPC Class Codes: H10K 85/633 : comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree

Abstract

An organic electroluminescent device includes at least two light-emissive units provided between a cathode electrode and an anode electrode opposed to the cathode electrode, each of the light-emissive units including at least one light-emissive layer. The light-emissive units are partitioned from each other by at least one charge generation layer, the charge generation layer being an electrically insulating layer having a resistivity of not less than 1.0×10² Ωcm.

Claims

1. A display device comprising an organic electroluminescent element comprising a plurality of light emissive units, each of which has at least one light emissive layer, provided between a first electrode and a second electrode opposed to said first electrode,

wherein said light emissive units are partitioned from each other by at least one charge generation layer,

wherein said charge generation layer comprises an electron accepting material and an electron donating material and has a resistivity of not less than 1.0×

10² Ω

cm,

wherein the organic electroluminescent element is configured to emit light from an area where the first electrode and the second electrode are vertically superimposed, and

wherein the area comprises a plurality of areas, each of the plurality of areas corresponding to pixels of the display device.

2. The display device according to claim 1, wherein said charge generation layer has a resistivity of not less than 1.0×

10⁵ Ω

cm.

3. The display device according to claim 1, wherein said charge generation layer comprises a laminated layer of said electron accepting material and said electron donating material.

4. The display device according to claim 1, wherein said charge generation layer comprises a mixed layer of said electron accepting material and said electron donating material.

5. The display device according to claim 1, wherein said light emissive layer contains a fluorescent material or a phosphorescent material.

6. The display device according to claim 1, wherein a plurality of said light-emissive units have mutually different emission spectrums.

7. The display device according to claim 6, wherein said organic electroluminescent element is configured to emit white light due to superimposing of different emission spectrums of each light-emissive unit.

8. The display device according to claim 1, wherein said charge generation layer has a visible light transmittance of not less than 50%.

9. The display device according to claim 1, wherein said organic electroluminescent element is configured to emit light only from where the area where said first electrode and said second electrode are vertically superimposed.

10. The display device according to claim 1, wherein said electron donating material comprises an arylamine compound, wherein said arylamine compound is represented by the following formula (I):

11. The display device according to claim 10, wherein said arylamine compound has a glass transition temperature of not lower than 90°

C.

12. The display device according to claim 10, wherein said arylamine compound has an ionization potential of less than 5.7 eV.

13. The display device according to claim 1, wherein said electron accepting material comprises an organic material having at least one cyano group or fluorine group.

14. The display device according to claim 1, wherein said electron accepting material comprises an organic material having both at least one cyano group and at least one fluorine group.

15. The display device according to claim 1, wherein said first electrode comprises an anode selected from ITO (indium tin oxide) or IZO (indium zinc oxide).

16. The display device according to claim 15, wherein said second electrode comprises a cathode selected from ITO (indium tin oxide) or IZO (indium zinc oxide).

17. The display device according to claim 15, wherein said second electrode comprises a cathode selected from Al (aluminum) or Ag (silver).

18. The display device according to claim 1, wherein said organic electroluminescent element comprises an electron injection layer as a layer that contacts with said charge generation layer on the side of said first electrode, and wherein said electron injection layer comprises an organic material and an electron donating dopant.

19. The display device according to claim 18, wherein a thickness of said electron injection layer is less than 5 nm.

20. The display device according to claim 1, wherein said organic electroluminescent element comprises a hole injection layer as a layer that contacts with said charge generation layer on the side of said second electrode, and wherein said hole injection layer comprises an organic material and an electron accepting dopant.

21. The display device according to claim 20, wherein the thickness of said hole injection layer is less than 30 nm.

22. The display device according to claim 1, wherein the first electrode and the second electrode are both in the form of a strip.

23. The display device according to claim 22, wherein the first electrode and the second electrode are crossed, thereby forming the area where the first electrode and the second electrode are vertically superimposed.

24. A method of emitting light from a device comprising applying a voltage to an organic electroluminescent element within the device, wherein the electroluminescent element comprising a plurality of light emissive units, each of which has at least one light emissive layer, provided between a first electrode and a second electrode opposed to said first electrode,

wherein said light emissive units are partitioned from each other by at least one charge generation layer,

wherein said charge generation layer comprises an electron accepting material and an electron donating material and has a resistivity of not less than 1.0×

10² Ω

cm,

wherein the organic electroluminescent element is configured to emit light from an area where the first electrode and the second electrode are vertically superimposed, and

wherein the area comprises a plurality of areas, each of the plurality of areas corresponding to pixels of the display device.

25. The method of claim 24, wherein the charge generation layer has a resistivity of not less than 1.0×

10⁵ Ω

cm.

26. The method of claim 24, wherein the charge generation layer comprises a laminated layer of said electron accepting material and said electron donating material.

27. The method of claim 24, wherein the first electrode and the second electrode are both in the form of a strip.

28. The method of claim 24, wherein the first electrode and the second electrode are crossed, thereby forming the area where the first electrode and the second electrode are vertically superimposed.