Stacked organic electroluminescent devices

• US 20050280359A1
• Filed: 06/18/2004
• Published: 12/22/2005
• Est. Priority Date: 06/18/2004
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: General Electric Company
• Inventors: Shiang, Joseph John, Liu, Jie, Duggal, Anil Raj
• Granted Patent: US 7,227,305 B2
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 59/8051 Anodes
• CPC Class Codes: H10K 59/8052 Cathodes
• CPC Class Codes: H10K 59/86 Series electrical configurations of multiple OLEDs

Abstract

A light-emitting device comprises a stack of organic electroluminescent (EL) elements, wherein an organic EL element in the stack overlaps at least a portion of another organic EL element, and the organic EL elements are electrically separate. Each of the organic EL elements of the stack is activated with a different level of voltage.

Claims

1. A light-emitting device comprises a plurality of organic EL elements arranged in a stack, wherein one organic EL element overlaps at least a portion of another organic EL element, and the organic EL elements are electrically separate.

2. The light-emitting device of claim 1, wherein each organic EL element is activated with a different voltage.

3. The light-emitting device of claim 1, wherein each organic EL element is activated with a different current.

4. The light-emitting device of claim 1, wherein each organic EL element comprises an organic EL material disposed between a pair of electrodes.

5. The light-emitting device of claim 1, wherein an organic EL material of one organic EL element is the same as an organic EL material of another organic EL element.

6. The light-emitting device of claim 1, wherein an organic EL material of one organic EL element is different from an organic EL material of another organic EL element.

7. The light-emitting device of claim 4, wherein one of the electrode comprises a material selected from the group consisting of indium tin oxide, tin oxide, indium oxide, zinc oxide, indium zinc oxide, zinc indium tin oxide, antimony oxide, carbon nanotubes, silver, gold, and mixtures thereof.

8. The light-emitting device of claim 4, wherein one of the electrode is a cathode and comprises a material selected from the group consisting of K, Li, Na, Mg, Ca, Sr, Ba, Al, Ag, Au, In, Sn, Zn, Zr, Sc, Y, elements of the lanthanide series, alloys thereof, mixtures thereof, Ag—

Mg alloy, Al—

Li alloy, In—

Mg alloy, Al—

Ca alloy, LiF, KF, and NaF.

9. The light-emitting device of claim 4, wherein one of the electrode is a cathode and comprises a material selected from the group consisting of indium tin oxide, tin oxide, indium oxide, zinc oxide, indium zinc oxide, zinc indium tin oxide, antimony oxide, carbon nanotubes, and mixtures thereof.

10. The light-emitting device of claim 9, wherein the cathode is a layer having a thickness from about 1 nm to about 10 nm.

11. The light-emitting device of claim 4, wherein the organic EL material comprises a material selected from the group consisting of poly(n-vinylcarbazole);

polyfluorene;

poly(alkylfluorene);

poly(praraphenylene);

poly(p-phenylene vinylene);

polythiophene;

poly(pyridine vinylene);

polyquinoxaline;

poly(quinoline); and

derivatives thereof.

12. The light-emitting device of claim 4, wherein the organic EL material comprises polysilane.

13. The light-emitting device of claim 12, wherein the polysilane is selected from the group consisting of poly(di-n-butylsilane), poly(di-n-pentylsilane), poly(di-n-hexylsilane), poly(methylphenylsilane), and poly{bis(p-butylphenyl)silane}.

14. The light-emitting device of claim 4, wherein the organic EL material comprises a material selected from the group consisting of organo-metallic complexes of 8-hydroxyquinoline, aluminum-acetylacetonate, gallium-acetylacetonate, and indium-acetylacetonate, aluminum-(picolymethylketone)-bis{2,6-di(t-butyl)phenoxide}, scandium-(4-methoxy-picolylmethylketone)-bis(acetylacetonate), and mixtures thereof.

15. The light-emitting device of claim 4, wherein each organic EL element in the stack is activated with a different voltage level.

16. A light-emitting device comprises a plurality of stacks of organic EL elements, wherein one organic EL element of a stack overlaps at least a portion of another organic EL element of the same stack, the organic EL elements of the same stack are electrically separate, one organic EL element of one stack is electrically connected in series to another organic EL element in an adjacent stack, and each organic EL element comprises an organic EL material disposed between a pair of electrodes.

17. The light-emitting device of claim 16, wherein organic EL elements of a stack emit different light colors.

18. The light-emitting device of claim 16, wherein organic EL elements that are electrically connected in series comprise the same organic EL material.

19. The light-emitting device of claim 16, wherein each series of organic EL element is activated with a different voltage level.

20. A method of making a light-emitting device, the method comprising disposing a plurality of organic EL elements in a stack such that one organic EL element of the stack overlaps with at least a portion of another organic EL element of the stack and such that the organic EL elements are electrically separate, wherein each organic EL element comprises an organic EL material disposed between a pair of electrodes.

21. A method of making a light-emitting device, the method comprising:

(a) providing a substrate;

(b) disposing a first organic EL element on the substrate;

(c) disposing an electrically non-conducting material on the first organic EL element;

(d) disposing a second organic EL element on the electrically non-conducting material;

wherein each organic EL element comprises an organic EL material sandwiched between a first electrode and a second electrode, and the electrically non-conducting material electrically separates the first and second organic EL elements.

22. The method of claim 21, wherein the step of disposing an organic EL element comprises:

(1) disposing a first electrically conducting material on an underlying layer;

(2) disposing an organic EL material on the first electrically conducting material; and

(3) disposing a second electrically conducting material on the organic EL material.

23. The method of claim 22;

wherein the step of disposing an electrically conducting material is effected by a method selected from the group consisting of physical vapor deposition, chemical vapor deposition, and sputtering, and the step of disposing an organic EL material is effected by a method selected from the group consisting of physical vapor deposition, chemical vapor deposition, spin coating, dip coating, spraying, ink-jet printing, gravure coating, flexo-coating, screen printing, and casting.

24. The method of claim 21, wherein the step of disposing an organic EL material is followed by a process selected from the group consisting of polymerizing and curing the organic EL material.

25. A method of generating light comprises providing an independent voltage to each organic EL element of a stack of plurality of organic EL elements, wherein one organic EL element of the stack overlaps with at least a portion of another organic EL element of the stack, the organic EL elements are electrically separate, and each organic EL element comprises an organic EL material disposed between a pair of electrodes.

26. A method of generating light comprises providing an independent current to each organic EL element of a stack of plurality of organic EL elements, wherein one organic EL element of the stack overlaps with at least a portion of another organic EL element of the stack, the organic EL elements are electrically separate, and each organic EL element comprises an organic EL material disposed between a pair of electrodes.