DEVICE HAVING SPACERS

• US 20080237612A1
• Filed: 03/29/2007
• Published: 10/02/2008
• Est. Priority Date: 03/29/2007
• Status: Active Grant

• Current Assignee: Nanoco Technologies Limited (Nanoco Group Plc)
• Original Assignee: Eastman Kodak Company
• Inventors: Cok, Ronald S.
• Granted Patent: US 7,564,067 B2
• Time in Patent Office: Days
• US Class Current: 257/88
• 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: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02557 Sulfides
• CPC Class Codes: H01L 21/0256 Selenides
• CPC Class Codes: H01L 21/02601 Nanoparticles fullerenes H10K85/211
• CPC Class Codes: H01L 21/02628 using solutions
• CPC Class Codes: H01L 33/18 within the light emitting region
• 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 50/8426 Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 50/8428 Vertical spacers, e.g. arranged between the sealing arrangement and the OLED
• CPC Class Codes: H10K 50/854 comprising scattering means
• CPC Class Codes: H10K 59/8722 Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 59/8723 Vertical spacers, e.g. arranged between the sealing arrangement and the OLED
• CPC Class Codes: H10K 59/877 comprising scattering means

Abstract

An electroluminescent device comprising: a substrate; one or more light-emitting elements formed over the substrate, the one or more light-emitting elements including first and second spaced-apart electrodes wherein at least one of the first and second electrodes is transparent and a light-emitting layer comprising quantum dots formed between the first and second electrodes; a cover located over the one or more light-emitting elements and spaced apart from the one or more light-emitting elements to form a gap between the cover and the one or more light-emitting elements; and separately formed spacer elements located in the gap between the cover and the one or more light-emitting elements and wherein the spacer elements are in physical contact with the one or more light-emitting elements, the cover, or both the one or more light-emitting elements and the cover.

Claims

1. An electroluminescent device comprising:

a substrate;

one or more light-emitting elements formed over the substrate, the one or more light-emitting elements including first and second spaced-apart electrodes wherein at least one of the first and second electrodes is transparent and a light-emitting layer comprising quantum dots formed between the first and second electrodes;

a cover located over the one or more light-emitting elements and spaced apart from the one or more light-emitting elements to form a gap between the cover and the one or more light-emitting elements; and

separately formed spacer elements located in the gap between the cover and the one or more light-emitting elements and wherein the spacer elements are in physical contact with the one or more light-emitting elements, the cover, or both the one or more light-emitting elements and the cover.

2. The electroluminescent device of claim 1, wherein the light-emitting layer is a polycrystalline inorganic light-emitting layer comprising core/shell quantum dots within an inorganic semiconductor matrix.

3. The electroluminescent device of claim 1, wherein the light-emitting layer is a hybrid light-emitting layer comprising core/shell quantum dots within an organic semiconductor matrix.

4. The electroluminescent device of claim 1, wherein the separately formed spacer elements are elastic compressible spacer elements.

5. The electroluminescent device of claim 1, wherein the separately formed spacer elements have a first average size and wherein the device further comprises separately formed light-scattering particles, wherein the light-scattering particles have a second average size smaller than the first average size, and are located in the gap, in contact with the one or more light-emitting elements and located between the spacer elements.

6. The electroluminescent device of claim 5, wherein the light-scattering particles and the spacer elements are deposited from a common dispersion.

7. The electroluminescent device of claim 1, wherein the first electrode lies over the substrate, the light-emitting layer lies over the first electrode on the side of the first electrode opposite the substrate, and the second electrode is the transparent electrode and lies over the light-emitting layer on the side of the light-emitting layer opposite the first electrode.

8. The electroluminescent device of claim 1, wherein further comprising light-scattering particles located on the transparent electrode on the side of the transparent electrode opposite the light-emitting layer.

9. The electroluminescent device of claim 1, wherein at least one of the electrodes is a patterned electrode defining independently controlled, spatially separated, light-emitting areas.

10. The electroluminescent device of claim 9, wherein the spacer elements are located in the light-emitting areas.

11. The electroluminescent device of claim 9, wherein the spacer elements are located between the light-emitting areas.

12. The electroluminescent device of claim 1, wherein the gap is maintained at a pressure of less than one atmosphere.

13. The electroluminescent device of claim 1, wherein the gap has an optical index lower than the optical index of any of the components of the one or more light-emitting elements.

14. The electroluminescent device of claim 1, wherein the spacer elements are selected from the group of titanium dioxide, polymer, barium oxide, calcium, and calcium oxide.

15. The electroluminescent device of claim 1, wherein the spacer elements are transparent.

16. The electroluminescent device of claim 1, wherein the spacer elements are affixed to the cover or to one or more light-emitting elements with an adhesive.

18. The electroluminescent device of claim 1, wherein the spacer elements are spherical, cylindrical, or randomly shaped particles.

19. The electroluminescent device of claim 1, wherein the spacer elements have a cross section greater than 1 micron.

20. The electroluminescent device of claim 1, wherein the spacer elements have a refractive index greater than the refractive index of any component of the light-emitting element.

17. The electroluminescent device of claim 17, wherein the adhesive is patterned.