TRANSPARENT CONDUCTIVE COATING WITH FILLER MATERIAL

• US 20110273085A1
• Filed: 12/19/2008
• Published: 11/10/2011
• Est. Priority Date: 12/20/2007
• Status: Active Grant

• Current Assignee: Clearview Films Limited
• Original Assignee: Cima NanoTech Israel Ltd. (Cima Nanotech, Inc.)
• Inventors: Granstrom, Eric L., Dela Vega, Fernando, Mangolini, Lorenzo, Garbar, Arkady
• Granted Patent: US 8,795,462 B2
• Time in Patent Office: Days
• US Class Current: 313/509
• CPC Class Codes: B32B 15/02 Layer formed of wires, e.g. mesh
• CPC Class Codes: H01B 1/22 the conductive material comprising metals or alloys
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 31/1884 Manufacture of transparent electrodes, e.g. TCO, ITO
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/42 Transparent materials
• CPC Class Codes: H05B 33/26 characterised by the composition or arrangement of the conductive material used as an electrode
• CPC Class Codes: H10K 30/83 comprising arrangements for extracting the current from the cell, e.g. metal finger grid systems to reduce the serial resistance of transparent electrodes
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 428/24876 Intermediate layer contains particulate material [e.g., pigment, etc.]
• CPC Class Codes: Y10T 428/24893 including particulate material

Abstract

An article is disclosed comprising a network-like pattern of conductive traces formed of at least partially-joined nanoparticles that define randomly-shaped cells that are generally transparent to light and contain a transparent filler material. In a preferred embodiment, the filler material is conductive such as a metal oxide or a conductive polymer. In another preferred embodiment, the filler material is an adhesive that is can be used to transfer the network from one substrate to another. A preferred method of forming the article is also disclosed wherein an emulsion containing the nanoparticles in the solvent phase and the filler material in the water phase is coated onto a substrate. The emulsion is dried and the nanoparticles self-assemble to form the traces and the filler material is deposited in the cells. An electroluminescent device is also disclosed wherein the article of the invention forms a transparent electrode in the device.

Claims

1. An article comprising a network-like pattern of conductive traces formed of at least partially-joined nanoparticles defining random-shaped cells generally transparent to light wherein at least a portion of the cells are at least partially filled with a transparent filler material.

2. The article of claim 1 wherein the filler material is conductive.

3. The article of claim 2 where the resistance of the filler material is in the range of 10² to 10⁸ ohm/sq.

4. The article of claim 2 wherein the filler material comprises a metal oxide.

5. The article of claim 4 wherein the metal oxide is indium tin oxide or antimony tin oxide.

6. The article of claim 2 wherein the filler material comprises a conductive polymer.

7. The article of claim 6 wherein the conductive polymer comprises, PEDOT, PEDOT:

PSS, polyaniline, polythiophenes, polyacetylene, polypyrrole, or derivatives or mixtures thereof.

8. The article of claim 2 wherein the filler material comprises carbon nanotubes or a low density matrix or array of metal nanoparticles or nanowires.

9. The article of claim 1 wherein the filler material is non-conductive or semi-conductive.

10. The article of claim 1 wherein the filler material is a high dielectric constant material.

11. The article of claim 9 wherein the filler material comprises an anti-reflective material.

12. The article of claim 11 wherein the antireflective material comprises glass frits, glass spheres, silicon nitrate, silicon monoxide, titanium dioxide or zinc oxide.

13. The article of claim 1 wherein such filler material is an adhesive.

14. The article of claim 12 wherein such adhesive comprises an epoxy or a UV curable acrylate.

15. The article of claim 1 wherein the filler material is abrasion resistant, scratch-resistant, moisture resistant, or any combination thereof.

16. The article of claim 1 further comprising at least one substrate layer covering one surface of the article.

17. The article of claim 16 wherein the article is flexible.

18. The article of claim 1 wherein the filler material completely fills the cells and extends above the cells.

19. The article of claim 1 wherein the filler material fills the cells to a level less than or equal to the top of the cells.

20. An electroluminescent device comprising the article of claim 1, a phosphor layer, a dielectric layer, and a counter electrode.

27. A process of forming the article of claim 1 comprising applying the liquid coating composition of claim 20 to the surface of a substrate and drying the coating composition.

28. The process of claim 27 further comprising a sintering step.

29. The process of claim 28 further comprising the step of removing the article from the substrate.

30. The process of claim 29 further comprising the step of applying the article to a second substrate.

31. A process of forming the article of claim 1 comprising:

a. applying a liquid emulsion comprising a continuous phase comprising conductive nanoparticles to the surface of a substrate;

b. drying the emulsion and subsequently forming a transparent conductive coating comprising a network-like pattern of traces formed of at least partially-joined nanoparticles defining randomly-shaped cells generally transparent to light and wherein at least a portion of the cells are filled with the filler material; and

c. applying a transparent filler material to at least partially fill at least some of the cells of the coating.

32. The process of claim 31 wherein the filler material is an adhesive.

33. The process of claim 32 further comprising the step of adhering a second substrate to the side of the article opposite the first substrate in contact with the adhesive.

34. The process of claim 33 further comprising the step of removing the first substrate from the article.

21. A liquid coating composition comprising an emulsion having a continuous phase comprising conductive nanoparticles and a discontinuous phase comprising a filler material, which emulsion, when coated onto a substrate, forms a transparent conductive coating comprising a network-like pattern of traces formed of at least partially-joined nanoparticles defining randomly-shaped cells generally transparent to light and wherein at least a portion of the cells are filled with the filler material.

22. The composition of claim 21 wherein the continuous phase comprises a solvent immiscible with water and the discontinuous phase comprises water or a water-miscible solvent.

23. The composition of claim 22 wherein the nanoparticles comprise silver, copper, carbon, graphite or mixtures or alloys thereof.

24. The composition of claim 22 wherein the filler material is conductive.

25. The composition of claim 24 wherein the filler material comprises a conductive polymer.

26. The composition of claim 25 wherein the conductive polymer is PEDOT, PEDOT:

PSS, polyaniline, polythiophenes, polyacetylene, polypyrrole, or derivatives or mixtures thereof.