Large-area transparent conductive coatings including alloyed carbon nanotubes and nanowire composites, and methods of making the same

• US 20110217455A1
• Filed: 03/04/2010
• Published: 09/08/2011
• Est. Priority Date: 03/04/2010
• Status: Active Grant

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Veerasamy, Vijayen S.
• Granted Patent: US 8,460,747 B2
• Time in Patent Office: Days
• US Class Current: 427/122
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3649 made of metals other than silver
• CPC Class Codes: C03C 2217/465 having a specific shape
• CPC Class Codes: C08K 3/041 Carbon nanotubes
• CPC Class Codes: C09D 1/00 Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances
• CPC Class Codes: C09D 11/52 Electrically conductive inks
• CPC Class Codes: C09D 11/54 Inks based on two liquids, one liquid being the ink, the other liquid being a reaction solution, a fixer or a treatment solution for the ink
• CPC Class Codes: C09D 5/24 Electrically-conducting paints conductive materials H01B1/00
• CPC Class Codes: C09D 7/62 modified by treatment with other compounds
• CPC Class Codes: C09D 7/70 characterised by shape, e.g. fibres, flakes or microspheres
• CPC Class Codes: H01L 21/288 from a liquid, e.g. electrolytic deposition
• CPC Class Codes: H01L 23/53276 containing carbon, e.g. fullerenes superconducting fullerenes H10N60/853
• 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 31/035227 the quantum structure being quantum wires, or nanorods carbon nanotubes H10K85/211
• CPC Class Codes: H10K 30/821 comprising carbon nanotubes
• CPC Class Codes: H10K 50/155 comprising dopants
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 59/8051 Anodes
• CPC Class Codes: H10K 85/221 : Carbon nanotubes
• CPC Class Codes: Y02E 10/549 : Organic PV cells
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

Certain example embodiments of this invention relate to large-area transparent conductive coatings (TCCs) including carbon nanotubes (CNTs) and nanowire composites, and methods of making the same. The σ_dc/σ_opt ratio of such thin films may be improved via stable chemical doping and/or alloying of CNT-based films. The doping and/or alloying may be implemented in a large area coating system, e.g., on glass and/or other substrates. In certain example embodiments, a CNT film may be deposited and then doped via chemical functionalization and/or alloyed with silver and/or palladium. Both p-type and n-type dopants may be used in different embodiments of this invention. In certain example embodiments, silver and/or other nanowires may be provided, e.g., to further decrease sheet resistance. Certain example embodiments may provide coatings that approach, meet, or exceed 90% visible transmission and 90 ohms/square target metrics.

Claims

1. A method of making a coated article comprising a substrate supporting a carbon nanotube (CNT) inclusive thin film, the method comprising:

providing a CNT-inclusive ink;

applying the ink to the substrate to form an intermediate coating;

providing a material over the intermediate coating to improve adhesion to the substrate;

preparing a solution of PdCl₂;

exposing the intermediate coating to the solution of PdCl₂ so that the Pd nucleates at junctions within the intermediate coating, thereby reducing porosity in the intermediate coating in forming the CNT-inclusive thin film; and

applying an overcoat or passivation layer over the intermediate coating following the exposing.

2. The method of claim 1, further comprising adjusting rheological properties of the CNT-inclusive ink by adding surfactants to the ink so that any semiconducting CNTs located within the ink are less likely to clump together.

3. The method of claim 2, further comprising using a slot die apparatus to apply the ink having the adjusted rheological properties to the substrate.

4. The method of claim 1, further comprising drying the intermediate coating or allowing the intermediate coating to dry.

5. The method of claim 1, wherein the material provided over the intermediate coating is PVP.

6. The method of claim 1, further comprising doping the intermediate coating so as to chemically functionalize the intermediate coating in forming the CNT-inclusive thin film.

7. The method of claim 1, wherein reducing porosity in the coating reduces sheet resistance.

8. The method of claim 7, wherein the sheet resistance is reduced while visible transmission remains relatively unchanged.

9. The method of claim 1, wherein the overcoat or passivation layer comprises PEDOT:

PSS, zirconia, a silicon-based thin film, a polymer, and/or a resins.

10. The method of claim 1, further comprising substantially planarizing the CNT-inclusive film to reduce surface roughness.

11. The method of claim 10, wherein the CNT-inclusive film is substantially planarized via the overcoat or passivation layer.

12. The method of claim 10, wherein the CNT-inclusive film is substantially planarized via deposition of an additional layer.

13. The method of claim 1, further comprising

providing a silvering solution;

and

exposing the intermediate coating to the silvering solution to short junctions in the intermediate coating.

14. The method of claim 13, wherein exposing of the intermediate coating to the silvering solution is performed after exposing the intermediate coating to the solution of PdCl₂.

15. The method of claim 1, further comprising

preparing a silvering solution by dissolving silver nitrate in deionized water;

and

exposing the intermediate coating to the silvering solution to short junctions in the intermediate coating.

16. The method of claim 15, wherein exposing of the intermediate coating to the silvering solution is performed after exposing the intermediate coating to the solution of PdCl₂.

17. A method of making a coated article comprising a substrate supporting a carbon nanotube (CNT) inclusive thin film, the method comprising:

providing a CNT-inclusive ink, the CNT-inclusive ink comprising double-wall nanotubes;

applying the ink to the substrate to form an intermediate coating using a slot die apparatus;

drying the intermediate coating or allowing the intermediate coating to dry;

providing an adhesion-promoting layer over the intermediate coating to improve adhesion to the substrate;

doping the intermediate coating with a salt and/or super acid so as to chemically functionalize the intermediate coating;

providing a solution of PdCl₂;

exposing the intermediate coating to the solution of PdCl₂ so that the Pd nucleates at junctions within the intermediate coating, thereby reducing porosity in the intermediate coating in forming the CNT-inclusive thin film; and

applying an overcoat or passivation layer over the intermediate coating following the exposing.

18. The method of claim 17, further comprising substantially planarizing the CNT-inclusive film.

19. The method of claim 17, further comprising

providing a silvering solution;

and

exposing the intermediate coating to the silvering solution to short junctions in the intermediate coating.

20. The method of claim 19, wherein exposing of the intermediate coating to the silvering solution is performed after exposing the intermediate coating to the solution of PdCl₂.

21. A method of making a coated article comprising a substrate supporting a carbon nanotube (CNT) inclusive thin film, the method comprising:

providing a CNT-inclusive ink, the CNT-inclusive ink comprising double-wall nanotubes;

applying the ink to the substrate to form an intermediate coating using a slot die apparatus;

drying the intermediate coating or allowing the intermediate coating to dry;

providing an adhesion-promoting layer over the intermediate coating to improve adhesion to the substrate;

providing a solution of PdCl₂;

exposing the intermediate coating to the solution of PdCl₂ so that the Pd nucleates at junctions within the intermediate coating, thereby reducing porosity in the intermediate coating;

providing a silvering solution;

exposing the intermediate coating to the silvering solution to short junctions in the intermediate coating in forming the CNT inclusive thin film; and

applying an overcoat or passivation layer over the intermediate coating following the exposing.

22. The method of claim 21, further comprising doping the intermediate coating with a salt and/or super acid so as to chemically functionalize the intermediate coating.

23. The method of claim 21, wherein exposure to the solution of PdCl₂ and silvering solutions is performed on a mirror line.