PROCESS FOR FORMING OPTICALLY CLEAR CONDUCTIVE METAL OR METAL ALLOY THIN FILMS AND FILMS MADE THEREFROM

• US 20120125660A1
• Filed: 07/26/2010
• Published: 05/24/2012
• Est. Priority Date: 08/03/2009
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Bright, Clark I.
• Granted Patent: US 9,012,044 B2
• Time in Patent Office: Days
• US Class Current: 174/126.4
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3644 the metal being silver
• CPC Class Codes: C03C 17/366 Low-emissivity or solar control coatings
• CPC Class Codes: C03C 17/3676 specially adapted for use as electromagnetic shield
• CPC Class Codes: C22C 5/06 Alloys based on silver
• CPC Class Codes: C23C 14/024 Deposition of sublayers, e.g. to promote adhesion of the coating C23C14/027 takes precedence
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: C23C 14/20 on organic substrates
• CPC Class Codes: C23C 14/562 for coating elongated substrates
• CPC Class Codes: H05K 9/0094 being light-transmitting, e.g. transparent, translucent

Abstract

A process of forming optically clear conductive metal or metal alloy thin films is provided that includes depositing the metal or metal alloy film on a polycrystalline seed layer that has been deposited directly on a nucleation layer of metal oxide comprising zinc oxide. Also conductive films made by this process are provided. In some embodiments, the metal alloy thin films include silver/gold alloys.

Claims

1. A method for forming an optically clear thin conductive film on a support comprising:

providing a layer of metal oxide adjacent to a transparent support;

forming a polycrystalline seed layer comprising zinc oxide directly upon the metal oxide layer;

depositing a first conductive metal or metal alloy layer directly upon the polycrystalline seed layer; and

depositing a barrier layer directly upon the metal or metal alloy layer.

2. A method according to claim 1, further comprising vapor coating a first polymeric material upon the support.

3. A method according to claim 1, wherein the metal oxide comprises tin oxide.

4. A method according to claim 1, wherein the polycrystalline seed layer further comprises aluminum oxide.

5. A method according to claim 1, wherein the first conductive metal or metal alloy comprises silver or gold.

6. A method according to claim 1, wherein the film has at least 80% optical transmittance of visible light at 550 nm.

7. A method according to claim 1, wherein the film has a sheet resistance of less than about 100 ohms/square resistance.

8. A method according to claim 1, further comprising:

depositing a second metal oxide layer adjacent to the barrier layer;

forming a second polycrystalline seed layer comprising zinc oxide upon the second metal oxide layer;

depositing a second conductive metal or metal alloy layer directly upon the second metal oxide layer; and

depositing a barrier layer directly upon the second conductive metal or metal alloy layer.

9. A method according to claim 8, comprising depositing a polymeric spacing layer between the first metal or metal alloy layer and the second metal or metal alloy layer to provide an infrared-rejecting Fabry-Perot stack.

10. A method according to claim 9, wherein the thickness of the polymeric spacing layer is from about 1 nm to about 5 nm.

11. An optically clear conductive film comprising:

a transparent support;

a layer of metal oxide upon the support;

a polycrystalline seed layer comprising zinc oxide disposed upon the metal oxide layer;

a conductive metal or metal alloy layer disposed upon the polycrystalline seed layer; and

a barrier layer disposed directly upon the metal or metal alloy layer.

12. A conductive film according to claim 11, further comprising a polymeric base coat layer between the transparent support and the metal oxide layer.

13. A conductive film according to claim 12, wherein the polymeric base coat layer comprises an acrylate polymer.

14. A conductive film according to claim 11, wherein the metal oxide comprises tin oxide.

15. A conductive film according to claim 11, wherein the conductive metal or metal alloy layer comprises silver.

16. A conductive film according to claim 11, further comprising a second polycrystalline seed layer disposed upon the metal or metal alloy layer and a second metal or metal alloy layer disposed upon the second seed layer.

17. A conductive film according to claim 11, wherein the metal or metal alloy layers are separated by a polymeric spacing layer and provide an infrared-rejecting Fabry-Perot stack.

18. An electronic device comprising the film of claim 11.

19. A method for making a glazing article comprising:

assembling a layer of glazing material and an optically clear film, wherein the film comprises;

a transparent support;

a layer of metal oxide upon the first polymeric material;

a polycrystalline seed layer comprising zinc oxide disposed upon the metal oxide layer;

a conductive metal or metal alloy layer disposed upon the polycrystalline seed layer; and

a barrier layer disposed upon the conductive metal or metal alloy layer; and

bonding the glazing material and the film together into a unitary article.

20. A method according to claim 19, wherein the glazing material comprises glass and the article comprises an adhesive layer between the film and the glass.