Process for forming optically clear conductive metal or metal alloy thin films and films made therefrom

• US 9,012,044 B2
• Filed: 07/26/2010
• Issued: 04/21/2015
• 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.
• Primary Examiner(s): Sample, David
• Assistant Examiner(s): Colgan, Lauern
• Application Number:
  US13/388,329
• Publication Number:
  US 20120125660A1
• Time in Patent Office: 1,730 Days
• Field of Search: 428/426, 428/428, 428/432, 428/688, 428/689, 428/699, 428/701, 428/702, 428/434, 427/402, 427/419.1, 427/419, 427/419.3, 427/207.1
• US Class Current: 428/701
• 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. An optically clear conductive film comprising:

a transparent support;

a layer of metal oxide comprising tin oxide upon the support;

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

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

a barrier layer atop the metal or metal alloy layer.

2. A conductive film according to claim 1, further comprising a polymeric base coat layer between the transparent support and the metal oxide layer.

3. A conductive film according to claim 2, wherein the polymeric base coat layer comprises an acrylate polymer.

4. A conductive film according to claim 1, wherein the conductive metal or metal alloy layer comprises silver.

5. A conductive film according to claim 1, further comprising a bi-layer including:

a crosslinked polymeric spacing layer directly upon the first conductive metal or metal alloy layer; and

a second conductive metal or metal alloy layer directly upon the crosslinked polymeric spacing layer, wherein the barrier layer is atop the second conductive metal or metal alloy layer.

6. A conductive film according to claim 5, comprising 2 to 4 bi-layers, to provide an infrared-rejecting Fabry-Perot stack.

7. An electronic device comprising the film of claim 1.

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

providing a layer of metal oxide comprising tin 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 atop the metal or metal alloy layer.

9. A method according to claim 8, further comprising vapor coating a first polymeric material upon the support.

10. A method according to claim 8, wherein the polycrystalline seed layer further comprises aluminum oxide.

11. A method according to claim 8, wherein the first conductive metal or metal alloy comprises silver or gold.

12. A method according to claim 8, wherein the film has at least 80% optical transmittance of visible light at 550 nm.

13. A method according to claim 8, wherein the film has a sheet resistance of less than about 100 ohms/square resistance.

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

depositing a crosslinked polymeric spacing layer directly upon the first conductive metal or metal alloy layer; and

depositing a second conductive metal or metal alloy layer directly upon the crosslinked polymeric spacing layer;

wherein the barrier layer is atop the second conductive metal or metal alloy layer.

15. A method according to claim 8, further comprising repeating the depositing steps of claim 14 to provide an infrared-rejecting Fabry-Perot stack, wherein the barrier layer is atop the Fabry-Perot stack.

16. A method according to claim 14, wherein the thickness of the polymeric spacing layer is from about 1 nm to about 5 nm.

17. 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 comprising tin oxide upon the first polymeric material;

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

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

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

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

18. A method according to claim 17, wherein the glazing material comprises glass and the article comprises an adhesive layer between the film and the glass.