TRANSPARENT CONDUCTORS AND METHODS FOR FABRICATING TRANSPARENT CONDUCTORS

• US 20090188697A1
• Filed: 01/28/2008
• Published: 07/30/2009
• Est. Priority Date: 01/28/2008
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Smith, Peter, Guiheen, James V.
• Granted Patent: US 7,642,463 B2
• Time in Patent Office: Days
• US Class Current: 174/126.400
• CPC Class Codes: H01B 1/02 mainly consisting of metals or alloys
• CPC Class Codes: H01B 1/16 the conductive material comprising metals or alloys
• CPC Class Codes: H01B 1/22 the conductive material comprising metals or alloys

Abstract

Transparent conductors with nanowires having silver oxide complexes and methods for fabricating such transparent conductors are provided. In one exemplary embodiment, a transparent conductor comprises a substrate and a transparent conductive coating disposed overlying the substrate. The coating comprises silver nanowires at least a portion of which has a silver oxide complex formed on or within surfaces thereof.

Claims

1. A transparent conductor comprising:

a substrate; and

a transparent conductive coating disposed overlying the substrate, wherein the transparent conductive coating comprises a plurality of silver nanowires, at least a portion of which has a silver oxide complex formed on or within surfaces thereof.

2. The transparent conductor of claim 1, wherein at least about 20% of the plurality of silver nanowires has the silver oxide complex formed on or within surfaces thereof.

3. The transparent conductor of claim 1, wherein the silver oxide complex has a refractive index (n) and an extinction coefficient (k), and wherein the silver oxide complex has a selected ratio (n:

k) of the refractive index to the extinction coefficient that is determined, at least in part, by a predetermined concentration ratio of a concentration of silver oxide divided by a sum of the concentration of silver oxide and a concentration of di-silver oxide ([AgO]/([AgO]+[Ag₂O])) of the silver oxide complex.

4. The transparent conductor of claim 3, wherein the refractive index (n) of the silver oxide complex is in the range of about 0.3 to about 2.1.

5. The transparent conductor of claim 3, wherein the extinction coefficient (k) of the silver oxide complex is in the range of about 0.1 to about 3.6.

6. The transparent conductor of claim 3, wherein the selected ratio (n:

k) is in the range of from about 0.08 to about 21.

7. A method for fabricating a transparent conductor, the method comprising the steps of:

forming a dispersion comprising a plurality of silver nanowires and a solvent;

applying the dispersion to a substrate;

permitting the solvent to at least partially evaporate; and

oxidizing the plurality of silver nanowires such that a silver oxide complex is formed on or within surfaces of at least a portion of the plurality of silver nanowires.

8. The method of claim 7, wherein the step of oxidizing comprises subjecting the plurality of silver nanowires to a plasma treatment.

9. The method of claim 7, further comprising the step of providing a medium material overlying the plurality of silver nanowires after the step of oxidizing.

10. The method of claim 7, wherein the step of forming a dispersion comprises forming a dispersion comprising the plurality of silver nanowires, the solvent, and a medium material that is oxygen-absorbent.

11. The method of claim 7, wherein the step of oxidizing comprises the step of oxidizing the plurality of silver nanowires such that the silver oxide complex is formed on or within surfaces of at least about 20% of the plurality of silver nanowires.

12. The method of claim 7, wherein the step of oxidizing comprises the step of oxidizing the plurality of silver nanowires such that the silver oxide complex has a predetermined concentration ratio of a concentration of silver oxide divided by a sum of the concentration of silver oxide and a concentration of di-silver oxide, wherein the silver oxide complex has a refractive index (n) and an extinction coefficient (k), and wherein the silver oxide complex also has a selected ratio (n:

k) of the refractive index divided by the extinction coefficient that is based, at least in part, on the predetermined concentration ratio.

13. The transparent conductor of claim 12, wherein the step of oxidizing comprises the step of oxidizing the plurality of silver nanowires such that the refractive index (n) of the silver oxide complex is in the range of about 0.3 to about 2.1.

14. The transparent conductor of claim 12, wherein the step of oxidizing comprises the step of oxidizing the plurality of silver nanowires such that the extinction coefficient (k) of the silver oxide complex is in the range of about 0.1 to about 3.6.

15. The transparent conductor of claim 12, wherein the step of oxidizing comprises the step of oxidizing the plurality of silver nanowires such that the selected ratio (n:

k) is in the range of about 0.08 to about 21.

16. A method for fabricating a transparent conductor, the method comprising the steps of:

providing a substrate; and

forming a transparent conductive coating comprising silver nanowires overlying the substrate, wherein the silver nanowires have silver oxides on or within surfaces of the silver nanowires.

17. The method of claim 16, wherein the step of forming comprises the step of forming the transparent conductive coating such that the silver oxides are present in a silver oxide complex having a concentration ratio of a concentration of silver oxide ([AgO]) divided by a sum of the concentration of silver oxide and a concentration of di-silver oxide ([AgO]+[Ag₂O]), and wherein the silver oxide complex exhibits a selected ratio (n:

k) of its refractive index (n) divided by its extinction coefficient (k) that corresponds to the concentration ratio.

18. The method of claim 17, wherein the step of forming a transparent conductive coating comprises the step of forming the transparent conductive coating such that the refractive index (n) of the selected ratio (n:

k) is in the range of about 0.3 to about 2.1.

19. The method of claim 17, wherein the step of forming a transparent conductive coating comprises the step of forming the transparent conductive coating such that the extinction coefficient (k) of the selected ratio (n:

k) is in the range of about 0.3 to about 3.6.

20. The method of claim 17, wherein the step of forming a transparent conductive coating comprises the step of forming the transparent conductive coating such that the selected ratio (n:

k) is in the range of about 0.08 to about 21.