Transparent conductors comprising metal nanowires
View Patent ↗A transparent conductor including a conductive layer coated on a substrate is described. More specifically, the conductive layer comprises a network of nanowires which may be embedded in a matrix. The conductive layer is optically transparent and flexible. It can be coated or laminated onto a variety of substrates, including flexible and rigid substrates.
1. A transparent conductor comprising:
a substrate; and
a conductive layer on the substrate, the conductive layer including a plurality of metal nanowires,
wherein the metal nanowires intersect and form a plurality of nanowire crossing points, and wherein at each of at least some of the crossing points, at least one of the intersecting nanowires has a flattened cross section, wherein the conductive layer includes a matrix that includes: an acrylate monomer; a multifunctional acrylate monomer; and at least one photoinitiator.
2. The transparent conductor of claim 1 wherein the metal nanowires are silver nanowires.
3. The transparent conductor of claim 2 wherein the transparent conductor has a surface resistivity of about 60Ω/□, and light transmission of about 87%.
4. The transparent conductor of claim 1 wherein each nanowire has an aspect ratio of greater than 100.
5. The transparent conductor of claim 1 wherein the transparent conductor is surface conductive.
6. The transparent conductor of claim 5 where the matrix material is polyurethane, polyacrylic, silicone, polyacrylate, polysilane, polyester, polyvinyl chloride, polystyrene, polyolefin, fluoropolymer, polyimide, polyimide, polynorbornene, acrylonitrile-butadiene-styrene copolymer, or copolymers or blends thereof.
7. The transparent conductor of claim 1 wherein the matrix is optically clear.
8. The transparent conductor of claim 1 wherein each metal nanowire or a portion of the plurality of metal nanowires includes at least one section that protrudes above a surface of the matrix.
9. The transparent conductor of claim 1 wherein the conductive layer is patterned such that first regions of the surface of the transparent conductor are conductive and second regions of the surface of the transparent conductor are non-conductive.
10. The transparent conductor of claim 1 wherein the substrate is flexible.
11. The transparent conductor of claim 10 wherein the substrate is polyacrylate, polyolefin, polyvinyl chloride, fluoropolymer, polyamide, polyimide, polysulfone, silicone, glass resin, polyetheretherketone, polynorbornene, polyester, polyvinyls, acrylonitrile-butadiene-styrene copolymer, or polycarbonate or a copolymer or blend or laminate of these materials.
12. The transparent conductor of claim 1 further comprising one or more anti-reflective layers, anti-glare layers, adhesive layers, barriers, hard coat, or a protective film.
13. The transparent conductor of claim 12 comprising an anti-reflective layer positioned over the conductive layer, and an adhesive layer positioned between the conductive layer and the substrate.
14. The transparent conductor of claim 12 comprising a hard coat over the conductive layer, a barrier layer positioned between the conductive layer and the substrate, and an anti-reflective layer below the substrate.
15. The transparent conductor of claim 12 comprising an anti-reflective layer, anti-glare and a barrier layer positioned above the conductive layer, an adhesive layer positioned between the conductive layer and the substrate, and an anti-reflective layer below the substrate.
16. The transparent conductor of claim 1 further comprising one or more corrosion inhibitors.
17. The transparent conductor of claim 16 wherein the one or more corrosion inhibitors are housed in one or more reservoirs and can be released in vapor phase.
18. The transparent conductor of claim 16 wherein the corrosion inhibitor is benzotriazole, tolytriazole, butyl benzyl triazole, dithiothiadiazole, alkyl dithiothiadiazoles and alkylthiols, 2-aminopyrimidine, 5,6-dimethylbenzimidazole, 2-amino-5-mercapto-1,3,4-thiadiazole, 2-mercaptopyrimidine, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, or 2-mercaptobenzimidazole.
19. The transparent conductor of claim 16 wherein the corrosion inhibitor is an H 2 S scavenger.
20. The transparent conductor of claim 19 wherein the corrosion inhibitor is acrolein, glyoxal, triazine, or n-chlorosuccinimide.
21. The transparent conductor of claim 17 wherein the corrosion inhibitor is benzotriazole, dithiothiadiazole or alkyl dithiothiadiazoles.
22. The transparent conductor of claim 1 wherein the flattened cross section of the at least one of the intersecting nanowires is where the intersecting nanowires have been pressed into each other.
23. The transparent conductor of claim 1 wherein a surface loading level of the metal nanowires on the substrate is about 0.05 μg/cm 2 to about 10 μg/cm 2 .
24. The transparent conductor of claim 1 wherein the matrix includes a prepolymer.
25. The transparent conductor of claim 24 wherein the prepolymer is photo-curable.
26. The transparent conductor of claim 1 wherein the matrix includes a corrosion inhibitor.
27. The transparent conductor of claim 1 wherein the metal nanowires are silver nanowires and the transparent conductor has a surface resistivity of about 60Ω/□, and light transmission of about 87%.
28. The transparent conductor of claim 1 wherein the intersecting metal nanowires have a contacting surface at each crossing point, and wherein the contacting surface is enlarged at the at least some of the crossing points.
29. The transparent conductor of claim 1 wherein the intersecting metal nanowires at the at least some of the crossing points have enhanced connectivity.
30. The transparent conductor of claim 1 wherein the conductive layer has resistivity of about 10-1000Ω/□ and light transmission of more than 85%.
31. A transparent conductor comprising a substrate; and a conductive layer on the substrate, the conductive layer including a plurality of metal nanowires and a matrix polymerized from:
an acrylate monomer: 2-ethylhexyl acrylate;
a multifunctional acrylate monomer: trimethylolpropane triacrylate (TMPTA);
an adhesion promoter; and
at least one photoinitiator.
32. The transparent conductor of claim 31 wherein the metal nanowires are silver nanowires.
33. A patterned transparent conductor comprising:
a substrate;
a conductive region on the substrate, the conductive region including a plurality of interconnecting metal nanowires; and
a non-conductive region on the substrate, wherein the conductive region and the non-conductive region are arranged in a predetermined pattern, wherein the non-conductive region includes metal nanowires at a lower concentration than that of the plurality of interconnecting metal nanowires in the conductive region.
34. The patterned transparent conductor of claim 33 wherein the non-conductive region has no metal nanowires.
35. The patterned transparent conductor of claim 33 wherein the conductive region further comprises an optically clear matrix.
36. The patterned transparent conductor of claim 35 wherein the optically clear matrix is a polymer.
37. The patterned transparent conductor of claim 36 wherein the optically clear matrix is a conductive polymer.
38. The patterned transparent conductor of claim 33 wherein the conductive region has resistivity of about 10-10000Ω/□ and light transmission of more than 85%.
39. A transparent conductor comprising:
a substrate;
a conductive layer on the substrate, the conductive layer including a plurality of metal nanowires, and
a matrix on the conductive layer, wherein the matrix is a conductive polymer, wherein the conductive polymer is poly(3,4-ethylenedioxythiophene), polyaniline, polythiophene, or polydiacetylene.
40. The transparent conductor of claim 39 wherein the metal nanowires are silver nanowires.
41. The transparent conductor of claim 39 wherein the metal nanowires have aspect ratio of greater than 50.
42. The patterned transparent conductor of claim 41 wherein the metal nanowires are silver nanowires.
43. A patterned transparent conductor comprising:
a substrate;
a conductive region on the substrate, the conductive region including a plurality of interconnecting metal nanowires; and
a non-conductive region on the substrate, wherein the conductive region and the non-conductive region are arranged in a predetermined pattern, wherein the non-conductive region has no metal nanowires.
44. The patterned transparent conductor of claim 43 wherein the conductive region further comprises an optically clear matrix.
45. The patterned transparent conductor of claim 43 wherein the optically clear matrix is a polymer.
46. The patterned transparent conductor of claim 45 wherein the optically clear matrix is a conductive polymer.
47. The patterned transparent conductor of claim 43 wherein the conductive region has resistivity of about 10-1000Ω/□ and light transmission of more than 85%.
48. The patterned transparent conductor of claim 43 wherein the metal nanowires are silver nanowires.