Nanowire-based transparent conductors and applications thereof
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 that may be embedded in a matrix. The conductive layer is optically clear, patternable and is suitable as a transparent electrode in visual display devices such as touch screens, liquid crystal displays, plasma display panels and the like.
1. A touch screen device comprising:
a first transparent conductive layer including metal nanowires, wherein the metal nanowires are at or above an electrical percolation level; and
a second transparent conductive layer positioned above the first transparent conductive layer and separated therefrom by a spacer, the second transparent conductive layer including metal nanowires, wherein the metal nanowires are at or above the electrical percolation level; wherein at least one of the first transparent conductive layer and the second transparent conductive layer is further coated with a transparent overcoat, the transparent overcoat including a plurality of conductive particles at below the electrical percolation level, and wherein the transparent overcoat is surface conductive.
2. The touch screen device of claim 1 wherein the conductive particles are ITO, ZnO, doped ZnO, metallic nanowires, metallic nanotubes, carbon nanotubes, or a mixture thereof.
3. The touch screen device of claim 1 wherein the transparent overcoat has a surface resistivity of at least 10 6 ohm/sq.
4. A multi-layer structure comprising:
a substrate;
a conductive layer formed on the substrate, wherein the conductive layer comprises a first plurality of metallic nanowires, the first plurality of metallic nanowires reaching an electrical percolation level; and
an overcoat formed on the conductive layer, the overcoat incorporating a second plurality of conductive particles, the second plurality of conductive particles being below the electrical percolation level, and wherein the overcoat is surface conductive.
5. The multi-layer structure of claim 4 wherein the conductive particles are ITO, ZnO, doped ZnO, metallic nanowires, metallic nanotubes, carbon nanotubes, or a mixture thereof.
6. The multi-layer structure of claim 4 wherein the conductive layer and the overcoat are optically clear.
7. The multi-layer structure of claim 4 having a surface resistivity of less than 10 6 ohm/sq.
8. A touch screen device comprising a multi-layer structure having:
a conductive layer, wherein the conductive layer comprises a first plurality of metallic nanowires, the first plurality of metallic nanowires reaching an electrical percolation level; and
an overcoat formed on the conductive layer, the overcoat incorporating a second plurality of conductive particles, the second plurality of conductive particles being below the electrical percolation level and wherein the overcoat is surface conductive.
9. The touch screen of claim 8 wherein the conductive particles are ITO, ZnO, doped ZnO, metallic nanowires, metallic nanotubes, carbon nanotubes, or a mixture thereof.
10. The touch screen of claim 8 wherein the conductive layer and the overcoat are optically clear.
11. The touch screen of claim 8 having a surface resistivity of less than 10 6 ohm/sq.