Nanowire-based transparent conductors and applications thereof

Abstract

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 .- 81 . (canceled) 
     
     
         82 . A method for providing electromagnetic shielding, comprising:
 providing a composite comprising a plurality of metallic nanowires and a matrix material;   applying the composite to a substrate; and   forming a conductive layer comprising the plurality of metallic nanowires dispersed in the matrix material, the conductive layer having a surface conductivity of no more than 10 8 Ω/square, wherein the conductive layer is configured to provide electromagnetic shielding.   
     
     
         83 . The method of  claim 82 , wherein the conductive layer is optically clear. 
     
     
         84 . A transparent conductor, comprising:
 a substrate; and   a conductive layer comprising:
 a first region comprising nanowires embedded in a matrix; and 
 a second region comprising treated nanowires embedded in the matrix, wherein:
 the second region has a higher resistivity than the first region, and 
 the first region and the second region have substantially the same optical properties. 
 
   
     
     
         85 . The transparent conductor of  claim 84 , wherein the nanowires of the first region are metal nanowires. 
     
     
         86 . The transparent conductor of  claim 85 , wherein the treated nanowires of the second region comprise oxidized metal nanowires. 
     
     
         87 . The transparent conductor of  claim 85 , wherein the treated nanowires of the second region comprise sulfided metal nanowires. 
     
     
         88 . The transparent conductor of  claim 84 , wherein the treated nanowires of the second region are shorter than the nanowires of the first region. 
     
     
         89 . The transparent conductor of  claim 84 , wherein the second region is more resistive than the first region by at least about 1500Ω/square. 
     
     
         90 . The transparent conductor of  claim 84 , wherein the second region and the first region have substantially the same optical transmission and haze. 
     
     
         91 . A method of forming a patterned transparent conductor, comprising:
 forming a conductive layer on a substrate, the conductive layer comprising a matrix and a network of electrically conductive nanowires embedded therein; and   treating a first region of the conductive layer to convert the electrically conductive nanowires within the first region to less-conductive nanowires, wherein the first region has a first resistivity and a second region of the conductive layer that is not treated has a second resistivity.   
     
     
         92 . The method of  claim 91 , wherein the conductive layer is optically clear. 
     
     
         93 . The method of  claim 91 , wherein the region and the second region have substantially the same optical properties. 
     
     
         94 . The method of  claim 93 , wherein the optical properties comprise optical transmission and haze. 
     
     
         95 . The method of  claim 91 , wherein the first resistivity the first region is higher than the second resistivity of the second region by at least about 1500Ω/square. 
     
     
         96 . The method of  claim 91 , wherein treating the first region of the conductive layer comprises chemically transforming the electrically conductive nanowires within in the first region to electrically insulating nanowires. 
     
     
         97 . The method of  claim 96 , wherein treating the first region of the conductive layer comprises oxidizing or sulfiding the electrically conductive nanowires within in the first region. 
     
     
         98 . The method of  claim 91 , wherein treating the first region of the conductive layer comprises physically shortening electrically conductive nanowires within in the first region. 
     
     
         99 . The method of  claim 91 , wherein:
 an optical transmission of the first region differs from an optical transmission of the second region by less than 0.7%, and   a haze of the first region differs from a haze of the second region by less than 0.62%.   
     
     
         100 . The method of  claim 99 , wherein the first resistivity of the first region is higher than the second resistivity of the second region by at least about 1500Ω/square. 
     
     
         101 . The method of  claim 82 , wherein forming the conductive layer comprises at least partially drying the composite after applying the composite to the substrate.