Transparent conductive coating with filler material

Abstract

An article is disclosed comprising a network-like pattern of conductive traces formed of at least partially joined nanoparticles that define randomly-shaped cells that are generally transparent to light and contain a transparent filler material. In a preferred embodiment, the filler material is conductive such as a metal oxide or a conductive polymer. In another preferred embodiment, the filler material is an adhesive that is can be used to transfer the network from one substrate to another. A preferred method of forming the article is also disclosed wherein an emulsion containing the nanoparticles in the solvent phase and the filler material in the water phase is coated onto a substrate. The emulsion is dried and the nanoparticles self-assemble to form the traces and the filler material is deposited in the cells. An electroluminescent device is also disclosed wherein the article of the invention forms a transparent electrode in the device.

What is claimed is: 
     
         1 . An article comprising a network-like pattern of conductive traces formed of at least partially joined nanoparticles defining random-shaped cells generally transparent to light wherein at least a portion of the cells are at least partially filled with a transparent filler material. 
     
     
         2 . The article of  claim 1  wherein the filler material is conductive. 
     
     
         3 . The article of  claim 2  where the resistance of the filler material is in the range of 10 2  to 10 8  ohm/sq. 
     
     
         4 . The article of  claim 2  wherein the filler material comprises a metal oxide. 
     
     
         5 . The article of  claim 4  wherein the metal oxide is indium tin oxide or antimony tin oxide. 
     
     
         6 . The article of  claim 2  wherein the filler material comprises a conductive polymer. 
     
     
         7 . The article of  claim 6  wherein the conductive polymer comprises, PEDOT, PEDOT:PSS, polyaniline, polythiophenes, polyacetylene, polypyrrole, or derivatives or mixtures thereof. 
     
     
         8 . The article of  claim 2  wherein the filler material comprises carbon nanotubes or a low density matrix or array of metal nanoparticles or nanowires. 
     
     
         9 . The article of  claim 1  wherein the filler material is non-conductive or semi-conductive. 
     
     
         10 . The article of  claim 1  wherein the filler material is a high dielectric constant material. 
     
     
         11 . The article of  claim 9  wherein the filler material comprises an anti-reflective material. 
     
     
         12 . The article of  claim 11  wherein the antireflective material comprises glass frits, glass spheres, silicon nitrate, silicon monoxide, titanium dioxide or zinc oxide. 
     
     
         13 . The article of  claim 1  wherein such filler material is an adhesive. 
     
     
         14 . The article of  claim 12  wherein such adhesive comprises an epoxy or a UV curable acrylate. 
     
     
         15 . The article of  claim 1  wherein the filler material is abrasion resistant, scratch-resistant, moisture resistant, or any combination thereof. 
     
     
         16 . The article of  claim 1  further comprising at least one substrate layer covering one surface of the article. 
     
     
         17 . The article of  claim 16  wherein the article is flexible. 
     
     
         18 . The article of  claim 1  wherein the filler material completely fills the cells and extends above the cells. 
     
     
         19 . The article of  claim 1  wherein the filler material fills the cells to a level less than or equal to the top of the cells. 
     
     
         20 . An electroluminescent device comprising the article of  claim 1 , a phosphor layer, a dielectric layer, and a counter electrode.