Transparent conductive electrodes comprising merged metal nanowires, their structure design, and method of making such structures

Abstract

A method for making a nanowire-based electrode having homogenous optical property and heterogeneous electrical property is disclosed. The method comprises coating a first solution comprising a first material on to the substrate to form a layer of nanowire network; evaporating to remove the solvent in the metal nanowire film; printing a second solution comprising a chemical reagent on top of the formed metal nanowire network layer; and oxidizing the first material into a second material by the chemical reagent, wherein the first material and second material has a refractive index difference less than 0.05 and second material is less conductive than the first material.

1 . A method for making a nanowire-based electrode having homogenous optical property and heterogeneous electrical property. The method of making a nanowire based conductive electrode comprises
 1) providing a substrate,   2) coating a first solution comprising a first material on to the substrate to form a layer of nanowire network;   3) evaporating to remove the solvent in the metal nanowire film;   4) printing a second solution comprising a chemical reagent on top of the formed metal nanowire network layer;   5) heating and drying to remove the solvent in the second solution; and   6) oxidizing the first material into a second material by the chemical reagent,   wherein the first material and second material has a refractive index difference less than 0.05 and second material is less conductive than the first material.   
     
     
         2 . The method of  claim 1 , wherein the chemical reagent is an acid or an oxidizing agent. 
     
     
         3 . The method of  claim 1 , wherein the first material is silver metal. 
     
     
         4 . The method of  claim 3 , wherein the second material is a silver oxide or silver salts. 
     
     
         5 . The method of  claim 1 , wherein the second solution is printed by an inkjet printing method. 
     
     
         6 . The method of  claim 1 , wherein the second solution is printed according to a predetermined pattern. 
     
     
         7 . The method of  claim 1 , wherein the second region has one dimension less than 50 um. 
     
     
         8 . The method of  claim 1 , wherein the first region has one dimension larger than 1 um. 
     
     
         9 . The method of  claim 1 , wherein the substrate is a flexible substrate. 
     
     
         10 . The method of  claim 1 , wherein the substrate is a glass substrate. 
     
     
         11 . The method of  claim 1 , wherein the nanowire in the first region has a diameter less than 50 nm. 
     
     
         12 . The method of  claim 1 , wherein the second solution is printed by an inkjet printing method. 
     
     
         13 . The method of  claim 1 , wherein the second solution is printed by roll to roll printing or sheet-by-sheet method 
     
     
         14 . The method of  claim 1 , wherein the resistivity ratio between the first and second region is over 1000 times. 
     
     
         15 . A method for making a nanowire-based electrode having homogenous optical property and heterogeneous electrical property, comprising
 1) providing a substrate,   2) coating a first solution comprising a first material on to the substrate to form a layer of nanowire network;   3) evaporating to remove the solvent in the metal nanowire film;   4) printing a second solution comprising a chemical reagent on top of the formed nanowire network layer;   5) heating and drying to remove the solvent in the second solution; and   6) reducing the first material into a second material by the chemical reagent,   
       wherein the first material and second material has a refractive index difference less than 0.05 and second material is more conductive than the first material. 
     
     
         16 . The method of  claim 15 , wherein the first material is a silver oxide or any silver salt precursor. 
     
     
         17 . The method of  claim 15 , wherein the second material is a silver metal.