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