Transparent conductive electrodes comprising 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 forming a pattern on the electrode using a photolytically process.
1. A method to patterning a conductive electrode comprising
providing a substrate,
coating a first solution comprising a first material on to the substrate to form a first layer of nanowire film;
evaporating away the solvent in the metal nanowire film; positioning a mask above the metal nanowire film, wherein the mask has a repeated open space permitting UV light to pass through and some areas shielding UV light away from the nanowire film;
shining UV light above the mask; converting the first material into a second material by a photo acid generator and UV light, wherein the first material and second material has a refractive index difference less than 0.2 and a haze difference of no more than 0.2%, and second material is less conductive than the first material; and
annealing the film removing the unreacted photo acid generator in the area shielded by the mask, wherein the first material forms the first region in the patterned electrode and the second material forms the second region in the patterned electrode.
2. The method of claim 1 , further comprising forming a second layer on top the nanowire layer, said layer comprising a photo acid generator homogenously distributed throughout the horizontal direction of the film.
3. The method of claim 1 , wherein the first solution further comprises a photo acid generator.
4. The method of claim 1 , wherein the first material is silver nanowire.
5. The method of claim 1 , wherein the second material is silver oxide nanowire.
6. The method of claim 2 , wherein the metal nanowire of the first material has a diameter of 50 nm or less.
7. The method of claim 1 , wherein the second layer has a thickness about 100 nm or less.
8. The method of claim 1 , Wherein the refractive index difference between first region and the second region is less than 0.05.
9. The method of claim 1 , wherein the open space in the mask has a dimension between 5-10 nm.
10. The method of claim 1 , wherein the first layer of nanowires has a thickness between 50-150 nm.
11. The method of claim 1 , wherein the second material has no metal nanowires.
12. The method of claim 1 , wherein the single layer does not comprise a polymer matrix.
13. The method of claim 1 , further comprising one or more anti-reflective layers, anti-glare layers, adhesive layers, bathers, hard coat, or a protective film.
14. A conductive electrode composition having homogenous optical property and heterogeneous electrical property, comprising
a first region, comprising a first material;
a second region, comprising a second material;
wherein the refractive index differences between the first and second material is less than 0.2, and a haze difference no more than 0.2%, one dimension of the first region is at least 10 um, the first material is converted to the second material by UV light and photo acid generator and the first region is more conductive than the second region.
15. The electrode of claim 14 , wherein the first material comprise silver nanowires.
16. The electrode of claim 14 , wherein the second material comprise silver oxide nanowires.
17. The electrode of claim 14 , wherein the average length of the nanowire in the second region is shorter than the average length of the first region.