Light influencing nano layer
View Patent ↗The present subject matter provides a transitional layer and related methods, used to increase the transmission or reflection of light between two mediums having different indices of refraction. The transitional layer is disposed between the two mediums and the transmission or reflection of light is increased by the interaction of light with the transitional layer. The transitional layer has light scattering particles dispersed therein, a single-layer gradient index-of-refraction, a multi-layer gradient index-of-refraction, alternating layers of high and low index-of-refraction, or a combination thereof, in order to increase the transmission or reflectance of light between the two mediums.
1. A method of forming a plurality of transitional layers with selectable indices of refraction on a substrate, the method comprising:
providing a substrate and a plurality of metal oxide precursor pastes, wherein the plurality of metal oxide precursor pastes each include at least one soluble metal complex, a complex-forming agent, and a resin dissolved in a solvent, wherein the complex-forming agent replaces at least one ligand on the metal complex to provide a metal compound that is less likely than the metal complex to oxidize in the presence of water or oxygen;
depositing each of the plurality of metal oxide precursor pastes on the substrate to form a plurality of coating layers; and
heating each of the plurality of coating layers to burn off the solvent and the resin, and oxidize the at least one soluble metal complex to thereby form a plurality of transparent transitional layers of metal oxide situated on top of one another on the substrate.
2. The method of claim 1 , wherein the plurality of transitional layers have increasing or decreasing index of refraction values going away from the substrate.
3. The method of claim 2 , wherein:
each of the plurality of coating layers are dried to remove at least a portion of the solvent before a subsequent one of the plurality of metal oxide precursor pastes are deposited on the substrate; and
heating is performed after all of the plurality of metal oxide precursor pastes have been deposited on the substrate.
4. The method of claim 3 , wherein the plurality of coating layers intermix such that the plurality of transitional layers do not have distinct boundaries between them and thereby define a single layer on the substrate.
5. The method of claim 2 , wherein each of the plurality of coating layers are heated to burn off the solvent and the resin, and oxidize the at least one soluble metal complex before a subsequent one of the plurality of metal oxide precursor pastes are deposited on the substrate.
6. The method of claim 5 , wherein the plurality of transitional layers have distinct boundaries between them.
7. The method of claim 1 , wherein the plurality of transitional layers have alternating higher and lower index of refraction values going away from the substrate to thereby form a light reflective layer on the substrate.
8. The method of claim 6 , wherein each of the plurality of transitional layers having the higher index of refraction values has a layer thickness of approximately ¼ the wavelength of UV-A, UV-B, or visible light.
9. The method of claim 7 , wherein each of the plurality of transitional layers having the lower index of refraction values has a layer thickness more than each of the plurality of transitional layers having the higher index of refraction values.
10. The method of claim 1 , wherein the at least one soluble metal complex comprises a metal alkoxide.
11. The method of claim 10 , wherein the metal alkoxide is selected from the group consisting of metal methoxide, metal ethoxide, metal isopropoxide, metal butoxide, and combinations thereof.
12. The method of claim 10 , wherein the metal in the metal alkoxide is selected from the group consisting of boron, aluminum, silicon, phosphorus, scandium, titanium, zinc, gallium, germanium, arsenic, yttrium, zirconium, niobium, molybdenum, indium, tin, antimony, lanthanum, hafnium, tantalum, tungsten, and combinations thereof.
13. The method of claim 10 , wherein the metal alkoxide is selected from the group consisting of tetraethyl orthosilicate, titanium (IV) isopropoxide, zirconium (IV) n-propoxide, and combinations thereof.
14. The method of claim 1 , wherein the resin comprises a water soluble resin.
15. The method of claim 1 , wherein the solvent comprises an organic solvent.
16. The method of claim 1 , wherein the complex-forming agent is selected from the group consisting of poly-acrylic acid, oxalic acid, maleic acid, succinic acid, dipropylene glycol, glymes, 1, 4 butane diol, 1, 3 butane diol, 1, 3 propane diol, pine rosin, citric acid, and combinations thereof.
17. The method of claim 1 , wherein the plurality of metal oxide precursor pastes each have a viscosity of about 1000-180,000 centipoise and the depositing comprises screen printing.
18. The method of claim 1 , wherein the metal oxide precursor paste has a viscosity of about 1-400 centipoise, and the depositing comprises digital printing.
19. The method of claim 1 , wherein the metal oxide precursor paste has a viscosity of about 100-25,000 centipoise, and the depositing comprises roll coating.