Corrosion resistant optical device
A corrosion-resistant optical device is disclosed. The device includes a substrate, a silver layer upon the substrate, and an insulating layer that provides abrasion resistance. The device is immersed in a thiol-rich solution. The thiols form a corrosion-inhibiting monolayer upon any exposed silver surface. This increases the environmental resistance of the optical device, keeping water from interacting with the silver layer.
1. A corrosion resistant optical device comprising:
a substrate;
an insulating layer; and
a silver layer located between the substrate and the insulating layer;
wherein a pinhole defect extends through the insulating layer to expose a portion of the silver layer; and
a corrosion-inhibiting monolayer formed from a hydrophobic thiol of the formula R—SH, wherein R is an alkyl group containing from 1 carbon atom to 24 carbon atoms;
wherein the corrosion-inhibiting monolayer is formed on the exposed portion of the silver layer by applying a solution containing the hydrophobic thiol to the insulating layer.
2. The optical device of claim 1 , further comprising a binding layer between the insulating layer and the silver layer, wherein the pinhole defect extends through the binding layer.
3. The optical device of claim 1 , further comprising an alloy layer between the silver layer and the substrate.
4. The optical device of claim 3 , wherein the alloy layer is in direct contact with the substrate.
5. The optical device of claim 3 , wherein the alloy layer is formed from a nickel-chromium alloy.
6. The optical device of claim 1 , wherein the corrosion-inhibiting monolayer is formed by immersing the insulating layer in a thiol-rich solution.
7. The optical device of claim 6 , wherein the insulating layer is immersed for a period of about 4 hours to about 36 hours.
8. The optical device of claim 1 , wherein the solution further comprises and an alcohol solvent.
9. The optical device of claim 1 , wherein the corrosion-inhibiting monolayer covers all exposed surfaces of the silver layer.
10. A method for forming a corrosion-resistant optical device, comprising:
forming a silver layer upon the substrate;
forming an insulating layer upon the silver layer to obtain a layered substrate; and
immersing the layered substrate in a thiol-rich solution to form a corrosion-inhibiting monolayer that covers at least a portion of any pinhole defect, said pinhole defect comprising an exposed surface of the silver layer.
11. The method of claim 10 , wherein the layered substrate is immersed for a period of about 4 hours to about 36 hours.
12. The method of claim 10 , wherein the thiol-rich solution contains at least one hydrophobic thiol.
13. The method of claim 12 , wherein the at least one hydrophobic thiol is of the formula R—SH, wherein R is an alkyl group containing from 1 to 24 carbon atoms.
14. The method of claim 10 , wherein the thiol-rich solution comprises an alkanethiol and an alcohol solvent.
15. The corrosion-resistant optical device formed by the method of claim 10 .