Apparatus and methods of electrically conductive optical semiconductor coating
A method of coating an optical substrate with a transparent, electrically conductive coating includes depositing a semiconductor coating over a surface of an optical substrate, wherein the semiconductor coating has broadband optical transmittance. A doped semiconductor is applied in a pattern over the semiconductor coating. The doped semiconductor in the pattern is activated for electrical conductivity in the doped semiconductor.
1. A window comprising:
a substrate that is transparent to radiation in at least one wavelength band; and
a coating disposed over the substrate,
wherein the coating comprises semiconducting regions formed of a first material and electrically conductive regions distributed in a pattern within the coating; and
wherein the electrically conductive regions comprise the first material and a dopant.
2. The window as recited in claim 1 , wherein the coating has broadband optical transmittance.
3. The window as recited in claim 1 , wherein the pattern comprises a grid.
4. The window as recited in claim 1 , further comprising a protective layer disposed over the coating.
5. The window as recited in claim 4 , further comprising a broadband anti-reflection layer disposed over the protective layer.
6. The window as recited in claim 1 , further comprising a broadband anti-reflection layer disposed over the coating.
7. The window as recited in claim 1 , wherein the first material comprises at least one of In 2 O 3 and ZnO.
8. The window as recited in claim 1 , wherein the dopant comprises at least one of Sn, Mo, W, Ti, Al, and Ga.
9. The window as recited in claim 1 , wherein the coating has broadband optical transmittance in at least visible and infrared spectral regions.
10. The window as recited in claim 1 , wherein the pattern extends over an entire surface of the coating.
11. The window as recited in claim 1 , wherein a surface of the coating is smooth.
12. The window as recited in claim 1 , wherein the coating and substrate are formed into a window without polishing or planarization.
13. The window as recited in claim 1 , wherein the semiconducting and electrically conductive regions of the coating have closely matched indices of refraction to mitigate light scattering.
14. The window as recited in claim 1 , wherein the pattern is configured to provide electromagnetic interference (EMI) shielding to the substrate.
15. The window as recited in claim 13 , wherein a refractive index difference between the semiconducting and electrically conductive regions of the coating is between 0.82 and 1.22.
16. The window as recited in claim 1 , wherein the pattern comprises a plurality of lines.