PHOTOVOLTAIC DEVICE WITH AN ANTI-REFLECTIVE SURFACE AND METHODS OF MANUFACTURING SAME
A photovoltaic device comprising a substrate which has a porous first surface and a transparent conductive oxide layer located on a second surface opposite the first surface. A method of manufacturing the device is also described.
1 . A photovoltaic device comprising:
a substrate comprising:
a porous first surface as an antireflective surface;
a second surface opposite the first surface; and
a transparent conductive oxide layer on the side of the second surface of the substrate.
2 . The photovoltaic device of claim 1 , wherein the porous first surface comprises an etched substrate surface.
3 . The photovoltaic device of claim 1 , wherein the substrate comprises glass.
4 . The photovoltaic device of claim 1 , wherein the porous first surface is alkaline depleted.
5 . The photovoltaic device of claim 1 , further comprising a protective layer adjacent to the transparent conductive oxide layer, wherein the protective layer comprises a material that is resistant to etching.
6 . The photovoltaic device of claim 5 , wherein the protective layer comprises a polymer material.
7 . The photovoltaic device of claim 1 , wherein the porous first surface reflects about 1% to about 4% less light having a wavelength from about 350 nm to about 1,000 nm, compared to a substrate which has a non-porous surface.
8 . The photovoltaic device of claim 1 , further comprising a semiconductor material on the side of the second surface of the substrate.
9 . The photovoltaic device of claim 8 , wherein the semiconductor material comprises a semiconductor window layer and a semiconductor absorber layer adjacent to the semiconductor window layer.
10 . The device of claim 9 , wherein the semiconductor absorber layer comprises cadmium telluride.
11 . The device of claim 9 , wherein the semiconductor absorber layer comprises copper indium gallium (di)selenide.
12 . The device of claim 9 , wherein the semiconductor window layer comprises cadmium selenide.
13 . The photovoltaic device of claim 1 , wherein the porous first surface comprises a porous skeletonized portion that is positioned adjacent to a substantially non-porous body of the substrate.
14 . The photovoltaic device of claim 1 , wherein the transparent conductive oxide is resistant to etching.
15 . The photovoltaic device of claim 13 , wherein the transparent conductive oxide layer comprises tin oxide.
16 . An article of manufacture comprising:
a substrate with a first etchable surface and second surface;
a transparent conductive oxide layer adjacent to the second surface; and
an etchant resistant protective layer adjacent to the transparent conductive oxide layer.
17 . The article of claim 16 , wherein the substrate comprises glass.
18 . The article of claim 16 , wherein the protective layer comprises a polymer material.
19 . The article of claim 18 , wherein the polymer material is dissolvable in a solvent.
20 . The article of claim 19 , wherein the polymer material is selected from the group consisting of polyethylene and polypropylene.
21 . A method for manufacturing a photovoltaic module comprising:
providing a light transmitting sheet, the sheet comprising:
a first surface configured to be illuminated, and
a second surface opposite the first surface;
forming a transparent conductive oxide layer adjacent to the second surface; and
contacting the first surface of the sheet with an etchant, thereby making at least a portion of the first surface porous.
22 . The method of claim 21 , wherein the light transmitting sheet comprises glass.
23 . The method of claim 21 , wherein the step of contacting the first surface of the light transmitting sheet with an etchant occurs prior to the step of forming a transparent conductive oxide layer.
24 . The method of claim 21 , wherein the step of forming a transparent conductive oxide layer occurs prior to the step of contacting the light transmitting sheet with an etchant.
25 . The method of claim 24 , further comprising forming a protective layer covering at least part of the transparent conductive oxide prior to contacting the light transmitting sheet with the etchant.
26 . The method of claim 21 , wherein the porous first surface portion of the light transmitting sheet reflects about 1% to about 4% less light having a wavelength in the range of about 350 nm to about 1000 nm incident on the porous first surface portion, compared to the light transmitting sheet without a porous surface.
27 . The method of claim 21 , wherein contacting the first surface of the sheet with the etchant comprises immersing at least part of the light transmitting sheet in a container containing the etchant.
28 . The method of claim 27 , wherein immersing at least part of the light transmitting sheet in a container containing the etchant comprises conveying the sheet through a container containing the etchant.
29 . The method of claim 27 wherein the transparent conductive oxide layer is not immersed in the container containing the etchant.
30 . The method of claim 27 , wherein the second surface of the sheet is not immersed in the container containing the etchant
31 . The method of claim 21 , wherein contacting the first surface of the light transmitting sheet with the etchant comprising spraying the light transmitting sheet with an etchant.
32 . The method of claim 21 , further comprising forming a protective layer adjacent to the transparent conductive oxide layer before contacting the first surface of the light transmitting sheet with the etchant.
33 . The method of claim 32 , further comprising removing the protective layer after contacting the light transmitting sheet with the etchant.
34 . The method of claim 23 , wherein the etchant comprises a fluorine-containing compound.
35 . The method of claim 34 , wherein the etchant comprises hydrogen fluoride.
36 . The method of claim 34 , wherein the etchant comprises fluorosilicic acid.
37 . The method of claim 13 , further comprising cleaning the light transmitting sheet after the step of contacting the first surface of the light transmitting sheet with the etchant.