Non-planar photocell
A photovoltaic cell having a substrate with at least one curved surface reduces the number of processing steps necessary to manufacture a completed cell. Such a photovoltaic cell can have semiconductor material on the outer surface of a curved substrate or on the inner surface of a curved substrate.
1 . A photovoltaic cell comprising a substrate having a curved surface and a first semiconductor material on the surface.
2 . The photovoltaic cell of claim 1 wherein the surface is concave.
3 . The photovoltaic cell of claim 1 wherein the surface is convex.
4 . The photovoltaic cell of claim 1 wherein the substrate has a polygonal cross section.
5 . The photovoltaic cell of claim 1 wherein the substrate includes a low iron glass.
6 . The photovoltaic cell of claim 1 wherein the substrate includes a low expansion glass.
7 . The photovoltaic cell of claim 1 wherein the substrate includes a soda lime glass.
8 . The photovoltaic cell of claim 1 wherein the substrate includes a borosilicate glass.
9 . The photovoltaic cell of claim 1 further comprising a bottom layer between the curved surface and the first semiconductor material.
10 . The photovoltaic cell of claim 9 wherein the bottom layer includes a conductive material.
11 . The photovoltaic cell of claim 10 wherein the conductive material is a transparent conductive layer.
12 . The photovoltaic cell of claim 10 wherein the conductive material is a transparent conductive oxide.
13 . The photovoltaic cell of claim 10 wherein the conductive material includes a tin oxide
14 . The photovoltaic cell of claim 9 further comprising a second semiconductor material between the first semiconductor material and the bottom layer.
15 . The photovoltaic cell of claim 14 wherein the second semiconductor material includes a binary semiconductor.
16 . The photovoltaic cell of claim 15 wherein the binary semiconductor is a Group II-VI semiconductor.
17 . The photovoltaic cell of claim 1 wherein the first semiconductor material is CdS.
18 . The photovoltaic cell of claim 14 wherein the second semiconductor material is CdTe.
19 . The photovoltaic cell of claim 9 further comprising a buffer layer in contact with the bottom layer and between the bottom layer and the first semiconductor material.
20 . The photovoltaic cell of claim 14 further comprising a top layer covering at least a portion of the first semiconductor material.
21 . The photovoltaic cell of claim 20 wherein the top layer includes a metal.
22 . The photovoltaic cell of claim 9 further comprising an electrical conductor electrically connected to the bottom layer.
23 . The photovoltaic cell of claim 20 further comprising an electrical conductor connected to the top layer.
24 . The photovoltaic cell of claim 1 wherein the substrate has an annular cross section and includes:
a first end;
a second end opposite the first end;
an inner surface connecting the first end and the second end; and
an outer surface opposite the inner surface.
25 . The photovoltaic cell of claim 24 wherein the substrate is a glass tube.
26 . The photovoltaic cell of claim 24 wherein the semiconductor material is on a portion of the inner surface of the substrate.
27 . The photovoltaic cell of claim 20 wherein the substrate has an annular cross section and includes:
a first end;
a second end opposite the first end;
an inner surface connecting the first end and the second end; and
an outer surface opposite the inner surface.
28 . The photovoltaic cell of claim 27 further comprising a first electrical connection connected to the top layer.
29 . The photovoltaic cell of claim 28 further comprising a second electrical connection connected to the bottom layer.
30 . The photovoltaic cell of claim 28 wherein the first end seals around the first electrical connection.
31 . The photovoltaic cell of claim 29 wherein the second end seals around the second electrical connection.
32 . The photovoltaic cell of claim 26 wherein the inner surface, the first end and the second end form a chamber.
33 . The photovoltaic cell of claim 32 wherein the chamber contains a gas having a pressure less than atmospheric pressure.
34 . The photovoltaic cell of claim 32 wherein the chamber contains an inert gas.
35 . The photovoltaic cell of 34 wherein the inert gas is helium, argon, nitrogen, or a combination thereof.
36 . The photovoltaic cell of claim 24 wherein the first semiconductor material is on a portion of the outer surface of the substrate.
37 . A method of making a photovoltaic cell comprising forming a coating of a semiconductor material on a curved surface of a substrate.
38 . The method of claim 37 further comprising extruding the substrate prior to coating the substrate.
39 . The method of claim 37 further comprising coating the extruding substrate.
40 . The method of claim 38 further comprising cutting the substrate to predetermined dimensions.
41 . The method of claim 38 wherein forming a coating includes depositing a layer of a semiconductor material on a portion of a surface of the substrate.
42 . The method of claim 40 wherein forming a coating includes generating a substantially uniform thickness layer on a portion of the surface of the substrate.
43 . The method of claim 38 wherein forming a coating on a surface includes depositing a chemical vapor on the surface.
44 . The method of claim 38 wherein the surface is a curved inner surface of the substrate.
45 . The method of claim 38 wherein the surface is a curved outer surface of the substrate.
46 . The method of claim 38 wherein forming the coating includes directing a deposition element adjacent to an inner surface of the curved substrate and depositing a chemical vapor on the surface.
47 . A method of generating electricity comprising:
exposing a photovoltaic cell having a curved surface to a light source.
48 . The method of claim 47 further comprising collecting charge generated by exposing the photovoltaic cell to the light source.
49 . The method of claim 48 wherein collecting charge includes transporting the charge to an electrical demand source.
50 . The method of claim 49 wherein transporting the charge to an electrical demand source includes storing the charge in a storage device.
51 . The method of claim 47 wherein the curved surface is a substrate of the photovoltaic cell, the photovoltaic cell includes a first semiconductor material on the surface.
52 . The method of claim 51 wherein the surface is concave.
53 . The method of claim 51 wherein the surface is convex.
54 . The method of claim 51 wherein the substrate has a polygonal cross section.
55 . The method of claim 51 wherein the substrate includes a low iron glass.
56 . The method of claim 51 wherein the substrate includes a low expansion glass.
57 . The method of claim 51 wherein the substrate includes a borosilicate glass.
58 . The method of claim 51 further comprising a bottom layer between the curved surface and the first semiconductor material.
59 . The method of claim 58 wherein the bottom layer includes a conductive material.
60 . The method of claim 58 wherein the conductive material is a transparent conductive layer.
61 . The method of claim 59 wherein the conductive material is a transparent conductive oxide.
62 . The method of claim 59 wherein the conductive material includes a tin oxide.
63 . The method of claim 58 further comprising a second semiconductor material between the first semiconductor material and the bottom layer.
64 . The method of claim 63 wherein the second semiconductor material includes a binary semiconductor.
65 . The method of claim 64 wherein the binary semiconductor is a Group II-VI semiconductor.
66 . The method of claim 51 wherein the first semiconductor material is CdS.
67 . The method of claim 63 wherein the second semiconductor material is CdTe.
68 . The method of claim 58 further comprising a buffer layer in contact with the bottom layer and between the bottom layer and the first semiconductor material.
69 . The method of claim 68 further comprising a top layer covering at least a portion of the first semiconductor material.
70 . The method of claim 69 wherein the top layer includes a metal.
71 . The method of claim 63 further comprising an electrical conductor electrically connected to the bottom layer.
72 . The photovoltaic cell of claim 68 further comprising an electrical conductor connected to the top layer.
73 . The method of claim 51 wherein the substrate has an annular cross section and includes:
a first end;
a second end opposite the first end;
an inner surface connecting the first end and the second end; and
an outer surface opposite the inner surface.
74 . The method of claim 73 wherein the substrate is a glass tube.
75 . The method of claim 74 wherein the semiconductor material is on a portion of the inner surface of the substrate.
76 . The method of claim 65 wherein the substrate has an annular cross section and includes:
a first end;
a second end opposite the first end;
an inner surface connecting the first end and the second end; and
an outer surface opposite the inner surface.
77 . The method of claim 76 further comprising a first electrical connection connected to the top layer.
78 . The method of claim 77 further comprising a second electrical connection connected to the bottom layer.
79 . The method of claim 76 wherein the first end seals around the first electrical connection.
80 . The method of claim 76 wherein the second end seals around the second electrical connection.
81 . The method of claim 76 wherein the inner surface, the first end and the second end form a chamber.
82 . The method of claim 81 wherein the chamber contains a gas having a pressure less than atmospheric pressure.
83 . The method of claim 81 wherein the chamber contains an inert gas.
84 . The method of claim 83 wherein the inert gas is helium, argon, nitrogen, or a combination thereof.
85 . The method of claim 76 wherein the first semiconductor material is on a portion of the outer surface of the substrate.
86 . A system for converting light into electrical energy comprising:
a plurality of photovoltaic cells, at least one of the photovoltaic cells having a curved surface; and
an electrical connection between at least two of the photovoltaic cells.
87 . The system of claim 86 further comprising a storage device for storing electricity electrically connected to the photovoltaic cells.
88 . The system of claim 86 further comprising a mounting apparatus for securing the photovoltaic cells to a light exposure surface.
89 . The system of claim 88 wherein the mounting apparatus includes electrical connections for each of the photovoltaic cells.
90 . The system of claim 88 wherein the light exposure surface includes a roof.
91 . The system of claim 86 further comprising a protective overlayer surrounding the curved photovoltaic cells.
92 . The system of claim 86 wherein each photovoltaic cell comprises a substrate that has an annular cross section and includes:
a first end;
a second end opposite the first end;
an inner surface connecting the first end and the second end; and
an outer surface opposite the inner surface.
93 . The system of claim 92 further comprising a bottom semiconductor layer and a top semiconductor layer on a surface of the substrate.
94 . The system of claim 93 further comprising a first electrical connection connected to the top semiconductor layer.
95 . The system of claim 94 further comprising a second electrical connection connected to the bottom layer.
96 . The photovoltaic cell of claim 95 wherein the first end seals around the first electrical connection.
97 . The photovoltaic cell of claim 96 wherein the second end seals around the second electrical connection.