BIFACIAL PHOTOVOLTAIC DEVICES
Described herein is a photovoltaic device operable to convert light to electricity, comprising a substrate, a first plurality of structures essentially perpendicular to the substrate and disposed on a first face of the substrate, and a second plurality of structures essentially perpendicular to the substrate and disposed on a second face of the substrate, wherein both the first plurality and the second plurality of structures are configured to convert light to electricity.
1 . A photovoltaic device operable to convert light to electricity, comprising a substrate, a first plurality of structures essentially perpendicular to the substrate and disposed on a first face of the substrate, and a second plurality of structures essentially perpendicular to the substrate and disposed on a second face of the substrate, wherein both the first plurality and the second plurality of structures are configured to convert light to electricity.
2 . The photovoltaic device of claim 1 , further comprising a reflective layer disposed on the substrate.
3 . The photovoltaic device of claim 1 , wherein the first plurality and second plurality of structures comprise one or more junctions therein or thereon.
4 . The photovoltaic device of claim 3 , wherein the one or more junctions are radial junctions.
5 . The photovoltaic device of claim 3 , wherein the one or more junctions are conformally disposed on the first plurality and second plurality of structures.
6 . The photovoltaic device of claim 3 , wherein the junctions of the first plurality of structures are different from the junctions of the second plurality of structures.
7 . The photovoltaic device of claim 1 , wherein the first plurality and the second plurality of structures do not completely overlap.
8 . The photovoltaic device of claim 1 , wherein the substrate is an electrically insulating material.
9 . The photovoltaic device of claim 1 , wherein the substrate is flexible.
10 . The photovoltaic device of claim 1 , wherein the substrate is transparent.
11 . The photovoltaic device of claim 1 , wherein the first and second plurality of structures are of the same composition as the substrate.
12 . The photovoltaic device of claim 1 , wherein the first and second plurality of structures and the substrate form a single crystal.
13 . The photovoltaic device of claim 1 , wherein a top portion of the first and second plurality of structures is rounded or tapered.
14 . The photovoltaic device of claim 3 , wherein the one or more junctions are selected from a group consisting of a p-i-n junction, a p-n junction, and a heterojunction.
15 . The photovoltaic device of claim 1 , wherein the first plurality and the second plurality of structures comprise nanowires.
16 . The photovoltaic device of claim 1 , further comprising a cladding layer.
17 . The photovoltaic device of claim 1 , wherein reflective layer is non-planar.
18 . The photovoltaic device of claim 1 , further comprising a cladding layer.
19 . The photovoltaic device of claim 18 , wherein the cladding layer is substantially transparent to visible light with a transmittance of at least 50%; the cladding layer is made of an electrically conductive material; the cladding layer is a transparent conductive oxide; the cladding layer is a material selected from a group consisting of indium tin oxide, aluminum doped zinc oxide, zinc indium oxide, Si 3 N 4 , Al 2 O 3 , and HfO 2 , and zinc tin oxide; the cladding layer has a thickness from 10 nm to 500 nm; and/or the cladding layer is configured as an electrode of the photovoltaic device.
20 . The photovoltaic device of claim 1 , wherein the reflective layer is an electrically conductive material; the reflective layer has a reflectance of at least 50% for visible light; the reflective layer has a thickness from about 20 nm to about 500 nm; and/or the reflective layer is an electrode of the photovoltaic device.
21 . The photovoltaic device of claim 3 , further comprising a surface passivation layer configured to passivate the one or more junctions.
22 . The photovoltaic device of claim 21 , wherein one or more junctions comprise an exposed area not covered by the surface passivation layer.
23 . A method of converting light to electricity comprising:
exposing a photovoltaic device to light, wherein the photovoltaic device comprises a substrate, a first plurality of structures essentially perpendicular to the substrate and disposed on a first face of the substrate, and a second plurality of structures essentially perpendicular to the substrate and disposed on a second face of the substrate;
drawing an electrical current from the photovoltaic device.
24 . A photo detector comprising the photovoltaic device of claim 1 , wherein the photo detector is configured to output an electrical signal when exposed to light.
25 . A method of detecting light comprises:
exposing the photovoltaic device of claim 1 to light;
measuring an electrical signal from the photovoltaic device.
26 . The method of claim 25 , wherein the electrical signal is an electrical current, an electrical voltage, an electrical conductance and/or an electrical resistance.
27 . The photovoltaic device of claim 1 , wherein the first plurality and the second plurality of structures comprise microwires.