Apparatus and methods for solar energy conversion using nanoscale cometal structures

• US 7,943,847 B2
• Filed: 08/24/2006
• Issued: 05/17/2011
• Est. Priority Date: 08/24/2005
• Status: Expired due to Fees

• Current Assignee: Trustees of Boston College (Boston College)
• Original Assignee: Trustees of Boston College (Boston College)
• Inventors: Rybczynski, Jakub A., Kempa, Krzysztof J., Naughton, Michael J., Ren, Zhifeng
• Primary Examiner(s): Nguyen; Nam X
• Assistant Examiner(s): Salzman; Kourtney R
• Application Number:
  US11/509,269
• Publication Number:
  US 20070137697A1
• Time in Patent Office: 1,727 Days
• Field of Search: 136243-265, 356/424, 356/434, 252/501.1
• US Class Current: 136/255
• CPC Class Codes: B01J 23/755 Nickel
• CPC Class Codes: B01J 37/348 Electrochemical processes, e.g. electrochemical deposition or anodisation
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H01L 31/035227 the quantum structure being quantum wires, or nanorods carbon nanotubes H10K85/211
• CPC Class Codes: H01L 31/07 the potential barriers being only of the Schottky type
• CPC Class Codes: H01L 31/1804 comprising only elements of Group IV of the Periodic Table
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

An apparatus and methods for solar conversion using nanoscale cometal structures are disclosed herein. The cometal structures may be coaxial and coplanar. A nanoscale optics apparatus for use as a solar cell comprises a plurality of nanoscale cometal structures each including a photovoltaic material located between a first electrical conductor and a second electrical conductor. A method of fabricating solar cells comprises preparing a plurality of nanoscale planar structures; coating a plurality of planar surfaces of the plurality of planar structures with a photovoltaic semiconductor while leaving space between the plurality of planar surfaces; and coating the photovoltaic semiconductor with an outer electrical conductor layer, wherein a portion of the outer electrical conductor layer is located between the planar structures to form coplanar structures.

Claims

1. A solar cell comprising:

a substrate having a major surface; and

a plurality of nanoscale cometal structures each comprising a photovoltaic material located between a first electrical conductor and a second electrical conductor,

wherein the first electrical conductor is configured to function as an electromagnetic radiation receiving antenna,

wherein the plurality of cometal structures are defined by a long dimension perpendicular to the major surface of the substrate, and wherein the long dimension is substantially parallel to a direction of propagation of incident electromagnetic radiation,

wherein a thickness of the photovoltaic material is equal to or less than a carrier diffusion length, and

wherein an overall inter-electrode spacing in each cometal structure is approximately equal to the thickness of the photovoltaic material and sufficiently small to propagate transverse electromagnetic (TEM) waves of incident electromagnetic radiation in between the first electrical conductor and the second electrical conductor.

2. The solar cell of claim 1 further comprising a protruding portion of the first electrical conductor extending beyond the second electrical conductor.

3. The solar cell of claim 1 wherein the substrate supports the plurality of nanoscale cometal structures.

4. The solar cell of claim 1 further comprising a transparent conductor located between the first electrical conductor and the second electrical conductor.

5. The solar cell of claim 1 wherein the plurality of cometal structures are connected in series, resulting in a total voltage being approximately a sum of voltages photo-generated by each cometal structure.

6. The solar cell of claim 1 wherein the plurality of cometal structures are connected in parallel, resulting in a total voltage between a minimum and a maximum of the voltages photo-generated by each cometal structure.

7. The solar cell of claim 1 wherein a the thickness of the photovoltaic material is approximately the same as the carrier diffusion length.

8. A solar cell comprising:

a substrate having a major surface; and

a plurality of nanoscale coaxial structures each comprising an electrically conducting core contacting a photovoltaic material and coated with an outer electrical conductor layer,

wherein the electrically conducting core is configured to function as an electromagnetic radiation receiving antenna,

wherein the plurality of coaxial structures are defined by a long dimension perpendicular to the major surface of the substrate, and wherein the long dimension is substantially parallel to a direction of propagation of incident electromagnetic radiation,

wherein a thickness of the photovoltaic material is equal to or less than a carrier diffusion length, and

wherein an overall inter-electrode spacing in each coaxial structure is approximately equal to the thickness of the photovoltaic material and sufficiently small to propagate transverse electromagnetic (TEM) waves of incident electromagnetic radiation in between the electrically conducting core and the outer electrical conductor layer.

9. The solar cell of claim 8 wherein the photovoltaic material contacts a portion of the electrically conducting core.

10. The solar cell of claim 8 further comprising a protruding portion of the electrically conducting core extending beyond the outer electrical conductor layer.

11. The solar cell of claim 8 wherein the substrate supports the plurality of nanoscale coaxial structures.

12. The solar cell of claim 8 wherein the photovoltaic material contains a p-n junction comprised of photovoltaic semiconductors.

13. The solar cell of claim 8 wherein the photovoltaic material contains a p-i-n junction formed of a p-type semiconductor layer, an intrinsic photovoltaic semiconductor layer and an n-type semiconductor layer.

14. The solar cell of claim 8 further comprising a transparent conductor located between the electrically conducting core and the outer electrical conductor layer.

15. The solar cell of claim 8 wherein the plurality of coaxial structures are connected in series, resulting in a total voltage being a sum of voltages photo-generated by each coaxial structure.

16. The solar cell of claim 8 wherein the plurality of coaxial structures are connected in parallel, resulting in a total voltage between a minimum and a maximum of the voltages photo-generated by each cometal structure.

17. The solar cell of claim 8 wherein the thickness of the photovoltaic material is approximately the same as the carrier diffusion length.