Photovoltaic cell and method of fabricating the same

Patent metadata

Field	Value
Publication number	US-2016204283-A1
Application number	US-201414912407-A
Country	US
Kind code	A1
Filing date	Aug 11, 2014
Priority date	Aug 18, 2013
Publication date	Jul 14, 2016
Grant date	—

Abstract

A photovoltaic cell device is disclosed. The device comprises: an active region having a plurality of spaced-apart elongated nanostructures aligned vertically with respect to an electrically conductive substrate, wherein each elongated nanostructure has at least one p-n junction characterized by a bandgap within the electromagnetic spectrum, and is coated by an electrically conductive layer being electrically isolated from the substrate.

First claim

1 . A photovoltaic cell, comprising:
an active region having a plurality of spaced-apart elongated nanostructures aligned vertically with respect to an electrically conductive substrate, wherein each elongated nanostructure has at least one p-n junction characterized by a bandgap within the electromagnetic spectrum, and is coated by an electrically conductive layer being electrically isolated from said substrate; and electronic circuitry for extracting from said substrate and said conductive layer electrical current and/or voltage generated responsively to light incident on said active region.

2 . The photovoltaic cell of claim 1 , wherein said electrically conductive layer comprises a metal.

3 . The photovoltaic cell of claim 1 , wherein said electrically conductive layer comprises a metal silicide selected from the list consisting of nickel silicide, cobalt silicide, palladium silicide, platinum silicide, iron silicide, titanium silicide and tungsten silicide.

4 - 5 . (canceled)

6 . The photovoltaic cell according to claim 1 , wherein said at least one p-n junction comprises a plurality of p-n junctions.

7 . The photovoltaic cell according to claim 1 , wherein said at least one p-n junction comprises a p-type region and an n-type region arranged generally concentrically in a core-shell relation.

8 . The photovoltaic cell of claim 7 , wherein said at least one p-n junction comprises a plurality of p-type regions and n-type regions arranged to form a plurality of generally concentric shells.

9 . The photovoltaic cell according to claim 7 , wherein at least a few of said p-type regions and n-type regions are graded thereamongst.

10 . The photovoltaic cell according to claim 9 , wherein at least a few of said p-type regions and n-type regions are made of a A x B 1-x compound, wherein x is from 0 to 1, wherein A and B are different semiconductor elements, and wherein said grading is characterized by a gradually varying value of x as a function of at least one of: (i) a radial direction of said respective elongated nanostructure and (ii) an axial direction of said respective elongated nanostructure.

11 . The photovoltaic cell according to claim 1 , wherein said at least one p-n junction comprises a plurality of p-type regions and n-type regions arranged to form a plurality of generally concentric shells, wherein at least a few of said p-type regions and n-type regions are made of a A x B 1-x compound, wherein x is from 0 to 1, wherein A and B are different semiconductor elements, and a value of x gradually varies as a function of at least one of: (i) a radial direction of said respective elongated nanostructure and (ii) an axial direction of said respective elongated nanostructure.

12 . The photovoltaic cell according to claim 10 , wherein A is silicon and B is germanium.

13 . The photovoltaic cell according to claim 2 , wherein each of at least a portion of said elongated nanostructure comprises an axially graded core, selected to constrain a unidirectional axial motion of charge carriers along said core.

14 . The photovoltaic cell according to claim 1 , wherein each of at least a portion of said elongated nanostructure comprises a plurality of concentric shells and an axially graded core, said axially graded core being selected to constrain a unidirectional axial motion of charge carriers along said core.

15 . The photovoltaic cell according to claim 1 , wherein said bandgap is within a range selected from the group consisting of the visible range, the ultraviolet range and the infrared range.

16 - 17 . (canceled)

18 . The photovoltaic cell according to claim 1 , wherein at least one of said elongated nanostructures is a single crystal heterostructure.

19 . A photovoltaic system comprising a plurality of photovoltaic cells, each being according to claim 1 .

20 . A method of harvesting solar energy, comprising:
exposing an active region of a photovoltaic cell to solar radiation, said active region having a plurality of spaced-apart elongated nanostructures aligned vertically with respect to an electrically conductive substrate, wherein each elongated nanostructure has at least one p-n junction characterized by a bandgap within the electromagnetic spectrum, and is coated by an electrically conductive layer being electrically isolated from said substrate; and extracting from said active region electrical current and/or voltage responsively to said solar radiation.

21 . The method of claim 20 , wherein said electrically conductive layer comprises a metal.

22 . The method according to claim 20 , wherein said at least one p-n junction comprises a plurality of p-n junctions.

23 . The method according to claim 20 , wherein said at least one p-n junction comprises a p-type region and an n-type region arranged generally concentrically in a core-shell relation.

24 . The method of claim 23 , wherein said at least one p-n junction comprises a plurality of p-type regions and n-type regions arranged to form a plurality of generally concentric shells.

25 . The method according to claim 23 , wherein at least a few of said p-type regions and n-type regions are graded thereamongst.

26 . The method according to claim 25 , wherein at least a few of said p-type regions and n-type regions are made of a A x B 1-x compound, wherein x is from 0 to 1, wherein A and B are different semiconductor elements, and wherein said grading is characterized by a gradually varying value of x as a function of at least one of: (i) a radial direction of said respective elongated nanostructure and (ii) an axial direction of said respective elongated nanostructure.

27 . The method according to claim 26 , wherein A is silicon and B is germanium.

28 . The method according to claim 20 , wherein each of at least a portion of said elongated nanostructure comprises an axially graded core, selected to constrain a unidirectional axial motion of charge carriers along said core.

29 - 32 . (canceled)

33 . A method of fabricating a photovoltaic cell, comprising:
growing on an electrically conductive substrate a plurality of spaced-apart elongated nanostructures aligned vertically with respect to said substrate, and having at least one p-n junction characterized by a bandgap within the electromagnetic spectrum; applying an electrically insulating layer on said substrate at a base level of said elongated nanostructures; and coating each of at least a portion of said elongated nanostructures by an electrically conductive layer, said electrically conductive layer being electrically isolated from said substrate by said electrically insulating layer.

34 - 46 . (canceled)

Assignees

• Univ Ramot

Inventors

• Patolsky Fernando
• Kosloff Alon

Classifications

• H10P14/3462

  Nanowires · CPC title

• H10P14/3411

  Silicon, silicon germanium or germanium · CPC title

• H10P14/3256

  Microstructure · CPC title

• H10P14/3254

  Graded layers · CPC title

• H10P14/3211 Primary

  Silicon, silicon germanium or germanium · CPC title