Foil-based metallization of solar cells

Patent metadata

Field	Value
Publication number	US-9627566-B2
Application number	US-201514954030-A
Country	US
Kind code	B2
Filing date	Nov 30, 2015
Priority date	Mar 28, 2014
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

Approaches for the foil-based metallization of solar cells and the resulting solar cells are described. In an example, a solar cell includes a substrate. A plurality of alternating N-type and P-type semiconductor regions is disposed in or above the substrate. A conductive contact structure is disposed above the plurality of alternating N-type and P-type semiconductor regions. The conductive contact structure includes a plurality of metal seed material regions providing a metal seed material region disposed on each of the alternating N-type and P-type semiconductor regions. A metal foil is disposed on the plurality of metal seed material regions, the metal foil having anodized portions isolating metal regions of the metal foil corresponding to the alternating N-type and P-type semiconductor regions.

First claim

What is claimed is:

1. A solar cell, comprising:
a substrate;
a plurality of alternating N-type and P-type semiconductor regions disposed in or above the substrate; and
a conductive contact structure disposed above the plurality of alternating N-type and P-type semiconductor regions, the conductive contact structure comprising:
a plurality of metal seed material regions providing a metal seed material region disposed on each of the plurality of alternating N-type and P-type semiconductor regions; and
a metal foil disposed on the plurality of metal seed material regions, the metal foil having anodized portions isolating metal regions of the metal foil corresponding to the plurality of alternating N-type and P-type semiconductor regions.

2. The solar cell of claim 1 , wherein all exposed surfaces of the metal foil are anodized.

3. The solar cell of claim 1 , wherein the metal foil is an aluminum metal foil, and wherein the anodized portions are aluminum oxide portions.

4. The solar cell of claim 1 , wherein the metal foil is spot welded to the plurality of metal seed material regions.

5. The solar cell of claim 1 , wherein the plurality of metal seed material regions is a plurality of aluminum regions.

6. The solar cell of claim 5 , wherein each of the plurality of metal seed material regions has a thickness approximately in the range of 0.3 to 20 microns and comprises aluminum in an amount greater than approximately 97% and silicon in an amount approximately in the range of 0-2%.

7. The solar cell of claim 1 , wherein the metal foil has a thickness approximately in the range of 5-100 microns, and the anodized portions have a thickness approximately in the range of 1-20 microns.

8. The solar cell of claim 1 , wherein the plurality of alternating N-type and P-type semiconductor regions comprises a polycrystalline silicon layer formed above the substrate.

9. The solar cell of claim 8 , further comprising:
a trench disposed between each of the plurality of alternating N-type and P-type semiconductor regions, the trenches extending partially into the substrate.

10. The solar cell of claim 1 , wherein the substrate is a monocrystalline silicon substrate, and wherein the plurality of alternating N-type and P-type semiconductor regions comprises alternating N-type and P-type semiconductor regions disposed in the monocrystalline silicon substrate.

11. A solar cell, comprising:
a substrate;
a plurality of semiconductor regions disposed in or above the substrate; and
a conductive contact structure disposed above the plurality of semiconductor regions, the conductive contact structure comprising a metal foil disposed above the plurality of semiconductor regions, the metal foil having anodized portions isolating metal regions of the metal foil corresponding to the plurality of semiconductor regions.

12. The solar cell of claim 11 , wherein all exposed surfaces of the metal foil are anodized.

13. The solar cell of claim 11 , wherein the metal foil is an aluminum metal foil, and wherein the anodized portions are aluminum oxide portions.

14. The solar cell of claim 11 , wherein the metal foil has a thickness approximately in the range of 5-100 microns, and the anodized portions have a thickness approximately in the range of 1-20 microns.

15. The solar cell of claim 11 , wherein the plurality of semiconductor regions comprises a polycrystalline silicon layer formed above the substrate.

16. The solar cell of claim 15 , further comprising:
a trench disposed between each of the plurality of alternating N-type and P-type semiconductor regions, the trenches extending partially into the substrate.

17. The solar cell of claim 11 , wherein the substrate is a monocrystalline silicon substrate, and wherein the plurality of semiconductor regions comprises semiconductor regions disposed in the monocrystalline silicon substrate.

18. A solar cell, comprising:
a substrate;
a plurality of semiconductor regions disposed in or above the substrate; and
a conductive contact structure disposed above the plurality of semiconductor regions, the conductive contact structure comprising:
a plurality of metal seed material regions providing a metal seed material region disposed on each of the plurality of semiconductor regions; and
a metal foil disposed on the plurality of metal seed material regions, the metal foil having anodized portions isolating metal regions of the metal foil corresponding to the plurality of semiconductor regions.

19. The solar cell of claim 18 , wherein the metal foil is spot welded to the plurality of metal seed material regions.

20. The solar cell of claim 18 , wherein the plurality of metal seed material regions is a plurality of aluminum regions.

Assignees

• Harley Gabriel
• Kim Taeseok
• Sewell Richard Hamilton
• Morse Michael
• Smith David D
• Moors Matthieu
• Moschner Jens-Dirk
• Sunpower Corp
• Total Marketing Services

Inventors

• Harley Gabriel
• Kim Taeseok
• Sewell Richard Hamilton
• Morse Michael
• Smith David D
• Moors Matthieu
• Moschner Jens-Dirk

Classifications

• Y02E10/547

  Monocrystalline silicon PV cells · CPC title

• Y02E10/50

  Photovoltaic [PV] energy · CPC title

• H10F77/223

  for metallisation wrap-through [MWT] photovoltaic cells · CPC title

• H10F77/219 Primary

  Arrangements for electrodes of back-contact photovoltaic cells · CPC title

• H10F71/00

  Manufacture or treatment of devices covered by this subclass (patterning processes to connect thin photovoltaic cells in integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/33; manufacture or treatment of encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/80; manufacture or treatment of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00) · CPC title