Electrolysis via vertical multi-junction photovoltaic cell

• US 8,293,079 B2
• Filed: 08/06/2009
• Issued: 10/23/2012
• Est. Priority Date: 08/28/2008
• Status: Expired due to Fees

• Current Assignee: MH Gopower Co., Ltd.
• Original Assignee: MH Solar Company Ltd.
• Inventors: Sater, Bernard L.
• Primary Examiner(s): Smith, Nicholas A.
• Application Number:
  US12/536,992
• Publication Number:
  US 20100051472A1
• Time in Patent Office: 1,174 Days
• Field of Search: 204/267, 205/628, 136/252
• US Class Current: 204/267
• CPC Class Codes: C25B 1/55 Photoelectrolysis
• CPC Class Codes: H01L 31/043 Mechanically stacked PV cells
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02E 60/36 Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Abstract

Systems and methods that employ a vertical multi junction (VMJ) photovoltaic cell, to provide electrolysis for water and generate hydrogen and oxygen. Electrical current generated by the VMJ flows through the electrolyte (e.g., salt water) for a decomposition thereof (e.g., hydrogen and oxygen)—whenever threshold voltage of electrolysis operation is reached (e.g., 1.6 volts for water electrolysis).

Claims

1. An electrolysis system comprising:

a vertical multi junction (VMJ) photovoltaic cell that includes a plurality of integrally bonded cell units, each cell unit with a plurality of layers that form a PN junction(s);

a textured surface of the VMJ photovoltaic cell for receipt of incident light, the textured surface for mitigation of bulk recombination losses for the VMJ photovoltaic cell, the textured surface facilitates confining light refraction of an incident light in a plane that cross sections the textured surface, the plane includes substantially repetitive cross sectional patterns, wherein light absorption is mitigated in p+ and n+ diffused doped regions of the VMJ;

an electrolyte that receives a current generated by the VMJ photovoltaic cell, a plurality of anodes and a plurality of cathodes formable by the integrally bonded cell units on a surface of the VMJ, to create the current that decomposes the electrolyte, and a plurality of metal layer protrusions, each protrusion bonded to one of the plurality of anodes and to one of the plurality of cathodes.

2. The electrolysis system of claim 1, the electrolyte is salt water.

3. The electrolysis system of claim 1, each cell units generates at least 0.6 volt.

4. The electrolysis system of claim 1, the VMJ photovoltaic cell has a grooved surface.

5. The electrolysis system of claim 4, the grooved surface is at least one of a V section, or U section, or combination thereof.

6. The electrolysis system of claim 1, each cell of the cell units includes a plurality of parallel semiconductor substrates that are stacked together, wherein a direction of stacking is substantially non-perpendicular to incident light that creates the current.

7. The electrolysis system of claim 6, a substrate includes impurity doped semiconductor material that form a PN junction.

8. The electrolysis system of claim 7 the substrate further includes a “

built-in”

electrostatic drift field that facilitates minority carrier movement towards the PN junction.

9. The electrolysis system of claim 7 the substrate having a back surface with reflection coatings.

10. The electrolysis system of claim 7 further comprising a buffer zone that safeguards the plurality of layers from at least one of a stress and strain induced on the VMJ photovoltaic cell.

11. The electrolysis system of claim 7, the buffer zone including substantially low resistivity material.

12. A method of electrolyzing an electrolyte comprising:

integrally bonding a plurality of active layers to form a VMJ photovoltaic cell;

generating a current from the VMJ cell for electrolysis of an electrolyte, forming a plurality of anodes and cathodes that protrude from a surface of the VMJ cell, and forming a plurality of metal layer protrusions, each protrusion bonded to one of the plurality of anodes and to one of the plurality of cathodes.

13. The method of claim 12 further comprising cooling the VMJ cell by a heat regulating assembly.

14. The method of claim 12 further comprising partially submerging the VMJ cell in the electrolyte.

15. The method of claim 12 further comprising

mitigating bulk losses in the VMJ cell via a textured surface of the VMJ cell that receives an incident light;

and

confining refracted incident light in a plane that cross sections the textured surface, the plane includes substantially repetitive cross sectional patterns.

16. The method of claim 12 further comprising increasing mechanical stability of the VMJ cell via buffer zones.

17. The method of claim 12, the integrally bonding act further comprising stacking cell units.

18. The method of claim 15 further comprising alloying silicon wafers and aluminum interfaces to form the VMJ cell.

19. The method of claim 15 further comprising employing impurity doped semiconductor material to form PN junctions in the VMJ cell.

20. An electrolysis system comprising:

decomposing means for decomposing an electrolyte via incident light comprising a plurality of anodes and cathodes on a surface of the decomposing means and comprising a plurality of metal layer protrusions, each protrusion bonded to one of the plurality of anodes and to one of the plurality of cathodes; and

means for mitigating bulk combination losses for the decomposing means, wherein refracted light is substantially confined in a plane that cross sections the means for mitigating bulk combination losses, the plane includes substantially repetitive cross sectional patterns;

wherein light absorption is mitigated in p+ and n+ diffused doped regions of the decomposing means.