Method of continuously forming an array of photovoltaic cells electrically connected in series

• US 4,746,618 A
• Filed: 08/31/1987
• Issued: 05/24/1988
• Est. Priority Date: 08/31/1987
• Status: Expired due to Term

• Current Assignee: United Solar Systems Corp.
• Original Assignee: Energy Conversion Devices
• Inventors: Barnard, Timothy, Nath, Prem
• Primary Examiner(s): Weisstuch, Aaron
• Application Number:
  US07/091,475
• Time in Patent Office: 267 Days
• Field of Search: 437/2, 437/4, 437/51, 437/64-65, 437/205, 437/211, 437/225, 437/228, 136/244, 136/258 AM
• US Class Current: 438/62
• CPC Class Codes: H01L 31/03921 including only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 31/03926 comprising a flexible substrate
• CPC Class Codes: H01L 31/046 PV modules composed of a plurality of thin film solar cells deposited on the same substrate
• CPC Class Codes: H01L 31/0463 characterised by special patterning methods to connect the PV cells in a module, e.g. laser cutting of the conductive or active layers
• CPC Class Codes: H01L 31/048 Encapsulation of modules
• CPC Class Codes: H01L 31/206 Particular processes or apparatus for continuous treatment of the devices, e.g. roll-to roll processes, multi-chamber deposition
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A method of continuously electrically interconnecting in series a plurality of smaller area photovoltaic cells from a continuous, elongated web of photovoltaic cell material which is maintained in continual motion.

Claims

1. A method of continuously electrically interconnecting in series a continually moving array of discrete photovoltaic cells formed from a single large area photovoltaic cell, said method including the steps of:

providing an elongated, continuous web of photovoltaic cell material, said continuous web comprising a continuous substrate upon which a plurality of continuous thin film layers of semiconductor alloy material are disposed;

continuously moving said photovoltaic cell material to a take-up station;

forming n slits, where n is an integer equal to or greater than 1, photovoltaic cell material for dividing said material into n+1 smaller area cells;

each said slit extending through the semiconductor alloy material and the substrate and being of a length selected to include a non-slitted connector between each terminus of said slit and the edge of said cell proximate thereto so that said connectors are adapted to maintain the structural integrity of said elongated web;

establishing electrical series communication between adjacent smaller area cells disposed on opposite sides of said slit; and

severing said connectors, whereby said continuous web of photovoltaic cell material is converted into an array of discrete photovoltaic cells electrically interconnected in series.

2. A method as in claim 1, including the further step of electrically isolating a minor portion of the surface of each discrete cell from a major portion of the surface of each discrete cell.

3. A method as in claim 2, wherein said step of electrically isolating comprises forming grooves through the layers of semiconductor alloy material.

4. A method as in claim 2, wherein said step of electrically isolating comprises removing the layers of semiconductor alloy material from the substrate.

5. A method as in claim 2, including the further step of insulating the slits so that adjacent cells are electrically isolated from one another.

6. A method as in claim 5, wherein the step of isolating adjacent cells comprises laminating the back surface of the substrate with an electrically insulating material;

and insulating the slitted space between adjacent cells with an electrically insulating material.

7. A method as in claim 5, wherein the step of isolating adjacent cells comprises:

utilizing an electrically insulating substrate and depositing a common layer of electrically conductive material prior to slitting said cells; and

insulating the slitted space between adjacent cells with an electrically insulating material.

8. A method as in claim 6, including the further step of electrically interconnecting adjacent cells across said insulated slit.

9. A method as in claim 8, wherein the step of interconnecting cells across said slit comprises forming a plurality of electrically conductive grid lines, which lines extend from said major portion of said surface of one discrete cell to said minor portion of said surface of said adjacent discrete cell, whereby the upper surface of said one cell is electrically connected in series to the lower surface of said adjacent cell.

10. A method as in claim 8, including the further step of electrically interconnecting in series a plurality of discrete cells so as to obtain a desired voltage therefrom.

11. A method as in claim 10, including the further step of encapsulating the the upper surface of said cells with an electrically insulating material.

12. An improved method of electrically connecting in series an array of smaller area photovoltaic cells formed from a continuous elongated web of photovoltaic cell material, said web formed from continuous layers of semiconductor alloy material deposited onto an elongated web of substrate material;

said method including the steps of;

forming a plurality of discrete smaller area photovoltaic cells from said web of cell material; and

electrically interconnecting said discrete cells in series while maintaining said web in continuous motion.

13. A method as in claim 12, including the further step of forming at least one slit in said elongated web of cell material, each said slit extending through the semiconductor alloy material and the substrate and being of a length selected to include a non-slitted connector between each terminus of said slit and the edge of said cell proximate thereto.

14. A method as in claim 13, wherein electrical communication between adjacent discrete cells on opposite sides of said slits is established by filling said slitted space with electrically insulating material and forming electrically conductive grid lines thereacross.

15. A method as in claim 14, including the further step of laminating both sides of the array of series connected smaller area photovoltaic cells.