Bifacial cell with extruded gridline metallization

• US 8,399,283 B2
• Filed: 06/01/2009
• Issued: 03/19/2013
• Est. Priority Date: 11/17/2005
• Status: Expired due to Fees

• Current Assignee: SolarWorld Industries GmbH
• Original Assignee: Solarworld Innovations GmbH (Solarworld AG)
• Inventors: Fork, David K., Shea, Stephen Patrick
• Primary Examiner(s): Smith, Zandra
• Assistant Examiner(s): Perkins, Pamela E
• Application Number:
  US12/476,228
• Publication Number:
  US 20090239332A1
• Time in Patent Office: 1,387 Days
• Field of Search: None
• US Class Current: 438/72
• CPC Class Codes: H01L 31/022425 for solar cells
• CPC Class Codes: H01L 31/02363 of the semiconductor body itself, e.g. textured active layers
• CPC Class Codes: H01L 31/048 Encapsulation of modules
• CPC Class Codes: H01L 31/056 the light-reflecting means being of the back surface reflector [BSR] type
• CPC Class Codes: H01L 31/0684 double emitter cells, e.g. bifacial solar cells
• CPC Class Codes: H01L 31/18 Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
• CPC Class Codes: H01L 31/1876 Particular processes or apparatus for batch treatment of the devices
• CPC Class Codes: Y02E 10/52 PV systems with concentrators
• 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

Provided is a bifacial photovoltaic arrangement comprising a bifacial cell which included a semiconductor layer having a first surface and a second surface, a first passivation layer formed on the first surface of the semiconductor layer and a second passivation layer formed on the second surface of the semiconductor layer, and a plurality of metallizations formed on the first and second passivation layers and selectively connected to the semiconductor layer. At least some of the metallizations on the bifacial photovoltaic arrangement comprising an elongated metal structure having a relatively small width and a relatively large height extending upward from the first and second passivation layers.

Claims

1. A method for producing a bifacial photovoltaic device, the photovoltaic device including a semiconductor layer, one or more doped regions, a first surface, a second surface, and a plurality of conductive lines disposed over the first surface and the second surface and contacting one or more doped regions at the first surface and the second surface, the method comprising:

forming a blanket passivation layer on each of the first surface and the second surface of the semiconductor; and

utilizing a direct-write metallization apparatus arrangement to deposit the plurality of conductive lines over the blanket passivation layer such that each of the plurality of conductive lines electrically contacts an associated doped region of the one or more doped regions the semiconductor layer,

wherein utilizing the direct-write metallization apparatus arrangement to deposit the plurality of conductive lines further comprises forming said conductive lines such that all of said conductive lines cover less than 10% of the first surface and the second surface.

2. The method of claim 1, further comprising:

utilizing a non-contact patterning apparatus arrangement to define a plurality of openings through the first passivation layer and the second passivation layer, each the openings exposing a corresponding one of the one or more doped regions of the semiconductor layer; and

utilizing the direct-write metallization apparatus to deposit a plurality of contact portions into the plurality of openings such that each said contact portion is disposed in a corresponding opening of the plurality of openings,

wherein utilizing the direct-write metallization apparatus arrangement to deposit the plurality of conductive lines comprises depositing each of the plurality of conductive lines over a corresponding group of said plurality of contact portions.

3. The method according to claim 1, wherein utilizing the direct-write metallization apparatus comprises utilizing an inkjet-type printhead.

4. The method according to claim 1, wherein utilizing the direct-write metallization apparatus comprises utilizing a dispensing nozzle.

5. The method according to claim 1, wherein utilizing the direct-write metallization apparatus to deposit the plurality of contact portions comprises depositing a silicide-forming metal into each of the plurality of openings.

6. The method according to claim 4, wherein utilizing the direct-write metallization apparatus further comprises depositing a second metal onto the silicide-forming metal disposed in each of the plurality of openings, wherein the second metal has a greater electrical conductivity than the silicide forming metal.

7. The method according to claim 1, wherein utilizing the direct-write metallization apparatus to deposit the plurality of contact portions comprises depositing a first silicide-forming metal in said openings formed through the first passivation layer and depositing a second silicide-forming metal in said openings formed through the second passivation layer, wherein the first silicide-forming metal differs from the second silicide-forming metal.

8. The method according to claim 1, wherein utilizing the direct-write metallization apparatus further comprises depositing a second metal onto the first silicide-forming metal disposed in said openings formed through the first passivation layer and depositing a third metal onto the second silicide-forming metal disposed in said openings formed through the second passivation layer, wherein the second metal differs from the third metal.

9. The method according to claim 1, wherein the semiconductor layer comprises at least one of crystalline silicon, amorphous silicon, CdTe (Cadmium Telluride), and CMS (copper-indium-gallium-diselenide).

10. The method according to claim 1, wherein utilizing the direct-write metallization apparatus arrangement to deposit the plurality of conductive lines further comprises forming said conductive lines such that each of said conductive lines has an aspect ratio exceeding 2:

1.

11. The method according to claim 1, wherein utilizing the direct-write metallization apparatus arrangement to deposit the plurality of conductive lines further comprises matching a first mechanical moment of the conductive lines disposed over the first surface with a second mechanical moment of the conductive lines disposed over the second surface.

12. The method according to claim 11, wherein matching the first and second mechanical moments comprises forming the conductive lines such that a first coefficient of thermal expansion of said conductive lines disposed over the first surface sufficiently match with a second coefficient of thermal expansion of said conductive lines disposed over the second surface such that counteracting forces are generated by thermal expansion/contraction of said conductive lines disposed over the first and second surfaces.

13. The method according to claim 11, wherein matching the first and second mechanical moments comprises forming an associated layer over each of the conductive lines disposed over the first surface such a first stress generated by thermal expansion of said conductive lines and said associated layers disposed over the first surface is equal to a second stress generated by said conductive lines disposed over the second surface.

15. The method of claim 13, further comprising utilizing a non-contact patterning apparatus to define a plurality of first openings through the first passivation layer to the first surface and a plurality of second openings through the second passivation layer to the second surface, each the first and second openings exposing a corresponding one of the one or more doped regions of the semiconductor layer.

17. The method of claim 15, wherein utilizing the direct-write metallization apparatus to form the plurality of second conductive lines comprises:

utilizing the direct-write metallization apparatus to deposit a plurality of second contact portions into the plurality of second openings such that each said second contact portion contacts the second surface; and

utilizing the direct-write metallization apparatus to deposit the plurality of second conductive lines such that each said second conductive line contacts a corresponding group of said plurality of second contact portions, whereby said each second conductive line is electrically connected to said corresponding one of the one or more doped regions by way of said corresponding group of said plurality of second contact portions.

14. A method for producing a bifacial photovoltaic device, the photovoltaic device including a semiconductor layer having one or more doped regions, and opposing first and second surfaces, the method comprising:

forming a first blanket passivation layer on the first surface and a second blanket passivation layer on the second surface;

utilizing a direct-write metallization apparatus to form a plurality of first conductive lines that extend over the first blanket passivation layer and electrically contact associated doped regions of the one or more doped regions through the first surface; and

utilizing the direct-write metallization apparatus to form a plurality of second conductive lines that extend over the second blanket passivation layer and electrically contact associated doped regions of the one or more doped regions through the second surface,

wherein utilizing the direct-write metallization apparatus to form the plurality of first and second conductive lines further comprises forming said first and second conductive lines such that all of said first and second conductive lines cover less than 10% of the first surface and the second surface.

16. The method of claim 14, wherein utilizing the direct-write metallization apparatus to form the plurality of first conductive lines comprises:

utilizing the direct-write metallization apparatus to deposit a plurality of first contact portions into the plurality of first openings such that each said first contact portion contacts the first surface; and

utilizing the direct-write metallization apparatus to deposit the plurality of first conductive lines such that each said first conductive line contacts a corresponding group of said plurality of contact portions, whereby said each first conductive line is electrically connected to said corresponding one of the one or more doped regions by way of said corresponding group of said plurality of contact portions.

18. The method of claim 14,

wherein utilizing the direct-write metallization apparatus deposit the plurality of second contact portions comprises depositing a first silicide-forming metal in said plurality of first openings, and

wherein utilizing the direct-write metallization apparatus deposit the plurality of second contact portions comprises depositing a second silicide-forming metal in said plurality of second openings, wherein the first silicide-forming metal differs from the second silicide-forming metal.

19. The method of claim 14, wherein utilizing the direct-write metallization apparatus to deposit the plurality of first and second conductive lines further comprises matching a first mechanical moment of the first conductive lines with a second mechanical moment of the second conductive lines.

20. A method for producing a bifacial photovoltaic device, the photovoltaic device including a semiconductor layer having opposing first and second surfaces, the method comprising:

forming a first blanket passivation layer on the first surface and a second blanket passivation layer on the second surface;

utilizing a non-contact patterning apparatus to define a plurality of first openings through the first passivation layer to the first surface and a plurality of second openings through the second passivation layer to the second surface;

utilizing a direct-write metallization apparatus to deposit a plurality of first contact portions into the plurality of first openings and a plurality of second contact portions into the plurality of second openings; and

utilizing the direct-write metallization apparatus to deposit a plurality of first conductive lines such that each said first conductive line contacts a corresponding group of said plurality of first contact portions, and to deposit a plurality of second conductive lines such that each said second conductive line contacts a corresponding group of said plurality of second contact portions,

wherein utilizing the direct-write metallization apparatus to deposit a plurality of first conductive lines further comprises forming said conductive lines such that all of said conductive lines cover less than 10% of the first surface and the second surface.