Bifacial cell with extruded gridline metallization

• US 20070107773A1
• Filed: 05/03/2006
• Published: 05/17/2007
• Est. Priority Date: 11/17/2005
• Status: Abandoned Application

• Current Assignee: Solarworld Innovations GmbH (Solarworld AG)
• Original Assignee: Palo Alto Research Center, Inc. (Xerox Holdings Corp.)
• Inventors: Fork, David, Shea, Stephen
• Application Number:
  US11/416,707
• Publication Number:
  US 20070107773A1
• Time in Patent Office: Days
• US Class Current: 136/256
• 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 bifacial photovoltaic arrangement comprising:

a bifacial cell including, 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 first surface and the second surface of the semiconductor layer,

wherein at least some metallizations comprise an elongated metal structure having a relatively small width and a relatively large height extending upward from the first and second passivation layers.

2. The photovoltaic arrangement of claim 1, further including the metallizations having contact portions extending through openings in the first passivation layer to the first surface of the semiconductor .

3. The photovoltaic arrangement of claim 2, further including the metallizations having contact portions extending through openings in the second passivation layer to the second surface of the semiconductor layer

4. The photovoltaic arrangement of claim 1, further including at least one support portion formed along a side edge of at least one of the metallizations, wherein the support portion comprises a transparent material.

5. The photovoltaic arrangement of claim 1, further including a plurality of the bifacial cells in electrical contact with each other to form a bifacial photovoltaic module.

6. The photovoltaic arrangement of claim 5, further including a reflector on one of a layer of glass or plastic, the reflector being integrated into the arrangement in a manner to be able to reflect light to backsides of the bifacial solar cells.

7. The photovoltaic arrangement of claim 6, wherein the integrated reflector is on an outer surface of the layer of plastic or glass.

8. The photovoltaic arrangement of claim 7, further including one of a layer of protective paint of plastic laminate provided to protect the reflector.

9. The photovoltaic arrangement of claim 6, wherein the integrated reflector is on an inner surface of the layer of plastic or glass.

10. The photovoltaic arrangement of claim 9, wherein the integrated reflector is metal.

11. The photovoltaic arrangement of claim 10, further including a transparent insulator positioned to separate the integrated metal reflector from the bifacial cells.

12. The photovoltaic arrangement of claim 11, wherein the transparent insulator has a higher melt temperature than an adjacent lamination material.

13. The photovoltaic arrangement of claim 6, wherein the integrated reflector is patterned so that no conductive path exists to short bifacial solar cells together.

14. The photovoltaic arrangement of claim 6, wherein the integrated reflector consists of dielectric films.

15. The photovoltaic arrangement of claim 14, wherein the dielectric films selectively reflect light that is useable to produce electricity in the bifacial solar cells and pass light that would heat the bifacial solar cells without generating appreciable electricity.

16. The photovoltaic arrangement of claim 6, wherein the reflector is a Lambertian.

17. The photovoltaic arrangement of claim 6, wherein the reflector is a specular reflector.

18. The photovoltaic arrangement of claim 5, wherein the bifacial cells are in a bifacial cell module with a plastic laminate front layer and a glass back layer.

19. The photovoltaic arrangement of claim 1, wherein the passivation layers of the bifacial cell are configured of amorphous silicon.

20. The photovoltaic arrangement of claim 1, wherein the semiconductor layer has a thickness of about 150 microns or less, and the metallizations on the first and second surfaces have substantially the same mechanical moments.

21. The photovoltaic arrangement of claim 1, wherein the metallizations cover less than 10% of the first and second surfaces.

22. 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 conductive lines to contact the doped regions of the semiconductor layer.

23. The method of claim 22, further including,

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 contact portions into the openings.

24. The method according to claim 22, wherein the direct-write metallization apparatus is an inkjet-type printhead.

25. The method according to claim 22, wherein the direct-write metallization apparatus is a dispensing nozzle.

26. The method according to claim 22, wherein utilizing the direct-write metallization apparatus to deposit the contact portion into each of the plurality of openings comprises depositing a silicide-forming metal into each of the openings.

27. The method according to claim 26, wherein utilizing the direct-write metallization apparatus further comprises depositing a second metal onto the silicide forming metal, wherein the second metal has a greater electrical conductivity than the silicide forming metal.

28. The method according to claim 27, wherein the silicide forming metal deposited in openings through the first passivation layer is different from the suicide forming metal deposited in openings through the second passivation layer.

29. The method according to claim 27, wherein the second metal deposited onto the suicide forming metal deposited in openings through the first passivation layer is different from the second metal deposited onto the silicide forming metal deposited in openings through the second passivation layer.

30. The method according to claim 22, wherein the semiconductor layer comprises at least one of crystalline silicon, amorphous silicon, CdTe (Cadmium Telluride), or CIGS (copper-indium-gallium-diselenide).

31. The method according to claim 22, wherein the conductive lines have an aspect ratio exceeding 2:

1.

32. The method according to claim 22, wherein the conductive lines cover less than 10% of the first surface and the second surface.

33. A bifacial photovoltaic arrangement comprising:

a bifacial cell including,

a semiconductor layer having a first surface and a second surface, and a thickness of about 150 microns or less;

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, the metallizations on the first passivation layer and the metallizations on the second passivation layer having sufficiently similar mechanical moments to maintain the semiconductor layer substantially un-warped.

34. The photovoltaic arrangement according to claim 33, wherein the matching of the mechanical moments to maintain the semiconductor layer substantially un-warped, includes using at least some multilayer metallizations.