Reverse Stack Structures for Thin-Film Photovoltaic Cells

• US 20130276888A1
• Filed: 04/20/2012
• Published: 10/24/2013
• Est. Priority Date: 04/20/2012
• Status: Active Grant

• Current Assignee: Zetta Research and Development LLC - AQT Series (Zetta Research, LLC)
• Original Assignee: AQT Solar Incorporated
• Inventors: Munteanu, Mariana Rodica, Murali, Amith Kumar, Bartholomeusz, Brian Josef, Hayes, Kirk
• Granted Patent: US 8,993,370 B2
• Time in Patent Office: Days
• US Class Current: 136/264
• CPC Class Codes: H01L 31/02008 for solar cells or solar cell modules
• CPC Class Codes: H01L 31/0322 comprising only AIBIIICVI chalcopyrite compounds, e.g. Cu In Se2, Cu Ga Se2, Cu In Ga Se2
• CPC Class Codes: H01L 31/0326 comprising AIBIICIVDVI kesterite compounds, e.g. Cu2ZnSnSe4, Cu2ZnSnS4
• CPC Class Codes: H01L 31/03928 including AIBIIICVI compound, e.g. CIS, CIGS deposited on metal or polymer foils
• CPC Class Codes: H01L 31/1864 Annealing
• CPC Class Codes: H01L 31/1892 methods involving the use of temporary, removable substrates
• CPC Class Codes: Y02E 10/541 CuInSe2 material PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

In one embodiment, a method includes depositing a photoactive layer onto a first substrate, depositing a contact layer onto the photoactive layer, attaching a second substrate onto the contact layer, and removing the first substrate from the photoactive layer, contact layer, and second substrate.

Claims

1. A method comprising:

depositing a photoactive layer onto a first substrate;

depositing a contact layer onto the photoactive layer;

attaching a second substrate onto the contact layer; and

removing the first substrate from the photoactive layer, contact layer, and second substrate.

2. The method of claim 1, further comprising depositing a buffer layer between the first substrate and the photoactive layer, the buffer layer comprising a metal.

3. The method of claim 2, further comprising annealing the photoactive layer and the buffer layer, wherein the metal from the buffer layer and a chalcogen from the photoactive layer react to form an n-type semiconductor material in the annealed buffer layer.

4. The method of claim 2, wherein the metal is Mo.

5. The method of claim 3, wherein the chalcogen of the photoactive layer that reacts with the metal comprises one or more of S or Se.

6. The method of claim 1, wherein attaching the second substrate onto the contact layer comprises applying a conductive adhesive to the second substrate and the contact layer.

7. The method of claim 6, wherein the conductive adhesive comprises silver epoxy.

8. The method of claim 1, wherein removing the first substrate from the photoactive layer, contact layer, and second substrate comprises peeling the photoactive layer, contact layer, and second substrate off of the first substrate.

9. The method of claim 1, further comprising:

depositing a semiconductor layer onto the photoactive layer; and

depositing a conducting layer onto the semiconductor layer.

10. The method of claim 1, wherein the photoactive layer comprises Cu, Zn, Sn, and one or more of S or Se.

11. The method of claim 1, wherein the photoactive layer comprises crystalline Cu₂ZnSn(S, Se)₄.

12. The method of claim 1, wherein the photoactive layer comprises Cu, one or more of In or Ga, and one or more of S or Se.

13. The method of claim 1, wherein the photoactive layer comprises crystalline CuIn_yGa_(1-y)(S, Se)₂, and wherein 0≦

y≦

1.

14. The method of claim 1, wherein the second substrate comprises a flexible metallic foil.

15. The method of claim 1, further comprising depositing a release layer between the photoactive layer and the first substrate to facilitate removal of the first substrate from the photoactive layer, contact layer, and second substrate.

16. The method of claim 15, wherein the release layer comprises BN.

17. The method of claim 1, wherein the first substrate comprises soda lime glass.

18. The method of claim 1, further comprising annealing the photoactive layer.

19. The method of claim 1, wherein heat is provided during annealing using a combination of radiative, convective, and conductive heating to the photoactive layer.

20. A method comprising:

depositing a conducting layer on a substrate;

depositing a buffer layer onto the conducting layer, the buffer layer comprising a metal; and

depositing a photoactive layer onto the buffer layer, the photoactive layer comprising chalcogenide material operable to react with the metal of the buffer layer to form an n-type semiconductor material in the buffer layer.

21. The method of claim 20, further comprising annealing the photoactive layer and the buffer layer, the annealed buffer layer including an n-type semiconductor formed from the metal and the chalcogenide material of the photoactive layer.

22. The method of claim 20, further comprising depositing a conductive layer onto the photoactive layer.

23. The method of claim 21, wherein the n-type semiconductor material formed in the buffer layer comprises MoSe₂.

24. The method of claim 20, further comprising forming a plurality of wires in a plurality of recessed portions of the substrate, the plurality of wires being electrically connected to the conducting layer.

25. The method of claim 20, further comprising forming a plurality of wires in a plurality of recessed portions of the conducting layer.

26. A photovoltaic cell comprising:

a substrate;

a conducting layer deposited onto the substrate;

a buffer layer disposed on the conducting layer, the buffer layer including an n-type semiconductor material; and

a photoactive layer deposited onto the buffer layer.

27. The photovoltaic cell of claim 26, wherein the n-type semiconductor material comprises Mo.

28. The photovoltaic cell of claim 26, wherein the n-type semiconductor comprises one or more of S or Se.

29. The photovoltaic cell of claim 26, further comprising a contact layer deposited onto the photoactive layer.

30. The photovoltaic cell of claim 26, further comprising a plurality of wires formed in a plurality of recessed portions of the substrate, the plurality of wires being electrically connected to the conducting layer.

31. The photovoltaic cell of claim 26, further comprising a plurality of wires formed in a plurality of recessed portions of the conducting layer.