Substrate and collector grid structures for integrated series connected photovoltaic arrays and process of manufacture of such arrays
View Patent ↗This invention comprises deposition of thin film photovoltaic junctions on metal substrates which can be heat treated following deposition in a continuous fashion without deterioration of the metal support structure. In a separate operation an interconnection substrate structure is produced in a continuous roll-to-roll fashion. In this way the interconnection substrate structure can be uniquely formulated from polymer-based materials since it does not have to endure high temperature exposure. Cells comprising the metal foil supported photovoltaic junctions are then laminated to the interconnection substrate structure. Conductive interconnections are deposited to complete the array. The conductive interconnections can be accomplished with a separately prepared interconnection component. The interconnected array is produced using continuous roll-to-roll processing which avoids the need to use the expensive and intricate material removal operations currently taught in the art to achieve electrical interconnections among arrays of photovoltaic cells.
1. In combination, a light incident surface of a photovoltaic cell and a current collector structure for collecting current from said light incident surface, said current collector structure comprising,
a sheetlike substrate having a first substrate surface, said first substrate surface being formed by a polymeric adhesive,
a first material positioned over said first substrate surface, said first material comprising a polymer and being selectively positioned over said first substrate surface in a first trace pattern,
a second material covering said first trace pattern, said second material being electrically conductive and forming a second pattern characterized as substantially replicating at least a portion of said first trace pattern,
said combination characterized by having said first substrate surface overlaying said light incident surface such that said first substrate surface and said light incident surface face each other,
said combination further characterized by having at least a portion of said second material positioned between said first material and said light incident surface.
2. The combination of claim 1 wherein said photovoltaic cell comprises a thin film semiconductor structure.
3. The combination of claim 2 wherein said thin film semiconductor structure is positioned on a self-supporting metal based foil.
4. The combination of claim 1 wherein portions of said first substrate surface are adhesively bonded in direct contact to said light incident surface.
5. The combination of claim 1 wherein said sheetlike substrate comprises a material containing silicon.
6. The combination of claim 5 wherein said silicon containing material is in the form of a barrier layer.
7. The combination of claim 1 wherein said second pattern comprises multiple fingers joined by a buss, and wherein said second pattern is further characterized as comprising a monolithic deposit of conductive material extending to form portions of both said multiple fingers and said buss.
8. The combination of claim 7 wherein said monolithic deposit of conductive material is an electrodeposit.
9. The combination of claim 7 wherein said light incident surface is contained within peripheral edges of said light incident surface, and further characterized as having a portion of said buss positioned outside a said peripheral edge to serve as a an electrical contact surface.
10. The combination of claim 1 wherein said first material comprises printed material.
11. The combination of claim 1 wherein said first material comprises a material component characterized as having the ability to assist deposition of metal.
12. The combination of claim 11 wherein said material component comprises a seed catalyst suitable for initiating chemical metal deposition.
13. The combination of claim 1 wherein said first material comprises an electrically conductive polymer consisting of a homogeneous mixture of conductive particles in a polymeric matrix.
14. The combination of claim 1 wherein said first material comprises a directly electroplateable resin (DER).
15. The combination of claim 1 wherein said second material comprises an electroplated metal or metal-based alloy.
16. The combination of claim 15 wherein said electroplated metal or metal-based alloy comprises copper.
17. The combination of claim 1 wherein said second material comprises a low melting point metal based material.
18. The combination of claim 17 wherein said second material comprises indium.
19. The combination of claim 1 wherein said first material comprises a polymeric material functioning to join said electrically conductive material to said first substrate surface.
20. The combination of claim 1 wherein said first material comprises a material blend of polymer and silver.
21. The combination of claim 1 wherein said first material comprises carbon black.
22. The combination of claim 1 wherein said second material is in direct contact with said light incident surface.
23. The combination of claim 1 wherein said first material is in direct contact with said first substrate surface.
24. The combination of claim 1 wherein said first material is not in direct contact with said first substrate surface.
25. The combination of claim 1 wherein said first and second materials are in direct contact.
26. The combination of claim 1 wherein said first and second materials are not in direct contact.