Novel Foil Interconnects for Back-Contact Silicon Solar Cells

Large area back-contact solar cells enable module costs almost as low as those of PERCs but with higher efficiency. Traditional tabbing and stringing interconnects are problematic for back-contact cells, however, as placing all the tabs on one side of the wafer causes bowing due to CTE mismatch. Back-contact cells can be effectively encapsulated using Cu conductive back-sheets (CBS) with electrically conductive adhesive (ECA) interconnects but the cost is higher than for ribbon tabbing. In this paper we present a method for replacing the Cu CBS with a cheaper Al version and the ECA with several cheaper and potentially more robust methods for connecting the foil to the cell.