A team from two renowned Swiss research institutes has created an innovative process which could simplify the production of rear contact silicon solar cells.
The process automatically aligns positive and negative contacts, first depositing a ‘negative’ contact through a plasma process, followed by a positive layer deposited over the full surface of the cell. The contact remains negative, even when covered with the positive contact.
EPFL states that the process has already achieved efficiencies of 23.2% in the laboratory, and that the potential exists to reach close to 26%.
The research was partly funded by Swiss PV equipment manufacturer Meyer Burger. They will work with EPFL and CSEM on developing industrial applications for the process, as part of ongoing developments in industrializing heterojunction technology. Further funding for the research came from the Commission for Technology and Innovation and the Swiss Federal Office of Energy.
Thanks to the potential for higher efficiencies and reduction of shading, back contact solar cells are a popular area of research in PV. Dutch equipment manufacturer Tempress announced earlier in April that it had completed a pilot line process for IBC cell production with efficiency above 21%, alongside partners ECN and Yingli.