Aluminum foil as back side metallization for LFC cells

The LFC (Laser-Fired-Contact) scheme procures certain modifications in the production process for the cell's back side, e.g. for the rear side metallization, compared to conventional cell manufacturing These changes yield the possibility to search for new, more efficient production processes, which are especially adapted to the LFC process. The slow and cost intensive but nevertheless standard evaporation step for the backside metallization layer of PERC cells can be replaced by using thin aluminum foil, which is fixed on the cell during the LFC laser step. First simple attempts have proven the feasibility of this approach. The first solar cells processed with this approach delivered efficiencies of up to 19.7 % compared to 21 % efficiency of the reference with evaporated aluminum so far.