Multilayer Foil Metallization for All Back Contact Cells

We present a new back-contact back-junction (BCBJ) cell metallization strategy based upon preformed multilayer laminates. Capable of being produced in low-cost roll-to-roll processes, the laminates consist of aluminum foil bonded to an insulating film of PET. Several methods to produce base contacts were studied. One method to achieve n+ base contacts involved laser firing of phosphorus-treated aluminum foils. Another method utilized carrier selective base contacts, and efficiencies as high as 20.7% were obtained. BCBJ cells with multilayer aluminum foil can lead to the production of low-cost PV modules with high performance.