Large metallization wrap through solar cells using electroless plating

In this paper we present a realisation of large area metallization wrap through (MWT) back contact solar cell with electroless plated contacts. The MWT cell is a very promising back contact solar cell concept, since if electroless metallization is used the additional effort required to process MWT compared to conventional buried contact cells is limited to the formation of a small number of holes. In addition, the concept can easily be applied to very large area cells and is suited to thin wafers. Two different metallization processes are investigated. The best MWT cells of each process reached an efficiency of 16.6% and 17.0% on an area of 140 cm/sup 2/. The efficiency difference originates from a difference in bulk lifetime, resulting from the generation of meta-stable defects during the Ni sintering step required for one of the processes.