Sn-Bi light-induced plating for interconnection of silicon solar cells

In this paper, the use of plated eutectic Sn-Bi for the interconnection of Ni/Cu plated laser-doped selective-emitter cells is reported. Coatings of eutectic Sn-Bi were formed over Ni/Cu plated fingers and busbars by controlling the Sn-Bi plating current density in a light-induced plating process. During lamination at 150 °C, the eutectic Sn-Bi alloy melts and provides good ohmic contact between the front busbar of the solar cell and interconnection ribbon therefore eliminating the need for soldering. Fill factors measured after lamination were comparable to those measured after plating, indicating that low resistance interconnection can be achieved.