18.8 % efficient laser-doped semiconductor fingers screen-printed silicon solar cell with light-induced plating

Abstract

The practical realization of high efficiency laser-doped semiconductor fingers (SCF) silicon solar cell is inhibited by high contact resistance. By plating the SCF with metal, a new SCF cell concept known as the “Advanced SCF” (AdvSCF) cell that can resolve the contact resistance problem is presented. In the first AdvSCF cells demonstrated in this work, the nickel (Ni) plating coverage across the cell was found to be non-uniform with Ni voids mostly concentrated around the busbar. This was found to be avoidable by ensuring that the spin-on phosphoric acid dopant layer was uniformly thick across the whole cell area and especially at the busbar. With uniform Ni plating coverage achieved, in a batch of 6 AdvSCF cells, an average batch efficiency of 18.40 % was achieved with the highest at 18.82 %. This was achieved without any experimental optimization of the front grid design or other cell properties, implying that there is potential to achieve significantly higher efficiency levels.