Silver-free contacts in silicon solar cells

The authors of the paper 'Self-aligned laser opening and stencil metallization for silver-free contacts in silicon solar cells' (published in APL Electronic Devices) present a silver-free metallisation technique using self-aligned laser ablation through a stainless-steel stencil mask followed by thermal evaporation of aluminium.  This enabled precise 20 μm-wide point contacts with minimal laser-induced damage and good alignment.

The resulting AI fingers achieved contact resistivity of 1.39 mΩ.cm² and line resistivity of 15.74Ω/cm.  A pseudo-efficiency of 18.8% was demonstrated on TOPCon devices.

This approach offers a scalable, silver-free, path compatible with terawatt-scale photovoltaics.