Improvement of Solar Cell Efficiencies for Ultrashort-Pulse Laser Contact Opening with Ni-Cu Plated Contacts by Optimized LCO-FFO Processing Order

We demonstrate that the standard fast firing (FFO) process at temperatures around 850°C can significantly reduce the damage caused by a UV picosecond pulse laser ablation for nickel-copper plated silicon solar cells. Although, the metallization via Ni/Cu/Ag plated contacts are a promising technology, disruption in the crystalline structure of silicon due to laser pulse damage pertains, which increases recombination and suppresses the efficiency of solar cell. We realize laser openings of linewidths ~12.7 mm to ~16.9 mm for metallization by plating on semi-finished industrial PERC solar cells and demonstrate that by flipping the chain of processes from FFO followed by laser ablation (LCO) to LCO followed by FFO, significant reduction is seen in laser-damage induced recombination which increases the power conversion efficiency () by 0.5% abs.