Progress in fine-line metallization by co-extrusion printing on cast monosilicon PERC solar cells

• We developed a production ready fine-line front side metallization system.
• This coextrusion printing system can print on square and pseudo square wafers.
• An efficiency gain of 0.25% compared to standard front screen printing is shown.
• We achieved a record efficiency on cast mono-PERC silicon solar cells of 21.42%.
• A cost of ownership calculation for coextrusion yields in a saving of 4.0 Ct€/cell.

In this paper, we present our progress in co-extrusion printing for fine-line metallization. With this technique, 30 µm wide and 20 µm tall front grid fingers are currently printed. Applied to industrial size cast silicon PERC solar cells, a world record conversion efficiency of 21.42% has been demonstrated. This result was achieved with a production-ready co-extrusion printer that runs at a throughput of 2700 wafers per hour. Furthermore, a printhead is presented that has been developed to enable co-extrusion printing on pseudo-square wafers. Finally the cost advantage of the technology is discussed.