Screen Printed, Large Area Bifacial N-PERT cells with Tunnel Oxide Passivated Back Contact

This paper reports on the effect of screen printed metallization on passivation quality of TOPCon structure. A metallized TOPCon using fire-through screen printing process showed excellent saturation current density (metallized J_0,TOPCon ~ 15 fA/cm²) with very low contact resistance (~6 mohm-cm²). However, screen printed metallization increased the recombination at low level injection level (≤ 0.1 sun) causing some degradation in iFF. We successfully fabricated 20.1% bifacial ntype PERT cells with ~180 ohm/□ implanted B emitter and TOPCon rear using screen printing and fire through contact technology. Detailed cell analysis showed that high series resistance and saturation current density of metallized B emitter limited the cell performance to ~20%.