Next generation printing technologies for fine-line metallization of Si solar cells

Next generation printing technologies for solar cell front side metallization have to allow for narrower finger grid lines with higher aspect ratios. Moreover, significant silver paste reductions have to be achieved. In this work the newly developed dispensing technology as well as stencil printing are presented and compared with conventional screen printing. The results show that the dispensing technology is the most promising approach to improve the Ag paste utilization by optimizing the finger geometry without the need of paste modifications. Homogenous finger grid lines with widths down to ~30µm are demonstrated. Furthermore dispensing leads to solar cell efficiency increases of 2% relative in comparison to state-of-the-art single step screen printing.