Non-contact printed aluminum metallization of Si photovoltaic devices

Alternative solution-based techniques such as aerosol jet printing offer the dual benefits of contactless pattern deposition and high material utilization. We have used aerosol jet printing to investigate non-contact printed Al metal ink as a replacement for screen printed Al back contacts on wafer Si solar cells. This particle-based ink can be prepared at high loadings of 60 weight % metal, which enables rapid deposition of 1 - 10 μm thick lines. Al lines printed on Si wafers and heated between 550 and 800 °C form low resistance contacts suitable for current extraction. The effectiveness of these printed Al back contacts has further been demonstrated by incorporating them into a series of 21 cm² crystalline Si solar cells that produced a champion power conversion efficiency of 13%.