Mask and plate copper metallization for silicon heterojunction and perovskite silicon tandem solar cells

To cope with the worldwide increasing demand for photovoltaics, it is inevitable for solar cell metallization to switch from scarce silver to abundantly available copper. To this end, this work offers a silver-free and industrially feasible ultra-low-temperature metallization approach called mask and plate. Using this metallization scheme, which is mainly based on inkjet printing of a resist and galvanic metal deposition, pure copper metal electrodes are applied to industrial M6-sized (edge length of 166 mm) silicon heterojunction (SHJ) solar cells' front sides. While the screen-printed reference cells use (6 ± 1) mg/W of silver, the mask and plate pendants use (4 ± 2) mg/W of copper instead on busbarless half cells' front sides. Due to a width reduction of the electrodes down to (14 ± 2) μm and the electrodes’ low lateral resistivity of (2.0 ± 0.6) μΩ cm, mask and plate outperforms screen printing regarding photoconversion efficiency by 0.6 %abs on average, while silver is completely substituted by copper. This work further demonstrates the applicability of mask and plate copper metallization to 1.21 cm2-sized perovskite silicon tandem solar cells without significant damage. It can, thus, be an enabler for silver-free industrial metallization of next-generation solar cells.