Laser-welded Interconnection of Screen-printed Si Solar Cells

We demonstrate the laser welding of Al interconnects to the BSF rear-side of screen-printed two-side-contacted solar cells. The Al paste on the rear side of solar cell is laser-welded to an Al foil. This reduces the silver consumption of the solar cells by making silver pads on the rear side obsolete. Our proof-of-concept modules are free of laser damage. A 3-cell-module from 6” solar cells shows no change in fill factor within the statistical measurement uncertainty after artificial aging in 500 humidity-freeze cycles.