Laser structuring for back junction silicon solar cells

Abstract We demonstrate mask‐free fabrication of a 22·0%‐efficient crystalline Si solar cell by applying laser ablation of Si and by laser ablation of protective coatings. The bulk absorber material is a p ‐type float zone silicon wafer and the designated cell area is 4 cm 2 . While the processing time of our laboratory‐type of laser system is far too slow for industrial processing, we estimate on the basis of our experiments that laser processing of 12·5 × 12·5 cm 2 ‐sized solar cells in just a few seconds is feasible with commercially available equipment. Copyright © 2006 John Wiley & Sons, Ltd.