Selective structuring of thin-film solar cells by ultrafast laser ablation

Thin film solar cells have shown a big potential to decrease cost of manufacturing for photovoltaic power generation. Despite of all research attempts to optimize materials and efficiency the mass production of thin film solar cells is still employing some mechanical steps of structuring, where thin films with a thickness of approximately 1 mu m are selectively separated to be galvanic isolated. Here we show the structuring of CIS (CuInSe2) thin films solar cells by picosecond laser ablation. We show a selective removal of single layers on sample substrates and on real solar cells. We utilized high repetition rate lasers in order to maximize process speed enabling an application of ultrafast laser structuring for mass production.