imec and SolarWorld presented ultra-thin (100µm), large-area (156x156mm2) PERC-type mono-silicon solar cells integrated in a 255Wp class A module. PERC-type silicon solar cells are promising candidates for next generation solar cell concepts for mass production because of their high conversion efficiencies combined with a reduced amount of silicon. Although the price of silicon feedstock for PV has come down significantly, it still makes sense for cost and performance reasons to explore technology solutions for thin, high-efficiency crystalline Si solar cells. The production yield for thin cells is typically an obstacle hindering full industrial adoption. In addition to increasing the conversion efficiency for thin cells by improving surface passivation, PERC technology also reduces the internal stress in the cells. This potentially enables less critical handling of the thin wafers in manufacturing. An averaged cell efficiency of 18.5 percent (+/- 0.5 percent) has been measured, with a best cell performing at 19 percent efficiency.