Review on Ribbon Silicon Techniques for Cost Reduction in PV

The shortage of Si feedstock and the goal of reducing W_p costs in photovoltaics (PV) is the driving force to look for alternatives to ingot grown multicrystalline (me) Si wafers which have the highest share in the PV market. Ribbon Si seems to be a very promising candidate as no kerf losses occur, resulting in reduced Si costs per W_p. In addition, there is no need for the energy consuming crystallization of the ingot and therefore energy payback times can be significantly reduced. The higher defect density in ribbon Si materials has to be taken into account during cell processing, but ribbon materials already commercially available show excellent efficiencies, while for the most promising techniques efficiencies are significantly lower, but very promising. In this presentation an overview of ribbon Si technologies currently under research will be given, based on available data on crystal growth as well as solar cell processing and cell parameters