Abrasive electrochemical multi-wire slicing of solar silicon ingots into wafers

To meet the growing demands of the global photovoltaic (PV) industry, preparing large scale and ultrathin solar wafers becomes one of the key issues. This paper presents the preparatory investigations of slicing solar silicon ingot into wafers by an abrasive electrochemical method based on a multi-wire saw system. The anodic passivation on silicon can be controlled by applying an anodic potential during the mechanical slicing process, which improves the surface integrity and material removal rate remarkably. This new hybrid machining method has no influence on subsequent cleaning of wafers and preparing the solar cells, and the average photoelectric transformation efficiency is >17.5%. (C) 2011 CIRP.