Ingots pulled with electron beam heating from skull - a new feedstock for FZ crystals applicable for solar cells

Efficiency of solar cells manufactured from FZ wafers is significantly higher than if CZ or multicrystalline wafers are used. High cost of FZ silicon, however, limits applicability of such wafers. The aim of present work was a creation of rather price-efficient way of FZ feedstock production on base of pulling from skull with electron beam heating. Ingots pulled from skull were then successfully used as a feedstock rods in industrial FZ pullers. Further an experimental furnace has been created which enables growth of crystals of rather stable diameter up to 240 mm from silicon chunks.