Silicon Recycling

Commercially available wafers have currently a thickness of 180 μm and are manufactured exclusively by wire saw technology. The kerf-loss is about 50 % of the utilized silicon. This doubles the material and energy costs per wafer. It stands to reason to replace traditional wire saw technology by other resource-saving technologies or to recycle the saw loss. Our R&D has developed  a recycling process for solar-grade silicon from kerf-loss. A recycling route with four main process steps was developed which enable the recycling of solar-grade silicon with high quality. The picture shows an CZ ingot produced by the four-step process starting from kerf-loss powder.  High lifetimes (Sinton) across the ingot length could be obtained.