In situ ultrasonic interface tracking for photovoltaic silicon directional solidification

This paper presents an experimental validation of in situ ultrasound technique for tracking the solid–liquid interface during directional solidification photovoltaic silicon. Ultrasound bursts are introduced from top into melt via tip a carbon glass waveguide directly plunged liquid. Several runs have been conducted using same thus demonstrating its reusability, mechanical resilience and appropriate acoustical chemical compatibility with melt. We present times flight analysis to track location interface. As part signal crosses solidifying ingot, we also measure cs, average celerity sound waves solid. Since cs exhibits significant dependance on crystal orientation, consider possibility use echoes extract some information crystalline orientation ingot. By quantifying uncertainties their dependence duration experiment particular, outline conditions necessary detect accurately