The Influence of Heat Flux Control Unit for Improving the Multi- Crystalline Silicon Ingot for Photovoltaic Application

This study investigates two kinds of heat exchanger block, one with heat flux control unit and the other without heat flux control unit for use in Directional solidification (DS) furnace to produce multi-crystalline silicon (mc-Si) ingot for photovoltaic application. A global numerical model was established to investigate the effect of both the configurations on the temperature distribution, thermal stress distribution, and impurities distribution in the solidified mc-Si ingot during the DS process. The numerical results indicate that the shape of the melt-crystal interfaces remained relatively slightly convex when the heat flux control unit was used and lowest thermal stress throughout the entire silicon ingots was obvious. Carbon concentration and silicon carbide (SiC) concentration also have been reduced due to the use of the heat flux control unit in DS furnace. The heat flux control unit used DS furnace has taken lower power compared to without use of heat flux control unit. The use of the heat flux control unit in the modified system gives better results compared to without use of heat flux control unit in the conventional system.