Towards implementation of floating cast method for growing large-scale high-quality multicrystalline silicon ingot using designed double crucibles

Abstract

We report on our attempt to scale up the floating cast method to grow high-quality multicrystalline silicon ingot using specially designed double crucibles. The cross section of the grown ingot showed the large crystal grain size originating from initially formed dendrite crystals around the top of the melt. By using double crucibles, the residual melt was spontaneously removed from the inner crucible to the outer one at the final stage of the crystal growth. Performance of small-scale solar cells revealed no significant changes between the top and the bottom part of the ingot except the edge of the bottom due to the non-uniform removal of the melt. This suggests that strong contact of the ingot with the crucible was successfully avoided by the double crucibles. Therefore, the floating cast method combined with specially designed double crucibles is concluded to be feasible, which could be implemented to realize high-quality multicrystalline silicon ingot for practical size wafers. Copyright © 2013 John Wiley & Sons, Ltd.