Migration behavior and aggregation mechanism of SiC particles in silicon melt during directional solidification process

SiC inclusions in a multicrystalline silicon ingot have a negative effect on the performance of solar cells. The migration behavior and aggregation mechanism of SiC particles in the silicon melt during the directional solidification process was studied. Results show that SiC particles collide and aggregate in the melt due to the effect of melt flow. Larger aggregation of SiC particles is easily deposited at the bottom of the melt, whereas smaller SiC particles are pushed to the top of melt. Meanwhile, the particles migrate to the edge of melt under the effect of electromagnetic force. Furthermore, the enrichment region of SiC particles can be controlled by adjusting the temperature field distribution of the melt. With an increase of the melt temperature, the SiC particles are enriched at the top of the silicon ingot, indicating that SiC particles can be effectively separated from silicon.