Numerical Simulation of Temperature Field in Directional Solidification Process of Polysilicon Ingot

The effects of the different process conditions on the solid-liquid interface shape and temperature gradient were investigated by the numerical simulation.The results can provide the reference for optimizing processing parameters in the polysilicon solidification process and controlling the solidification process effectively.The simulation results show that the crystal growth rate and the temperature gradient increase with the crucible descending ratio increase.When crucible descending ratio is less than 60mm/h,the solid-liquid interface maintains a concave interface.Keeping a certain crucible descending ratio and constant cold source temperature,cooling rate has no effect on solid-liquid interface shape.But it influences the temperature gradient in the ingot obviously.The cooling rate increases with the temperature gradient in the ingot.