Simulation of directional solidification furnace with bottom opening insulation to grow quality mc-Si ingot for PV applications

Abstract

Abstract2D axi-symmetric transient simulation based on the thermo-plastic model was carried out for analyzing the thermal field of directional solidification (DS) furnaces during the solidification process. The simulation was carried out for two different furnaces: One conventional DS furnace and the other a modified DS furnace. In the modified DS furnace the bottom insulation was provided with a circular shape opening. The simulation was performed for conventional and modified furnaces which suggest that the lifting velocity of the side insulation in the conventional DS furnace significantly affects the solidification process of mc-Si ingot and the opening speed of the bottom insulation in the modified DS furnace has less influence on solidification and also gives optimal conditions to grow good quality mc-Si ingots. The results for conventional and modified DS grown mc-Si ingots were taken with two different insulation lifting profiles and their influence on thermally induced stress, dislocation density and growth rate were compared and analyzed.