Method for polycrystalline silicon ingot casting
A method for polycrystalline silicon ingot casting is disclosed, which is as follows: a. using a crystal with both density and melting point higher than that of silicon as induction seed crystal for crystal growth and impurity absorption center, b. cutting the prepared crystal into single crystal wafer, c. chemically washing the resulting single crystal wafer, d. putting the washed single crystal wafer into the bottom of quartz ceramic crucible with a graphite guard board, e. then feeding silicon material into the quartz ceramic crucible, f. putting the quartz ceramic crucible into a polycrystalline growth furnace, g. evacuating the polycrystalline growth furnace and charging argon gas as a protective gas, h. heating and melting silicon material, i. adjusting the temperature to make the molten silicon material gradually solidify from the bottom to the top, j. finally finishing the growth of polycrystalline silicon by means of high temperature annealing and cooling. A method for polycrystalline silicon ingot casting by means of induction of a crystal with certain crystal orientation is disclosed. The fluctuating range of crystal quality in different zones of the crystal ingot is greatly reduced, therefore decreasing the fluctuating range of battery efficiency and improving quality of the crystal.