NOVELTY - Manufacturing a polysilicon ingot, comprises: (a) providing molten silicon in a container having a base portion; (b) maintaining a surface temperature of the molten silicon higher than the melting point of silicon; (c) increasing the temperature of the base portion of the container to a temperature (T2) lower than the melting point of silicon; (d) maintaining the surface temperature of the molten silicon higher than the melting point of silicon; and (e) reducing the temperature of the molten silicon to form the polysilicon ingot.    USE - The method is useful for manufacturing a polysilicon ingot (claimed) which is useful for a solar cell.    ADVANTAGE - The method: makes the polysilicon ingot having large grains, less grain boundaries, and good crystal quality, and thus exhibiting enhanced photoelectric conversion efficiency; and provides a photoelectric conversion efficiency of up to 17.47% and an open circuit voltage of up to 0.625 V for the solar cell.    DETAILED DESCRIPTION - Manufacturing a polysilicon ingot, comprises: (a) providing molten silicon in a container having a base portion; (b) maintaining a surface temperature of the molten silicon higher than the melting point of silicon while decreasing the temperature of the base portion of the container to a temperature (T1) lower than the melting point of silicon at a rate of at least 2.6 degrees C/minute; (c) increasing the temperature of the base portion of the container to a temperature (T2) lower than the melting point of silicon while maintaining the surface temperature of the molten silicon higher than the melting point of silicon; (d) maintaining the surface temperature of the molten silicon higher than the melting point of silicon while decreasing the temperature of the base portion of the container to a temperature lower than the melting point of silicon and then increasing the temperature of the base portion of the container to a temperature lower than the melting point of silicon; and (e) reducing the temperature of the molten silicon to form the polysilicon ingot.