NOVELTY - The system for directional solidification of silicon, comprises an outer mold jacket (210), an insulation layer lining a wall of the outer mold jacket, and a heat conducting layer lining a bottom of the outer mold jacket, where the heat conducting layer includes a graphite containing layer (214) adjacent to the outer mold jacket and a cast silicon carbide layer (216) forming an exposed surface to contact molten silicon when in use. The silicon carbide layer has a thickness of 2-3 inches. The graphite containing layer has a thickness of 1-2 inches.    USE - The system is useful for directional solidification of silicon to produce a silicon material for use in a solar cell.    ADVANTAGE - The system provides high degree of control over the temperature gradient and the corresponding directional crystallization, thus allowing more effective directional solidification and producing silicon with higher purity.    DETAILED DESCRIPTION - The system comprises an outer mold jacket (210), an insulation layer lining a wall of the outer mold jacket, and a heat conducting layer lining a bottom of the outer mold jacket, where the heat conducting layer includes a graphite containing layer (214) that is provided adjacent to the outer mold jacket and a cast silicon carbide layer (216) forming an exposed surface to contact molten silicon when in use. The silicon carbide layer has a thickness of 2-3 inches. The graphite containing layer has a thickness of 1-2 inches. A bottom of the outer mold jacket includes a steel layer having thickness of 0.76 inches. The graphite containing layer includes a set of separate graphite bricks, and semi graphite. The system further comprises a support structure spacing a mold (200) above a floor surface and defining a space between the mold and the floor, an air circulation system to move air within a set of flow pathways in the space, and adjustable baffles to control the flow of air within the space. The air circulation system includes horizontal fan located within the space. An INDEPENDENT CLAIM is included for a method for directional solidification of silicon.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic cross-sectional view of a mold.    Mold (200)    Floor (202)    Outer mold jacket (210)    Graphite containing layer (214)    Cast silicon carbide layer. (216)