Numerical Investigation of Cone Shape Grooved DS Block to Improve the mc–Si Ingot Quality

Abstract

Multicrystalline silicon solar cells occupy 62% in crystalline silicon solar cell production. It is grown by the directional solidification process. Solidification control has a vital role in directional solidification process. Cone shape groove is made in the directional solidification block to enhance the outgoing heat flux in the center region than the peripheral region. Five directional solidification furnaces are simulated for making a multicrystalline silicon ingot. First furnace is the conventional furnace, the second furnace has 30 mm × 85 mm groove block, the third furnace has 40 mm × 85 mm groove block, the fourth furnace has 50 mm × 85 mm groove block and the fifth furnace has 60 mm × 85 mm groove block. The von Mises stress in the maximum volume of the conventional and modified grown ingots are below the range of critical value. In conventional case 7% of the ingot volume is above critical stress value and in the modified cases 2.5% of the ingot volume is above critical stress value. If axial and radial temperature gradient is combined in the 50 mm × 85 mm groove block leads to better results.