| 摘要 |
PURPOSE:To obtain an Si crystal for a solar cell without fixing the crystal and a mold by selecting the mixing ratio of Sn in a eutectic liquid of Si and Sn on starting. CONSTITUTION:Melt 3 consisting of high-purity Sn is brought into contact with columnar polysilicon 2 in a mold 1 composed of high-purity graphite. The mixing ratio of Sn in a starting melt is selected within a proper range. A heat flow 6 in the melt in the mold is generated only in the major axis direction of the mold during coagulation after heating, and the melt is grown in the shape of a columnar crystal aggregate excellently developing in the major axis direction. A residual melt rich in Sn is extruded naturally to the side wall of the mold in a cross section, which crosses at right angles with the major axis of the mold and in which there is no heat flow, and lastly remains positively in a shape that a section between the crystal and the side wall of the mod is filled, and the heat flow is controlled by a heater 4. According to the method, the crystal is not fixed to the mold when it is extracted from the mold. Sn adhering on the periphery can be melted and removed by Hcl. |
