| 摘要 |
PURPOSE:To enable the mass production of high-purity silicon in a short time at a low cost by charging metallic silicon into a crucible nonoxidizing the metallic silicon, melting the metallic silicon in a nonoxidizing atmosphere and then keeping the silicon in this molten state in the atmosphere under a reduced pressure. CONSTITUTION:Metallic silicon is purified. In the process, the silicon is charged into a crucible nonoxidizing the silicon and then melted in a nonoxidizing atmosphere. The resultant silicon in this molten state is kept in the atmosphere under a reduced pressure of <=10Pa to carry out the purification of the metallic silicon. P, As, Ca, O, N, etc., can be removed to <=1ppm content according to this method for purification and the yield of the silicon after purification thereof is high. The high-purity silicon can be mass-produced at a low cost in a short time by using inexpensive metallurgical silicon as a starting raw material. Thereby, the cost of a solar cell heretofore using conventional expensive silicon for semiconductors can be reduced. |
