摘要
The removal of impurity phosphorus from metallurgical grade silicon is one of the major problems on purification of metallurgical grade silicon for solar grade silicon preparation. The thermodynamics on vacuum refining process of the metallurgical grade silicon was studied via separation coefficient of impurity phosphorus in the metallurgical grade silicon and vapor-liquid equilibrium composition diagram of Si-P binary alloy at different temperatures. The behaviors of impurity phosphorus in the vacuum distillation process were examined. The results show that the vacuum distillation should be taken to obtain silicon with less than 10-7 P,and the impurity phosphorus is volatilized easily by vacuum distillation in thermodynamics. Phosphorus is distilled from the molten silicon and concentrated in vapor phase.
The removal of impurity phosphorus from metallurgical grade silicon is one of the major problems on purification of metallurgical grade silicon for solar grade silicon preparation. The thermodynamics on vacuum refining process of the metallurgical grade silicon was studied via separation coefficient of impurity phosphorus in the metallurgical grade silicon and vapor-liquid equilibrium composition diagram of Si-P binary alloy at different temperatures. The behaviors of impurity phosphorus in the vacuum distillation process were examined. The results show that the vacuum distillation should be taken to obtain silicon with less than 10^-7 P, and the impurity phosphorus is volatilized easily by vacuum distillation in thermodynamics. Phosphorus is distilled from the molten silicon and concentrated in vapor phase.
出处
《中国有色金属学会会刊:英文版》
CSCD
2007年第A02期1022-1025,共4页
Transactions of Nonferrous Metals Society of China
基金
Project(50674050) supported by the National Natural Science Foundation of China
Project(2006BAE01B08) supported by Sustentation Project of Science and Technology of China
Project(20060674004) supported by the Doctorial Programs Foundation of Ministry of Education of China.
关键词
冶金学
硅
真空蒸馏精炼
除磷
热力学
metallurgical grade silicon
solar grade silicon
refining
vacuum distillation
thermodynamics
phosphorus removal