Segregation of Si-Al Alloy to remove boron and boron activity in silicon solid phase
Solar grade silicon(6 N)was adopted as raw material,aluminum and boron as impurity research objects in Si-Al Alloy.Concentration ratio of silicon to boron was kept constant during the experiment,then changed the process temperature and the ratio of Si to Al concentration.The result shows that impurity Boron moves from solid Si phase to Si-Al alloy phase,and thus the purpose of Boron removal is achieved.The most obvious effect of Boron removal are under the condition of temperature at 1 623 K and the condition of mass ratio of silicon to aluminum at 5∶4,the removal rate of Boron has reached 87.8％.It infers that temperature and mass ratio of silicon to aluminum are important factors affecting the boron removal efficiency.Under lower temperature and mass ratio of silicon to a-luminum conditions,boron impurities can be removed more effectively from silicon.What's more,the activity of Boron in solid Si phase is also studied,the expression of the activity of Boron has been obtained.It is found that the activity of Boron in solid Si phase is inversely proportional to the temperature and proportional to the content of Bo-ron in solid Si phase.
NETL
NSTL
万方数据
