Thermodynamic properties of Si-Al, -Ca, -Mg binary and Si-Ca-Al, -Ti, -Fe ternary alloys

Metallic impurities such as Al, Ca, Mg, Ti, and Fe in Si deteriorate solar cell efficiency to a large extent. To discuss the possibility and efficienc y of impurity elimination process, the evaluation of their thermodynamic pr operties in molten Si are crucial. In the present work, the self-interactio n parameters of Al, Ca, and Mg and interaction parameters between Ca-M (M: Al, Ti, Fe) in molten Si at 1723 K were investigated by applying a chemical equilibration technique for Si based alloys with Pb. The activity coeffici ents of Al and Ca in molten Si at 1723-1823 K were also determined by the K nudsen effusion method.