Wettability of Silicon with Refractory Materials: A Review

Abstract

The wettability of ceramics by liquid metals is a key fac¬tor in many fields of high temperature materials science and engineering. The wetting behavior of liquid-silicon/refractory-materials system is especially important in refining and crystallization of silicon with respect to production of low cost solar cells but also in the production of silicon carbide based materials for advanced applications. This paper is a review on the wetting properties of molten silicon with various carbon, silicon carbide, silicon nitride and silica materials at high temperatures. Emphasis is given to reported data of the contact angles between molten silicon and ceramic substrates. The sessile drop method is the mainly used technique to determine the contact angles. A simple description of this method is also presented in this paper. In relation to chemical reaction between silicon and carbon with the formation of solid silicon carbide a model for the reaction kinetics and mechanisms is reported. Finally, the direction of future investigation of wettability of liquid-silicon with various refractory materials is proposed.