Modelling of solution growth of silicon from small indium droplets – homogeneous nucleation

Abstract

The nucleation frequency and the size of the critical nucleus of silicon in an indium solution have been described on the basis of the classical theory. Due to a lack of reliable data for the free interface energy of crystalline silicon and liquid indium a simple approximation using the Young's equation and the Eötvös's rule has been applied. The results of the calculation have been compared with experimental data of melt solidification both of the chemically similar Ge and of a substance with a low melting point. In spite of the remaining uncertainties, the homogeneous nucleation of semiconductors in metallic solutions requires considerable undercooling. The high values of the interface energy are mainly responsible for this behaviour. From the calculated dependence of the size of the critical nucleus on the undercooling one can expect that micro-crystallites are stable in a slightly undercooled solution.