Crystallization in amorphous germanium

Abstract

Crystallization has been studied in amorphous germanium layers produced by evaporation. The crystalline fraction is deduced from conductivity measurements. Depending upon the conditions of evaporation homogeneous or heterogeneous nucleation is observed and the crystallization is induced at the surface or in the bulk. The variations with temperature of the growth rate of crystallization and of the nucleation rate are obtained from the kinetics of the crystallization measured at various temperatures. The results allow to provide orders of magnitude for the thermodynamical parameters which characterize the crystallization.