Numerical Study of Interplay between Double-diffusive Convection and Interfacial Phenomena in Vertical Bridgman Crystal Growth of CdZnTe

The influence of transient heat and mass transfer processes in the melt, crystal and crucible on melt–solid interface shape and solute segregation in Bridgman growth of CdZnTe is investigated numerically. The computations elucidate a crucial role that the radial temperature gradient, formed by an interaction of latent heat release and external heat flux near the interface, plays in the evolution of the interface shape. Analysis of melt motion shows that solutal buoyancy force reduces the intensity of thermally induced convection up to a very low level. As a result, solute distribution in the melt is characteristic of diffusive transport regime. At the advanced stages of the process, when the growth interface moves slowly, and concentration of ZnTe in the melt becomes nearly homogeneous, complete mixing model is suitable for the description of axial ZnTe distribution in the crystal.