Decreasing lateral segregation in cadmium zinc telluride via ampoule tilting during vertical Bridgman growth

We employ a 2D, planar computational model to study the effects of ampoule tilting on zinc segregation during the growth of cadmium zinc telluride in a low-gradient vertical Bridgman process. Tilting the axis of the ampoule away from the direction of gravity strongly affects the structure and strength of melt convection, which, in turn, modifies heat transfer and the shape of the solid–liquid interface. While these effects have relatively little direct effect on axial segregation, the pattern of lateral segregation is significantly changed by tilting. Optimal tilt angles are found that locally flatten lateral compositional profiles and that decrease a measure of overall segregation, compared to the case of growth in a perfectly vertical ampoule.