Buoyancy and rotation in small-scale vertical Bridgman growth of cadmium zinc telluride using accelerated crucible rotation

Theoretical simulations of vertical Bridgman growth of cadmium zinc telluri de are performed to study the effects of the accelerated crucible rotation technique (ACRT). The results indicate that thermal buoyancy has a dramatic effect on the flow, even in a relatively small system at high rotation rat e, contrary to assertions made in recent papers by Liu et al. (J. Crystal G rowth 219 (2000) 22). We demonstrate their prior results greatly overstate the effectiveness of ACRT at promoting mixing. Contrary to conventional wis dom, the ACRT rotation cycle considered here for a small-scale growth syste m actually suppresses mixing in the melt near the ampoule wall, resulting i n diffusion-limited mass transport there. (C) 2001 Elsevier Science B.V. Al l rights reserved.