Flow and segregation control by accelerated rotation for vertical Bridgman growth of cadmium zinc telluride: ACRT versus vibration

The control of flow and segregation by accelerated crucible rotation is investigated by computer simulation of vertical Bridgman crystal growth of cadmium zinc telluride. In view of the cycle frequency, two extremes, i.e., the accelerated crucible rotation technique (ACRT) and angular vibration technique (AVT), are investigated and compared. For a simple benchmark system, it is clear that ACRT generates significant oscillatory growth and segregation, while increasing slightly the global mixing. On the other hand, AVT provides, essentially, a steady control and can reverse easily the radial segregation without enhancing the global mixing. Although both techniques generate similar averaged flow structures and reduce radial segregation, AVT is more effective for growth control.