Abstract
Three-dimensional axisymmetric, time-dependent simulations of the high-pressure vertical Bridgman growth of large-diameter cadmium zinc telluride are performed to study the effect of accelerated crucible rotation (ACRT) on crystal growth dynamics. The model includes details of heat transfer, melt convection, solid-liquid interface shape, and dilute zinc segregation. Application of ACRT greatly improves mixing in the melt, but causes an overall increased deflection of the solid-liquid interface. The flow exhibits a Taylor-Gortler instability at the crucible sidewall, which further enhances melt mixing. The rate of mixing depends strongly on the length of the ACRT cycle, with an optimum half-cycle length between 2 and 4 Ekman time units. Significant melting of the crystal occurs during a portion of the rotation cycle, caused by periodic reversal of the secondary flow at the solid-liquid interface, indicating the possibility of compositional striations.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 734-750 |
| Number of pages | 17 |
| Journal | Journal of Crystal Growth |
| Volume | 209 |
| Issue number | 4 |
| DOIs | |
| State | Published - Feb 2 2000 |
Bibliographical note
Funding Information:This work was supported in part by Sandia National Laboratory under contract SNL/LG-5513 and by the National Aeronautics and Space Administration, Microgravity Materials Science. Computational resources were provided by the University of Minnesota Supercomputing Institute and the Army High Performance Computing Research Center under the auspices of the Department of the Army, Army Research Laboratory cooperative agreement DAAH04-95-2-0003/contract DAAH04-95-C-0008, the content of which does not necessarily reflect the position or policy of the government, and no official endorsement should be inferred.