Analysis of the growth of cadmium zinc telluride in an electrodynamic gradient freeze furnace via a self-consistent, multi-scale numerical model

A multi-scale model has been developed to study the growth of single crystals of cadmium zinc telluride (CZT) in an industrial electrodynamic gradient freeze (EDG) furnace. A global model (CrsyVUn) that computes furnace heat transfer is coupled with a local model (CATS2D) that solves for heat transfer, melt flow, and melt-crystal interface shape in an iterative scheme to compute a self-consistent solution. Details of how the two models are coupled have a strong bearing on the convergence of the iterations. One-way coupling of the models, i.e., providing either flux or temperature boundary conditions from the global model to the local model without iteration, yields solutions that differ significantly from the self-consistent solution of the multi-scale model.