Understanding horizontal Bridgman shelf growth of cadmium telluride and cadmium zinc telluride .1. Heat and momentum transfer

Heat and momentum transport during the horizontal Bridgman (HB) growth of cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) are investigated using a large-scale numerical model. The model employs the Galerkin finite element method to calculate two-dimensional, quasi-steady thermal and velocity fields in the presence of a free boundary, the solidification interface. Of particular interest in this study is the exploration of the shelf growth morphology during the HB growth of CdTe and CdZnTe. Our calculations clearly show that shelf growth naturally arises from simple heat transfer effects in the low-gradient system studied here. We also demonstrate how the shelf shape can be altered by process modifications. These results lend important insight to the benefits of shelf growth for production of CdTe and CdZnTe.