Control of interface shape of cadmium zinc telluride grown via an electrodynamic gradient freeze furnace

We consider the feasibility of closed-loop control to control the interface shape of cadmium zinc telluride (CZT) grown via an electrodynamic gradient freeze (EDG) furnace. A simple proportional control algorithm is applied to a quasi-steady-state model to control the interface shape by adjusting the thermal gradient of the furnace temperatures. Three scenarios are enacted: actuation along the entire external boundary, along the solid portion only, and along the melt portion only. Actuation along the solid only proved to be the most successful of the three scenarios, and produced the unexpected benefit of a favorable convex interface shape.