Simulation of Single Crystalline CdZnTe Solidification Process

Abstract

Single crystals of Cd1-xZnxTe (0 ≤ x ≤ 0.1) (CZT/CdZnTe) are used in manufacture of gamma and X-ray detectors and as substrates for epitaxial growth of HgCdTe. Computer simulation for the solidification of CZT was performed using finite elements. The simulation results indicate that a lower translation speed of the quartz ampoule within the Bridgman furnace determines a lower concavity of the liquid interface which assures a good crystalline quality. When the rate is 3.32 mm/h the concavity is 58% greater than for a speed of 0.50 mm/h. It was experimentally found that when growing at low speed, 1.66 mm/h, the process is more stable and improves the crystalline quality due that only two grains were generated in CZT ingots. Meanwhile a faster growth speed- 3.32 mm/h- generates a large amount of grains in the CZT ingot.