Study on CdZnTe crystal growth parameters optimization

The factors influencing the shape of solid-liquid interface during the process of CdZnTe vertical Bridgman growth were investigated in this paper. The relationship between the temperature gradient and the solid-liquid interface parameter ¿ near the growth interface with different crucible dropping rate was obtained. Here ¿ represents the solid-liquid interfacial concave-convex extent. If ¿ is positive, the solid-liquid interface will be convex into solid phase region and if ¿ is negative, the solid-liquid interface will be convex into liquid phase region. Simulation results show that when the crucible dropping rate (Vp) was rather high (Vp = 50 mm/h), the value of ¿ dropped greatly with the increase of the solid-liquid interface temperature gradient, and when Vp was low (for example, Vp = 0.1 mm/h), the value of ¿ declined slowly and had a trend of turning positive value to negative value with the increase of temperature gradient. In particular, when Vp was about 1 mm/h, the solid-liquid interface tended to be flat with the increase of the temperature gradient. Therefore, it might be concluded that when the temperature gradient of solid-liquid interface was greater than 10 K/cm, and Vp was about 1 mm/h, rather flat solid-liquid interface during the process of crystal growth could be obtained. In addition, based on the simulation results, actual crystal growth experiments were implemented. The experimental results are roughly consistent with the simulation results.