Kinetics of the Vapor Growth of II-VI Compound Crystals. II. Zinc Selenide

Vapor growth of ZnSe crystals was made by a modified Piper method in Ar atmosphere at relatively low temperatures, 1490°K and 1400°K. Temperature gradient was varied from 1.6 to 7.0 deg/cm and Ar pressure from 0.20 to 0.33 atm at 1490°K and from 0.03 to 0.09 atm at 1400°K. Single crystals of the size of 1 cm 3 were obtained at 1490°K. The growth rate was measured to be ranging from 10 -8 to 10 -7 mol/cm 2 sec, and found to be limited by the diffusion process of vapors at 1490°K but, if anything, by the vaporization or condensation process at 1400°K at low Ar pressures. Vaporization-rate constant under equilibrium vapor pressure, k s , was estimated to be at least 2×10 -3 mol/atm 3 / 2 cm 2 sec at 1400°K.