Optimize stoichiometric ratio of ZnSe polycrystalline materials by open system

The ZnSe polycrystalline materials which were synthesized using Zn and Se as the raw matierials and the iodine as the transport agent were purified by open system. High purity argon gas as protective atmosphere, purified temperatures were 500°C, 550°C and 800°C, EDS and TGA results indicate that the stoichiometric ratio of ZnSe polycrystalline materials treated at 800°C is very close to the ideal stoichiometric ratio, and the starting temperature of sublimation of polycrystalline materials is higher than 850°C. The results of crystal growth by chemical vapor transport (CVT) method showed that ZnSe polycrystalline materials treated at 800°C eliminated Se deposition in the growth zone. After purification, the polycrystalline materials could satisfy the requirements of CVT method. In addition, mixed gas (H₂ 10% + Ar 90%) as protective atmosphere, the stoichiometric ratio of ZnSe polycrystalline materials treated under the same conditions is closer to the ideal stoichiometric ratio, the results are better than that argon gas as protective atmosphere.