Abstract：Single-phase ZnGeP2 polycrystals were successfully synthesized by modified two-zone vapor-transporting method（MTVM）and mechanic oscillations technique, directly from high pure(6N) Zn, Ge, and red P elements according to the ZnGeP2 stoichiometry and 0.1~0.3% P-rich. The synthesis reaction was carried in a special quartz ampoule to prevent the ampoule exploding by controlling the temperature. With the presynthesized polycrystalline, the integral and gray-black ZnGeP2 single crystals with size of Φ15mm×25mm were obtained by modified Vertical Bridgman Method (VBM). As-grown crystals were characterized by X-ray diffraction and IR spectrophotometer. It was found that there were two spontaneous cleavage faces which were (112) and (101) orientations respectively. After annealed at 550~600℃ surrounded by the ZnGeP2 powder in vacuum, the infrared transmission of a ZGP wafer with size of 10×10×2mm3 is above 55% in the region of 2~12μm .
