Abstract: Ternary chalcopyrite semiconductor ZnGeAs2 is a nonlinear optical material, which is expected to have important applications in laser frequency conversion.In this paper, the formation and synthesis mechanism of ZnGeAs2 polycrystal were discussed, and a method of ZnGeAs2 polycrystal synthesis was reported.High-purity (6N) Zn, Ge and As, were weighed as raw materials according to the stoichiometry with the excess of 1‰ Zn and 2‰ As.A single-phase ZnGeAs2 polycrystalline ingot was successfully synthesized, using two-temperature zone synthesis method, combining with mechanical oscillation, temperature oscillation and gradient cooling techniques.The X-ray diffraction (XRD) and Energy Dispersive Spectrometer (EDS) results show that the lattice constants of the synthesized products are a=b=0.56745 nm, c=1.11580 nm, which are consistent with the standard PDF card (No.730397).The atomic ratio of the elements is Zn∶Ge∶As=1.00∶0.98∶1.95, which is close to the ideal stoichiometric ratio.The results demonstrate that the synthesized products can be used for the growth of ZnGeAs2 single crystals, and lay a good foundation for further study of nonlinear optical properties and applications on ZnGeAs2 crystals.

Key words: Ternary chalcopyrite semiconductor ZnGeAs2 is a nonlinear optical material, which is expected to have important applications in laser frequency conversion.In this paper, the formation and synthesis mechanism of ZnGeAs2 polycrystal were discussed, and a method of ZnGeAs2 polycrystal synthesis was reported.High-purity (6N) Zn, Ge and As, were weighed as raw materials according to the stoichiometry with the excess of 1‰ Zn and 2‰ As.A single-phase ZnGeAs2 polycrystalline ingot was successfully synthesized, using two-temperature zone synthesis method, combining with mechanical oscillation, temperature oscillation and gradient cooling techniques.The X-ray diffraction (XRD) and Energy Dispersive Spectrometer (EDS) results show that the lattice constants of the synthesized products are a=b=0.56745 nm, c=1.11580 nm, which are consistent with the standard PDF card (No.730397).The atomic ratio of the elements is Zn∶Ge∶As=1.00∶0.98∶1.95, which is close to the ideal stoichiometric ratio.The results demonstrate that the synthesized products can be used for the growth of ZnGeAs2 single crystals, and lay a good foundation for further study of nonlinear optical properties and applications on ZnGeAs2 crystals.