Growth And Calculation Of Zinc Germanium Phosphide Crystals

The ternary chalcopyrite structure semiconductors have two outstanding merits: a large nonlinear optical coefficient and a wide range of transparency in mid-far IR. They are infrared nonlinear optical materials which have been attracting interest due to their important applications. Zinc germanium diphosphide is the best of all. We mostly studied and discussed the crystal in the article.Study growth of ZnGeP₂ crystals. The ZnGeP₂ polycrystalline ingots had been synthesized by improved single-zone method. XRD and TG had been suggested that the quality of the polycrystalline ingots was agreed with the standard one. The ZnGeP₂ single crystals could be grown using a visual horizontal gradient freezing technique with small angle lean. The section of the single crystal had been suggested that its quality was agreed with the standard one.Calculate theoretically about perfect ZnGeP₂ crystals. The structure of perfect ZnGeP₂ crystals was optimized and performed by adopting the first principles with plane wave pseudopotential method based on the density function theory. The lattice parameters and single point energy were given, and the theory data were offered for the research of the crystals. The energy band structure, the density of states and the absorption spectrum of perfect ZnGeP₂ crystals were calculated. The results suggested that the crystals had a pseudo-direct band gap, the origin of the absorption spectrum was related to the electron transition from valence band to conduction band, and the site of peaks was related to the contribution of the electronic density of states.Calculate theoretically about ZnGeP₂ crystals with defects. EPR and ENDOR had been suggested that the dominant acceptor and donor in ZnGeP₂ were V_Zn^- and Ge_Zn⁺, respectively. The energy band structure, the density of states and the absorption spectrum of ZnGeP₂ crystals with defects were calculated after optimization of the structure. The results suggested that the structure of ZnGeP₂ crystal with defects slightly distorted tetrahedral chalcopyrite, ZnGeP₂ crystals with V_Zn^- had a direct band gap, ZnGeP₂ crystals...