Impurity phases analysis of ZnGeP2 single crystal grown by Bridgman method

X-ray photoelectron spectroscopy (XPS) was proposed as suitable method to study the low content of impurity phases on ZnGeP2 (ZGP) single crystals which are excellent materials in non-linear infrared fields. Besides it, X-ray diffraction (XRD) and Energy Dispersive Spectrometer (EDS) tests were carried out to characterize the components homogeneity of the crystal. It is found that impurity phases Zn3P2 and ZnP2, which are undetectable by X-ray diffraction (XRD) method due to low content, results in the heterogeneity of components and phases of ZGP single crystal. Meanwhile, Oxides of P2O5 and GeO2 were found to exist on the surface of the crystal.