Polycrystal Synthesis and Single Crystal Growth of CdGeAs2

CdGeAs2 polycrystal was synthesized by the raw materials of 99.9999% Cd, Ge and As in stoichiometric weights with proper excess of Cd and As through mechanical and temperature oscillation of melt(MTOM). An integral, crack free CdGeAs2 single crystal with size of phi 15 mm x 40 mm was obtained by modified vertical descending cubic technique. The CdGeAs2 polycrystal and as-grown crystals were characterized by X-ray diffraction and infrared spectroscopy. XRD riteveld analysis indicates that the synthetic product is high-purity CdGeAs2 polycrystal in chalcopyrite structure, the lattice constants of a and c are 0.5946nm and 1.1217nm, respectively. The as-grown crystal is integrated in structure and crystallized well. It is also found that the cleavage plane of the crystal is (101). CdGeAs2 wafer with 1.0 mm thickness is transparent in range of 589-4250cm(-1), and the band width is calculated to be 0.67eV.