GROWTH AND CHARACTERIZATION OF ORDERED VACANCY CHALCOPYRITE CUIN3SE5 AND CU(IN, GA)(3)SE-5 SINGLE-CRYSTALS

Single crystals of CuIn3Se5 and Cu(In, Ga)(3)Se-5 were grown by the ch emical transport reaction method. The structural and the optical prope rties of these compounds were investigated by XRD, Raman, and optical absorption measurements. These crystals have an ordered vacancy chalco pyrite structure with lattice constants of a = 5.742 Angstrom and c = 11.450 Angstrom for CuIn3Se5 and a = 5.702 Angstrom and c = 11.421 Ang strom for Cu(In, Ga)(3)Se-5. The Raman peak, related to the A(1) vibra tional mode, was observed at 152 cm(-1) for CuIn3Se5 and at 156 cm(-1) for Cu(In, Ga)(3)Se-5. The energy gap at 292 K was found to be 1.26 e V for CuIn3Se5 and 1.40 eV for Cu(In, Ga)(3)Se-5 single crystals at ro om temperature.