SOME CHARACTERISTICS OF AGGAS2 SINGLE-CRYSTALS GROWN FROM THE MELT

The three-phase co-existing line of AgGaS2 was briefly determined as a function of controlled sulfur vapor pressures (Ps2), one of the constituent elements, and the P(S2)-T diagram was made. Step structures which relate to the growth mechanism were observed on the (112) surface and the crystallographic orientation was determined. Photoluminescence (PL) spectra at 4.2 K showed prominent band-edge emissions at 2.63 and 2.673 eV and it is expected that the emissions relate to the native defects such as Ag vacancies. The electrical conductivity of the as-grown crystals showed an extremely low conductivity of 10(-10) (OMEGA cm)-1 and shallow traps with activation energies of 0.03 and 0.11 eV were found.