Preparation and characterization of AgGaS2 thin films by vacuum evaporation

AgGaS2 thin films have been prepared by the vacuum evaporation method on GaAs(100). Elemental silver, gallium and sulfur have been used as the source materials. The X-ray diffraction and the RHEED analysis show that the good epitaxial films with the c-axis normal to the GaAs(100) substrate are grown for the stoichiometric composition. The non-stoichiometric films show that the two different orientational types coexist in a film. One type is that the c-axis is normal to the substrate. The other type is that the c-axis is parallel to the two a-axes of GaAs.