Preparation and characterization of AgGaS2 thin films by vacuum evaporation

AgGaS 2 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.