Growth and characterization of CuInxGa1-xS2 and CuInSySe2-y thin films by reactive sputtering

In this work, CuIn_xGa_1–xS₂ and CuInS_ySe_2–y thin films were fabricated by using reactive sputtering in the H₂S/Ar mixture gas in which CuIn_xGa_1–x and CuInSe₂ targets were employed. The film’s properties were investigated by XRD,AES depth profile, SEM and optical absorption measurements. The carrier mobility and concentration were measured by room Temperature Hall Measurements. Single phase CuIn_xGa_1–xS₂ and CuInS_ySe_2–y thin films were identified from the X-ray diffraction pattern. The SEM photographs show that the grain sizes as large as μm order could be obtained. The optical bandgap of the deposited CuInS_ySe_2–y films was found to range between 1.10 and 1.41eV just by varying the H₂S gas flow. The deposited CuIn_xGa_1–xS₂ films have significant composition change near the surface at some substrate temperatures determined by the AES depth profile. A growth model was proposed that this phenomenon could be explained by thermal reactions mainly involved H₂S with the constituent elements