CuIn sub(1-x)Al sub(x)S sub(2) thin films prepared by sulfurization of metallic precursors

CuIn sub(1-x)Al sub(x)S sub(2) thin films (x = 0, 0.09, 0.27, 0.46, 0.64, 0.82 and 1) with thicknesses of approximately 1 mu m were formed by the sulfurization of DC sputtered Cu-In-Al precursors. All samples were sulfurized in a graphite container for 90 min at 650 degree C in a 150 kPa Ar + S atmosphere. Final films were studied via X-ray diffraction (XRD), scanning electron microscopy (SEM) and micro-Raman spectroscopy. It was found that all samples were polycrystalline in nature and their lattice parameters varied slightly nonlinearly from {a = 5.49 Aa, c = 11.02 Aa} for CuInS sub(2) to {a = 5.30 Aa, c = 10.36 Aa} for CuAlS sub(2). No unwanted phases such as Cu sub(2-x)S or others were observed. Raman were recorded at a room temperature and the most intensive and dominant A sub(1) phonon frequency varied nonlinearly from 294 cm super(-1) (CuInS sub(2)) to 314 cm super(-1) (CuAlS sub(2)).