Identification of growth mechanism of CBD CIAS thin films from SEM analysis

Near stoichiometric and stoichiometric CuIn(1−x)Al(x)Se2 (CIAS) thin films have been prepared by chemical bath deposition (CBD) technique. X-ray diffraction (XRD) and energy dispersive x-ray analysis (EDAX) spectra have been employed to confirm the structure and composition of the prepared films. SEM analysis of near-stoichiometric and stoichiometric CIAS thin films enabled us to estimate the grain size, to identify the growth mechanism and also to visualize the surface morphology. Transmittance spectra have been employed to determine the type of transition and other optical parameters such as absorption coefficient, extinction coefficient, dielectric constant, refractive index, Sellmeier parameters and bandgap which are reported in this paper in detail.