Structural, morphological and optical properties of CuAlS2 films deposited by spray pyrolysis method

The structural, morphological and optical properties of CuAlS2 films deposited by spray pyrolysis method have been investigated. CuAlS2 in the form of films is prepared at different deposition conditions by a simple and economical spray pyrolysis method. The structural, surface morphology and optical properties of the films were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM) and absorbance spectra, respectively. The films were polycrystalline, crystallized in a tetragonal structure, and are preferentially orientated along the (1 1 2) direction. Grain size values, dislocation density, and d% error of CuAlS2 films were calculated. The optical band gap of the CuAlS2 film was found to be 3.45 eV. The optical constants such as refractive index, extinction coefficient and dielectric constants of the CuAlS2 film were determined. The refractive index dispersion curve of the film obeys the single oscillator model. Optical dispersion parameters Eo and Ed developed by Wemple–DiDomenico were calculated and found to be 3.562 and 12.590 eV.