CuAlS2 thin films - Dip coating deposition and characterization

CuAlS2 thin films were deposited by a dip coating technique at room temperature. The X-ray energy dispersive (EDAX) and X-ray diffraction (XRD) analysis showed that the deposited CuAlS2 thin film is nearly stoichiometric and possesses a tetragonal unit cell structure. The crystallite sizes determined from the XRD data employing Scherrer's formula and modified forms of Hall-Williamson relation like the uniform deformation model (UDM), uniform stress deformation model (USDM), uniform deformation energy density model (UDEDM), and the size-strain plot method (SSP) were in good agreement with each other. The transmission electron microscopy (TEM) and scanning electron microscopy (SEM) studies of the thin film revealed that the deposited film is uniform without any cracks and the film covers the whole of the substrates. The atomic force microscopy (AFM) of the as-synthesized thin film surfaces showed spherical grains having coalescences between them. The optical absorbance spectrum analysis showed that the thin films possess both direct and indirect band gaps. The semiconducting and p-type nature of the thin films was confirmed from dc - electrical resistivity versus temperature, room temperature Hall effect, and Seebeck coefficient versus temperature measurements. The effect of the different illuminations on the CuAlS2 thin film showed that it can be used as a material for absorption of ultra-violet radiation. All the obtained characterization results are deliberated in detail.