Effect of complexing agent TEA: The structural, morphological, topographical and optical properties of FexSx nano thin films deposited by SILAR technique

Iron sulfide thin films (FexSx) (x = 0.05 M, 0.10 M, 0.15 M, 0.20 M and 0.25 M) were deposited by SILAR method from equimolar and equivolume aqueous solutions of ferrous nitrate and sodium sulfide with the addition of complexing agent TEA. The structural, morphological and optical characteristics of the films were derived from X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and UV-vis spectral techniques. The mixed characteristics (crystalline and amorphous) of the deposited films and the increasing crystalline qualities with the concentrations were understood from the XRD analysis. The grain sizes and roughness of the films were decreases with the increasing concentration and also at the higher concentration films are shown by the same images presence of hexagonal like crystallite structure. The influence of complexing agent TEA on the surface roughness and morphological properties are confirmed by the atomic force microscope (AFM) results. The effect of increasing substrate concentration on the absorption and transmission measurements and its impact on the optical band-gap energy were enumerated from the UV-vis analysis.