Structural, microstructural and optical characterization of polyol-mediated ZnS/PVP nanocomposite powders and films

Poly-N-vinyl-2-pyrrolidone (PVP) capped ZnS nanoparticles were prepared by the so-called polyol process starting from zinc acetate salt, thiourea and PVP40 polymer in diethyleneglycol. Dense nanocrystalline ZnS/PVP composite films were elaborated by spray pyrolysis on a moderately heated glass substrate, using a polyolmediated sol. X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) confirmed the formation of cubic ZnS phase as nanocrystals into the polymer matrix. Optical analysis based on Kubelka-Munk method of the recorded absorption UV-Visible spectra of the films showed an enhancement of the gap value compared to that of the bulk material. This enhancement is discussed in relation with the crystal size of the semiconductor and its dispersion in the polymer matrix.