ZnS nanobelts grown in a polymer matrix by chemical bath deposition

Transparent polycrystalline ZnS nanobelts have been grown by chemical bath deposition within the pores of polyvinyl alcohol on glass and Si substrates. Zinc acetate and sodium sulphide, dissolved in an alkaline medium, were taken as the source of zinc and sulfur respectively. X-ray diffraction and transmission electron microscopy studies confirmed the cubic nanocrystalline ZnS phase formation. TEM micrographs of the films revealed the formation of ZnS nanobelts of width 5-20 nm and length of a few microns. UV-vis spectrophotometric measurement showed high transparency (around 80% in the wavelength range 350-800 nm) of the film with a direct allowed band gap in the range 4.03-3.90 eV; the band gap decreases with the increase of deposition temperature. Studies of the dielectric properties showed high dielectric constant (in the range 70-130) compared to only PVA and bulk ZnS thin film.