Structural and optical properties of SdC/PVA nanocomposites thin films

Abstract

CdS nanoparticles are successfully capped by poly vinyl-alcohol (PVA). In additional, CdS/PVA nanocomposites thin films were synthesized using chemical bath deposition method on microscopic glass substrates at 75 oC. Cadmium acetate Cd(CH3OOH)2 and cadmium chloride (CdCl2) were used as a cadmium (Cd2+ ) ions source while thiourea was used as a sulphur ions (S2-) source with different molar concentrations of PVA. The structural properties of the obtained samples were characterized using X-ray diffraction technique (XRD). The variation of the polymer molar concentrations on the structural parameters such as the lattice constants, the strain value and the dislocation density has been obtained. The Fourier transform infrared spectra (FTIR) of pure PVA, CdS powder and PVA capped CdS nanoparticles was studied and the vibration bands were determined. The transmission electron microscopy (TEM) images of one of samples showed the bonding of the CdS-PVA nanocomposites. The optical absorption spectra of the CdS/PVA nanocomposites thin films were studied and the values of optical energy gap of the nanocomposites thin films have been calculated. The particles size of CdS nanoparticles and CdS/PVA nanocomposites that were calculated from the X- ray data and the optical band gap are affected by the PVA molar concentrations.