Modified Surface and Tuned Optical Band Gap of Polymer Nanocomposite Thin Films

Thin films of nanocomposites, polyvinyl alcohol (PVA) dispersed with Zinc Oxide (ZnO) nanoparticles (nps) were deposited by solution casting method. Films were characterized for structural, optical, photoluminescent properties and topographical parameters. X-ray diffraction analysis confirmed the presence of ZnO, with improved crystallinity observed at higher ZnO concentrations. Ultraviolet-visible spectrum showed absorption at 289.00 nm for pure PVA and the addition of ZnO nanoparticles at 1 wt% and 5 wt% in the PVA matrix showed a shift in absorption peaks to 370.00 nm and 379.00 nm respectively. Photoluminescence spectroscopy showed strong emission peaks at 371 nm corresponding to near-band-edge. Atomic Force Microscopy ensured uniform dispersion of nanoparticles in the PVA matrix.