Structural and optical characterization of hybrid nanocomposite ZnO/PMMA

The present study focuses on the structural and optical properties of thin films of ZnO/PMMA nanocomposite deposited on glass substrate using a colloidal solution and spin-coating technique. XRD study reveals that the ZnO particles in amorphous PMMA host matrix have hexagonal (wurtzite) structure and they have arbitrary orientation. Optical absorption spectrum shows three bands in the UV-Visible area at 377.70, 461.14 and 624.81 nm with a shift to high energies of the absorption edge because of quantum confinement induced by the very small size of ZnO crystallites which was estimated to 4.77 nm. Photoluminescence spectrum at low temperature (77°K) (excitation with 355 nm) shows a wide and intense emission band in the visible area (400 - 700 nm). Emission is due to excitons, trapped imperfection sites and surface electrons.