Synthesis and Optical Investigations of the Guest-Host Nanostructures Alumina-SiC and Alumina-In2O3

Several strategies were developed to synthesise two classes of nanostructured thin films with nanocrystals of SiC (nc-SiC) or In2O3 (nc-In2O3) confined in alumina. The syntheses were performed by using Rf-sputtering and co-pulverisation process of the suitable reactants. Thus, Al2O3/nc-SiC and Al2O3/nc-In2O3 composite thin films were obtained and their structural and optical features analyzed respectively by XRD, XPS and UV-VIS absorption. The deposition conditions and the post-synthesis treatments were optimized in order to improve the crystalline character of confined nanocrystals. The optical properties were compared in the range 200 nm-1200 nm for bare alumina films or nanostructured ones with the semiconducting nanocrystals. The direct and indirect band band gaps were evaluated and discussed with regard to the stoechiometry and morphologies of the nanocomposite films