Résumé:
The present work consists in the elaboration and characterization of the undoped and
cobalt-doped ZnO with different concentrations of cobalt (Co) (0.5, 1, 5 and 10% in
weight) thin films in order to improve the structural, morphological, optical and electrical
properties of ZnO. The samples were prepared using the Sol-Gel method and deposited on
glass substrates by the Dip-coating ""Dipping-Drawing"" technique.
Structural characterization showed the formation of ZnO of hexagonal structure
(wurtzite) with a preferential orientation according to plane (002) and made it possible to
determine the nanometric size of the crystallites. The SEM and AFM images revealed the
nanometric character of our layers. Raman scattering confirmed the results of the XRD,
namely the formation of ZnO with an hexagonal structure (wurtzite).
UV-visible spectroscopy has shown that our layers have a transparency, in the visible,
which varies between 80 and 98%. It has shown also that the gap decreases with the increase
in doping. The photoluminescence of the films showed ultraviolet (UV) and visible emissions
related to defects.
The codoping of aluminum to cobalt allowed us also to improve the structural
and optical properties.
