Elaboration and Characterization of ZnO Thin Films Doped with Cobalt
Zinc oxide (ZnO) is a binary semiconductor material with direct band gap (3,37 eV) because of
their good optoelectronics properties, ZnO films find several applicatio
ns such as: solar cells, gas
sensors, piezoelectric sensors, waves guides... etc.
ZnO thin films can be prepared by several
techniques, such as: spray, thermal evaporation, reactive sputtering, sol gel, laser ablation... etc.
In the present work and in
the order to obtain conducting transparent layers, ZnO thin films
were deposited by ultrasonic spray technique on glass substrates. Our interest is on the
as a molarity, growth time and substrate temperature
and substrate temperature
on the structural, optical and electrical properties of ZnO thin
The DRX analyses indicated that undoped ZnO films deposited at
polycrystalline nature and hexagonal wurtzite structure wit
h (002) preferential orientation and the
maximum average crystallite size of
deposition and in an concentration of 0.1 mol/l.
conditions regardless the starting solution
ansmittance spectra showed transmittance higher than 80 % within the visible
wavelength region. Hence, the values of the gap were found to be between 3.11 to 3.25 eV
deposition parameters. The minimum resistivity of the ZnO films is 0.13
analysis by the method of X
ray diffraction revealed that CZO and IZO films crystallize in
the hexagonal wurtzite structure of ZnO with a preferential orientation along the (002) plane
maximum average crystallite size of ZnO
spectra and optical absorption indicates
that the CZO films are haily transparency in the
visible range and low absorption for IZO films.
The band gap energy of the thin films increased after
result in narrawing the conduction band and the valence band
And decrease for the IZO from 3.25 to 3.18
The electrical conductivity of ZnO films
As a result, the crystallinity, the optical and electrical properties of IZO thin films are improved
with annealing temperature can be influenced by oxygen diffusion with annealing temperature.