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International audience; Un-doped, Zn-doped, and Al–Zn co-doped CdO thin films were deposited onto glass substrates at 350 °C by spray pyrolysis. X-ray diffraction (XRD) analysis was conducted to investigate the structural properties of the films. The XRD patterns confirmed that all the films crystallize in a cubic structure and that the addition of Zn and Al did not alter the CdO crystal structure. Energy-dispersive X-ray spectroscopy analysis further confirmed the successful incorporation of Zn and Al into the CdO films. Theoretical calculations based on first-principles were performed, and crystallographic information files (CIF) were obtained for optimized theoretical supercells in space group Pm3-m. The CIF files were used as input for experimental XRD spectra Rietveld refinement, to determine the Wyckoff positions of the dopants and their occupation rates. The optical properties of the films were characterized using transmittance measurements in the wavelength range of 300–1700 nm. The optical data indicated an increase in the average transmittance from 60 to 70% within the wavelength range of 600–1700 nm upon Al–Zn co-doping. The estimated direct optical band gap of the un-doped, doped, and co-doped CdO thin films is varied between 2.41 and 2.50 eV. All the samples exhibited n-type conductivity with low electrical resistivity of about 1.32 × 10–4 Ω⋅cm. Co-doped CdO thin films with 1% Al and 3% Zn exhibited higher carrier concentration (4.39 × 10+20 cm−3) than the other samples.

TM (TM = Sn, Al) doped and co-doped CdO thin films were deposited by spray pyrolysis technique on glass substrate at temperature 350 ˚C. The effect of TM doping and co-doping on the structural, morphological, optical, and electrical properties of CdO thin films was investigated. The obtained films are crystallized in the cubic structure and oriented along the preferential (111) crystallographic plane. The average optical transmittance reaches 79% in the visible range for Sn doped CdO films and 74% for Al-Sn co-doped films. The gap values of the obtained samples are between 2.29 and 2.49 eV. All the deposited films exhibit n-type conductivity with a low electrical resistivity of 7.85.10-4 Ω.cm obtained for Al doped CdO films.

International audience; Un-doped, Al-doped, and Sn-Al co-doped ZnO thin films have been successfully synthesized by Spray Pyrolysis method. Zinc Nitrate (Zn(NO3)2), Tin Chloride (SnCl2) and Aluminum Nitrate (Al(NO3)3) were used as starting chemicals at different compositions. Films depositions were carried out on glass substrates at 350 °C. The X-ray diffraction confirmed that the Al-Sn co-doping did not change the ZnO Hexagonal Wurtzite structure. The obtained un-doped ZnO films were highly oriented along the preferential (002) crystallographic plane while the Sn- Al co-doped ZnO films were disoriented with slight loss of crystallinity. The optical measurement showed an increase of the average transmittance from 65 % to 81 % and the band gap energy (Eg) from 3.23 to 3.30 eV. The electrical conductivity has increased with the Al-Sn co-doping concentration to reach the value of 0.335 (Ω.cm)−1.

The zinc oxide thin films, highly transparent, doped aluminium were prepared on glass substrates by the reactive chemical spray method. The incorporation nature of Al atoms in the ZnO lattice was determined by X-ray diffraction and optical analyses. Indeed, for low doping ⩽2%, the results of X-ray spectra analysis show a simultaneous reduction of lattice parameters (a and c), this variation, which follows VEGARD’s law, tends to indicate a substitution of Zn by Al. By against for doping >2% the increase in the lattice parameters thus the grain sizes, in accordance with the VEGARD’s law can be explained by occupation of the interstitial sites by Al atoms. Beyond 4%, the material tends to get disorderly and the crystallites orientation is random. The studied optical properties show that the variation of the optical gap follows a law of the x3/2 form for x

International audience

Vanadium oxide thin films have been successfully deposited in the first time by spray pyrolysis technique at two substrate temperatures, 200 and 250 °C. In view of defining the optimal conditions for elaboration of vanadium oxide films, the as-deposited films were studied as a function of spray solution concentrations, using X-ray diffraction (XRD) and optical measurements. V2O5 and V4O9 polycrystalline films with an orthorhombic structure were easily obtained under the different spraying conditions. The AFM result indicates a grain size of approximately 50 and 80 nm for V2O5 and V4O9, respectively. The optical results show that the optical gap is equal to 2.44 eV for V2O5 and 2.34 eV for V4O9.