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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.

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.

Polycrystalline films of Sn 2 S 3 compound were prepared on glass substrates by the spray pyrolysis technique at a substrate temperature of 270 ∘ C using tin chloride (SnCl 2 ) and thiourea (Cs(NH 2 ) 2 ) solutions with a concentration of 0.1 M. The X-ray diffraction pattern reveals an orthorhombic structure and an average grain size equal to 130 A. The optical properties of the films were studied using optical transmittance and reflectance measurements over the wavelength range 200–2500 nm. The variation of refractive index n and extinction coefficient k with photon energy are reported. The dispersion of the refractive index in Sn 2 S 3 is analysed using the concept of a single oscillator. The values of oscillator energy E 0 and dispersion energy E d are determined to be 3.98 eV and 13.5 eV, respectively. The optical constants confirm that the Sn 2 S 3 thin films have a direct band gap of 2 eV. A value of 4.35×10 −3 (Ω cm) −1 for the room temperature conductivity is found using the four-probe method.