Influence of Pb doping on the structural, morphological and optical properties of sol–gel ZnO thin films

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Na doping effects on the structural, conduction type and optical properties of sol–gel ZnO thin films.

International audienceIn this work we report on the sol–gel deposition of Na doped ZnO thin films on quartz substrates. The effects of Na doping concentrations (0, 3, 6 and 9 at.%) on structural, morphological, electrical and optical properties of the synthesized films were systematically investigated by X-ray diffraction (XRD), Raman spectroscopy, atomic force microscopy (AFM), Hall-effect measurements, UV–Vis–NIR spectrophotometry and photoluminescence (PL) spectroscopy. XRD patterns showed that the prepared films were highly c-axis oriented exhibiting hexagonal wurtzite structure of ZnO. Raman spectra of All the ZnO films exhibited similar scattering peaks corresponding to the Raman active modes of ZnO wurtzite hexagonal structure. AFM images indicated that grain size and surface roughness of the films were affected by Na doping. From the Hall-effect measurements, it was found that carrier type is dependent on Na content. The UV–Vis–NIR spectroscopy analyses revealed that all the films were highly transparent in the visible region. Room temperature PL spectra demonstrated that UV emission of the Na-doped ZnO thin films depends on the Na concentration. In particular, the undoped sample shows the highest emission intensity, while the p-type Na doped ZnO film at 3 at.% exhibits the lowest one

Doping effect investigation of Li-doped nanostructured ZnO thin films prepared by sol-gel process.

International audienceIn this work, we report the effects of Li doping concentration (5, 10 and 15 at.%) on structural, morphological, electrical and optical properties of Li doped ZnO films. We used X-ray diffraction (XRD), scanning electronic microscopy (SEM), Hall-Effect measurements, UV–Vis–NIR and photoluminescence (PL) spectroscopies. XRD patterns showed that the deposited films had a hexagonal-wurtzite crystal structure with preferred orientation along the c-axis. SEM micrographs indicated that grain dispersion in the films were homogeneous. Hall-effect measurements revealed that ZnO thin films doped with 5, 10 and 15 at.% of Li have p-type conduction. The UV–Vis–NIR spectroscopy analyses demonstrated that all thin films were highly transparent in the visible region and the optical transmittance was dependent on the Li doping content. Room temperature PL spectra put into evidence that all Li-doped ZnO thin films emitted a UV-blue light and the emission intensities were found to be affected by Li concentration