Yazar "Ayyildiz, E." seçeneğine göre listele

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    Solution-processed nanostructured ZnO/CuO composite films and improvement its physical properties by lustrous transition metal silver doping
    (Springer, 2020) Akkaya, A.; Sahin, B.; Aydin, R.; cetin, H.; Ayyildiz, E.
    This paper has reported the fabrication and characterization of pristine, and silver (Ag)-doped nanostructured ZnO/CuO composite thin films that have not been previously reported. The thin films were synthesized by the successive ionic layer adsorption and reaction (SILAR) technique. The morphological, crystalline structure, optical and electrical characterizations of the films have been achieved utilizing scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), atomic force microscopy (AFM), X-ray diffraction (XRD) analysis, Fourier transform infrared spectrum (FTIR) analysis, ultraviolet-visible (UV-Vis) spectrophotometry and the four-point probe measurements. Particle sizes of pristine and Ag-doped ZnO/CuO thin films were found to vary from 32 to 58 nm. Crystallite size was changed from 16.40 to 18.90 nm with changing Ag dopant in the ZnO/CuO composite film. FTIR spectra that have the absorption peaks at similar to 725 and similar to 510 cm(-1) referred to the stretching vibration of Zn-O and Cu-O bonds during the synthesis of ZnO/CuO nanofilms. The bandgap values of ZnO/CuO composite films increased from 2.05 to 2.36 eV as Ag content increased from 0 to 2 M%. The activation energies of the samples were obtained from the Arrhenius plots of sigma versus 1/T. The multiple activation process was observed. It was noteworthy that Ag-doping results in a significant difference in conductivity at all temperature values.
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    Synthesis of Al and In dual-doped CuO nanostructures via SILAR method: Structural, optical and electrical properties
    (Elsevier, 2023) Kahveci, O.; Akkaya, A.; Aydin, R.; Sahin, B.; Ayyildiz, E.
    In this article, we investigated the doping characteristics of Al-doped CuO (ACO), and Al/In co-doped CuO (AICO) thin films, which were synthesized on glass substrates, via the solution-based successive ionic layer adsorption and reaction (SILAR) technique. The surface morphological, chemical composition, structural, optical, and electrical properties of the nanocrystalline films were characterized by Field Emission Scanning Electron Microscopy (FE-SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier-transform Infrared Spectroscopy (FTIR), Ultraviolet-visible (UV-vis.) spectrophotometry, and Transmission Line Method (TLM), respectively. Surface morphology studies exhibited that a decrease in the films' thickness caused an increment in the optical transmittance. XRD patterns displayed that the obtained samples were polycrystalline and crystallized in a bare CuO monoclinic structure. FTIR studies of the CuO samples displayed that Al and In codoping influenced the forms and the violence of the absorption bands. The optical bandgap energy of bare CuO was determined to increase from 1.45 to 1.78 eV as a result of the co-doping. The substitution of In displayed in the irregularity of the morphology, owing to its wide ionic radius, which caused an increase in band gap energy and a decrease in resistance. The co-doping of Al and In is hence anticipated to ensure an extensive range of physical and optical properties of nanostructured metal oxide samples for a variety of technological applications.