Browsing by Author "Lamia Radjehi"

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    Air and Vacuum Annealing Effect on the Highly Conducting and Transparent Properties of the Undoped Zinc Oxide Thin Films Prepared by DC Magnetron Sputtering
    (2023-03-31) Lamia Radjehi
    In this study, we aim to investigate the effect of zinc interstitials (Zni) and oxygen vacancies (VO) on the ZnO electrical conductivity. ZnO films were synthesized via DC magnetron sputtering process using pure Zn target in gases mixture of Ar/O2 = 80/17.5 sccm. In order to improve the optical and electrical prosperities, the obtained films were subjected to air and vacuum annealing treatment. Several techniques such as field emission scanning electron microscopy (FESEM), Grazing Incidence X-ray Diffraction (GIXRD), Raman spectroscopy, photoluminescence spectroscopy (PL) and UV-visible were used to study the influence of heat treatment on ZnO properties. Electrical conductivity of ZnO films was determined by measuring the sheet resistance and thickness of the films. As deposited and under vacuum annealing films showed a lower electrical resistivity of 2.72×10−3 and 1.17×10−2 Ωcm, respectively, due to the Zn-rich conditions. ZnO films under air treatment show a intensity decrease of (103) plane and an optical transmittance of 87 %.
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    Oxygen effect on structural and optical properties of zinc oxide
    (2018-09-05) Lamia Radjehi
    This article deals with an investigation of the effect of oxygen content on optical and structural properties of ZnO films. Zinc oxide films were deposited with the DC reactive magnetron sputtering process on Si(100) and glass substrates. ZnO films were elaborated at different oxygen flow rates from (O2) 12 to 35 sccm. The evolution of optical and structural properties as a function of O2 was investigated by X-ray diffraction, Profilometer, Field Emission Scanning Electron Microscopy (FESEM) and ultraviolet–visible. By increasing O2, the crystallite size increases from 20 to 27 nm, which leads to an enlargement in the ZnO band gap from 3.18 to 3.30 eV. At 30 sccm of O2, the films present a significant improvement in the band gap (3.30 eV). The results reveal that with increasing O2, all films show a high crystallinity in the wurtzite phase and present a (002)ZnO preferential orientation along the c-axis. ZnO exhibited a good self-texture
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    ZnO Films Elaborated by D.C. Magnetron Sputtering
    (2021) Lamia Radjehi
    The effect of the oxygen flow rate on the structural and optical properties of ZnO films was investigated. Zinc oxide films were deposited Si (100) wafers and glass substrate by a DC magnetron sputtering technique using Zn targets in an Ar/O2 mixture atmosphere. The oxygen content was changed from 10 to 30 sccm. The different properties were analyzed by using XRD, SEM, profilometer, and UVvisible. The evolution of optical and structural proprieties as O2 was investigated by XRD, Profilometer, FESEM and UV-visible. O2 increasing lead to improve ZnO crystallinity in wirtzite phase and the films present (002) preferential orientation along the c-axis. ZnO films present a significant improvement in band gap that present an enlargement from 3.13 to 3.30 eV due to the crystallite size increase from 22 to 30 nm.