Browsing by Author "Osasona, O."

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    Electrical properties of vacuum evaporated PbSnS 3 thin films
    (International Journal of Materials Science, 2006-02) Kuku, T.A; Osasona, O.; Azi, Samuel
    Electrical conduction of evaporated PbSnS3 films of thickness ranging between 0.1 and 2.0 μm were studied by measuring the dc current in both parallel (planar) and transverse (cross plane) directions to the substrate surface. Conduction mechanisms relevant to various regions of the current-voltage characteristics are discussed. The obtained film conductivities were of the order 10−5 S cm−1 at room temperature and increased exponentially with increasing temperature. No consistent modification of the conductivity values and nature were observed when the films are doped with CdCl2, PbCl2 and CuI impurities. While planar conductivity activation energies were constant with voltage and increased slightly with deposition temperature, the cross plane values were found to depend on both voltage and film deposition temperature.
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    Preparation and characterization of metallorganic chemical vapour deposited LixMoyO2 using a single source solid precursor
    (International journal of Ionics, 2005-09) Ilori, Olusoji O.; Eleruja, Adebola Marcus; Osasona, O.; Egharevba, G.O
    Thin films of LixMoyOz have been deposited on glass substrate in a one step chemical vapour deposition using a single source solid precursor. The films were characterized using Rutherford Backscattering Spectroscopy (RBS), X-Ray Diffractometry, Scanning Electron Microscopy (SEM), Impedance Spectroscopy (IS), van der Pauw conductivity measurement and Ultraviolet-Visible Spectroscopy. Results of the characterization showed that the films are dendritic, polycrystalline and semiconducting with an optical transition energy of 3.0 eV. IS characterization gave a semicircle in the complex impedance plot. The conductivity vs. temperature plot showed a transition at 450 C and also a hysteresis. Analysis showed the film to be mixture of phase
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    Preparation and characterization of metallorganic chemical vapour deposited molybdenum (II) oxide (MoO) thin films
    (International journal of Thin Solid Films, 2005-01) Ilori, Olusoji O.; Eleruja, Adebola Marcus; Osasona, O.; Egharevba, G.O
    Thin films of molybdenum monoxide were deposited by metallorganic chemical vapour deposition and characterized using Rutherdford backscattering spectroscopy, Fourier Transformed Infrared and UV–Visible spectroscopies, X-ray diffraction, van der Pauw conductivity measurement and impedance spectroscopy measurement. MoO2(C5H7O2)2 was used as a precursor. Results show that the film is crystalline and semiconducting. Optical characterization gave an energy gap of 3.02 eV. DC conductivity measurements show the conductivity mechanism to be that of small polaron hopping with an activation energy of 0.992 eV and also the existence of a sharp transition in conductivity at about 450 °C. Impedance data show that the film has two conductivity phases