Yazar "Alharbi, S. R." seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Öğe
    Band offsets, dielectric dispersion and some applications of CdSe/GeO2 heterojunctions
    (Elsevier GmbH, 2021) Khusayfan, Najla M.; Qasrawi, Atef Fayez; Alharbi, S. R.; Khanfar, Hazem K.; Kayed, T. S.
    Herein, the formation, structural, morphological, compositional, optical, dielectric, photoelectrical and electrical properties of the CdSe/GeO2 heterojunctions are explored. While the surface displayed formation of deficient GeO, the bulk of the films exhibited correct stoichiometry of GeO2 and CdSe. It is found that stacking of GeO2 onto CdSe enhances the crystallinity of CdSe by reducing the defects concentrations. It blue shifts the energy band gap of CdSe from 1.74 eV to 2.60 eV. The stacked layers of CdSe/GeO2 displayed conduction and valence band offsets of 2.34 eV and 1.23 eV, respectively. In addition, the Drude-Lorentz model analyses have shown that the coating of GeO2 onto CdSe, highly increases the drift mobility of charge carriers and tunes the plasmon frequency making it more appropriate for optoelectronic device applications. When exposed to light irradiation, an illumination intensity dependent photosensitivity is observed. The photoconduction mechanism is governed by the sublinear recombination with exponential trap distribution. Moreover, the capacitance –voltage characteristics of the device revealed metal-oxide-semiconductor field effect transistors (MOSFET) characteristics. The built in potential for this device under reverse biasing conditions reached 4.74 eV.
  • Küçük Resim
    Öğe
    Effects of Ag2O nanosheets on the structural, optical, and dielectric properties of GeO2 stacked layers
    (Wiley-VCH Verlag, 2021) Alharbi, S. R.; Qasrawi, Atef Fayez; AlGarni, Sabah E.
    Herein, the effects of insertion of Ag2O nanosheets of thicknesses 25–75 nm between stacked layers of GeO2 on the structural, morphological, and optical properties of germanium dioxide are explored. While the stacking of GeO2/Ag2O/GeO2 layers does not alter the amorphous nature of the structure, significant effects on the transmittance, reflectance, absorption coefficient, Urbach's tails, and dielectric constant are observed. Silver oxide nanosheets successfully enhance the light absorbability of germanium dioxide in the visible and the infrared (IR) range of light. The light absorbability is increased by more than 12 times after the insertion of 75 nm-thick Ag2O nanosheets. In addition, a widening in Urbach's tails and narrowing in the indirect bandgap of GeO2 are detected as a result of increasing Ag2O layer thickness. The dielectric constant and optical conductivity are also increased by ?59.6% and 191.4% in the IR range of light. The enhancement in the optical properties of GeO2 that results from the insertion of Ag2O nanosheets makes germanium dioxide more appropriate for optoelectronic applications.