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  • Article
    Carrier Scattering Mechanisms in GaS0.5Se0.5 Layered Crystals
    (Wiley-VCH Verlag GmbH, 2002) Qasrawi, AF; Gasanly, NM
    Systematic dark electrical resistivity and Hall mobility measurements have been carried out in the temperature range 150-400 K on n-type GaS0.5Se0.5 layered crystals. The analysis of temperature dependent electrical resistivity and carrier concentration reveals the extrinsic type of conduction with a donor impurity level located at 0.44 eV, donor and acceptor concentrations of 3.4x10(17) and 4.1x10(17) cm(-1), respectively, and an electron effective mass of 0.41 m(o). The Hall mobility is limited by the electron-phonon short-range interactions scattering at high temperatures combined with the ionized impurity scattering at low temperatures. The electron-phonon short-range interactions scattering mobility analysis reveals an electron-phonon coupling constant of 0.25 and conduction band deformation potential of 5.57 eV/Angstrom.
  • Article
    Crystal Data, Electrical Resistivity, and Hall Mobility of n-Type AgIn5S8 Single Crystals
    (Wiley-VCH Verlag GmbH, 2001) Qasrawi, AF; Gasanly, NM
    The X-ray diffraction has revealed that AgIn5S8 is a single phase crystal of cubic spinel structure. The value of the unit cell parameter for this crystal is 1.08286 nm. The electrical resistivity and Hall effect of n-type AgIn5S8 crystals are measured in the temperature range of 50-400 K. A carrier effective mass of 0.20 m(0), an acceptor to donor concentration ratio of 0.8 and an acoustic phonons deformation potential of 20 eV are identified from the Hall effect measurement. The Hall mobility data art: analyzed assuming the carrier scattering by acoustic and polar optical phonons, and ionized impurities.
  • Article
    Carrier Transport Properties of Ins Single Crystals
    (Wiley-Blackwell, 2002) Qasrawi,A.F.; Gasanly,N.M.
    The electrical resistivity and Hall effect of indium sulfide single crystals are measured in the temperature range from 25 to 350 K. The donor energy levels located at 500, 40 and 10 meV below the conduction band are identified from both measurements. The data analysis of the temperature-dependent Hall effect measurements revealed a carrier effective mass of 0.95 m0, a carrier compensation ratio of 0.9 and an acoustic deformation potential of 6 eV. The Hall mobility data are analyzed assuming the carrier scattering by acoustic and polar optical phonons, and ionized impurities.
  • Article
    Citation - WoS: 10
    Citation - Scopus: 10
    Effects of Indium Slabs on the Structural and Electrical Properties of Stacked Layers of Cu2o
    (Natl inst R&d Materials Physics, 2020) Qasrawi, A. F.; Omar, A.; Department of Electrical & Electronics Engineering
    In this work, the structural and electrical properties of stacked layers of Cu2O that comprises indium slabs in its structure are reported. The stacked layers which are coated onto glass and Au substrates under vacuum pressure of 10(-5) mbar are characterized by the X-ray diffraction and impedance spectrometry techniques. While the Cu2O/Cu2O (CC) layers exhibited amorphous nature of growth, those which contained indium slabs (CIC) displayed weak crystallinity The insertion of indium slabs between stacked layers of cuprous oxide highly increased the electrical resistivity and shifted the acceptor level closer to the valance band edge. In addition, the analyses of the conductance and capacitance spectra in the frequency domain of 0.01-1.0 GHz have shown that these two physical parameters are strongly affected by the insertion of indium slabs and by surface deformation effects. The capacitance spectra showed negative capacitance effect (NC) in all the studied frequency domain The NC effects become less pronounced in the CIC samples owing to the changes in the polarization mechanism. The feature of NC effects make both of the CC and CIC samples more appropriate for electronic and telecommunication technology as it can be used in amplifiers to enhance he gain, as parasitic cancellers and as noise reducers.
  • Article
    Crystal Data, Photoconductivity and Carrier Scattering Mechanisms in CuIn5S8 Single Crystals
    (Wiley-VCH Verlag GmbH, 2001) Qasrawi, AF; Gasanly, NM
    The X-ray diffraction has revealed that CuIn5S8 is a single phase crystal of cubic spinet structure. The value of the unit cell parameter for this crystal is 1.06736 nm. The crystal is assigned to the conventional space group Fd3m. The photocurrent is found to have the characteristic of monomolecular and bimolecular recombination at low and high illumination intensities, respectively. The electrical resistivity and Hall effect of CuIn5S8 crystals are measured in the temperature range of 50-400 K. The crystals are found to be intrinsic and extrinsic above and below 300 K, respectively. An energy band gap of similar to1.35 eV at 0 K, a carrier effective mass of 0.2 m(0), an acceptor to donor concentration ratio of 0.9, an acoustic phonon deformation potential of 10 eV and a nonpolar optical phonon deformation potential of 15 eV are identified from the resistivity and Hall measurements. The Hall mobility data are analyzed assuming the carrier scattering by polar optical phonons, acoustic combined with nonpolar optical phonons, and ionized impurities.