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  • Article
    Citation - WoS: 27
    Citation - Scopus: 30
    Crystal Data, Electrical Resistivity, and Hall Mobility of N-Type Agin5s8< Single Crystals
    (Wiley-v C H 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
    Citation - WoS: 11
    Cd-Doping Effects on the Properties of Polycrystalline Α-in2se3< Thin Films
    (Wiley-v C H verlag Gmbh, 2002) Qasrawi, AF
    The X-ray diffraction has revealed that the polycrystalline hexagonal structured alpha-In2Se3 thin films grown at substrate temperature of 200degreesC with the unit cell parameters a=4.03degreesA and c=19.23degreesA becomes polycrystalline hexagonal structured InSe with a unit cell parameters of a=4.00degreesA and c=16.63degreesA by Cd-doping. The analysis of the conductivity temperature dependence in the range 300-40 K revealed that the thermionic emission of charged carriers and the variable range hopping are the predominant conduction mechanism above and below 100 K, respectively. Hall measurements revealed that the mobility is limited by the scattering of charged carriers through the grain boundaries above 200 K and 120 K for the undoped and Cd-doped samples, respectively. The photocurrent (I-ph) increases with increasing illumination intensity (T) and decreasing temperature up to a maximum temperature of similar to100 K, below which I-ph is temperature invariant. It is found to have the monomolecular and bimolccular recombination characters at low and high illumination intensities, respectively. The Cd-doping increases the density of trapping states that changes the position of the dark Fermi level leading to the deviation from linearity in the dependence of I-ph on F at low illumination intensities.
  • Article
    Citation - WoS: 21
    Citation - Scopus: 22
    Investigation of Carrier Scattering Mechanisms in Tiins2 Single Crystals by Hall Effect Measurements
    (Wiley-v C H verlag Gmbh, 2004) Qasrawi, AF; Gasanly, NM
    TlInS2 single crystals are studied through the conductivity and Hall effect measurements in the temperature regions of 100-400 and 170-400 K, respectively. An anomalous behavior of Hall voltage, which changes sign below 315 K, is interpreted through the existence of deep donor impurity levels that behave as acceptor levels when are empty. The hole and electron mobility are limited by the hole- and electron-phonon short range interactions scattering above and below 315 K, respectively. An energy level of 35 meV and a set of donor energy levels located at 360, 280, 220 and 170/152 meV are determined from the temperature dependencies of the carrier concentration and conductivity. A hole, electron, hole-electron pair effective masses of 0.24 in,, 0.14 m(o) and 0.09 m(o) and hole- and electron-phonon coupling constants of 0.50 and 0.64, respectively, are obtained from the Hall effect measurements. The theoretical fit of the Hall coefficient reveals a hole to electron mobility ratio of 0.8. (C) 2004 WILEY-VCH Verlag Gmbh & Co. KGaA, Weinheim.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 3
    Crystal Data and Some Physical Properties of Tl2ingate4< Crystals
    (Wiley-v C H verlag Gmbh, 2007) Qasrawi, A. F.; Gasanly, N. M.
    The room temperature crystal data, Debye temperature, dark and photoelectrical properties of the Bridgman method grown Tl2InGaTe4 crystals are reported for the first time. The X-ray diffraction technique has revealed that Tl(2)lnGaTe(4) is a single phase crystal of tetragonal body-centered structure belonging to the D-4H(18) - I4mcm space group. A Debye temperature of 124 K is calculated from the results of the X-ray data. The current-voltage measurements have shown the existence of the switching property of the crystals at a critical voltage of 80 V. The dark electrical resistivity and Hall effect measurements indicated the n-type conduction with an electrical resistivity, electron density and Hall mobility of 2.49x 10(3) Omega cm, 4.76x 10(12) cm(-3) and 527 cm V-2(-1) s(-1), respectively. The photosensitivity measurements on the crystal revealed that, the variation of photocurrent with illumination intensity is linear, indicating the domination of monomolecular recombination at room temperature. Moreover, the spectral distribution of the photocurrent allowed the determination of the energy band gap of the crystal studied as 0.88 cV.
  • Article
    Citation - WoS: 26
    Citation - Scopus: 26
    Etectron-Phonon Short-Range Interactions Mobility and P- To N-Type Conversion in Tlgas2 Crystal
    (Wiley-v C H verlag Gmbh, 2006) Qasrawi, AF; Gasanly, NM
    The conductivity type conversion from p- to n-type at a critical temperature of 315 K in TlGaS2 crystals is observed through the Hall effect measurements in the temperature range of 200-350 K. The analysis of the temperature-dependent electrical resistivity, Hall coefficient and carrier concentration data reveals the extrinsic type of conduction with donor impurity levels that behave as acceptor levels when are empty. The data analysis allowed the calculation of hole and electron effective masses of 0.36m(0) and 0.23m(0), respectively. In addition, the temperature-dependent Hall mobility is found to decrease with temperature following a logarithmic slope of similar to 1.6. The Hall mobility in the n-region is limited by the electron-phonon short-range interactions scattering with an electron-phonon coupling constant of 0.21. (c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
  • Article
    Citation - WoS: 18
    Citation - Scopus: 19
    Crystal Data, Photoconductivity and Carrier Scattering Mechanisms in Cuin5s8< Single Crystals
    (Wiley-v C H 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.