Browsing by Author "Qasrawi,A.F."

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Carrier Transport Properties of Ins Single Crystals
(2002) Qasrawi,A.F.; Gasanly,N.M.; Department of Electrical & Electronics Engineering
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.
Citation - Scopus: 13
Carrier Transport Properties of Ins Single Crystals
(2002) Qasrawi,A.F.; Gasanly,N.M.; Department of Electrical & Electronics Engineering
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.
Carrier Transport Properties of Ins Single Crystals
(2002) Qasrawi,A.F.; Gasanly,N.M.; Department of Electrical & Electronics Engineering
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.
Citation - Scopus: 11
Cd-Doping Effects on the Properties of Polycrystalline Α-In2se3 Thin Films
(2002) Qasrawi,A.F.; Department of Electrical & Electronics Engineering
The X-ray diffraction has revealed that the polycrystalline hexagonal structured α-In2Se3 thin films grown at substrate temperature of 200°C with the unit cell parameters a=4.03°A and c=19.23°A becomes polycrystalline hexagonal structured InSe with a unit cell parameters of a=4.00°A and c=16.63°A 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 (Iph) increases with increasing illumination intensity (F) and decreasing temperature up to a maximum temperature of ∼100 K, below which Iph is temperature invariant. It is found to have the monomolecular and bimolecular 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 Iph on F at low illumination intensities.
Citation - Scopus: 3
Effect of Y, Au and Yau Nanosandwiching on the Structural, Optical and Dielectric Properties of Znse Thin Films
(S.C. Virtual Company of Phisics S.R.L, 2019) Qasrawi,A.F.; Taleb,M.F.; Department of Electrical & Electronics Engineering
In this article, we report the effects of insertion of yttrium, gold and yttrium-gold (YAu) metallic nano-slabs on the structural, optical and dielectric properties of ZnSe thin films. The ZnSe thin films which are prepared by the thermal evaporation technique under vacuum pressure of 10-5 mbar exhibit hexagonal structure. While the insertion of the 70 nm thick Y layers does not alter the lattice parameters and stress values, the Au and YAu layers increased the lattice parameters along the a- and c-axes and decreased the stress values. In addition, the insertion of these metallic layers slightly alters the value of the energy band gap and increases the width of the interbands. The light absorbability are increased by 1.4, 2.0 and 2.4 times upon insertion of Y, Au and YAu, slabs, respectively. On the other hand, the dielectric and optical conductivity analyses has shown that the use of the YAu stacked metal layers increases the real part of the dielectric constant, the optical conductivity, the drift mobility and extended the plasmon frequency range from 35.1 to 254.0 (Ωcm)−1, from 1098 to 1766 cm2/Vs and from 0.94-3.11 GHz to 2.13-4.83 GHz, respectively. The insertion of the two stacked metallic layers between two layers of ZnSe makes the ZnSe more appropriated for thin film transistor technology. © 2019, S.C. Virtual Company of Phisics S.R.L. All right reserved.
Citation - Scopus: 12
Production of Anorthite From Kaolinite and Caco3 Via Colemanite
(Trans Tech Publications Ltd, 2004) Mergen,A.; Kayed,T.S.; Bilen,M.; Qasrawi,A.F.; Gürü,M.; Department of Electrical & Electronics Engineering
Boron oxide has been found to be useful flux for the preparation of dense anorthite ceramics (CaO.Al2O3.2SiO2). Inexpensive starting materials of kaolinite, calcium carbonate and silica were used for anorthite ceramic production. Colemanite (2CaO.3B2O 3.5H2O) was added into the mixtures and the effects of colemanite upon the transformation towards anorthite and on the densification were investigated between 900-1400°C. Single phase anorthite ceramic formed at lower temperatures in boron containing mixtures. Boron containing powder compacts were sintered above 90% theoretical density at 1350°C.
Citation - Scopus: 2
Role of au nanosheets in enhancing the performance of yb/zns/cds/au tunneling photosensors
(S.C. Virtual Company of Phisics S.R.L, 2020) Abusaa,M.; Qasrawi,A.F.; Asaad,B.M.; Khanfar,H.K.; Department of Electrical & Electronics Engineering
In this study, the effects of Au nanosheets of thicknesses of 50 nm on the structural, electrical and photoelectrical properties of Yb/ZnS/CdS/Au (ZAC-0) devices is considered. Stacked layers of ZnS and CdS which are prepared by the thermal evaporation technique onto Yb substrates under vacuum pressure of 10-5 mbar exhibits rectifying characteristics. For these diodes a reverse to forward current ratios of ~105 at biasing voltage of 0.60 V is determined. Insertion of Au nanosheets between the stacked layers of ZnS and CdS increased the current values by three orders of magnitude and changed the current conduction mechanism from thermionic emission to tunneling under reverse biasing conditions. The ZAC-0 device, exhibit a barrier height lowering and barrier widening upon insertion of Au nanosheets. After the participation of Au nanosheets in the structure of the ZAC-0 devices, large photosensitivity and responsivity accompanied with high external quantum efficiency is observed. The responsivity to 406 nm laser radiation is biasing voltage dependent and reaches 135 mA/W at 0.60 V. The features of the Yb/ZnS/Au/CdS/Au photosensors nominate them as promising candidates for use in light communication technology as signal receivers. © 2020, S.C. Virtual Company of Phisics S.R.L. All rights reserved.