Qasrawı, Atef Fayez Hasan

Profile Picture
Profile URL
https://hdl.handle.net/20.500.14411/7716
Name Variants
Qasrawi, Atef Fayez
Atef Fayez Hasan, Qasrawı
Qasrawı,A.F.H.
Qasrawi,A.F.H.
Q., Atef Fayez Hasan
Q.,Atef Fayez Hasan
Atef Fayez Hasan, Qasrawi
Qasrawi, Atef Fayez Hasan
A.F.H.Qasrawı
A.F.H.Qasrawi
A., Qasrawi
A.,Qasrawı
Qasrawı, Atef Fayez Hasan
Qasrawi, A. F.
Qasrawi,A.F.
Qasrawi, AF
Qasrawi, Atef F.
Qasrawi, Atef A.
Qasrawi, Atef Fayez
Qasrawi, Atef F.
Qasrawi, Atef A.
Qasrawi, Atef
Job Title
Doçent Doktor
Email Address
atef.qasrawi@atilim.edu.tr
Main Affiliation
Department of Electrical & Electronics Engineering
Status
Former Staff
Website
ORCID ID
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID

Sustainable Development Goals

2

ZERO HUNGER
ZERO HUNGER Logo

0

Research Products

11

SUSTAINABLE CITIES AND COMMUNITIES
SUSTAINABLE CITIES AND COMMUNITIES Logo

0

Research Products

14

LIFE BELOW WATER
LIFE BELOW WATER Logo

0

Research Products

6

CLEAN WATER AND SANITATION
CLEAN WATER AND SANITATION Logo

0

Research Products

1

NO POVERTY
NO POVERTY Logo

0

Research Products

5

GENDER EQUALITY
GENDER EQUALITY Logo

0

Research Products

9

INDUSTRY, INNOVATION AND INFRASTRUCTURE
INDUSTRY, INNOVATION AND INFRASTRUCTURE Logo

0

Research Products

16

PEACE, JUSTICE AND STRONG INSTITUTIONS
PEACE, JUSTICE AND STRONG INSTITUTIONS Logo

1

Research Products

17

PARTNERSHIPS FOR THE GOALS
PARTNERSHIPS FOR THE GOALS Logo

0

Research Products

15

LIFE ON LAND
LIFE ON LAND Logo

0

Research Products

10

REDUCED INEQUALITIES
REDUCED INEQUALITIES Logo

0

Research Products

7

AFFORDABLE AND CLEAN ENERGY
AFFORDABLE AND CLEAN ENERGY Logo

17

Research Products

8

DECENT WORK AND ECONOMIC GROWTH
DECENT WORK AND ECONOMIC GROWTH Logo

0

Research Products

4

QUALITY EDUCATION
QUALITY EDUCATION Logo

0

Research Products

12

RESPONSIBLE CONSUMPTION AND PRODUCTION
RESPONSIBLE CONSUMPTION AND PRODUCTION Logo

0

Research Products

3

GOOD HEALTH AND WELL-BEING
GOOD HEALTH AND WELL-BEING Logo

0

Research Products

13

CLIMATE ACTION
CLIMATE ACTION Logo

0

Research Products
This researcher does not have a Scopus ID.
This researcher does not have a WoS ID.
Scholarly Output

222

Articles

218

Views / Downloads

639/0

Supervised MSc Theses

0

Supervised PhD Theses

0

WoS Citation Count

1886

Scopus Citation Count

1906

WoS h-index

21

Scopus h-index

21

Patents

0

Projects

0

WoS Citations per Publication

8.50

Scopus Citations per Publication

8.59

Open Access Source

17

Supervised Theses

0

Google Analytics Visitor Traffic

JournalCount
Journal of Electronic Materials15
Crystal Research and Technology13
physica status solidi (a)12
Journal of Alloys and Compounds11
Materials Science in Semiconductor Processing11
Current Page: 1 / 11

Scopus Quartile Distribution

Competency Cloud

GCRIS Competency Cloud

Filters

2001 - 2009232010 - 20164
Reset filters

Settings

Subject: [No Keyword Available]

Scholarly Output Search Results

Now showing 1 - 10 of 27
  • Thumbnail Image
    Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Dispersive Optical Constants of Tl2ingase4< Single Crystals
    (Iop Publishing Ltd, 2007) Qasrawi, A. F.; Gasanly, N. M.
    The structural and optical properties of Bridgman method grown Tl2InGaSe4 crystals have been investigated by means of room temperature x-ray diffraction, and transmittance and reflectance spectral analysis, respectively. The x-ray diffraction technique has shown that Tl2InGaSe4 is a single phase crystal of a monoclinic unit cell that exhibits the lattice parameters of a = 0.77244 nm, b = 0.64945 nm, c = 0.92205 nm and beta = 95.03 degrees . The optical data have revealed an indirect allowed transition band gap of 1.86 eV. The room temperature refractive index, which was calculated from the reflectance and transmittance data, allowed the identification of the dispersion and oscillator energies, static dielectric constant and static refractive index as 28.51 and 3.45 eV, 9.26 and 3.04, respectively.
  • Thumbnail Image
    Article
    Citation - WoS: 3
    Citation - Scopus: 3
    Optoelectronic Properties of Ga4se3< Single Crystals
    (Iop Publishing Ltd, 2008) Qasrawi, A. F.; Gasanly, N. M.; Ilaiwi, K. F.
    The optoelectronic properties of Bridgman method-grown Ga(4)Se(3)S single crystals have been investigated by means of room temperature electrical resistivity, temperature-dependent photosensitivity and temperature-dependent optical absorption. The photosensitivity was observed to increase with decreasing temperature, the illumination dependence of which was found to exhibit monomolecular recombination in the bulk at 300 K. The absorption coefficient, which was calculated in the incident photon energy range of 2.01-2.35 eV, increased with increasing temperature. Consistently, the absorption edge shifts to lower energy values. The fundamental absorption edge corresponds to an indirect allowed transitions energy gap (2.08 eV at 300 K) that exhibits a temperature coefficient of -95 x 10(-4) eVK(-1).
  • Thumbnail Image
    Article
    Citation - WoS: 3
    Citation - Scopus: 4
    Hall Mobility and Photoconductivity in Tlgases Crystals
    (Amer inst Physics, 2013) Qasrawi, A. F.; Gasanly, N. M.
    In this work, the fundamental properties of the TlGaSeS single crystals are investigated by means of temperature dependent electrical resistivity and Hall mobility. The crystal photo-responsibility as function of illumination intensity and temperature is also tested in the temperature range of 350-160 K. The study allowed the determination of acceptor centers as 230 and 450 meV below and above 260 K, and recombination centers as 181, 363, and 10 meV at low, moderate, and high temperatures, respectively. While the temperature-dependent Hall mobility behaved abnormally, the photoconductivity analysis reflected an illumination intensity dependent recombination center. Namely, the recombination center increased from 10 to 90 meV as the light intensity increased from 27.9 to 76.7 mW cm(-2), respectively. That strange behavior was attributed to the temporary shift in Fermi level caused by photoexcitation. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4775577]
  • Thumbnail Image
    Article
    Citation - WoS: 30
    Citation - Scopus: 30
    Optoelectronic and Electrical Properties of Tlgas2 Single Crystal
    (Wiley-v C H verlag Gmbh, 2005) Qasrawi, AF; Gasanly, NM
    The optoelectronic and electrical properties of TIGaS2 single crystals have been investigated by means of room temperature transmittance and reflectance spectral analysis, Hall coefficient, dark electrical resistivity and photocurrent measurements in the temperature range of 200-350 K. The optical data have revealed an indirect and direct allowed transition band gaps of 2.45 and 2.51 eV, an oscillator and dispersion energy of 5.04 and 26.45 eV, respectively, a static dielectric constant of 6.25 and static refractive index of 2.50. The dark Hall coefficient measurements have shown that the crystals exhibit a conductivity type conversion from p-type to n-type at a critical temperature of 315 K. Deep donor and acceptor energy levels of 0.37/0.36 eV and 0.66 eV has been calculated from the temperature dependence of Hall coefficient and resistivity, and photocurrent measurements, respectively. The photocurrent decreases with decreasing temperature. The analysis of the photocurrent data have revealed that, the recombination mechanism is linear and supralinear above and below 290 K, respectively. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
  • Thumbnail Image
    Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Polarization Sensitive Reflection and Dielectric Spectra in Gase Thin Films
    (Hindawi Ltd, 2016) Khanfar, Hazem K.; Qasrawi, Atef A.
    The light polarization effects on the optical reflective and dielectric spectra of GaSe thin films are studied in the incident light wavelength range of 200-1100 nm. In this range of measurement, the angle of incidence (theta(i)) of light was varied between 30 degrees and 80 degrees. In addition, at theta(i) of 30 degrees the light polarizing angle (delta) was altered in the range of 0-90 degrees. Regardless of the value of lambda, for all theta(i) > 65 degrees, the total reflectance sharply decreased with increasing theta(i). In addition, when theta(i) is fixed at 30 and delta was varied, the amplitudes ratio of the polarized waves exhibits a resonance-antiresonance phenomenon at a wavelength that coincides with the film's thickness (800 nm). This behavior was assigned to the coupled interference between incident and reflected waves and to the strong absorption effects. Two main resonance peaks are observed as response to s-polarized and normal incident beam: one is at similar to 540 (556 nm) and the other at similar to 420 THz (714 nm). The dielectric constant of the GaSe films exhibits anisotropic characteristics that nominate it for use as multipurpose optoelectronic devices.
  • Thumbnail Image
    Article
    Citation - WoS: 1
    Citation - Scopus: 1
    Hole-Polar Phonon Interaction Scattering Mobility in Chain Structured Tlse0.75s0.25< Crystals
    (Wiley-blackwell, 2009) Qasrawi, A. F.; Gasanly, N. M.
    In this study, the electrical resistivity, charge carriers density and Hall mobility of chain structured TlSe0.75S0.25 crystal have been measured and analyzed to establish the dominant scattering mechanism in crystal. The data analyses have shown that this crystal exhibits an extrinsic p-type conduction. The temperature-dependent dark electrical resistivity analysis reflected the existence of three energy levels located at 280 meV, 68 meV and 48 meV. The temperature dependence of carrier density was analyzed by using the single donor-single acceptor model. The carrier concentration data were best reproduced assuming the existence of an acceptor impurity level being located at 68 meV consistent with that observed from resistivity measurement, The model allowed the determination of the hole effective mass and the acceptor-donor concentration difference as 0.44m(0) and 2.2 x 10(12) cm(-3), respectively. The Hall mobility of the TlSe0.75S0.25 crystal is found to be limited by the scattering of charged carriers over the (chain) boundaries and the scattering of hole-polar phonon interactions above and below 300 K, respectively. The value of the energy barrier height at the chain boundaries was found to be 261 meV. The polar phonon scattering mobility revealed the high-frequency and static dielectric constants of 13.6 and 15.0, respectively. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • Thumbnail Image
    Article
    Citation - WoS: 16
    Citation - Scopus: 17
    Investigation of Localized Levels in Gas0.5se0.5< Layered Crystals by Means of Electrical, Space-Charge Limited Current and Photoconductivity Measurements
    (Wiley-v C H verlag Gmbh, 2002) Qasrawi, AF; Gasanly, NM
    To identify the localized levels in GaS0.5Se0.5 single crystals, the dark electrical conductivity, current-voltage characteristics and photoconductivity measurements were carried out in the temperature range of 250-400 K. Temperature dependence of dark electrical conductivity and the space-charge limited current studies indicate the presence of a single discrete trapping level located at 0.31 eV below the conduction band with a density of about 1.3 x 10(15) cm(-3). The conductivity data above 320 K reveal an additional donor level with activation energy of 0.40 eV indicating the extrinsic nature of conduction. The spectral distribution of photocurrent in the photon energy range of 0.65-5.9 eV reveals an indirect band gap of 2.26 eV. The photocurrent-illumination intensity dependence follows the law I-ph proportional to F-gamma, with gamma being 1.0, 0.65, and 0.5 at low, moderate and high illumination intensities, respectively. The corresponding behavior indicates the domination of monomolecular recombination, near equal densities of trapped and recombination centers and bimolecular recombination. It is observed that the photocurrent increases in the temperature range from 250 K up to T-m = 360 K and decreases for T > T-m. The temperature dependence of the photocurrent reveals two additional impurity levels with activation energies of 0.14 and 0.10 eV below and above Tm, respectively.
  • Thumbnail Image
    Article
    Citation - WoS: 13
    Citation - Scopus: 13
    Light Illumination Effect on the Electrical and Photovoltaic Properties of In6s7< Crystals
    (Iop Publishing Ltd, 2006) Qasrawi, AF; Gasanly, NM
    The electrical and photoelectrical properties of In6S7 crystals have been investigated in the temperature regions of 170-300 K and 150-300 K, respectively. The dark electrical analysis revealed the intrinsic type of conduction. The energy band gap obtained from the temperature-dependent dark current is found to be 0.75 eV. It is observed that the photocurrent increases in the temperature range of 150 K up to T-m = 230 K and decreases at T > T-m. Two photoconductivity activation energies of 0.21 and 0.10 eV were determined for the temperature ranges below and above Tm, respectively. The photocurrent (I-ph)-illumination intensity (F) dependence follows the law I-ph alpha F-gamma. The value of. decreases when the temperature is raised to T-m, then it starts increasing. The change in the value. with temperature is attributed to the exchange in role between the recombination and trapping centres in the crystal. The crystals are found to exhibit photovoltaic properties. The photovoltage is recorded as a function of illumination intensity at room temperature. The maximum open-circuit voltage and short-circuit photocurrent density, which are related to an illumination intensity equivalent to one sun, are 0.12 V and 0.38 mA cm(-2), respectively.
  • Thumbnail Image
    Conference Object
    Citation - WoS: 15
    Citation - Scopus: 15
    Refractive Index, Static Dielectric Constant, Energy Band Gap and Oscillator Parameters of Ga2ses Single Crystals
    (Wiley-v C H verlag Gmbh, 2007) Qasrawi, A. F.; Gasanly, N. M.
    The optical properties of Bridgman method grown Ga2SeS crystals have been investigated by means of room-temperature transmittance and reflectance spectral analysis. The optical data have revealed direct and indirect allowed transition band gaps of 2.49 and 2.10 eV, respectively. The room-temperature refractive index, which was calculated from the reflectance and transmittance data, allowed the identification of the dispersion and oscillator energies, static dielectric constant and static refractive index as 20.93 eV and 4.01 eV, 6.21 and 2.49, respectively.
  • Thumbnail Image
    Article
    Citation - WoS: 18
    Citation - Scopus: 18
    Growth, Electrical and Structural Characterization of Β-Gase Thin Films
    (Springer, 2003) Parlak, M; Qasrawi, AF; Erçelebi, Ç
    GaSe thin films were deposited onto the glass substrates kept at 200degrees and 300degreesC by the thermal evaporation of GaSe crystals under the pressure of 10(-5) Torr. X-ray analysis of the films revealed that films grown at 200. C are amorphous in nature while the films grown at 300degreesC are polycrystalline beta-GaSe. The temperature dependent electrical conductivity measurements in the region of 320-100 K for the films grown at 300degreesC showed that the transport mechanisms are the thermionic emission of charged carriers and the variable range hopping above and below 180 K, respectively. Space charge limited current (SCLC) studies have also been performed on these films through the current-voltage measurements at different temperatures and a dominant hole trap at 0.233 eV from the top of the valance band with a trap density of similar to1.6 x 10(11) cm(-3) is identified. (C) 2003 Kluwer Academic Publishers.