Browsing by Author "Gasanly, Nizami M."
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Article Citation Count: 3Analysis of the Junction Properties of C/GaSe0.5S0.5/C Back-to-Back Schottky-Type Photodetectors(Ieee-inst Electrical Electronics Engineers inc, 2015) Qasrawı, Atef Fayez Hasan; Qasrawi, Atef F.; Gasanly, Nizami M.; Department of Electrical & Electronics EngineeringIn this paper, a C/GaSe0.5S0.5/C metal-semiconductor-metal photodetector is suggested and described. The device is explored by means of current-voltage and capacitance-voltage (C-V) characteristics under different photoexcitation intensities. It was observed that the design of the back-to-back Schottky device has reduced the dark current of the normal Ag/GaSe0.5S0.5/C Schottky diode by 13 times and increased the photosensitivity from 3.8 to similar to 2.1x10(3). The device exhibited a barrier height of 0.842 eV in the dark. The barrier height is reduced via photoexcitation. In addition, the C/GaSe0.5S0.5/C device exhibited an ON/OFF switching property from low injection OFF to high injection ON at specific biasing voltages. This voltage decreased with the increasing illumination intensity. On the other hand, the C-V characteristics of the device, which was recorded for an ac input signal with 100 MHz at different levels of photoexcitation shifted up when the intensity of light was increased. When the same measurement was repeated at signal frequency of 1.6 GHz, the C-V characteristics reflected a different level of capacitance response. These features of C/GaSe0.5S0.5/C photodetectors nominate the device to be used as multipurpose optical switches being suitable to store different levels of electromagnetic energy at microwave frequencies.Article Citation Count: 7Low temperature thermoluminescence of Gd2O3 nanoparticles using various heating rate and Tmax - Texc. methods(Elsevier, 2019) Işık, Mehmet; Isik, Mehmet; Gasanly, Nizami M.; Department of Electrical & Electronics EngineeringThermoluminescence (FL) measurements for Gd2O3 nanoparticles were carried out for various heating rates between 0.3 and 0.8 K/s at low temperatures (10-280 K). TL spectrum exhibited two observable and one faint peaks in the temperature region of 10-100 K, and four peaks in the temperature region of 160-280 K. Heating rate analysis was achieved to understand the behaviors of trap levels. It was seen that the peak maximum temperatures and TL intensities of all peaks increase with increasing heating rate. This behavior was ascribed to anomalous heating rate effect. T-max - T(exc )analysis was accomplished for TL, peaks at relatively higher temperature region to reveal the related traps depths. T-max - T-exc plot presented a staircase structure indicating that the TL glow curve is composed of well separated glow peaks. Mean activation energies of trapping centers corresponding to these separated peaks were found as 0.43, 0.50, 0.58 and 0.80 eV.Article Citation Count: 1p-TlGaSeS/n-BN heterojunction as a microwave filter and as a photovoltaic device(Wiley-v C H verlag Gmbh, 2015) Qasrawı, Atef Fayez Hasan; Omar, Ahmad; Azamtta, Ala' M.; Gasanly, Nizami M.; Department of Electrical & Electronics EngineeringIn this work, a p-n junction made of p-type TlGaSeS and n-type boron nitride (BN) is investigated and characterized. The bilayer was studied by means of capacitance-voltage characteristics, current-voltage characteristics and Bode signal and photovoltaic effect diagnostics. It was observed that the pTlGaSeS/n-BN bilayer exhibits negative capacitance values in the frequency range of 30-80 MHz. For an ac signal of 30 MHz, the built-in voltage and density of noncompensating carriers for the device are found to 1.06 eV and 1.72 x 10(12) cm(-3), respectively. The characteristic Bode curve analysis indicated that the bilayer behaves as a lowpass microwave filter that blocks all signals of frequencies larger than 1.28 GHz. The time constant for this device is 124 ps. In addition, the p-TlGaSeS/n-BN junction exhibited a well-pronounced photovoltaic effect. The device showed switching properties from low to high-current injection at a particular switching voltage. The switching voltage is sensitive to the light energy and intensity. It decreased systematically with increasing light intensity and energy. The device responsivity is similar to 7.64mAW(-1). The filtering and photovoltaic properties of the device suggest its use as an optoelectronic switch and as a microwave filter being suitable for multipurpose operations. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim