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Article Citation - WoS: 14Citation - Scopus: 15An Accurate Optical Gain Model Using Adaptive Neuro-Fuzzy Inference System(Natl inst Optoelectronics, 2009) Celebi, F. V.; Altindag, T.; Computer EngineeringThis paper presents a single, simple, new and an accurate optical gain model based on adaptive neuro-fuzzy inference system (ANFIS) which combines the benefits of Artificial Neural Networks (ANNs) and Fuzzy Inference Systems (FISs). The dynamic optical gain model results are in very good agreement with the previously published experimental findings.Article Citation - WoS: 3Citation - Scopus: 3Current Transport Mechanism in Au-p-mgo-ni Schottky Device Designed for Microwave Sensing(Natl inst Optoelectronics, 2016) Qasrawi, A. F.; Khanfar, H. K.; Department of Electrical & Electronics EngineeringAu/MgO/Ni back to back Schottky tunnelling barriers are designed on the surface of an MgO thin layer and are electrically characterized. The current voltage curve analysis has shown that thermionic emission, field effect thermionic (FET) emission and space charge limited current are dominant transport mechanism in distinct biasing regions. It was shown that, while the device is reverse biased with voltages less than 0.31 V, it conducts by tunnelling (FED though an energy barrier of 0.88 eV with a depletion region width of 15.7 nm. As the voltage exceeds 0.46 V, the tunnelling energy barrier is lowered to 0.76 eV and the depletion region widens and arrives at the reach-through running mode. The device was tested in the microwave electromagnetic power range that extends from Bluetooth to WLAN radiation levels at oscillating frequencies of 0.5 and 2.9 GHz. In addition, a low power resonating signal that suits mobile data is superimposed in the device. It was observed that the Au/MgO/Au sensors exhibit a wide tunability range via voltage biasing or via frequency control. The signal quality factor is 3.53 x 10(3) at 2.9 GHz. These properties reflect applicability in microwave technology as wireless and connectorized microwave amplifiers, microwave resonators and mixers.Article Citation - WoS: 2Determination of Optical Constants and Temperature Dependent Band Gap Energy of Gas0.25se0.75< Single Crystals(Natl inst Optoelectronics, 2017) Isik, M.; Gasanly, N.Optical properties of GaS0.25Se0.75 single crystals were investigated by means of temperature -dependent transmission and room temperature reflection experiments. Derivative spectrophotometry analysis showed that indirect band gap energies of the crystal increase from 2.13 to 2.26 eV as temperature is decreased from 300 to 10 K. Temperature dependence of band gap energy was fitted under the light of theoretical expression. The band gap energy change with temperature and absolute zero value of the band gap energy were found from the analyses. The Wemple-DiDomenico single effective oscillator model and Sellmeier oscillator model were applied to the spectral dependence of room temperature refractive index to find optical parameters of the GaS0.25Se0.75 crystal. Chemical composition of the crystal was determined using the energy dispersive spectral measurements.Article Driving Electric Field Effects on the Space Charge Limited Photocurrent of In6s7<(Natl inst Optoelectronics, 2013) Qasrawi, A. F.; Al-Balshi, Madleen A.; Gasanly, N. M.; Department of Electrical & Electronics EngineeringA new type of photovoltaic materials, which are designed on the base of In6S7 single crystals using silver and gold metals to construct Ag/In6S7/Au point contacted photocells, are reported and discussed. The influence of the driving electric field on the performance of the device was tested. The current density-electric field dependence curve reflected a space charge limited photocurrent effect being dominant in the field region of 1.0-4.3 V/cm. In addition, the In6S7 photocell short circuit and loaded current dependencies on the excitation intensity were measured. The short circuit current was observed to exhibit exponential trap distribution effect and supralinear recombination at low and high illumination intensities, respectively. The device displays a current density of 0.5 mA/cm(2) for excitation intensity of 76 klux. When loaded, it displayed a stable power dissipation curve. Such behavior reflects the novelty of these types of cells for future application.
