2 results
Search Results
Now showing 1 - 2 of 2
Article Citation - WoS: 9Citation - Scopus: 9Investigation of the Electrical Parameters of Ag/P-tlgases Schottky Contacts(Elsevier, 2012) Qasrawi, A. F.; Gasanly, N. M.p-type TlGaSeS single crystal was used to fabricate a Schottky device. Silver and carbon metals were used as the Ohmic and Schottky contacts, respectively. The device which displayed wide RF band at 13.200 and narrow band at 62.517 kHz with Q value of 1.4 and of 6.3 x 10(4), respectively, is characterized by means of current (I)-voltage (V), capacitance (C)-voltage characteristics as well as capacitance-frequency (f) characteristics. The device series resistance, ideality factor and barrier height are determined from the I-Vcurve as 35.8 M Omega, 1.2 and 0.74 eV, respectively. The apparent acceptor density and the build in voltage of the device increased with increasing ac signal frequency. The high Q value, observed at 62.517 kHz. indicated a much lower rate of energy loss relative to the stored energy of the device. The energy loss (Q(-1)) is much less than 0.001% of the stored value. The device was tested and found to remain at the same mode of resonance for several hours. It never switched or ceased unless it was tuned off. (c) 2012 Elsevier B.V. All rights reserved.Article Citation - WoS: 5Citation - Scopus: 5Dielectric and photo-dielectric properties of TlGaSeS crystals(indian Acad Sciences, 2014) Qasrawi, A. F.; Abu-Zaid, Samah F.; Ghanameh, Salam A.; Gasanly, N. M.The room temperature, dark and photo-dielectric properties of the novel crystals TlGaSeS are investigated in the frequency, intensity and biasing voltage having ranges of similar to 1-120 MHz, 14-40 klux and 0-1 V, respectively. The crystals are observed to exhibit a dark high frequency effective dielectric constant value of similar to 10.65 x 10(3) with a quality factor of similar to 8.84 x 10(4) at similar to 120 MHz. The dielectric spectra showed sharp resonance-antiresonance peaks in the frequency range of similar to 25-250 kHz. When photoexcited, pronounced increase in the dielectric constant and in the quality factor values with increasing illumination intensity are observed. Signal amplification up to similar to 33% with improved signal quality up to similar to 29% is attainable via photoexcitation. On the other hand, the illuminated capacitance voltage characteristics of the crystals reflected a downward shift in the voltage biasing and in the built-in voltage of the device that is associated with increase in the uncompensated carrier density. The increase in the dielectric constant with increasing illumination intensity is ascribed to the decrease in the crystal's resistance as a result of increased free carrier density. The light sensitivity of the crystals, the improved dielectric properties and the lower biasing voltage obtained via photoexcitation and the well-enhanced signal quality factor of the crystals make them promising candidates for optical communication systems.
