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Article Citation - WoS: 8Citation - Scopus: 8Design and performance of Yb/ZnS/C Schottky barriers(Elsevier Science Bv, 2017) Khusayfan, Najla M.; Al Garni, S. E.; Qasrawi, A. F.In this work, ZnS thin films are deposited onto glass and transparent ytterbium substrates under vacuum pressure of 10(-5) mbar. The effects of the Yb substrate on the structural, mechanical, optical, dielectric and electrical performance of the ZnS are explored by means of the energy dispersion X-ray analyzer, X-ray diffraction, UVeVIS spectroscopy, current-voltage characteristics and impedance spectroscopy techniques. The techniques allowed determining the lattice parameters, the grain size, the degree of orientation, the microstrain, the dislocation density, the optical and the excitonic gaps, the energy band offsets and the dielectric resonance and dispersion. The (111) oriented planes of glass/ZnS and Yb/ZnS exhibited 2.06% lattice mismatch between Yb and ZnS and degree of orientation values of 63% and 51.6%, respectively. The interfacing of the ZnS with Yb shrunk the energy band gap of ZnS by 0.50 eV. On the other hand, the electrical analysis on the Yb/ZnS/C Schottky device has revealed a rectification ratio of 3.48 x 10(4) at a biasing voltage of 0.30 V. The barrier height and ideality factor was also determined. Moreover, the impedance spectroscopy analysis have shown that the Yb/ZnS/C device is very attractive for use as varactor devices of wide tunability. The device could also be employed as microwave resonator above 1337 MHz. (C) 2016 Elsevier B. V. All rights reserved.Article Citation - WoS: 9Citation - Scopus: 8Plasmon Interactions at the (ag, Al)/Inse Thin-Film Interfaces Designed for Dual Terahertz/Gigahertz Applications(Springer, 2017) Al Garni, S. E.; Omar, A.; Qasrawi, A. F.In this article, we investigate the plasmon-dielectric spectral interaction in the Ag/InSe and Al/InSe thin-film interfaces. The mechanism is explored by means of optical absorbance and reflectance at terahertz frequencies and by the impedance spectroscopy at gigahertz frequencies. It was observed that the interfacing of the InSe with Ag and Al metals with a film thickness of 250 nm causes an energy band gap shift that suits the production of thin-film optoelectronic devices. The reflectance and dielectric constant and optical conductivity spectral analysis of these devices displayed the properties of wireless band stop filters at 390 THz. The physical parameters which are computed from the conductivity spectra revealed higher mobility of charge carriers at the Al/InSe interface over that of Ag/InSe. The respective electron-bounded plasmon frequencies are found to be 2.61 and 2.13 GHz. On the other hand, the impedance spectral analysis displayed a microwave resonator feature with series resonance peak position at 1.68 GHz for the Al/InSe/Ag interface. In addition, the temperature-dependent impedance spectra, which were recorded in the temperature range of 300-420 K, revealed no significant effect of temperature on the wave trapping properties of the Al/InSe/Ag interface. The sensitivity of the interfaces to terahertz and gigahertz frequencies nominates it as laser light/microwave traps, which are used in fibers and communications.
