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Article Citation - WoS: 7Citation - Scopus: 7Plasmon-Electron Dynamics at the Au/Inse and Y/Inse Interfaces Designed as Dual Gigahertz-Terahertz Filters(Elsevier Gmbh, Urban & Fischer verlag, 2017) Alharbi, S. R.; Qasrawi, A. F.In this work, the X-ray diffraction, the Scanning electron microscopy, the energy dispersive X-ray, the Raman, The UV-vis light and the impedance spectral techniques are employed to explore the structural, vibrational, optical and electrical properties of the Au/InSe and Y/InSe thin film interfaces. It was shown that with its amorphous nature of crystallization, the InSe thin films exhibited n-type conductivity due to the 3% excess selenium. For this form of InSe, the only active Raman spectral line is 121 (cm(-1)). In addition to the design of the energy band diagram, the analysis the dielectric spectra and the optical conductivities were possible in the frequency range of 270-1000 THz. The modeling of the optical conductivities of the Au, Y, Au/InSe and Y/InSe with the help of Lorentz approach for optical conduction, assured that the conduction is dominated by the resonant plasmon-electron interactions at the metals and metals/semiconductors interfaces. It also allowed tabulating the necessary parameters for possible applications in terahertz technology: These parameters are the electron effective masses, the free electron densities, the electron bounded plasmon frequencies, the electron scattering times, the reduced resonant frequencies and the drift mobilities. On the other hand, the impedance spectral analysis of the Y/InSe/Au interfaces in the frequency range of 0.01-1.80 GHz, revealed negative capacitance effect associated with band filter features that exhibit maximum transition line at 1.17 GHz. This value nominates the interface as a member of filter classes in the gigahertz technology. (C) 2017 Elsevier GmbH. All rights reserved.Article Citation - WoS: 26Citation - Scopus: 27Impact of Yb, In, Ag and Au Thin Film Substrates on the Crystalline Nature, Schottky Barrier Formation and Microwave Trapping Properties of Bi2o3< Films(Elsevier Sci Ltd, 2017) Khusayfan, Najla M.; Qasrawi, A. F.; Khanfar, Hazem K.The effect of the Yb, In, Ag and Au thin film metal substrates on the structural and electrical properties of Bi2O3 thin films are investigated by means of X-ray diffraction, impedance spectroscopy an current-voltage characteristic techniques. The Bi2O3 films are observed to exhibit a crystallization nature depending on the crystal structure of the substrate. Particularly, when the metal substrate is facing centered cubic, the Bi2O3 prefers the gamma-phase of body centered cubic crystallization for the (Yb, Ag and Au)/Bi2O3 interfaces. Whereas when a tetragonal substrate (indium) is used, the tetragonal beta-Bi2O3 single phase is preferred. All structural parameters presented by the lattice constant, degree of orientation, dislocation density, micro-strain and grain size are observed to strongly depend on the crystal type. In addition, the evaluation of the Schottky barrier formation at the (Yb, In, Ag, Au)/Bi2O3/Au interfaces by the current-voltage characteristics, revealed that the (In, Au)/Bi2O3/Au interface exhibit ohmic nature of contact and the (Yb,Ag)/Bi2O3/Au are of Schottky type, the rectification ratio for the Yb/Bi2O3/Au interface reaches a value of 10(5) indicating the applicability of these interfaces in CMOS digital logic devices. Moreover, the impedance spectroscopy analysis revealed that the ohmic interfaces exhibit a negative capacitance effect. The In/beta-Bi2O3/Au and Yb/.-Bi2O3/Au interfaces are performing as microwave traps with wave absorption percentage of 62% and 92% at frequencies of 193 and 1200 MHz, respectively. The features of the devices are promising as they indicate the applicability as microwave resonator and fast electronic switches.
