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Article Citation - WoS: 15Citation - Scopus: 17Dielectric Dispersion in Ga2s3< Thin Films(Springer, 2017) Alharbi, S. R.; Qasrawi, A. F.In this work, the structural, compositional, optical, and dielectric properties of Ga2S3 thin films are investigated by means of X-ray diffraction, scanning electron microscopy, energy dispersion X-ray analysis, and ultraviolet-visible light spectrophotometry. The Ga2S3 thin films which exhibited amorphous nature in its as grown form are observed to be generally composed of 40.7 % Ga and 59.3 % S atomic content. The direct allowed transitions optical energy bandgap is found to be 2.96 eV. On the other hand, the modeling of the dielectric spectra in the frequency range of 270-1,000 THz, using the modified Drude-Lorentz model for electron-plasmon interactions revealed the electrons scattering time as 1.8 (fs), the electron bounded plasma frequency as similar to 0.76-0.94 (GHz) and the reduced resonant frequency as 2.20-4.60 x10(15) (Hz) in the range of 270-753 THz. The corresponding drift mobility of electrons to the terahertz oscillating incident electric field is found to be 7.91 (cm (2)/Vs). The values are promising as they nominate the Ga2S3 thin films as effective candidates in thin-film transistor and gas sensing technologies.Article Citation - WoS: 9Citation - Scopus: 9Effect of Ytterbium, Gold and Aluminum Transparent Metallic Substrates on the Performance of the Ga2s3< Thin Film Devices(Elsevier Science Bv, 2017) Alharbi, S. R.; Qasrawi, A. F.In the current work, the structural, optical, dielectric and electrical properties of the Ga2S3 thin films which are deposited onto transparent thin Al, Yb and Au metal substrates are characterized by means of transmittance electron microscopy, X-ray diffraction, ultraviolet visible light spectroscopy and impedance spectroscopy techniques. The effects of the metallic substrates on the crystalline nature, energy band gap and dielectric spectra are also investigated. The modeling of the dielectric spectra allowed determining the effect of the Al, Yb and Au thin layers on the electron scattering time, the plasmon frequency, free electron density and drift mobility. In addition, a Yb/Ga2S3/Au Schottky barrier and All Ga2S3/Au back to back Schottky barrier devices (metal-semiconductor-metal (MSM) device) are fabricated and characterized by means of capacitance-voltage characteristics and capacitance and conductance spectra in the frequency range of 10-1800 MHz. While the Schottky barrier device displayed three distinct positions of resonance-antiresonance phenomena, the MSM device displayed one peak with narrow bandwidth of 10 MHz. The MSM devices exhibited an inversion, depletion and accumulation modes within a voltage range of 0.25 V width at 250 MHz. The study indicates the applicability of these device as smart capacitive switches, as Plasmon devices and as wavetraps. (C) 2017 Elsevier B.V. All rights reserved.Article Citation - WoS: 1Citation - Scopus: 1Characterization of the Nanosandwiched Ga2s3< Interfaces as Microwave Filters and Thermally Controlled Electric Switches(Elsevier Gmbh, 2018) Alharbi, S. R.; Nazzal, Eman O.; Qasrawi, A. F.In this work, an indium layer of 50 nm thicknesses is sandwiched between two 500 nm thick Ga2S3 layers. The effect of indium nansandwiching on the composition, structure, morphology, light absorbability, capacitance and reactance spectra, and temperature dependent electrical conductivity of the Ga2S3 films are investigated by means of X-ray diffraction, scanning electron microscopy, energy dispersion X-ray spectroscopy, Raman spectroscopy, visible light spectrophotometry, impedance spectroscopy and current voltage characteristics. While the nansandwiched films are observed to exhibit an amorphous nature of structure with indium content of Owing to the nucleation mechanisms that take place during the film growth, the accumulation of some unit cells in groups to form grains should be a significant reason for the existence of many different sizes of grains in the nanosand-wiched films (Alharbi and Qasrawi, 2016). 0, the Raman spectra displayed three vibrational modes at 127.7,145.0 and 274.3 cm(-1). It was also observed that the indium insertion in the structure of the Ga2S3 shrinks the energy band gap by 0.18 eV. The nanosandwiched films are observed to exhibit a semiconductor metal (SM) transition at 310 K. The SM transition is associated with thermal hysteresis that exhibited a maximum value of 16% at 352 K. This behavior of the nanosandwiched films nominate it for use as thermally controlled electric switches. In addition, the impedance spectral analysis in the range of 10-1800 MHz has shown a capacitance tunability of more than 70%. The measurements of the wave trapping property displayed a bandpass/reject filter characteristics above 1.0 GHz which allow using the Ga2S3/In/Ga2S3 thin films as microwave resonator. (C) 2017 Elsevier GmbH. All rights reserved.Article Citation - WoS: 18Citation - Scopus: 21Engineering the Optical and Dielectric Properties of the Ga2s3< Nanosandwiches Via Indium Layer Thickness(Springer, 2018) Nazzal, Eman O.; Qasrawi, A. F.; Alharbi, S. R.In this study, the effect of the nanosandwiched indium slab thickness (20-200 nm) on the performance of the Ga2S3/In/Ga2S3 interfaces is explored by means of X-ray diffraction, Raman spectroscopy, and optical spectroscopy techniques. The indium slab thickness which was varied in the range of 20-200 nm is observed to enhance the visible light absorbability of the Ga2S3 by 54.6 times, engineered the energy band gap in the range of 3.7-1.4 eV and increases the dielectric constant without, significantly, altering the structure of the Ga2S3. The broad range of the band gap tunability and the increased absorbability nominate the Ga2S3 thin films for photovoltaic applications. In addition, the dielectric spectral analysis and modeling have shown that a wide variety in the plasmon resonant frequency could be established within the Ga2S3/In/Ga2S3 trilayers. The plasmon frequency engineering in the range of 0.56-2.08 GHz which is associated with drift mobility of 12.58-5.76 cm(2)/Vs and electron scattering time at femtosecond level are promising for the production of broad band high frequency microwave filters.
