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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.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: 8Citation - Scopus: 8Spectral Dynamics of the n-inse Heterojunction(Springer, 2015) Alharbi, S. R.; Qasrawi, A. F.The design and characterization of the InSe/BN heterojunction were investigated by study of optical reflectance, transmittance, and absorbance spectra in the incident wavelength range 300-1100 nm. Three absorption band edges related to conduction-valence band splitting of 2.75, 1.49, and 3.90 eV were observed. These bands shifted to 1.06 eV, 2.25 eV, and 3.85 eV on preparation of the InSe/BN interface. Analysis of dielectric spectra in the frequency range 275-1000 THz revealed the presence of three main resonance peaks at 333, 308, and 280 THz for the InSe substrate and at 341, 316, and 286 THz for the InSe/BN interface. The dispersion energy of the substrate increased from 27.43 eV to 33.77 eV on preparation of the InSe/BN interface. The quality factor of the heterojunction was found to be three times greater than that of InSe. The device seems to have potential, because the results suggest use of the heterojunction in thin-film transistor and optical communication technology.
