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Article Citation - WoS: 9Citation - Scopus: 9Yb/Inse Straddling-Type Tunneling Devices Designed as Photosensors, Mos Capacitors, and Gigahertz Bandstop Filters(Ieee-inst Electrical Electronics Engineers inc, 2021) Alfhaid, Latifah Hamad Khalid; Qasrawı, Atef Fayez Hasan; Qasrawi, A. F.; AlGarni, Sabah E.; Qasrawı, Atef Fayez Hasan; Department of Electrical & Electronics Engineering; Department of Electrical & Electronics EngineeringIn this work, amorphous InSe thin films coated with 30-160-nm-thick SiO2 are used as an active material to fabricate multifunctional devices. The n-InSe/p-SiO2 layers that are deposited onto ytterbium substrates are optically and electrically characterized. It was observed that the coating of SiO2 nanosheets onto the surface of InSe enhances the light absorbability in the near-infrared range without remarkable altering of the bandgap. Significant increase in the steady-state photocurrent values accompanied by faster photocurrent responses resulted from the coating of SiO2 nanosheets. Electrically, while the Yb/InSe/Au channels display tunneling Schottky barrier characteristics, the Yb/InSe/SiO2/Au channels show pn junction features. Both channels displayed metal-oxide-semiconductors (MOS) capacitance-voltage characteristics. In addition, the analyses of the current-voltage characteristics have shown that the currents in the Yb/InSe/Au and Yb/InSe/SiO2 (30 nm)/Au channel are dominated by electric field-assisted thermionic emission (tunneling) of charge carriers through barriers of widths of 18/14 and 30/16 nm under reverse-/forward-biasing conditions, respectively. Further increase in the oxide layer thickness lowered the barrier height of the devices. On the other hand, when an ac signal of low amplitude is imposed through the device channels, the conductance, capacitance, and reflection coefficient spectra displayed bandstop filter characteristics near 1.6 GHz. The microwave cutoff frequency spectra show a remarkable increase in the cutoff frequency values as a result of the coating of InSe with SiO2 nanosheets. The features of the device assure its applicability as rectifying diodes, fast photosensors, MOS capacitors, and microwave bandstop filters.Article Citation - WoS: 21Citation - Scopus: 21Design and Applications of Yb/Ga2< Schottky Barriers(Ieee-inst Electrical Electronics Engineers inc, 2017) Khanfar, Hazem K.; Qasrawı, Atef Fayez Hasan; Qasrawi, Atef F.; Zakarneh, Yasmeen A.; Gasanly, N. M.; Qasrawı, Atef Fayez Hasan; Department of Electrical & Electronics Engineering; Department of Electrical & Electronics EngineeringIn this paper, the Ga2Se3 crystals are used to design a Yb/Ga2Se3/C Schottky barrier. The device structure is investigated by the X-ray diffraction technique, which reveals a monoclinic-face-centered cubic interfacing type of structure. The barrier is studied by means of current (I)-voltage (V) characteristics in the dark and under light through photoexcitation from tungsten lamp and from the He-Ne laser. In addition, the impedance spectroscopy of these devices is studied in the frequency range of 10-1400 MHz. The photoexcited I-V curve analysis allowed investigating the biasing voltage, illumination power, and energy effects on the diode physical parameters, which are presented by the rectification ratio, the Schottky barrier height, the ideality factor, the series resistance, the photosensitivity, the responsivity, and the external quantum efficiency (EQE). While a maximum photosensitivity of 42 was observed for laser excitation with a wavelength of 632 nm at a reverse bias of 4.4 V, the EQE reached value of 1652% at 19.0 V. On the other hand, the ac current conduction analysis of the electrical conductivity, which was determined from the impedance spectral analysis, indicated that the ac signal processing through the Yb/Ga2Se3/C samples is due to the correlated hopping conduction through localized states of Fermi density of 3.98 x 10(19) eV(-1) cm(-3). The high-and biasing-dependent EQE% nominates the Yb/Ga2Se3/C as a tunable optoelectronic device.
