Fabrication and characterization of Se/WO3 heterojunctions designed as terahertz/gigahertz dielectric resonators

Qasrawi, F.; Daragme, Rana B.

doi:10.1016/j.ijleo.2022.168719

Cited by 12 publications

(5 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While the peak centered at ≈ 2.10 can be attributed to the coupled oscillations between selenium vacancy and selenium intrinsic defect centers, [ 26 ] the critical energy values centered at 1.64 eV correspond to the indirect allowed transitions within the energy band gap of Se. [ 27 ] On the other hand, ε r spectra of Pt/MgSe film display one broaden peak centered at 1.91 eV. The absolute maxima of

{\varepsilon}_{r}

spectra of glass/MgSe (centered at 1.64 eV) disappeared.…”

Section: Resultsmentioning

confidence: 99%

Enhanced Optical and Electrical Interactions at the Pt/MgSe Interfaces Designed for 6G Communication Technology

Algarni

Qasrawi

Khusayfan

2022

Cryst. Res. Technol.

View full text Add to dashboard Cite

Magnesium selenide thin films are coated onto glass and semitransparent Pt substrates (nanosheets) by the vacuum evaporation technique under a vacuum pressure of 10 −5 mbar. The effect of Pt nanosheets of thicknesses of 100 nm on the structural, compositional, optical, and electrical properties of MgSe is explored. It is found that platinum nanosheets enhance the light absorbability in the visible and infrared ranges of light. They slightly redshift the energy bandgap and decrease the dielectric constant. The strong interaction between Pt and MgSe increases the electrical conductivity by five orders of magnitude. Pt forms shallow impurity levels in the energy bandgap of MgSe allowing the tunneling process at the Pt/MgSe interfaces. Practically, a Pt/MgSe/Pt tunneling type device is fabricated and tested by the microwave impedance spectroscopy technique. It is found that Pt/MgSe/Pt devices can exhibit resonance-antiresonance and negative capacitance effects which are important in electronic circuits as parasitic capacitance cancelers, signal amplifiers, and noise reducers. In addition, evaluation of the cutoff frequency spectra has shown the ability of using the Pt/MgSe/Pt devices as microwave resonators appropriate for 5G/6G technologies. A cutoff frequency larger than 70 GHz can be achieved by imposing ac signal of amplitude of 0.10 V.

show abstract

{\varepsilon}_{r}

spectra of glass/MgSe (centered at 1.64 eV) disappeared.…”

Section: Resultsmentioning

confidence: 99%

Enhanced Optical and Electrical Interactions at the Pt/MgSe Interfaces Designed for 6G Communication Technology

Algarni

Qasrawi

Khusayfan

2022

Cryst. Res. Technol.

View full text Add to dashboard Cite

show abstract

“…Particularly, Se/WO 3 bilayers displayed maximum light absorbability of 5.29 at 1.46 eV. The energy band gap of WO 3 decreased to 1.70 eV and the terahertz cutoff frequency varied in the range of 14-65 THz in the visible range of light [19]. Replacement of Se by Pb (current work) resulted in high light absorbability of R = l 10 at 3.06 eV and lowers the terahertz cutoff frequency to ∼9 THz keeping it invariant in the visible range of light.…”

Section: Optical Conductivity Analysesmentioning

confidence: 97%

“…However, coating of WO 3 onto Pb films altered this trend of variation and forced formation of wide peak centered at E value of 2.77 eV. On the other hand, figure 2(c) illustrates the absorption coefficient spectra (a) which is calculated from the relation [19,20],…”

Section: Optical Spectroscopy Analysesmentioning

confidence: 99%

“…The terahertz cutoff frequency spectra reach value of 9.0 THz at 3.06 eV (406 nm). The IR and visible light energies centered at 1.50 eV and at 3.06 eV correspond to IR lasers known as 820 nm-IR laser and 406 nm-blue laser used in communication technology to transfer data at high rates [19,27]. It means that the currently proposed Pb/WO 3 interfaces are ideal for the design of optical receivers employable in wireless optical mobile networks [27,28].…”

Section: Optical Conductivity Analysesmentioning

confidence: 99%

“…Numerical data about the performance of these optical receivers can be obtained from the Drude-Lorentz fitting for the optical conductivity. The Drude-Lorentz approach defines the optical conductivity by the relations [10,19],…”

Section: Optical Conductivity Analysesmentioning

confidence: 99%

See 2 more Smart Citations

Lead-tungsten oxide interfaces designed as gigahertz/terahertz filters

Alkhamisi¹,

Qasrawi

Khanfar

2023

Phys. Scr.

View full text Add to dashboard Cite

Herein amorphous tungsten oxide thin films of thicknesses of 300 nm are coated onto semitransparent Pb films (100 nm) by the thermal evaporation technique under a vacuum pressure of 10-5 mbar. Optical investigations in these films have shown that Pb nanosheets enhances the light absorbability in the visible and infrared ranges of light without significant change in the energy band gap value. In addition deep analyses of the optical conductivity and terahertz cutoff frequency spectra of the Pb/WO3 optical filters revealed that the cutoff frequency value in the visible range of light is invariant with light signal energy indicating the possibly of filtering none-monochromatic light signals. On the other hand imposing an ac signal between the terminals of Pb/WO3/Au devices has proofed the ability of the device to perform as low pass and as band stop filters workable in the microwave frequency domain. The microwave cutoff frequency for this device reached ~9 GHz nominating it for use in 5G mobile technology. The current study showed that coating of tungsten oxide onto semitransparent Pb substrate and coverage small area of the top contact with Au can allow functioning the device as gigahertz/ terahertz band filters suitable for communication technology.

show abstract

Enhanced Performance of Fe/WO₃ Terahertz Dielectric Lenses

Khanfar,

Qasrawi

2024

Cryst. Res. Technol.

View full text Add to dashboard Cite

Herein transparent iron nanosheets deposited by the ionic coating technique onto glass and WO3 dielectric lenses are studied and characterized. The thickness of Fe nanosheets is varied in the range of 70–350 nm. It is observed that the transmittance and reflectance of the Fe nanosheets are highly affected by the layer roughness. Coating of iron nanosheets onto WO3 dielectric lenses increases the light absorption of WO3 by more than 240 times and red‐shifts the energy bandgap. Remarkable enhancements in the dielectric constant and in the optical conductivity are achieved via Fe coatings. In addition, iron coated dielectric lenses show higher terahertz cutoff limits varying in the range of 1.0–30 THz. Iron nanosheets remarkably increase the free charge carrier density and plasmon frequency in the infrared range of light. Moreover, the temperature dependent electrical conductivity shows high temperature stability and an increased electrical conductivity by more than 7 orders of magnitude by coating WO3 with 70 nm thick Fe nanosheets. The stability of the electrical conductivity at low temperatures and the wide range of terahertz cutoff limits in addition to the well‐enhanced light absorbability makes the iron coated tungsten oxide dielectric lenses promising for multifunction optoelectronic applications.

show abstract

Fabrication and characterization of Se/WO3 heterojunctions designed as terahertz/gigahertz dielectric resonators

Cited by 12 publications

References 43 publications

Enhanced Optical and Electrical Interactions at the Pt/MgSe Interfaces Designed for 6G Communication Technology

Enhanced Optical and Electrical Interactions at the Pt/MgSe Interfaces Designed for 6G Communication Technology

Lead-tungsten oxide interfaces designed as gigahertz/terahertz filters

Enhanced Performance of Fe/WO₃ Terahertz Dielectric Lenses

Contact Info

Product

Resources

About

Fabrication and characterization of Se/WO3 heterojunctions designed as terahertz/gigahertz dielectric resonators

Cited by 12 publications

References 43 publications

Enhanced Optical and Electrical Interactions at the Pt/MgSe Interfaces Designed for 6G Communication Technology

Enhanced Optical and Electrical Interactions at the Pt/MgSe Interfaces Designed for 6G Communication Technology

Lead-tungsten oxide interfaces designed as gigahertz/terahertz filters

Enhanced Performance of Fe/WO3 Terahertz Dielectric Lenses

Contact Info

Product

Resources

About

Enhanced Performance of Fe/WO₃ Terahertz Dielectric Lenses