Усиление терагерцовых электромагнитных волн в структуре с двумя слоями графена при протекании постоянного электрического тока: гидродинамическое приближение

The amplification of electromagnetic terahertz radiation in a structure with two layers of hydrodynamic graphene with a direct electric current is studied theoretically. The hydrodynamic conductivity of graphene is investigated. It is shown that the real part of the graphene conductivity can be negative in the terahertz frequency range at the drift velocities of charge carriers in graphene that are lower than the phase velocity of the electromagnetic wave. For small wavevectors of a terahertz wave incident on a graphene structure, the spatial dispersion insignificantly contributes to the hydrodynamic graphene conductivity. Because of this, the amplification efficiency does not depend on the direction of currents in each of the graphene layers. It is shown that graphene with direct electric current can be used to create THz amplifiers operating at room temperature.

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Charge carriers drift induced THz amplification in dual-layer graphene structure

Journal of Physics Conference Series ◽

10.1088/1742-6596/2015/1/012094 ◽

2021 ◽

Vol 2015 (1) ◽

pp. 012094

Author(s):

I.M. Moiseenko ◽

V.V. Popov ◽

D.V. Fateev

Keyword(s):

Electric Current ◽

Direct Current ◽

Spatial Dispersion ◽

Charge Carriers ◽

Frequency Range ◽

Direct Electric Current ◽

The Real ◽

Layer Graphene

Abstract The terahertz plasmon amplification in structure based on graphene with spatial dispersion of its hydrodynamic conductivity is investigated theoretically. The spatial dispersion of graphene conductivity is related to accounting of charge carriers pressure forces and direct current in graphene. It was shown that the real part of graphene conductivity becomes negative at THz frequency range due to direct electric current in graphene.

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Photothermal, Photoelectric, and Photothermoelectric Effects in Bi-Sb Thin Films in the Terahertz Frequency Range at Room Temperature

Photonics ◽

10.3390/photonics8030076 ◽

2021 ◽

Vol 8 (3) ◽

pp. 76

Author(s):

Mikhail K. Khodzitsky ◽

Petr S. Demchenko ◽

Dmitry V. Zykov ◽

Anton D. Zaitsev ◽

Elena S. Makarova ◽

...

Keyword(s):

Thin Films ◽

Terahertz Radiation ◽

Room Temperature ◽

Voltage Drop ◽

Radiation Detection ◽

Radiation Detectors ◽

Thz Radiation ◽

Terahertz Frequency ◽

Frequency Range ◽

Terahertz Frequency Range

The terahertz frequency range is promising for solving various practically important problems. However, for the terahertz technology development, there is still a problem with the lack of affordable and effective terahertz devices. One of the main tasks is to search for new materials with high sensitivity to terahertz radiation at room temperature. Bi1−xSbx thin films with various Sb concentrations seem to be suitable for such conditions. In this paper, the terahertz radiation influence onto the properties of thermoelectric Bi1−xSbx 200 nm films was investigated for the first time. The films were obtained by means of thermal evaporation in vacuum. They were affected by terahertz radiation at the frequency of 0.14 terahertz (THz) in the presence of thermal gradient, electric field or without these influences. The temporal dependencies of photoconductivity, temperature difference and voltage drop were measured. The obtained data demonstrate the possibility for practical use of Bi1−xSbx thin films for THz radiation detection. The results of our work promote the usage of these thermoelectric materials, as well as THz radiation detectors based on them, in various areas of modern THz photonics.

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Anisotropic ultrasensitive PdTe2-based phototransistor for room-temperature long-wavelength detection

Science Advances ◽

10.1126/sciadv.abb6500 ◽

2020 ◽

Vol 6 (36) ◽

pp. eabb6500

Author(s):

Cheng Guo ◽

Yibin Hu ◽

Gang Chen ◽

Dacheng Wei ◽

Libo Zhang ◽

...

Keyword(s):

Room Temperature ◽

High Mobility ◽

Charge Carriers ◽

Terahertz Frequency ◽

Large Area ◽

Long Wavelength ◽

Terahertz Band ◽

High Anisotropy ◽

Topological Semimetals ◽

Wavelength Detection

Emergent topological Dirac semimetals afford fresh pathways for optoelectronics, although device implementation has been elusive to date. Specifically, palladium ditelluride (PdTe2) combines the capabilities provided by its peculiar band structure, with topologically protected electronic states, with advantages related to the occurrence of high-mobility charge carriers and ambient stability. Here, we demonstrate large photogalvanic effects with high anisotropy at terahertz frequency in PdTe2-based devices. A responsivity of 10 A/W and a noise-equivalent power lower than 2 pW/Hz0.5 are achieved at room temperature, validating the suitability of PdTe2-based devices for applications in photosensing, polarization-sensitive detection, and large-area fast imaging. Our findings open opportunities for exploring uncooled and sensitive photoelectronic devices based on topological semimetals, especially in the highly pursuit terahertz band.

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Negative conductivity of graphene with direct electric current

Nonlinear World ◽

10.18127/j20700970-202102-06 ◽

2021 ◽

Author(s):

I.M. Moiseenko ◽

V.V. Popov ◽

D.V. Fateev

Keyword(s):

Reflection Coefficient ◽

Electric Current ◽

Terahertz Radiation ◽

Room Temperature ◽

Negative Real Part ◽

Wave Incident ◽

Thz Radiation ◽

Direct Electric Current ◽

Radiation Sources ◽

Dc Current

Problem formulating. Currently, there are no compact, efficient terahertz radiation sources operating at room temperature. To create such sources and amplifiers, structures based on graphene with DC-current can be used. Goal. Finding conditions for achieving the negative real part of graphene conductivity and amplification of THz radiation in graphene with a direct electric current. Result. It is shown that for a certain value of direct electric current in graphene, the reflection coefficient of the THz wave incident on the structure based on graphene with DC-current exceeds unity, which indicates the amplification of THz radiation in the structure. The amplification of the THz radiation in graphene is achieved due to negative values of the real part of the graphene conductivity. Practical meaning. Results can be used to create sources and amplifiers of terahertz radiation.

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Optically controlled dielectric properties of single-walled carbon nanotubes for terahertz wave applications

Nanoscale ◽

10.1039/c8nr03740j ◽

2018 ◽

Vol 10 (26) ◽

pp. 12291-12296 ◽

Cited By ~ 21

Author(s):

Serguei Smirnov ◽

Ilya V. Anoshkin ◽

Petr Demchenko ◽

Daniel Gomon ◽

Dmitri V. Lioubtchenko ◽

...

Keyword(s):

Carbon Nanotubes ◽

Single Walled Carbon Nanotubes ◽

Terahertz Wave ◽

Complex Dielectric Constant ◽

Light Illumination ◽

Terahertz Frequency ◽

Frequency Range ◽

Terahertz Frequency Range ◽

Single Walled Carbon ◽

Walled Carbon Nanotubes

The complex dielectric constant of single-walled carbon nanotubes is tuned in the terahertz frequency range under light illumination.

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Гидродинамические терагерцовые плазмоны и электронный звук в графене с пространственной дисперсией

Физика и техника полупроводников ◽

10.21883/ftp.2020.08.49626.02 ◽

2020 ◽

Vol 54 (8) ◽

pp. 785

Author(s):

Д.В. Фатеев ◽

В.В. Попов

Keyword(s):

Electron Transport ◽

Electron Density ◽

Spatial Dispersion ◽

Diffusion Mechanism ◽

Transverse Magnetic ◽

Density Gradients ◽

Terahertz Frequency ◽

Frequency Range ◽

Terahertz Frequency Range ◽

Electron Fluid

Transverse-magnetic eigenmodes in graphene with spatial dispersion are theoretically investigated in the hydrodynamic regime in terahertz frequency range. It is shown that the spatial dispersion emerges by the diffusion mechanism of the electron transport as a result of the spreading the electron density gradients under the action of the pressure in electron fluid. Screened and unscreened plasmons as well as electron sound are considered.

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Laser Engineering of Barrier Structures Based on Solid Solution ZnCdHgTe.

MRS Proceedings ◽

10.1557/proc-719-f8.35 ◽

2002 ◽

Vol 719 ◽

Author(s):

Galina Khlyap

Keyword(s):

Room Temperature ◽

Film Surface ◽

Charge Carriers ◽

Barrier Structure ◽

Free Charge ◽

Current Voltage ◽

Capacitance Voltage ◽

Laser Engineering ◽

Charged Defects ◽

Epilayer Surface

AbstractRoom-temperature electric investigations carried out in CO2-laser irradiated ZnCdHgTe epifilms revealed current-voltage and capacitance-voltage dependencies typical for the metal-semiconductor barrier structure. The epilayer surface studies had demonstrated that the cell-like relief has replaced the initial tessellated structure observed on the as-grown samples. The detailed numerical analysis of the experimental measurements and morphological investigations of the film surface showed that the boundaries of the cells formed under the laser irradiation are appeared as the regions of accumulation of derived charged defects of different type of conductivity supplying free charge carriers under the applied electric field.

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