2015 Opto-Electronics and Communications Conference (OECC), 2015
We report on the possibilities of graphene channel FET (G-FET) as a photonic frequency double-mix... more We report on the possibilities of graphene channel FET (G-FET) as a photonic frequency double-mixing conversion device for future fully coherent access network systems. A 112.5-GHz RF signal whose amplitude was coded with a 5-GHz rectangular signal was input to the gate, concurrently a 1.58-μm wavelength photomixed dual CW laser beam having a beat frequency of 87.5 GHz was incident to the FET, generating the local (LO) signal. The RF and LO signals were mixed to reproduce the down-converted 5-GHz signal onto the 25-GHz intermediate frequency (IF) signal successfully.
We calculate the current-voltage characteristic of a two-dimensional electron system (2DES) subje... more We calculate the current-voltage characteristic of a two-dimensional electron system (2DES) subjected to a magnetic field at strong electric fields. The interaction of electrons with piezoelectric acoustic phonons is considered as a major scattering mechanism governing the current-voltage characteristic. It is shown that at a sufficiently strong electric field corresponding to the Hall drift velocity exceeding the velocity of sound, the dissipative current exhibits an overshoot. The overshoot of the dissipative current can result in a breakdown of the absolute negative conductivity caused by microwave irradiation and, therefore, substantially effect the formation of the domain structures with the zero-resistance and zero-conductance states and supersonic electron streams.
We study plasma effects in a micromachined high-electron mobility transistor (HEMT) with the micr... more We study plasma effects in a micromachined high-electron mobility transistor (HEMT) with the microcantilever serving as the gate using the developed a model. The model accounts for mechanical motion of the microcantilever and spatio-temporal variations (plasma effects) of the two-dimensional electron gas(2DEG) system in the transistor channel. The microcantilever mechanical motion is described in the point-mass approximation. The hydrodynamic electron transport model is used to describe distributed electron plasma phenomena in the 2DEG system. Using the developed model, we calculated the response function characterizing the amplitude microcantilever oscillations and the output electric signal as functions of the signal frequency and the bias voltage for the devices with different parameters. We find the voltage dependences of the frequency of the mechanical resonance and its damping. In particular, it is demonstrated that the amplitudes of the mechanical oscillations and output electric signal exhibit pronounced maxima at the bias voltages close to the voltage of the 2DEG channel depletion followed by a steep drop with further increase in the bias voltage.
We calculate the contribution of the photon-assisted interaction of electrons with leaky interfac... more We calculate the contribution of the photon-assisted interaction of electrons with leaky interface phonons to the dissipative dc photoconductivity of a two-dimensional electron system in a magnetic field. The calculated photoconductivity as a function of the frequency of microwave radiation and the magnetic field exhibits pronounced oscillations. The obtained oscillation structure is different from that in the case of photon-assisted interaction with impurities. We demonstrate that at a sufficiently strong microwave radiation in the certain ranges of its frequency (or in certain ranges of the magnetic field) this mechanism can result in the absolute negative conductivity.
In a continuous search for the energy-efficient electronic switches, a great attention is focused... more In a continuous search for the energy-efficient electronic switches, a great attention is focused on tunnel field-effect transistors (TFETs) demonstrating an abrupt dependence of the source-drain current on the gate voltage. Among all TFETs, those based on one-dimensional (1D) semiconductors exhibit the steepest current switching due to the singular density of states near the band edges, though the current in 1D structures is pretty low. In this paper, we propose a TFET based on 2D graphene bilayer which demonstrates a record steep subthreshold slope enabled by van Hove singularities in the density of states near the edges of conduction and valence bands. Our simulations show the accessibility of 3.5 × 104 ON/OFF current ratio with 150 mV gate voltage swing and a maximum subthreshold slope of (20 μV/dec)−1 just above the threshold. The high ON-state current of 0.8 mA/μm is enabled by a narrow (~0.3 eV) extrinsic band gap, while the smallness of the leakage current is due to an all-e...
Physica E: Low-dimensional Systems and Nanostructures, 2004
We overview mechanisms of absolute negative conductivity in two-dimensional electron systems in a... more We overview mechanisms of absolute negative conductivity in two-dimensional electron systems in a magnetic field irradiated with microwaves and provide plausible explanations of the features observed in recent experiments related to the so-called zero-resistance (zero-conductance) states.
We review the occurrence of periodic or near periodic electric-field domains stimulated by bound-... more We review the occurrence of periodic or near periodic electric-field domains stimulated by bound-tocontinuum transitions under the influence of infrared radiation in multiple uncoupled quantum wells. The conditions of formation of such domains and their stability are studied theoretically using the proposed phenomenological model.
32nd European Solid-State Device Research Conference, 2002
We propose and evaluate a novel device based on integration of quantum well infrared photodetecto... more We propose and evaluate a novel device based on integration of quantum well infrared photodetector (QWIP), heterostructure bipolar transistor (HBT), and light emitting diode (LED) for up-conversion of middle infrared into near infrared (visible) radiation. Its operation is associated with intersubband absorption of middle infrared radiation in the QWIP, amplification of the QWIP output electric signal in the HBT and emission of near infrared or visible radiation from the LED driven by the current injected from the HBT. The integrated QWIP-HBT-LED device can serve as a highly effective pixel for infrared focal plane arrays.
Simulation of Semiconductor Processes and Devices 2007
Formation of shock waves in two-dimensional electron channels by electrical signals is studied us... more Formation of shock waves in two-dimensional electron channels by electrical signals is studied using analytical and numerical models based on hydrodynamic electron transport equations coupled with two-dimensional Poisson equation.
Three-terminal laser-transistors with a quantum well active region and a resonant-tunnelling coll... more Three-terminal laser-transistors with a quantum well active region and a resonant-tunnelling collector are proposed and considered. It is shown that the laser-transistor is controlled by the collector voltage due to electron extraction via the resonant-tunnelling structure. The current-voltage and light-voltage characteristics are calculated. Both of them reflect effective voltage control and possible bistable behaviour of the laser-transistor in a certain range of the collector voltage. The electron heating due to electron injection and extraction can significantly affect the controllability and bistability of the laser-transistor.
Plasma waves in two-dimensional electron channels, with a non-trivial geometry and governing elec... more Plasma waves in two-dimensional electron channels, with a non-trivial geometry and governing electrodes, are described by the hydro-dynamical equations, combined with the Poisson equation for the self-consistent electric potential. If the amplitudes of the oscillations of the velocity, the concentration and the potential, are much smaller than the stationary values of these variables, then the hydrodynamical equation for oscillations can be linearizedtransformed to the wave equation on a two-dimensional network. We consider the scattering problem for the wave equation and develop a semi-analytic method for calculation of transmission coefficients through the junction. The formulae have resonance character and may be used for manipulation of plasma waves in 2D networks of electron channels.
The resistivity of gated graphene is studied taking into account electron and hole scattering by ... more The resistivity of gated graphene is studied taking into account electron and hole scattering by short-and long-range structural imperfections (the characteristics of disorder were taken from the scanning tunneling microscopy data) and by acoustic phonons. The calculations are based on the quasiclassical kinetic equation with the normalization condition fixed by surface charge. The gatevoltage and temperature effects on the resistance peak, which is centered at the point of intrinsic conductivity, are found to be in agreement with the transport measurements.
2015 Opto-Electronics and Communications Conference (OECC), 2015
We report on the possibilities of graphene channel FET (G-FET) as a photonic frequency double-mix... more We report on the possibilities of graphene channel FET (G-FET) as a photonic frequency double-mixing conversion device for future fully coherent access network systems. A 112.5-GHz RF signal whose amplitude was coded with a 5-GHz rectangular signal was input to the gate, concurrently a 1.58-μm wavelength photomixed dual CW laser beam having a beat frequency of 87.5 GHz was incident to the FET, generating the local (LO) signal. The RF and LO signals were mixed to reproduce the down-converted 5-GHz signal onto the 25-GHz intermediate frequency (IF) signal successfully.
We calculate the current-voltage characteristic of a two-dimensional electron system (2DES) subje... more We calculate the current-voltage characteristic of a two-dimensional electron system (2DES) subjected to a magnetic field at strong electric fields. The interaction of electrons with piezoelectric acoustic phonons is considered as a major scattering mechanism governing the current-voltage characteristic. It is shown that at a sufficiently strong electric field corresponding to the Hall drift velocity exceeding the velocity of sound, the dissipative current exhibits an overshoot. The overshoot of the dissipative current can result in a breakdown of the absolute negative conductivity caused by microwave irradiation and, therefore, substantially effect the formation of the domain structures with the zero-resistance and zero-conductance states and supersonic electron streams.
We study plasma effects in a micromachined high-electron mobility transistor (HEMT) with the micr... more We study plasma effects in a micromachined high-electron mobility transistor (HEMT) with the microcantilever serving as the gate using the developed a model. The model accounts for mechanical motion of the microcantilever and spatio-temporal variations (plasma effects) of the two-dimensional electron gas(2DEG) system in the transistor channel. The microcantilever mechanical motion is described in the point-mass approximation. The hydrodynamic electron transport model is used to describe distributed electron plasma phenomena in the 2DEG system. Using the developed model, we calculated the response function characterizing the amplitude microcantilever oscillations and the output electric signal as functions of the signal frequency and the bias voltage for the devices with different parameters. We find the voltage dependences of the frequency of the mechanical resonance and its damping. In particular, it is demonstrated that the amplitudes of the mechanical oscillations and output electric signal exhibit pronounced maxima at the bias voltages close to the voltage of the 2DEG channel depletion followed by a steep drop with further increase in the bias voltage.
We calculate the contribution of the photon-assisted interaction of electrons with leaky interfac... more We calculate the contribution of the photon-assisted interaction of electrons with leaky interface phonons to the dissipative dc photoconductivity of a two-dimensional electron system in a magnetic field. The calculated photoconductivity as a function of the frequency of microwave radiation and the magnetic field exhibits pronounced oscillations. The obtained oscillation structure is different from that in the case of photon-assisted interaction with impurities. We demonstrate that at a sufficiently strong microwave radiation in the certain ranges of its frequency (or in certain ranges of the magnetic field) this mechanism can result in the absolute negative conductivity.
In a continuous search for the energy-efficient electronic switches, a great attention is focused... more In a continuous search for the energy-efficient electronic switches, a great attention is focused on tunnel field-effect transistors (TFETs) demonstrating an abrupt dependence of the source-drain current on the gate voltage. Among all TFETs, those based on one-dimensional (1D) semiconductors exhibit the steepest current switching due to the singular density of states near the band edges, though the current in 1D structures is pretty low. In this paper, we propose a TFET based on 2D graphene bilayer which demonstrates a record steep subthreshold slope enabled by van Hove singularities in the density of states near the edges of conduction and valence bands. Our simulations show the accessibility of 3.5 × 104 ON/OFF current ratio with 150 mV gate voltage swing and a maximum subthreshold slope of (20 μV/dec)−1 just above the threshold. The high ON-state current of 0.8 mA/μm is enabled by a narrow (~0.3 eV) extrinsic band gap, while the smallness of the leakage current is due to an all-e...
Physica E: Low-dimensional Systems and Nanostructures, 2004
We overview mechanisms of absolute negative conductivity in two-dimensional electron systems in a... more We overview mechanisms of absolute negative conductivity in two-dimensional electron systems in a magnetic field irradiated with microwaves and provide plausible explanations of the features observed in recent experiments related to the so-called zero-resistance (zero-conductance) states.
We review the occurrence of periodic or near periodic electric-field domains stimulated by bound-... more We review the occurrence of periodic or near periodic electric-field domains stimulated by bound-tocontinuum transitions under the influence of infrared radiation in multiple uncoupled quantum wells. The conditions of formation of such domains and their stability are studied theoretically using the proposed phenomenological model.
32nd European Solid-State Device Research Conference, 2002
We propose and evaluate a novel device based on integration of quantum well infrared photodetecto... more We propose and evaluate a novel device based on integration of quantum well infrared photodetector (QWIP), heterostructure bipolar transistor (HBT), and light emitting diode (LED) for up-conversion of middle infrared into near infrared (visible) radiation. Its operation is associated with intersubband absorption of middle infrared radiation in the QWIP, amplification of the QWIP output electric signal in the HBT and emission of near infrared or visible radiation from the LED driven by the current injected from the HBT. The integrated QWIP-HBT-LED device can serve as a highly effective pixel for infrared focal plane arrays.
Simulation of Semiconductor Processes and Devices 2007
Formation of shock waves in two-dimensional electron channels by electrical signals is studied us... more Formation of shock waves in two-dimensional electron channels by electrical signals is studied using analytical and numerical models based on hydrodynamic electron transport equations coupled with two-dimensional Poisson equation.
Three-terminal laser-transistors with a quantum well active region and a resonant-tunnelling coll... more Three-terminal laser-transistors with a quantum well active region and a resonant-tunnelling collector are proposed and considered. It is shown that the laser-transistor is controlled by the collector voltage due to electron extraction via the resonant-tunnelling structure. The current-voltage and light-voltage characteristics are calculated. Both of them reflect effective voltage control and possible bistable behaviour of the laser-transistor in a certain range of the collector voltage. The electron heating due to electron injection and extraction can significantly affect the controllability and bistability of the laser-transistor.
Plasma waves in two-dimensional electron channels, with a non-trivial geometry and governing elec... more Plasma waves in two-dimensional electron channels, with a non-trivial geometry and governing electrodes, are described by the hydro-dynamical equations, combined with the Poisson equation for the self-consistent electric potential. If the amplitudes of the oscillations of the velocity, the concentration and the potential, are much smaller than the stationary values of these variables, then the hydrodynamical equation for oscillations can be linearizedtransformed to the wave equation on a two-dimensional network. We consider the scattering problem for the wave equation and develop a semi-analytic method for calculation of transmission coefficients through the junction. The formulae have resonance character and may be used for manipulation of plasma waves in 2D networks of electron channels.
The resistivity of gated graphene is studied taking into account electron and hole scattering by ... more The resistivity of gated graphene is studied taking into account electron and hole scattering by short-and long-range structural imperfections (the characteristics of disorder were taken from the scanning tunneling microscopy data) and by acoustic phonons. The calculations are based on the quasiclassical kinetic equation with the normalization condition fixed by surface charge. The gatevoltage and temperature effects on the resistance peak, which is centered at the point of intrinsic conductivity, are found to be in agreement with the transport measurements.
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Papers by Victor Ryzhii