We have fabricated a grating-gate InGaAs/GaAs field-effect transistor structure with narrow slits between the grating gate fingers. The resonant photoconductive response of this structure has been measured in the sub-terahertz frequency range. The frequencies of the photoresponse peaks correspond to the excitation of the plasmon resonances in the structure channel. The obtained responsivity exceeds the responsivity reported previously for similar plasmonic terahertz detectors by two orders of magnitude due to enhanced coupling between incoming terahertz radiation and plasmon oscillations in the slit-grating-gate field-effect transistor structure.
We study instability of plasmons in a dual-grating-gate graphene field-effect transistor induced by dc current injection using self-consistent simulations with the Boltzmann equation. With only the acoustic-phonon-limited electron scattering, it is d
emonstrated that a total growth rate of the plasmon instability, with the terahertz/mid-infrared range of the frequency, can exceed $4times10^{12}$ s$^{-1}$ at room temperature, which is an order of magnitude larger than in two-dimensional electron gases based on usual semiconductors. By Comparing the simulation results with existing theory, it is revealed that the giant total growth rate originates from simulataneous occurence of the so-called Dyakonov-Shur and Ryzhii-Satou-Shur instabilities.
We report on terahertz radiation detection with InGaAs/InAlAs Field Effect Transistors in quantizing magnetic field. The photovoltaic detection signal is investigated at 4.2 K as a function of the gate voltage and magnetic field. Oscillations analogo
us to the Shubnikov-de Haas oscillations, as well as their strong enhancement at the cyclotron resonance, are observed. The results are quantitatively described by a recent theory, showing that the detection is due to rectification of the terahertz radiation by plasma waves related nonlinearities in the gated part of the channel.
We report on experimental studies of terahertz (THz) radiation transmission through grating-gate graphene-channel transistor nanostructures and demonstrate room temperature THz radiation amplification stimulated by current-driven plasmon excitations.
Specifically, with increase of the direct current (dc) under periodic charge density modulation, we observe a strong red shift of the resonant THz plasmon absorption, its complete bleaching, followed by the amplification and blue shift of the resonant plasmon frequency. Our results are, to the best of our knowledge, the first experimental observation of energy transfer from dc current to plasmons leading to THz amplification. We present a simple model allowing for the phenomenological description of the observed amplification phenomena. This model shows that in the presence of dc current the radiation-induced correction to dissipation is sensitive to the phase shift between THz oscillations of carrier density and drift velocity, and with increase of the current becomes negative, leading to amplification. The experimental results of this work as all obtained at room temperature, pave the way towards the new 2D plasmons based, voltage tuneable THz radiation amplifiers.
Ferroelectric field-effect transistors employ a ferroelectric material as a gate insulator, the polarization state of which can be detected using the channel conductance of the device. As a result, the devices are of potential to use in non-volatile
memory technology, but suffer from short retention times, which limits their wider application. Here we report a ferroelectric semiconductor field-effect transistor in which a two-dimensional ferroelectric semiconductor, indium selenide ({alpha}-In2Se3), is used as the channel material in the device. {alpha}-In2Se3 was chosen due to its appropriate bandgap, room temperature ferroelectricity, ability to maintain ferroelectricity down to a few atomic layers, and potential for large-area growth. A passivation method based on the atomic-layer deposition of aluminum oxide (Al2O3) was developed to protect and enhance the performance of the transistors. With 15-nm-thick hafnium oxide (HfO2) as a scaled gate dielectric, the resulting devices offer high performance with a large memory window, a high on/off ratio of over 108, a maximum on-current of 862 {mu}A {mu}m-1, and a low supply voltage.
Fundamental physical properties limiting the performance of spin field effect transistors are compared to those of ordinary (charge-based) field effect transistors. Instead of raising and lowering a barrier to current flow these spin transistors use
static spin-selective barriers and gate control of spin relaxation. The different origins of transistor action lead to distinct size dependences of the power dissipation in these transistors and permit sufficiently small spin-based transistors to surpass the performance of charge-based transistors at room temperature or above. This includes lower threshold voltages, smaller gate capacitances, reduced gate switching energies and smaller source-drain leakage currents.
D. M. Yermolayev
,K. M. Maremyanin
,D. V. Fateev
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(2011)
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"Terahertz detection in a slit-grating-gate field-effect-transistor structure"
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Denis Yermolayev
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