Détection et Emission Terahertz par les ondes de plasma dans des transistors HEMT à base d'hétérostructures GaN/AlGaN et InGaAs/InAlAs

Abstract : We report on detection of terahertz radiation by high electron mobility nanometer transistors. The photovoltaic type of response was observed at the 1.8–3.1 THz frequency range, which is far above the cut-off frequency of the transistors. The resonant response was observed and was found to be tunable by the gate voltage. The resonances were interpreted as plasma wave excitations in the gated two-dimensional electron gas. The minimum noise equivalent power was estimated, showing possible application of these transistors in sensing of terahertz radiation. Also, we report on the demonstration of room temperature, tuneable terahertz detection obtained by 50 nm gate length InGaAs/InAlAs High Electron Mobility Transistors (HEMT). We show that the physical mechanism of the detection is related to the plasma waves excited in the transistor channel and that the increasing of the drain current leads to the transformation of the broadband detection to the resonant and tuneable one. In addition we report on terahertz emission by two-dimensional electron plasma oscillations in nanometric transistors at room temperature. We observe the room temperature emission for transistors based on two types of heterostructures- InGaAs/InAlAs and AlGaN/GaN. For both types we obtain a well-defined source-drain voltage threshold for the integrated emission, which depends on the gate bias. For InGaAs/InAlAs, we observe only emission signal integrated over the total frequency range (0.1 – 10 THz). High intensity of the Thz emission from GaN/AlGaN structures allowed analysing its spectral content. The emission is interpreted as resulting from a current driven plasma
instability leading to oscillations in the transistor channel (Dyakonov–Shur instability)
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Condensed Matter [cond-mat]. Université Montpellier II - Sciences et Techniques du Languedoc, 2007. French


https://tel.archives-ouvertes.fr/tel-00182726
Contributor : Abdelouahad El Fatimy <>
Submitted on : Friday, October 26, 2007 - 7:47:38 PM
Last modification on : Monday, October 29, 2007 - 9:58:16 AM

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  • HAL Id : tel-00182726, version 1

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Abdelouahad El Fatimy. Détection et Emission Terahertz par les ondes de plasma dans des transistors HEMT à base d'hétérostructures GaN/AlGaN et InGaAs/InAlAs. Condensed Matter [cond-mat]. Université Montpellier II - Sciences et Techniques du Languedoc, 2007. French. <tel-00182726>

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