Accueil du site >
Annuaire > Page Personnelle

N'est plus au Laboratoire.
VIDELIER Hadley

Hadley.Videlier

univ-montp2.fr       

0467140000
Domaines de Recherche: - Physique/Physique/Physique Générale
- Physique/Matière Condensée/Science des matériaux
|
Dernieres productions scientifiques :

|
|
Temperature enhancement of terahertz responsivity of plasma field effect transistors 
Auteur(s): Klimenko O., KNAP W., Iniguez Benjamin, COQUILLAT D., Mityagin Yury a., TEPPE F., DIAKONOVA N., Videlier H., BUT D., Lime Francois, Marczewski Jacek, Kucharski Krzysztof
(Article) Publié:
Journal of Applied Physics, vol. 112 p.014506 (2012)
DOI: 10.1063/1.4733465
Résumé: Temperature dependence of THz detection by field effect transistors was investigated in a wide range of temperatures from 275K down to 5 K. The important increase of the photoresponse following 1/T functional dependence was observed when cooling from room temperature down to 30K. At the temperatures below similar to 30 K, the THz response saturated and stayed temperature independent. Similar behavior was observed for GaAs, GaN, and Si based field effect transistors. The high temperature data were successfully interpreted using recent theory of overdamped plasma excitation in field effect transistors. The low temperature saturation of the photoresponse was tentatively explained by the change of the transport regime from diffusive to ballistic or traps governed one. Our results clearly show that THz detectors based on field effect transistors may improve their responsivity with lowering temperature but in the lowest temperatures (below similar to 30 K) further improvement is hindered by the physics of the electron transport itself.
|

|
|
Field Effect Transistors for Terahertz Detection and Emission 
Auteur(s): KNAP W., NADAR S., Videlier H., Boubanga-tombet Stephane, COQUILLAT D., DIAKONOVA N., TEPPE F., Karpierz Kristoph, Lusakowski Jerzy, Sakowicz Maciej, Kasalynas Irmantas, Seliuta Dalius, Valusis Gintaras, Otsuji Taiichi, Meziani Yahya, EL FATIMY A., Vandenbrouk Simon, Madjour Kamel, Theron Didier, Gaquiere Christophe
(Article) Publié:
-JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES, vol. 32 p.618-628 (2011)
Ref HAL: hal-00814487_v1
Résumé: Resonant frequencies of the two-dimensional plasma in field effect transistors (FETs) increase with the reduction of the channel dimensions and can reach the Terahertz (THz) range. Nonlinear properties of the plasma/electron gas in the transistor channel can be used for the rectification and detection of THz radiation. The excitation of plasma waves by sub-THz and THz radiation was demonstrated for short gate transistors at cryogenic temperatures. At room temperature plasma oscillations are usually overdamped, but the FETs can still operate as efficient broadband rectifiers/detectors in the THz range. We present a few recent experimental results on THz detection by FETs showing some new ways of improvement of FETs for THz imaging at room temperature as well as the new physical phenomena like detection in quantizing magnetic fields. We also demonstrate THz emission properties of GaN based FETs.
Commentaires: , DOI = 10.1007/s10762-010-9647-7
|

|
|
A 280-GHz Schottky Diode Detector in 130-nm Digital CMOS 
Auteur(s): Han Ruonan, Zhang Yaming, COQUILLAT D., Videlier H., KNAP W., Brown Elliott, Kenneth K. o.
(Article) Publié:
IEEE JOURNAL OF SOLID-STATE CIRCUITS, vol. 46 p.2602-2612 (2011)
Ref HAL: hal-00814188_v1
DOI: 10.1109/JSSC.2011.2165234
Résumé: A 2 x 2 array of 280-GHz Schottky-barrier diode detectors with an on-chip patch antenna (255 x 250 mu m(2)) is fabricated in a 130-nm logic CMOS process. The series resistance of diode is minimized using poly-gate separation (PGS), and exhibits a cut-off frequency of 2 THz. Each detector unit can detect an incident carrier with 100-Hz similar to 2-MHz amplitude modulation. At 1-MHz modulation frequency, the estimated voltage responsivity and noise equivalent power (NEP) of the detector unit are 250 V/W and 33 pW/Hz(1/2), respectively. An integrated low-noise amplifier further boosts the responsivity to 80 kV/W. At supply voltage of 1.2 V, the entire chip consumes 1.6 mW. The array occupies 1.5 x 0.8 mm(2). A set of millimeter-wave images with a signal-noise ratio of 48 dB is formed using the detector. These suggest potential utility of Schottky diode detectors fabricated in CMOS for millimeter wave and sub-millimeter wave imaging.
|

|
|
Terahertz Photovoltaic Response of Si-MOSFETs: Spin Related Effect
Auteur(s): Videlier H., DIAKONOVA N., TEPPE F., CONSEJO C., CHENAUD B., KNAP W., Lusakowski J., Tomaszewski D., Marczewski J., Grabiec P.
(Article) Publié:
Acta Physica Polonica A, vol. 120 p.927-929 (2011)
Résumé: We report on investigations of photovoltaic response of Si-MOSFETs subjected to terahertz radiation in high magnetic fields. Then a DC drain-to-source voltage is developed that shows singularities in magnetic fields corresponding to paramagnetic resonance conditions. These singularities are investigated as a function of incident frequency, temperature and two-dimensional carrier density. We tentatively attribute these resonances to spin transitions of the electrons bound to Si dopants and discuss the possible physical mechanism of the photovoltaic signal generation
|

|
|
Device loading effect on nonresonant detection of terahertz radiation in dual grating gate plasmon-resonant structure using InGaP/InGaAs/GaAs material systems
Auteur(s): El moutaouakil Amine, Suemitsu Tetsuya, Otsuji Taiichi, Videlier H., Boubanga-tombet Stephane-albon, COQUILLAT D., KNAP W.
Conference: 37th International Symposium on Compound Semiconductors (ISCS) ((JAPAN), FR, 2010-05-31)
Actes de conférence: PHYSICA STATUS SOLIDI C: CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 8, NO 2, vol. 8 p.346 (2011)
Résumé: We report on nonresonant detection of terahertz radiation using our original InGaP/InGaAs/GaAs plasmonresonant high-electron-mobility transistor having a dual grating gate (DGG) structure. The experiments were performed at room temperature using a Gunn diode operating at 0.30 THz as the THz source. Using a deviceloading model, the intrinsic responsivity was extracted and was dependent on the polarization of the incident THz wave. The device exhibited highest response when the electric-field vector of the incident THz radiation was directed in the source-drain direction. The 2D spatial distribution image of the transistor responsivity shows a clear beam focus centred on the transistor position, which proves the appropriate coupling of the THz radiation to the device, due to the DGG structure. The device also showed a high intrinsic responsivity of similar to 90 V/W and a noise equivalent power (NEP) as low as similar to 10-10 WHz(-0.5). (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
|
Plus...