A5091021385- Plasmonic and Surface Plasmon Research
- Photonic and Optical Devices
- GaN-based semiconductor devices and materials
- Gold and Silver Nanoparticles Synthesis and Applications
- Optical Coatings and Gratings
- Ga2O3 and related materials
- Semiconductor Quantum Structures and Devices
- Terahertz technology and applications
- ZnO doping and properties
- Thermal Radiation and Cooling Technologies
- Photonic Crystals and Applications
- Metamaterials and Metasurfaces Applications
- Advanced Semiconductor Detectors and Materials
- Nanowire Synthesis and Applications
- Advanced biosensing and bioanalysis techniques
- Topological Materials and Phenomena
- Semiconductor materials and devices
- Vibration and Dynamic Analysis
- Advanced machining processes and optimization
- Metal and Thin Film Mechanics
- Advanced Theoretical and Applied Studies in Material Sciences and Geometry
- Fluid Dynamics and Vibration Analysis
- Spectroscopy Techniques in Biomedical and Chemical Research
- Elasticity and Material Modeling
- Soil Mechanics and Vehicle Dynamics
Institut d'Électronique et des Systèmes
2015-2024
Centre des Matériaux
2024
Université de Montpellier
2015-2023
Centre National de la Recherche Scientifique
2011-2023
COMUE Languedoc-Roussillon Universités
2016-2019
Chalmers University of Technology
2013-2014
CEA Grenoble
2011-2013
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2011-2013
Institut Nanosciences et Cryogénie
2011-2013
Eletrobras (Brazil)
2012
We report on the photocurrent behavior of single GaN n-i-n nanowires (NWs) grown by plasma-assisted molecular-beam epitaxy Si(111). These structures present a photoconductive gain in range 10(5)-10(8) and an ultraviolet (350 nm) to visible (450 responsivity ratio larger than 6 orders magnitude. Polarized light couples with NW geometry maximum photoresponse for polarization along axis. The scales sublinearly optical power, following I ~ P(β) law (β < 1) measured β increasing measuring...
GaN nanowires (NWs) with an AlN insertion were studied by correlated optoelectronic and aberration-corrected scanning transmission electron microscopy (STEM) characterization on the same single NW. Using annular bright field high angle dark STEM, we identify NW growth axis to be N-polar [000-1] direction. The electrical transport characteristics of NWs are explained polarization-induced asymmetric potential profile presence AlN/GaN shell around base wire. blocks flow through core, confining...
We propose 1D periodic, highly doped InAsSb gratings on GaSb substrates as biosensing platforms applicable for surface plasmon resonance and enhanced infrared absorption spectroscopies. Based finite-difference time-domain simulations, the electric field enhancement sensitivity refractive index variations are investigated different grating geometries. The proposed, optimized system achieves sensitivities of 900 nm RIU-1. A clear red shift well an line presented 2 thin adlayers in simulations....
Abstract A metamaterial perfect absorber based on layered, doped and undoped semiconductors is experimentally theoretically investigated. Design rules are given to control the multispectral, narrow, strong absorption features (>98% absorption) in mid‐IR spectrum. The proposed sub‐wavelength grating structures support localized surface plasmons photonic resonances associated quarter wavelength optical thickness of spacer layer. hybridize depending geometric setup material properties...
The effect of spatial dispersion on the electrodynamics surfaces is studied for a phenomenological model which describes surface scattering elementary excitations in terms parameter p, specular being case p = 1. Surface impedance, reflectivity and mode relation are obtained arbitrary without resorting to additional boundary conditions. It thus shown that problem sufficiently defined if model, including surface, specified. Various forms conditions used literature discussed characterized as...
Abstract Tailored plasmonic nanoantennas are needed for diverse applications, among those sensing. Surface-enhanced infrared absorption (SEIRA) spectroscopy using adapted nanoantenna substrates is an efficient technique the selective detection of molecules by their vibrational spectra, even in small quantity. Highly doped semiconductors have been proposed as innovative materials plasmonics, especially more flexibility concerning targeted spectral range. Here, we report on rectangular-shaped,...
Surface-enhanced spectroscopy techniques using plasmonic nanoantennas or metasurfaces help to reduce the detection limit for biochemical sensing. While infrared is an excellent tool identify a molecular species, typically expensive IR light source needed. We report surface enhanced technique based on thermal emission of III–V semiconductor metasurfaces. The presence species grafted modulates spectrum analogously modulation achieved in surface-enhanced absorption (SEIRA) spectroscopy....
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The impact of <emphasis emphasistype="italic">in situ</emphasis> low-power <formula formulatype="inline"><tex> $\hbox{N}_{2}$</tex></formula> plasma pretreatment, prior to silicon-nitride (SiN) deposition, was investigated in AlGaN/GaN high-electron mobility transistors (HEMTs). These studies reveal that the use formulatype="inline"><tex>$\hbox{N}_{2}$</tex></formula> HEMT passivation reduces...
We report on temperature-dependent terahertz spectroscopy of a three-layer InAs/GaSb/InAs quantum well (QW) with inverted-band structure. The interband optical transitions, measured up to 16 T at different temperatures by Landau-level magnetospectroscopy, demonstrate the structure QW. photoluminescence allows us directly extract gap in vicinity $\mathrm{\ensuremath{\Gamma}}$ point Brillouin zone. Our results experimentally that QWs is temperature independent and exceeds four times maximum...
Abstract Plasmonic nanoantennas have earned outstanding credits for their powerful ability to couple light from free‐space into sub‐wavelength‐sized structures and enhance the electric field confinement. One of most appealing plasmonic applications is biosensing: detect identify many bio‐information a molecule in single test. Consequently, surface enhanced spectroscopy broad infrared (IR) range required. In this article, barcode‐like nanostructured metal‐insulator‐metal (MIM) platform serves...
We report a detailed analysis of the influence doping level and nanoribbon width on localized surface plasmon resonance (LSPR) by means reflectance measurements. The plasmonic system, based one-dimensional periodic gratings highly Si-doped InAsSb/GaSb semiconductor nanostructures, is fabricated simple, accurate large-area technique fabrication. Increasing blueshifts peak while increasing ribbon results in redshift, as confirmed numerical simulations. This provides an efficient fine-tuning...
Abstract Surface-enhanced infrared absorption (SEIRA) spectroscopy is a competent method to detect trace quantity of molecules and even protein conformational flexibility by enhancing their vibrational modes. To improve the features, we propose surface with honeycomb-like (HC) arrangement aluminum equilateral triangles within metal-insulator-metal configuration. With adjustable geometric parameters, HC nanoantennas allow tunable wide spectral coverage in IR. The reflectance measurements...
We report on the clear evidence of massless Dirac fermions in two-dimensional system based III-V semiconductors. Using a gated Hall bar made three-layer InAs/GaSb/InAs quantum well, we restore Landau levels fan chart by magnetotransport and unequivocally demonstrate gapless state our sample. Measurements cyclotron resonance at different electron concentrations directly indicate linear band crossing $\Gamma$ point Brillouin zone. Analysis experimental data within analytical Dirac-like...
The effects of power and time conditions in situ <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{N}_{2}$</tex></formula> plasma treatment, prior to silicon nitride (SiN) passivation, were investigated on an AlGaN/GaN high-electron mobility transistor (HEMT). These studies reveal that is a critical parameter control the SiN/AlGaN interface quality, which directly affects 2-D electron gas...
We report on the fabrication and photovoltaic characterization of In 0.12 Ga 0.88 N/GaN multi-quantum-well (MQW) solar cells grown by metal–organic vapor phase epitaxy (0001) sapphire substrates. Increasing number MQWs in active region from 5 to 30 improves a factor 10 peak external quantum efficiency device at price slight reduction increase shunt series resistance, respectively. Solar with exhibit an 38% 380 nm, open circuit voltage 2.0 V, short current density 0.23 mA/cm 2 fill 59% under...
The results of x-ray characterization presented in this work show that the strain state AlGaN and GaN layers is modified by Ohmic contact deposition subsequent annealing, as well SiN passivation. In both cases, tensile for layer decreases whereas residual compressive consistently increased free-contact area. However, we difference chemical composition surface main factor explaining reduction channel carrier concentration observed capacitance-voltage measurements, with a variation large ∼2×1012 cm−2.
In this work, we compare the photodetector performance of single nearly defect-free undoped and n-i-n GaN nanowires (NWs). Undoped NWs present a dark current three orders magnitude lower than structures, about ten times gain, strong dependence measurement environment. vacuum, react with an increase their responsivity, accompanied by stronger nonlinearities persistent photoconductivity effects. This behavior is attributed to unpinned Fermi level at m-plane NW sidewalls, which enhances role...
The evolution of GaN growth on AlN and nucleation layers is compared through morphological structural analyses, including ion beam analysis. By using layer grown at high temperature, improved crystalline quality exhibited by 300 nm thin epilayers. (002) x-ray rocking curve as narrow 168 arc sec atomic-step surface morphology characterize such a film AlN. Defects are strongly confined into the first 50 growth, whereas fast laterally coherent observed when increasing thickness, an effect...
We present a study of the structural properties GaN/AlN heterostructured nanowires grown by plasma-assisted molecular-beam epitaxy. combine transmission electron microscopy measurements with theoretical calculations strain distribution and band diagram in order to gain understanding potential these nanostructures. The effects surface states formation core–shell heterostructure are discussed. correlated performance GaN-based nanowire photodetectors sensors. In particular, we discuss sensor...