Publications de Nicolas Grandjean

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We report on progress in the realization of Field Emission Devices (FED) with AlN-based anodes emitting in the spectral window of 200-230nm for persistent disinfection of air and surfaces in the presence of humans. Modeling, experimental studies, and trade ...

Critical thickness and strain relaxation of c-plane GaN layers grown by molecular beam epitaxy on AlN were studied as a function of growth temperature and threading dislocation density (TDD). For this purpose we used AlN/sapphire templates and AlN single c ...

Design considerations and performance of n(++) GaN/InAlN/AlN/GaN normally off high-electron mobility transistors (HEMTs) are analyzed. Selective and damage-free dry etching of the gate recess through the GaN cap down to a 1-nm-thick InAlN barrier secures p ...

The photoluminescence (PL) from GaN quantum dots (QDs) embedded in AlN has been investigated under hydrostatic pressure. The measured pressure coefficient of emitted light energy [dE(E)/dP] shows a negative value, in contrast with the positive pressure coe ...

A detailed experimental investigation of the phonon-assisted emission in a high-quality c-plane GaN epilayer is presented up to 200 K. By performing photoluminescence and reflectivity measurements, we find important etaloning effects in the phonon-replica ...

We report on lattice-matched InAlN/GaN MOSHEMTs with an oxide-filled recess, self-aligned to the gate prepared by thermal oxidation at 800 degrees C in oxygen atmosphere. The device delivered a maximum current density of 2.4 A/mm. Pulse measurements showed ...

Applications such as optical clocks, gas spectroscopy, and optical coherent tomography stand to benefit significantly from the integration of on-chip supercontinuum sources. Materials exhibiting both second- and third-order nonlinearities are particularly ...

This article presents the dynamics of excitons in a-plane (Al,Ga)N/GaN single quantum wells of various thicknesses grown on bulk GaN substrates. For all quantum well samples, recombination is observed to be predominantly radiative in the low-temperature ra ...

We have investigated an inductively coupled plasma etching recipe using SiCl4 and SF6 with a resulting selectivity >10 for GaN in respect to InAlN. The formation of an etch-resistant layer of AlF3 on InAlN required about 1 min and was noticed by a 4-times- ...

III-nitride membranes offer promising perspectives and improved device designs in photonics, electronics, and optomechanics. However, the removal of the growth substrate often leads to a rough membrane surface, which increases scattering losses in optical ...

The electrical properties and deep trap spectra were compared for near-UV GaN/InGaN quantum well (QW) structures grown on free-standing GaN substrates. The structures differed by the presence or absence of a thin (110 nm) InGaN layer inserted between the h ...

We report a numerical and experimental investigation of fabrication tolerances and outcoupling in optically pumped III-nitride nanolasers operating near lambda = 460 nm, in which feedback is provided by a one-dimensional photonic crystal nanobeam cavity an ...

We measure the modal absorption coefficient of the InGaN quantum wells (QWs) in the absorber section of (Al,In)GaN multisection laser diodes as a function of bias voltage and photon energy using optical gain-spectroscopy. In the examined laser diodes, the ...

IIIV photonics on silicon is an active and promising research area. Here, we demonstrate room-temperature (RT) lasing in short-wavelength III-nitride photonic crystal nanobeam cavities grown on silicon featuring a single InGaN quantum well (QW). In the low ...

III-N optoelectronic devices are of great interest for many applications. Visible emitters (based on InGaN) are widely used in the lighting, display and automotive fields. Ultraviolet LEDs (based on AlGaN) are expected to be widely used for disinfection, m ...

We investigate the density of defects and the degradation rate in InGaN light-emitting diodes having identical dislocation density and epitaxial structure, but different indium content in the quantum well (QW; 12%, 16%, 20%). Our results, based on combined ...

A 3 lambda/2 (In,Ga)N/GaN resonant cavity, designed for similar to 415nm operation, is grown by molecular beam epitaxy and is sandwiched between a 39.5-period (In,Al)N/GaN distributed Bragg reflector (DBR), grown on c-plane GaN-on-sapphire pseudo-substrate ...

Thermal healing of focused ion beam-implanted defects in GaN is investigated by off-axis electron holography in TEM. The data reveal that healing starts at temperatures as low as about 250 degrees C. The healing processes result in an irreversible transiti ...

We discuss the characteristics of In0.17Al0.83N/GaN high-electron mobility transistors with barrier thicknesses between 33 and 3 nm, which are grown on sapphire substrates by metal-organic chemical vapor deposition. The maximum drain current (at V-G = +2.0 ...

We present an overview on the growth and the optical properties of GaN quantum dots (QDs) embedded in planar AlN grown on the following three different types of substrates: single AlN crystal, AlN on sapphire, and AIN on Si(111). QD density control over th ...

Nicolas Grandjean

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AlN-based anodes for far-UVC field emission device at 225 nm

Critical thickness of GaN on AlN: impact of growth temperature and dislocation density

Proposal and Performance Analysis of Normally Off n(++) GaN/InAlN/AlN/GaN HEMTs With 1-nm-Thick InAlN Barrier

Strong electric field and nonuniformity effects in GaN/AlN quantum dots revealed by high pressure studies

Probing exciton density of states through phonon-assisted emission in GaN epilayers: A and B exciton contributions

InAlN/GaN MOSHEMT With Self-Aligned Thermally Generated Oxide Recess

Multi-octave bandwidth supercontinuum generation in crystalline Aluminum Nitride-on-sapphire waveguides

Temperature-Dependence of Exciton Radiative Recombination in (Al,Ga)N/GaN Quantum Wells Grown on a-Plane GaN Substrates

Characterization of Plasma-Induced Damage of Selectively Recessed GaN/InAlN/AlN/GaN Heterostructures Using SiCl4 and SF6

Smooth GaN membranes by polarization-assisted electrochemical etching

Deep traps in InGaN/GaN single quantum well structures grown with and without InGaN underlayers

Fabrication defects and grating couplers in III-nitride photonic crystal nanobeam lasers (Conference Presentation)

Bias-dependent absorption coefficient of the absorber section in GaN-based multisection laser diodes

Continuous Wave Blue Lasing in III-Nitride Nanobeam Cavity on Silicon

III-N Optoelectronic Devices: Understanding the Physics of Electro-Optical Degradation

Effects of quantum-well indium content on deep defects and reliability of InGaN/GaN light-emitting diodes with under layer

Q-factor of (In,Ga)N containing III-nitride microcavity grown by multiple deposition techniques

Identification and thermal healing of focused ion beam-induced defects in GaN using off-axis electron holography

Barrier-layer scaling of InAlN/GaN HEMTs

Room temperature single photon emission from planar GaN/AlN quantum dot samples grown by MBE