Publications de Nicolas Grandjean

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Far-UVC light sources in the spectral range of200-230 nm effectively kill bacteria and deactivate viruses while being not harmful to health, enabling persistent disinfection of air and surfaces in the presence of humans. So far only excimer lamps have been ...

The authors report on the achievement of a vertically oriented three pair airgap/GaN distributed Bragg reflector realized by controlled oxidation and wet-chemical etching of AlInN sacrificial layers. Microreflectivity measurements exhibit high peak reflect ...

We report on ultrahigh-speed 80 nm AlInN/GaN high-electron-mobility transistors (HEMTs) grown on (111) high-resistivity silicon substrates. The devices feature a peak measured transconductance g(M) = 415 mS/mm, a maximum current of 1.43 A/mm with a ratio I ...

Optical bistability is observed in cw-operating InGaN-based laser diodes including a saturable absorber (SA) section. The dependence of the light-current hysteresis on the SA section length and reverse bias (VSA) has been studied. An analytical approach is ...

It is shown that in GaN/AlN multiple quantum wells (MQWs), strain is a critical parameter for achieving short-wavelength intersubband transitions (ISBTs). This is investigated by comparing GaN/AlN MQWs grown by metal organic vapor phase epitaxy on either A ...

Defects can significantly modify the electrical and optical properties of quantum well (QW) structures based on InGaN. We present an overview of our recent results on the properties of point and extended defects in InGaN/GaN QW devices. By analyzing single ...

In order to improve the current injection in GaN-based blue vertical-cavity surface-emitting lasers (VCSELs) a dielectric aperture is generally used in combination with an indium-tin-oxide (ITO) layer on the top intracavity p-contact layer. The most straig ...

The effect of anodic oxidation on the electronic characteristics of lattice-matched AlInN/GaN heterostructures was investigated using field-effect transistor (FET) structures with the gate areas in direct contact with the electrolytes. The gate surface of ...

The growth by hydride vapor phase epitaxy (HVPE) of high quality thin GaN layers (d=8 mu m) on c-plane sapphire substrates with dislocation densities lower than 2x10(8) cm(-2) is demonstrated using a two-step process similar to that of metal organic vapor ...

Intersubband (lSB) optical absorption in different nitride-based heterostructures grown by metal-organic chemical vapour deposition (MOCVD) is reported. The role of indium in AlInN/GaN multi-quantum wells (MQWs) is investigated. At high concentration (15%) ...

The authors report on the micron scale characterization of a monolithic GaN microcavity (MC) with lattice matched AlInN/GaN distributed Bragg reflectors by means of a microtransmission setup. This technique allows extracting very high quality factors (Q up ...

One-hundred-nanometer-gate (Al, In) N/GaN highelectron- mobility transistors (HEMTs) grown on semi-insulating SiC achieve a maximum current density of 1.84 A/mm at V-GS = 0 V, an extrinsic transconductance of 480 mS/mm, and a peak current gain cutoff frequ ...

The authors report on the achievement of narrow ultraviolet emission using GaN/AlGaN quantum wells grown by metal organic vapor phase epitaxy. The origin of the inhomogeneous broadening of the emission is explained by means of micro-photoluminescence and a ...

We report the fabrication and characterization of 30-nm-gate fully passivated AlInN/GaN high-electron mobility transistors (HEMTs) with cutoff frequencies f(T) and f(MAX) simultaneously exceeding 200 GHz at a given bias point. The current gain cutoff frequ ...

In the last decade, aluminum nitride (AlN) has proven to be an attractive material for both linear and nonlinear integrated photonics, due to its large transparency window, its low propagation losses and the presence of both second- and third-order nonline ...

We report on the fabrication of InGaN-based multiple-quantum-well laser diodes (LDs) emitting at 420 nm. Structures with standard claddings (p-and n-AlGaN), asymmetric claddings (p-GaN and n-AlGaN), and AlGaN-free claddings were grown by metal organic vapo ...

We have studied multi-section InGaN multiple-quantum-well (MQW) laser diodes grown on c-plane freestanding GaN substrate consisting of an absorber section (AS) and an amplifier gain section. As a result of the interplay between external bias applied to the ...

We report the growth of highly reflective distributed Bragg reflectors (DBRs) in the UV region using the Al0.85In0.15N/Al0.2Ga0.8N lattice-matched system. The DBRs were deposited on nearly strain-free Al0.2Ga0.8N templates to avoid strain-induced structura ...

Spatio-time-resolvedcathodoluminescence (STRCL) spectroscopy isimplemented to assess the local carrier dynamics in a 70 nm-thick, very low threading dislocation (TD) density, pseudomorphic m-plane In GaN epilayer grown on a freestanding GaN substrate by me ...

Contrary to the case of III-nitride based visible light-emitting diodes for which the inhomogeneous linewidth broadening characteristic of InGaN-based multiple quantum well (MQW) heterostructures does not appear as a detrimental parameter, such a broadenin ...

Nicolas Grandjean

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Monolayer-Thick GaN/AlN Quantum Well Anodes and Far-UVC Field Emission Device at 226 nm

High reflectivity airgap distributed Bragg reflectors realized by wet etching of AlInN sacrificial layers

Ultrahigh-Speed AlInN/GaN High Electron Mobility Transistors Grown on (111) High-Resistivity Silicon with F-T=143 GHz

Optical bistability in InGaN-based multisection laser diodes

Strain-induced interface instability in GaN/AlN multiple quantum wells

Defects in InGaN QW Structures: Microscopic Properties and Modeling

Engineering the Lateral Optical Guiding in Gallium Nitride-Based Vertical-Cavity Surface-Emitting Laser Cavities to Reach the Lowest Threshold Gain

Effect of anodic oxidation on the characteristics of lattice-matched AlInN/GaN heterostructures

High quality thin GaN templates grown by hydride vapor phase epitaxy on sapphire substrates

Nitride-based heterostructures grown by MOCVD for near- and mid-infrared intersubband transitions

Impact of disorder on high quality factor III-V nitride microcavities

100-nm-Gate (Al,In)N/GaN HEMTs Grown on SiC With F-T=144 GHz

Narrow UV emission from homogeneous GaN/AlGaN quantum wells

Fully Passivated AlInN/GaN HEMTs With f(T)/f(MAX) of 205/220 GHz

On the influence of the buffer layer on the optical quality of AlN-on-sapphire epilayers for photonic integrated devices

AlGaN-Free Blue III-Nitride Laser Diodes Grown on c-Plane GaN Substrates

Static and dynamic properties of multi-section InGaN-based laser diodes

Crack-free highly reflective AlInN/AlGaN bragg mirrors for UV applications

Implementation of spatio-time-resolved cathodoluminescence spectroscopy for studying local carrier dynamics in a low dislocation density m-plane InGaN epilayer grown on a freestanding GaN substrate

InGaN/GaN quantum wells for polariton laser diodes: Role of inhomogeneous broadening