Publications de Nicolas Grandjean

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It has been widely observed that an increasing carrier density in a strongly coupled semiconductor microcavity (MC) alters the dispersion of cavity polaritons, below and above the condensation threshold. The interacting nature of cavity polaritons stems fr ...

We report on the demonstration of low-loss, single-mode GaN-InAlN ridge waveguides (WGs) at fiber-optics telecommunication wavelengths. The structure grown by metal-organic vapor phase epitaxy contains AlInN cladding layers lattice-matched to GaN. For slab ...

Gate and drain-lag effects are studied in (GaN)/InAlN/GaN and InAlN/AlN/GaN HEMTs grown on sapphire. Electron trapping on the surface states between the gate and the drain forming the net negative charge up-to similar to 2 x 10(13) cm(-2) is found to be re ...

AllnN/GaN high electron mobility transistors (HEMTs) on sapphire substrate have yielded a maximum drain current density of 1.26 A/mm with a current gain cutoff and maximum oscillation frequencies about 26 and 40 GHz, respectively, for a 0.25 mu m gate leng ...

In this work, we report on the efficiency of single InGaN/GaN quantum wells (QWs) grown on thin (

The high temperature stability of AlGaN/GaN and lattice-matched InAlN/GaN heterostructure FETs has been evaluated by a stepped temperature test routine under large-signal operation. While AlGaN/GaN high-electron mobility transistors (HEMTs) have failed in ...

A room temperature polariton condensate realized in a microcavity with embedded GaN quantum wells emits linearly polarized light at threshold with the plane of polarization pinned to one of the crystallographic axes. With increasing pumping power, a depinn ...

Off-axis electron holography has been used to measure the built-in potential profile across an Al0.85In0.15N/AlN/GaN high electron mobility transistor heterostructure. Profile measurements indicated a polarization-induced electric field of 6.9 MV/cm within ...

Polariton lasers are mostly based on planar cavities. Here we focus on an alternative configuration with slab waveguide modes strongly coupled to excitons confined in GaN/AlGaN quantum wells. We study experimentally and theoretically polariton relaxation a ...

We report the coupling and interaction between shallow donors and microcavities in bulk GaN at THz frequencies. At 4K, the shallow donors lead to an absorption at 23.5 meV (5.7 THz) under optical pumping above the bandgap of GaN. The microcavities are base ...

In this study, we propose a novel, high-conductivity multi-channel heterostructure based on lattice-matched InAlN/GaN channels with modulation-doping-induced two-dimensional electron gases (2DEGs). To facilitate device processing, the channel period thickn ...

c-plane GaN/AlN quantum dots (QDs) are promising zero-dimensional quantum nanostructures that exhibit single photon emission properties up to room temperature and even above. In this context, it is of prime interest to gain a deeper insight into the recomb ...

We discuss the impact of kinetics, and in particular the effect of the Ehrlich-Schwobel barrier (ESB), on the growth and surface morphology of homoepitaxial GaN layers. The presence of an ESB can lead to various self-assembled surface features, which stron ...

A method for marking a product (1) with a photoluminescent mark, said mark comprising a photoluminescent portion (10) which is transparent under normal light conditions and revealed by photoluminescence under UV illumination, said mark further comprising a ...

We investigate Al2O3- and ZrO2/InAlN/GaN metal-oxide-semiconductor heterostructures (MOS-H) using capacitance-time transients in the temperature range of 25-300 degrees C. A deep-level transient spectroscopy based analysis revealed the maximum interface st ...

Cooperative emission due to spontaneous build-up and rapid decay of macroscopic polarization in a strongly inverted gain medium is drastically different from the lasing dynamics. The medium polarization and not the cavity field drives the emission from a d ...

We report on InAlN underlayer (UL) to improve the efficiency of near ultraviolet (NUV) light emitting diodes (LEDs). While InGaN UL is commonly used in high-efficiency blue LEDs it may absorb light for shorter wavelengths. InAlN lattice-matched to GaN exhi ...

Nonpolar GaN based microcavity (MC) made of a bottom AlN/GaN distributed Bragg reflector (DBR) and a top dielectric SiO2/SiNx DBR has been fabricated on a-plane GaN template. The 13 pair AlN/GaN DBR, centered around 372 nm, exhibits a peak reflectivity of ...

Photonic crystal point-defect cavities were fabricated in a GaN free-standing photonic crystal slab. The cavities are based on the popular L3 design, which was optimized using an automated process based on a genetic algorithm, in order to maximize the qual ...

Highly selective oxidation of an AlInN interlayer buried in a GaN matrix is demonstrated. This technique was successfully applied to form current apertures in III-nitride light-emitting diodes (LEDs). GaN LEDs were grown by metal-organic vapor phase epitax ...

Nicolas Grandjean

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Impact of saturation on the polariton renormalization in III-nitride based planar microcavities

Lattice-matched GaN-InAlN waveguides at lambda=1.55 mu m grown by metal-organic vapor phase epitaxy

Gate-lag and drain-lag effects in (GaN)/InAlN/GaN and InAlN/AlN/GaN HEMTs

Evaluation of AllnN/GaN HEMTs on sapphire substrate in microwave, time and temperature domains

Investigation of the Impact of Point Defects in InGaN/GaN Quantum Wells with High Dislocation Densities

Testing the Temperature Limits of GaN-Based HEMT Devices

Pinning and Depinning of the Polarization of Exciton-Polariton Condensates at Room Temperature

Polarization field mapping of Al0.85In0.15N/AlN/GaN heterostructure

Polariton relaxation and polariton nonlinearities in nonresonantly cw-pumped III-nitride slab waveguides

Interaction between meta-materials and shallow donors in bulk GaN at THz frequency

High conductivity InAlN/GaN multi-channel two-dimensional electron gases

Dark-level trapping, lateral confinement, and built-in electric field contributions to the carrier dynamics in c-plane GaN/AlN quantum dots emitting in the UV range

Critical impact of Ehrlich-Schwobel barrier on GaN surface morphology during homoepitaxial growth

Method for labeling products with a transparent photoluminescent label, and transparent photoluminescent label

Interface States and Trapping Effects in Al1O3- and ZrO2/InAlN/AlN/GaN Metal-Oxide-Semiconductor Heterostructures

Two faces of superradiance in tandem-cavity ridge waveguide heterostructures

InAlN underlaver for near ultraviolet InGaN based light emitting diodes

Nonpolar GaN-based microcavity using AlN/GaN distributed bragg reflector

Gallium nitride L3 photonic crystal cavities with an average quality factor of 16 900 in the near infrared

Selective oxidation of AlInN layers for current confinement in III-nitride devices