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Nicolas Grandjean

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Publications associées (249)

Standard-free composition measurements of AlxIn1-xN by low-loss electron energy loss spectroscopy

Jean-François Carlin, Nicolas Grandjean

We demonstrate a standard-free method to retrieve compositional information in AlxIn1-xN thin films by measuring the bulk plasmon energy (E-p), employing electron energy loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM). Two se ...

2011

Contactless electroreflectance of polar and nonpolar GaN/AlGaN quantum wells

Nicolas Grandjean

Contactless electroreflectance (CER) has been applied to study optical transitions between the ground and excited states in polar and a-plane nonpolar 2 nm wide GaN/Al0.12Ga0.88N quantum well (QW) structures. In addition to the fundamental transition, CER ...

2011

Defects in a-GaN grown on r-sapphire by hydride vapor phase epitaxy

Pierre Stadelmann, Denis Martin, Nicolas Grandjean, Tiankai Zhu

Non-polar a-GaN films grown on r-sapphire by hydride vapor phase epitaxy (HVPE) are studied using transmission electron microscopy (TEM). Despite the small lattice mismatch in a-GaN ([1 0 (1) over bar 0] similar to 1.1% and [0 00 1] similar to 16%), high d ...

2011

Optical bistability in InGaN-based multisection laser diodes

Jean-François Carlin, Julien Dorsaz, Dmitri Boiko, Nicolas Grandjean, Luca Alex Milo Sulmoni

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 ...

AIP American Institute of Physics2011

Self heating in AlInN/AlN/GaN high power devices: Origin and impact on contact breakdown and IV characteristics

Jean-François Carlin, Marcel Py, Nicolas Grandjean, Eric Feltin, Marcus Gonschorek

It is observed experimentally that high electron mobility transistor devices with short channel length processed from nitride AlInN/AlN/GaN heterostructures containing 2D electron gases (2DEGs) with densities beyond 2 x 10(13) cm(-2) exhibit temperatures u ...

American Institute of Physics2011

Recombination coefficients of GaN-based laser diodes

Jean-François Carlin, Julien Dorsaz, Nicolas Grandjean, Luca Alex Milo Sulmoni

We measure the charge carrier recombination coefficients of InGaN quantum wells by analyzing the dynamical properties of (Al,In)GaN laser diodes emitting in the violet spectral range. Relaxation oscillations and turn-on delays are fitted to a rate equation ...

2011

Tailoring the light-matter coupling in anisotropic microcavities: Redistribution of oscillator strength in strained m-plane GaN/AlGaN quantum wells

Gatien Cosendey, Jacques Levrat, Nicolas Grandjean, Raphaël Butté, Marlene Glauser, Georg Rossbach, Munise Nevin Cobet

We present a comprehensive study of the anisotropic optical properties of nonpolar GaN/AlGaN multiple quantum wells intentionally designed to act as an active region of a planar microcavity operating in the strong-coupling regime. The strain induced by the ...

2011

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

Benoît Marie Joseph Deveaud, Jean-Daniel Ganière, Nicolas Grandjean, Pierre Michel Corfdir, Munehito Kagaya

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 ...

2011

Stress-modulated composition in the vicinity of dislocations in nearly lattice matched AlxIn1-x N/GaN heterostructures: A possible explanation of defect insensitivity

Jean-François Carlin, Pierre Stadelmann, Jean-Luc Rouvière, Marco Cantoni, Nicolas Grandjean, Eric Feltin, Anas Mouti

Evidence of composition fluctuations around threading dislocations at scales ranging from atomic distances to tens of nanometers is provided by z-contrast imaging, strain measurement, and energy dispersive x-ray spectroscopy in AlxIn1-x N/GaN heterostructu ...

2011

Investigation of the In composition in InGaN/GaN quantum wells deposited by MOVPE and/or MBE with emission from violet to green

Denis Martin, Nicolas Grandjean, Nils Asmus Kristian Kaufmann

Transmission electron microscopy and photoluminescence investigations have been carried out on a series of quantum wells grown by molecular beam epitaxy and metal organic vapour phase epitaxy. In both cases, the emission wavelength and the peak width agree ...

2011

Diamond overgrown InAlN/GaN HEMT

Jean-François Carlin, Nicolas Grandjean

In this work the technology and characterization of nanocrystalline diamond (NCD) films directly grown on InAlN/GaN HEMTs is presented. Optimization of GaN based HEMT process steps including metallization stacks is discussed. A fully processed InAlN/GaN HE ...

2011

Si-interdiffusion in heavily doped AlN-GaN-based quantum well intersubband photodetectors

Denis Martin, Nicolas Grandjean, Joab Di Francesco

We demonstrate the effect of rapid thermal annealing on heavily Si-doped AlN/GaN quantum wells. After 1000 degrees C annealing during 5, 10, and 20 min, the dominant effect was interdiffusion of Si rather than intermixing between the Al and Ga atoms. Both ...

AIP American Institute of Physics2011

High-speed and low-noise AlInN/GaN HEMTs on SiC

Jean-François Carlin, Nicolas Grandjean, Eric Feltin, Marcus Gonschorek

A comparison of devices with different source-drain gaps has been performed on AlInN/GaN high electron mobility transistors (HEMTs) grown on SiC. The cut-off frequency is effectively improved through shrinking source drain space and reducing gate parasitic ...

Wiley2011

LIGHT-EMITTING DIODES Solid-state lighting on glass

Nicolas Grandjean, Raphaël Butté

Nature Publishing Group2011

Self-Pulsation at Zero Absorber Bias in GaN-Based Multisection Laser Diodes

Jean-François Carlin, Julien Dorsaz, Nicolas Grandjean, Luca Alex Milo Sulmoni

We study the influence of pump current and absorber bias voltage on the pulse width and frequency of sustained pulsation in GaN-based multisection laser diodes. The observed frequencies and pulse widths range from 1.5 to 4.5GHz and 90 to 18 ps, respectivel ...

2011

Role of stable and metastable Mg-H complexes in p-type GaN for cw blue laser diodes

Jean-François Carlin, Nicolas Grandjean, Antonino Francesco Castiglia

Secondary ion mass spectroscopy (SIMS) and capacitance-voltage measurements were combined to thoroughly study Mg doping in GaN layers grown by metal organic vapor phase epitaxy. First we found that the Mg steady-state incorporation regime occurs for a surf ...

AIP American Institute of Physics2011

Low-Noise Microwave Performance of 0.1 mu m Gate AlInN/GaN HEMTs on SiC

Jean-François Carlin, Nicolas Grandjean, Eric Feltin, Marcus Gonschorek

We report the first microwave noise characterization of AlInN/GaN HEMTs. Transistors with a 0.1 mu m gate implemented on a semi-insulating SiC substrate achieve a maximum current density of 1.92 A/mm at V-GS = 0 V, a measured transconductance g(M) = 480 mS ...

2010

High Power Blue-Violet Superluminescent Light Emitting Diodes with InGaN Quantum Wells

Jean-François Carlin, Julien Dorsaz, Gatien Cosendey, Nicolas Grandjean, Marco Rossetti, Eric Feltin, Antonino Francesco Castiglia

We report on the characteristics of blue superluminescent light emitting diodes based on the emission of InGaN quantum wells. Narrow ridge-waveguide devices realized by standard processing techniques and with extremely low facet reflectivity show single la ...

2010

Metal-related gate sinking due to interfacial oxygen layer in Ir/InAlN high electron mobility transistors

Jean-François Carlin, Nicolas Grandjean, Marcus Gonschorek

We report on an annealing-induced "gate sinking" effect in a 2-nm-thin In0.17Al0.83N/AlN barrier high electron mobility transistor with Ir gate. Investigations by transmission electron microscopy linked the effect to an oxygen containing interlayer between ...

2010

Exact determination of electrical properties of wurtzite Al1−xInxN/(AlN)/GaN heterostructures (0.07 ≤ x ≤ 0.21) by means of a detailed charge balance equation

Jean-François Carlin, Marcel Py, Nicolas Grandjean, Eric Feltin, Marcus Gonschorek

Cambridge, Cambridge University Press2010

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