Publications by Denis Martin | EPFL Graph Search

Related publications (34)

Broadened Bandwidth Amplified Spontaneous Emission from Blue GaN-Based Short-Cavity Superluminescent Light-Emitting Diodes

Hua Zhang, Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Denis Martin, Hezhi Zhang

We report broad bandwidth blue superluminescent light-emitting diodes (SLEDs) based on a short-cavity active region. The dependencies of amplified spontaneous emission (ASE) output power and gain bandwidth on cavity length were investigated in devices whos ...

2019

Exciton recombination dynamics in a-plane (Al,Ga)N/GaN quantum wells probed by picosecond photo and cathodoluminescence

Nicolas Grandjean, Benoît Marie Joseph Deveaud, Jean-Daniel Ganière, Denis Martin, Laurent Balet, Pierre Michel Corfdir, Samuel Sonderegger

We present a combined low-temperature time-resolved cathodoluminescence and photoluminescence study of exciton recombination mechanisms in a 3.8 nm thick a-plane (Al,Ga)N/GaN quantum well (QW). We observe the luminescence from QW excitons and from excitons ...

American Institute of Physics2010

One-dimensional exciton luminescence induced by extended defects in nonpolar GaN/(Al,Ga)N quantum wells

Nicolas Grandjean, Pierre Stadelmann, Raphaël Butté, Benoît Marie Joseph Deveaud, Jean-Daniel Ganière, Jacques Levrat, Denis Martin, Pierre Michel Corfdir

In this study, we present the optical properties of nonpolar GaN/(Al,Ga)N single quantum wells (QWs) grown on either a- or m-plane GaN templates for Al contents set below 15%. In order to reduce the density of extended defects, the templates have been proc ...

Institute of Physics2011

AlN grown on Si(111) by ammonia-molecular beam epitaxy in the 900-1200 degrees C temperature range

Nicolas Grandjean, Denis Martin, Sebastian Pascal Tamariz Kaufmann

We present a comprehensive study of AlN growth on Si(111) substrate by gas source molecular beam epitaxy with ammonia as nitrogen precursor in the high temperature range. We first demonstrate that the observation of the silicon 7 x 7 surface reconstruction ...

Elsevier2017

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

Nicolas Grandjean, Denis Martin, Pirouz Sohi

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 ...

2017

Exciton localization on basal stacking faults in a-plane epitaxial lateral overgrown GaN grown by hydride vapor phase epitaxy

Nicolas Grandjean, Benoît Marie Joseph Deveaud, Jean-Daniel Ganière, Denis Martin, Jacques Levrat, Pierre Michel Corfdir

We present a detailed study of the luminescence at 3.42 eV usually observed in a-plane epitaxial lateral overgrowth (ELO) GaN grown by hydride vapor phase epitaxy on r-plane sapphire. This band is related to radiative recombination of excitons in a commonl ...

American Institute of Physics2009

Backward diodes using heavily Mg-doped GaN growth by ammonia molecular-beam epitaxy

Nicolas Grandjean, Denis Martin, Marco Malinverni

We grew heavily Mg-doped GaN using ammonia molecular-beam epitaxy. The use of low growth temperature (740 degrees C) allows decreasing the incorporation of donor-like defects (

Amer Inst Physics2016

Low-temperature time-resolved cathodoluminescence study of exciton dynamics involving basal stacking faults in a-plane GaN

Nicolas Grandjean, Benoît Marie Joseph Deveaud, Jean-Daniel Ganière, Denis Martin, Pierre Michel Corfdir

Time-resolved cathodoluminescence at 27 K has been performed on a-plane GaN grown by epitaxial lateral overgrowth. We detail the relaxation and recombination mechanisms of excitons [free or bound to neutral donors, or bound to I1-type basal stacking faults ...

AIP American Institute of Physics2009

Ultrathin InAlN/GaN heterostructures on sapphire for high on/off current ratio high electron mobility transistors

Nicolas Grandjean, Jean-François Carlin, Denis Martin, Marcel Py, Lorenzo Lugani

We report on InAlN/GaN high electron mobility transistors (HEMTs) grown by metal organic vapor phase epitaxy on sapphire with ultrathin buffers. Two dimensional electron gas (2DEG) exhibiting high mobility (1100 cm(2) /V s) and low sheet resistivity (356 O ...

Amer Inst Physics2013

Short cavity InGaN-based laser diodes with cavity length below 300 mu m

Hua Zhang, Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Denis Martin, Hezhi Zhang

We report on a practical method for developing InGaN-based edge emitting laser diodes of cavity length down to 45 mu m. Samples consisting of one uncoated cleaved facet and one etched facet coated with a high-reflectivity (HR) dielectric distributed Bragg ...

2019

Burying non-radiative defects in InGaN underlayer to increase InGaN/GaN quantum well efficiency

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Denis Martin, Gwénolé Jean Jacopin, Camille Haller

The insertion of an InGaN underlayer (UL) is known to strongly improve the performance of InGaN/GaN quantum well (QW) based blue light emitting diodes (LEDs). However, the actual physical mechanism responsible for it is still unclear. We thus conduct a sys ...

American Institute of Physics2017

InGaN laser diodes emitting at 500 nm with p-layers grown by molecular beam epitaxy

Nicolas Grandjean, Eric Feltin, Denis Martin, Julien Dorsaz, Antonino Francesco Castiglia, Marco Rossetti, Marco Malinverni, Jean-Michel Jacques Lamy, Lise Lahourcade

We demonstrate hybrid laser diodes by combining n-type layers and an active region grown by metal organic vapor phase epitaxy with p-type layers grown by molecular beam epitaxy. These p-doped layers, grown at 740 degrees C, exhibit state-of-the-art electri ...

Japan Society of Applied Physics2015

GaN surface as the source of non-radiative defects in InGaN/GaN quantum wells

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Denis Martin, Wei Liu, Gwénolé Jean Jacopin, Camille Haller

Blue light-emitting diodes based on III-nitride semiconductors are nowadays widely used for solid-state lighting. They exhibit impressive figures of merit like an internal quantum efficiency close to 100%. This value is intriguing when considering the high ...

2018

Stress control in GaN/sapphire templates for the fabrication of crack-free thick layers

Nicolas Grandjean, Marc Ilegems, Denis Martin

The reduction of the tensile stress contained in GaN layers grown oil sapphire by metalorganic vapor phase epitaxy (MOVPE) is achieved using a low density of initial GaN crystallites. The template layers exhibit a significant reduction in dislocation densi ...

2006

InGaN laser diode with metal-free laser ridge using n(+)-GaN contact layers

Nicolas Grandjean, Denis Martin, Antonino Francesco Castiglia, Camille Haller, Marco Rossetti, Marco Malinverni

We report on InGaN edge emitting laser diodes with a top metal electrode located beside the laser ridge. Current spreading over the ridge is achieved via a highly doped n(+)-type GaN layer deposited on top of the structure. The low sheet resistance of the ...

Iop Publishing Ltd2016

Low temperature p-type doping of (Al)GaN layers using ammonia molecular beam epitaxy for InGaN laser diodes

Nicolas Grandjean, Eric Feltin, Denis Martin, Julien Dorsaz, Antonino Francesco Castiglia, Marco Malinverni, Jean-Michel Jacques Lamy

We demonstrate state-of-the-art p-type (Al) GaN layers deposited at low temperature (740 degrees C) by ammonia molecular beam epitaxy (NH3-MBE) to be used as top cladding of laser diodes (LDs) with the aim of further reducing the thermal budget on the InGa ...

Amer Inst Physics2014

GaN grown on (111) single crystal diamond substrate by molecular beam epitaxy

Nicolas Grandjean, Denis Martin, Antonino Francesco Castiglia, Marco Malinverni

GaN epilayers are grown on (111) oriented single crystal diamond substrate by ammonia-source molecular beam epitaxy. Each step of the growth is monitored in situ by reflection high energy electron diffraction. It is found that a two-dimensional epitaxial w ...

2009

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

Nicolas Grandjean, Pierre Stadelmann, Denis Martin

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

Study of the epitaxial relationships between III-nitrides and M-plane sapphire

Nicolas Grandjean, Denis Martin

GaN films epitaxially-grown on M-sapphire may have different orientations, either nonpolar and semipolar. In this paper, the different epitaxial relationships are investigated in details thanks to transmission electron microscopy. It is shown that these re ...

2010

High-Mobility AlGaN/GaN Two-Dimensional Electron Gas Heterostructure Grown on (111) Single Crystal Diamond Substrate

Nicolas Grandjean, Pierre Stadelmann, Denis Martin, Marcel Py, Anas Mouti, Marco Malinverni

High mobility Al0.28Ga0.72N/GaN two-dimensional electron gas (2DEG) is achieved on ( 111) oriented single crystal diamond substrate. The surface morphology of the epilayer is free of cracks thanks to the use of an AlN interlayer for strain relaxation. The ...

2010