Publications by Denis Martin | EPFL Graph Search

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

Jean-François Carlin, Denis Martin, Nicolas Grandjean, Raphaël Butté, Hua Zhang, Ching-Wen Shih

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

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

Jean-François Carlin, Denis Martin, Nicolas Grandjean, Raphaël Butté, Hua Zhang, Ching-Wen Shih

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

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

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

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

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

Denis Martin, Nicolas Grandjean, 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

Denis Martin, Nicolas Grandjean, 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

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

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

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

Stabilisation of the gravity structure of the Romanesque Abbey of Payerne Switzerland

Eugen Brühwiler, Denis Martin

2017

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

Denis Martin, Nicolas Grandjean, Marco Malinverni, Hironori Okumura

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

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

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

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 p-type contact resistance by field-emission tunneling in highly Mg-doped GaN

Denis Martin, Nicolas Grandjean, Hironori Okumura

Mg-doped GaN with a net acceptor concentration (NA-ND) in the high 10 19 cm(-3) range was grown using ammonia molecular-beam epitaxy. Electrical properties of NiO contact on this heavily doped p-type GaN were investigated. A potential-barrier height of 0.2 ...

Amer Inst Physics2016

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

Denis Martin, Nicolas Grandjean, Nils Asmus Kristian Kaufmann, Lise Lahourcade

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 ...

Elsevier Science Bv2016

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

Denis Martin, Julien Dorsaz, Nicolas Grandjean, Marco Rossetti, Eric Feltin, Antonino Francesco Castiglia, 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

InGaN based micro light emitting diodes featuring a buried GaN tunnel junction

Denis Martin, Nicolas Grandjean, Marco Malinverni

GaN tunnel junctions (TJs) are grown by ammonia molecular beam epitaxy. High doping levels are achieved with a net acceptor concentration close to similar to 10(20) cm(-3), thanks to the low growth temperature. This allows for the realization of p-n juncti ...

Amer Inst Physics2015

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

Denis Martin, Julien Dorsaz, Nicolas Grandjean, Eric Feltin, 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

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

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

Thermal annealing of molecular beam epitaxy-grown InGaN/GaN single quantum well

Denis Martin, Nicolas Grandjean, Nils Asmus Kristian Kaufmann

The effect of thermal annealing on In0.25Ga0.75N/GaN quantum wells grown by molecular beam epitaxy at 550 degrees C is investigated. A strong increase in the 300 K photoluminescence (PL) intensity is observed for samples annealed at 880 degrees C, while de ...

Iop Publishing Ltd2012

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

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

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

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

Benoît Marie Joseph Deveaud, Jean-Daniel Ganière, Pierre Stadelmann, Denis Martin, Jacques Levrat, Nicolas Grandjean, Raphaël Butté, Yadira Arroyo Rojas Dasilva, Tiankai Zhu, 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