Personne

Denis Martin

Cette personne n’est plus à l’EPFL

Publications associées (70)

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

Nicolas Grandjean, Marco Malinverni, Denis Martin, 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

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

Nicolas Grandjean, Denis Martin, 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

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In this paper, we show that the quality of the porous layers produced by photoelectrochemical (PEC) etching of HVPE GaN in oxalic acid is better than that of the initial material, and the quality of GaN films overgrown on porous layers can be improved by a ...

Springer2016

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Vacancy-type defects in Mg-doped GaN were probed using a monoenergetic positron beam. GaN films with a thickness of 0.5-0.7 mu m were grown on GaN/sapphire templates using ammonia-based molecular beam epitaxy and characterized by measuring Doppler broadeni ...

Amer Inst Physics2016

Selective heteroepitaxy on deeply grooved substrate: A route to low cost semipolar GaN platforms of bulk quality

Nicolas Grandjean, Denis Martin

Semipolar GaN crystal stripes larger than 100 mu m with dislocation densities below 5 x 10(6) cm(-2) are achieved using a low cost fabrication process. An original sapphire patterning procedure is proposed, enabling selective growth of semipolar oriented G ...

Amer Inst Physics2016

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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

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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

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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

Large-k exciton dynamics in GaN epilayers: Nonthermal and thermal regimes

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Eric Feltin, Denis Martin, Massimo Gurioli

We present a detailed investigation performed at low temperature (T < 50 K) concerning the exciton dynamics in GaN epilayers grown on c-plane sapphire substrates, focusing on the exciton formation and the transition from the nonthermal to the thermal regim ...

Amer Physical Soc2013

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