Publications de Lorenzo Lugani

Photocapacitance spectroscopy of InAlN nearly lattice-matched to GaN

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

We study the deep levels in InAlN nearly lattice-matched to GaN by photocapacitance spectroscopy. This technique allows the study of very deep levels having too slow thermal emission rates to be detected by other deep level spectroscopy techniques. We will ...

Amer Inst Physics2016

Capacitance behavior of InAlN Schottky diodes in presence of large concentrations of shallow and deep states related to oxygen

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

The capacitance-voltage-temperature characteristics of nonintentionally doped In0.16Al0.84 N/n+- GaN Schottky diodes were measured at 1 MHz and in the 90–400 K range. They are discussed in the framework of existing theories, which properly treat the Poiss ...

American Institute of Physics2015

Leakage mechanisms and contact technologies in InAlN/GaN high electron mobility transistors

Lorenzo Lugani

GaN based electronic devices have progressed rapidly over the past decades and are nowadays starting to replace Si and classical III-V semiconductors in power electronics systems and high power RF amplifiers. AlGaN/GaN heterostructures have been, until rec ...

EPFL2015

94-GHz Large-Signal Operation of AlInN/GaN High-Electron-Mobility Transistors on Silicon With Regrown Ohmic Contacts

Nicolas Grandjean, Jean-François Carlin, Marco Malinverni, Lorenzo Lugani

We report the first 94-GHz (W-band) large-signal performance of AlInN/GaN high-electron-mobility transistors (HEMTs) grown on high-resistivity silicon (111) substrates. A maximum output power density of 1.35 W/mm and peak power-added-efficiency of 12% are ...

Institute of Electrical and Electronics Engineers2015

Thermal stability and in situ SiN passivation of InAlN/GaN high electron mobility heterostructures

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

We investigate the thermal stability of nearly lattice-matched InAlN layers under metal organic vapor phase epitaxy conditions for temperatures >800 degrees C and show that they are not fully stable. In particular, InAlN top layers undergo degradation duri ...

Amer Inst Physics2014

Shallow donor and deep DX-like center in InAlN layers nearly lattice-matched to GaN

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

Nonintentionally doped 200-nm-thick In0.16Al0.84N/n(+)-GaN samples were grown by metal-organic vapor phase epitaxy and used for the electrical characterization of InAlN. In the temperature range 180-400 K, the forward current of Schottky diodes is dominate ...

Amer Physical Soc2014

Leakage mechanisms in InAlN based heterostructures

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

We propose a model for leakage currents in Schottky contacts on InAlN/GaN heterostructures based on two distinct tunneling mechanisms. Our modeling relies on structural parameters, in particular, InAlN dielectric constant, interface polarization charges an ...

Amer Inst Physics2014

n(+)-GaN grown by ammonia molecular beam epitaxy: Application to regrown contacts

Nicolas Grandjean, Jean-François Carlin, Etienne François Olivier Giraud, Marco Malinverni, Lorenzo Lugani, Daniel Marti

We report on the low-temperature growth of heavily Si-doped (>10(20) cm(-3)) n(+)-type GaN by N-rich ammonia molecular beam epitaxy (MBE) with very low bulk resistivity (

Amer Inst Physics2014

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

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

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

Modeling of InAs-InSb nanowires grown by Au-assisted chemical beam epitaxy

Lorenzo Lugani, Vladimir Dubrovskii

Interesting phenomena during the Au-assisted chemical beam epitaxy of InAs-InSb nanowire heterostructures have been observed and interpreted within the framework of a theoretical model. An unusual, non-monotonous diameter dependence of the InSb nanowire gr ...

2012