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Publications associées (29)

Optical bistability in InGaN-based multisection laser diodes

Nicolas Grandjean, Jean-François Carlin, Julien Dorsaz, Dmitri Boiko, 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

Time-resolved cathodoluminescence on polychromatic light emitting (In,Ga)N quantum wells grown on (11-22) GaN facets

Jean-François Carlin, Nicolas Grandjean, Benoît Marie Joseph Deveaud, Jean-Daniel Ganière, Eric Feltin, Pierre Michel Corfdir, Dobri Simeonov

We present a low-temperature time-resolved cathodoluminescence study on (In,Ga)N/GaN quantum wells grown on the (11-22) facets of non-coalesced ELO-GaN. Taking advantage of the quantum confined Stark effect, such structures have been proposed as promising ...

V C H Publishers, Suite 909, 220 E 23Rd St, New York, Ny 10010 Usa2011

Dynamic switching of hole character and single photon polarization using the quantum confined Stark effect in quantum dot-in-dot structures

Elyahou Kapon, Valentina Troncale

The engineering of the three-dimensional (3D) heterostructure potential in GaAs/AlGaAs pyramidal quantum dot-in-dots (DiDs) provides control over the valence band symmetry and hence on the polarization of the emitted photons. We propose a technique for dyn ...

Institute of Physics2010

Synthesis and optical investigation of single polar GaN/AlN quantum dots

Dobri Simeonov

Over the past few decades, III-V nitrides have attracted much attention due to the possibility to realize high efficiency optoelectronic devices covering all the UV and visible part of the light spectrum. However, the device fabrication has gone much faste ...

EPFL2009

Different pressure behavior of GaN/AlGaN quantum structures grown along polar and nonpolar crystallographic directions

Nicolas Grandjean

High quality GaN/AlGaN multiquantum well (QW) structures were grown by ammonia molecular beam epitaxy along the (0001) polar and (11 (2) over bar0) nonpolar directions. Each sample contains three QWs with thicknesses of 2, 3, and 4 nm as well as 10 nm Al0. ...

2009

Complex behavior of biexcitons in GaN quantum dots due to a giant built-in polarization field

Nicolas Grandjean, Raphaël Butté, Dobri Simeonov

In-depth optical spectroscopic studies of single polar GaN/AlN quantum dots (QDs) grown by molecular beam epitaxy are carried out by means of low-temperature microphotoluminescence. Luminescence linewidths as low as 700 mu eV are obtained allowing thorough ...

2008

Role of nonadiabatic untrapped electrons in global electrostatic ion temperature gradient driven modes in a tokamak

Laurent Villard, Stephan Brunner, Paolo Angelino

In this work, role of nonadiabatic untrapped electrons in the context of a global ion temperature gradient driven mode has been investigated. In past studies, untrapped electrons have been assumed to be able to respond "instantaneously" to a disturbance. I ...

American Institute of Physics2008

Impact of quantum confinement and quantum confined Stark effect on biexciton binding energy in GaN/AlGaN quantum wells

Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Jacques Levrat, Eric Feltin, Dobri Simeonov, Massimo Gurioli

We report on time-resolved photoluminescence measurements carried out along the thickness gradient of two types of GaN/AlGaN quantum wells with low Al content in the barriers (5% and 9%, respectively). A reduction of the biexciton binding energy with incre ...

2008

Highly frustrated magnetic clusters: The kagome on a sphere

Frédéric Mila, Ioannis Rousochatzakis

We present a detailed study of the low-energy excitations of two existing finite-size realizations of the planar kagome Heisenberg antiferromagnet on the sphere: the cuboctahedron and the icosidodecahedron. After highlighting a number of special spectral f ...

2008

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