Publications de Yannik Fontana

Lamellar carbon-aluminosilicate nanocomposites with macroscopic orientation

Yannik Fontana, Anna Fontcuberta i Morral, Holger Frauenrath, Emad Oveisi, Dragana Paripovic, Enzo Jean Raymond Bomal

Novel preparative approaches towards lamellar nanocomposites of carbon and inorganic materials are relevant for a broad range of technological applications. Here, we describe how to utilize the co-assembly of a liquid-crystalline hexaphenylene amphiphile a ...

ROYAL SOC CHEMISTRY2021

Optically active quantum dots in bottom-up nanowires

Yannik Fontana

This thesis is dedicated to the discovery and progressive study of quantum emitters embedded in the shell of coaxial gallium arsenide/ aluminum gallium arsenide nanowires. The bottom-up core/shell nanowires were grown in a molecular beam epitaxy machine. D ...

EPFL2015

Quantum dots in the GaAs/AlxGa1-xAs core-shell nanowires: Statistical occurrence as a function of the shell thickness

Yannik Fontana, Anna Fontcuberta i Morral, Gözde Tütüncüoglu, Léo Duchêne, Sonia Conesa Boj, Federico Matteini, Luca Francaviglia

Quantum dots (QDs) embedded in nanowires represent one of the most promising technologies for applications in quantum photonics. Self-assembled bottom-up fabrication is attractive to overcome the technological challenges involved in a top-down approach, bu ...

American Institute of Physics2015

Tailoring the diameter and density of self-catalyzed GaAs nanowires on silicon

Yannik Fontana, Anna Fontcuberta i Morral, Gözde Tütüncüoglu, Federico Matteini, Vladimir Dubrovskii

Nanowire diameter has a dramatic effect on the absorption cross-section in the optical domain. The maximum absorption is reached for ideal nanowire morphology within a solar cell device. As a consequence, understanding how to tailor the nanowire diameter a ...

Institute of Physics2015

Tuning the g-factor of neutral and charged excitons confined to self-assembled (Al,Ga)As shell quantum dots

Yannik Fontana, Pierre Michel Corfdir, Anna Fontcuberta i Morral, Martin Heiss, Eleonora Russo

We study the neutral exciton (X) and charged exciton (CX) transitions from (Al,Ga) As shell quantum dots located in core-shell nanowires, in the presence of a magnetic field. The g-factors and the diamagnetic coefficients of both the X and the CX depend on ...

American Institute of Physics2014

Three-dimensional nanoscale study of Al segregation and quantum dot formation in GaAs/AlGaAs core-shell nanowires

Yannik Fontana, Anna Fontcuberta i Morral, Martin Heiss, Sonia Conesa Boj, Eleonora Russo, Luca Francaviglia

GaAs/Al-GaAs core-shell nanowires fabricated by molecular beam epitaxy contain quantum confining structures susceptible of producing narrow photoluminescence (PL) and single photons. The nanoscale chemical mapping of these structures is analyzed in 3D by a ...

American Institute of Physics2014

Nanoskiving Core-Shell Nanowires: A New Fabrication Method for Nano-optics

Yannik Fontana, Anna Fontcuberta i Morral, Martin Heiss, Eleonora Russo

This paper describes the fabrication of functional optical devices by sectioning quantum-dot-in-nanowires systems with predefined lengths and orientations. This fabrication process requires only two steps, embedding the nanowires in epoxy and using an ultr ...

Amer Chemical Soc2014

Exciton footprint of self-assembled AlGaAs quantum dots in core-shell nanowires

Samuel Sonderegger, Yannik Fontana, Pierre Michel Corfdir, Anna Fontcuberta i Morral, Martin Heiss, Eleonora Russo

Quantum-dot-in-nanowire systems constitute building blocks for advanced photonics and sensing applications. The electronic symmetry of the emitters impacts their function capabilities. Here we study the fine structure of gallium-rich quantum dots nested in ...

American Physical Society2014

Quantum Dot Opto-Mechanics in a Fully Self-Assembled Nanowire

Yannik Fontana, Anna Fontcuberta i Morral, Martin Heiss, Eleonora Russo

We show that optically active quantum dots (QDs) embedded in MBE-grown GaAs/AlGaAs core-shell nanowires (NWs) are coupled to the NW mechanical motion. Oscillations of the NW modulate the QD emission energy in a broad range exceeding 14 meV. Furthermore, th ...

American Chemical Society2014

Functional carbon nanosheets prepared from hexayne amphiphile monolayers at room temperature

Guillaume Pasche, Yannik Fontana, Anne-Clémence Corminboeuf, Anna Fontcuberta i Morral, Holger Frauenrath, Emad Oveisi, Stephen Schrettl, Javier Reguera Gomez, Riccardo Petraglia

Carbon nanostructures that feature two-dimensional extended nanosheets are important components for technological applications such as high-performance composites, lithium-ion storage, photovoltaics and nanoelectronics. Chemical functionalization would ren ...

Nature Publishing Group2014

Self-assembled quantum dots in a nanowire system for quantum photonics

Marco Cantoni, Yannik Fontana, Anna Fontcuberta i Morral, Martin Heiss, Bernt Ketterer, Sonia Conesa Boj, Eleonora Russo, Nicola Marzari

Quantum dots embedded within nanowires represent one of the most promising technologies for applications in quantum photonics. Whereas the top-down fabrication of such structures remains a technological challenge, their bottom-up fabrication through self-a ...

Nature Publishing Group2013