Emanuele Uccelli

Cette personne n’est plus à l’EPFL

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Publications associées (19)

Untangling the Electronic Band Structure of Wurtzite GaAs Nanowires by Resonant Raman Spectroscopy

Anna Fontcuberta i Morral, Martin Heiss, Emanuele Uccelli, Bernt Ketterer

In semiconductor nanowires, the coexistence of wurtzite and zinc-blende phases enables the engineering of the electronic structure within a single material. This presupposes an exact knowledge of the band structure in the wurtzite phase. We demonstrate tha ...

American Chemical Society2011

Supercooling of nanoscale Ga drops with controlled impurity levels

Anna Fontcuberta i Morral, Emanuele Uccelli

We use in situ observations by variable temperature transmission electron microscopy on Ga drops at the tips of GaAs nanowires to investigate the phase behavior of nanoscale Ga. Experiments on pure Ga drops are compared with drops containing well-defined l ...

2011

InAs Quantum Dot Arrays Decorating the Facets of GaAs Nanowires

Anna Fontcuberta i Morral, Emanuele Uccelli

InAs quantum dot arrays are obtained on GaAs nanowire facets by molecular beam epitaxy. The GaAs nanowires are first grown by the gallium-assisted catalyst-free method. Decoration of the nanowire facets with InAs quantum dots is achieved only when the face ...

American Chemical Society2010

Compensation mechanism in silicon-doped gallium arsenide nanowires

Anna Fontcuberta i Morral, Emanuele Uccelli, Bernt Ketterer

P-type gallium arsenide nanowires were grown with different silicon doping concentrations. The incorporation is monitored by Raman spectroscopy of the local vibrational modes. For Si-concentrations up to 1.4 x 10(18) cm(-3), silicon incorporates mainly in ...

American Institute of Physics2010

Optical Properties of InAs Quantum Dot Array Ensembles with Predetermined Lateral Sizes from 20 to 40 nm

Anna Fontcuberta i Morral, Emanuele Uccelli, Laura Waller

Cleaved edge overgrowth and selective area epitaxy were combined for the synthesis of InAs quantum dot (QD) arrays with lateral sizes from 20 to 40 nm. The optical properties were locally assessed by confocal photoluminescence spectroscopy experiments at l ...

2010

Thermal conductivity of GaAs nanowires studied by micro-Raman spectroscopy combined with laser heating

Anna Fontcuberta i Morral, Emanuele Uccelli

The thermal properties of freely suspended GaAs nanowires are investigated by applying a method which relies on laser heating and the determination of the local temperature by Raman spectroscopy. In order to determine the values for the thermal conductivit ...

American Institute of Physics2010

P-Doping Mechanisms in Catalyst-Free Gallium Arsenide Nanowires

Anna Fontcuberta i Morral, Emanuele Uccelli, Carlo Colombo, Bernt Ketterer, Tonko Garma, Marco Nicotra

Doped catalyst-free GaAs nanowires have been grown by molecular beam epitaxy with the gallium-assisted method. The spatial dependence of the dopant concentration and resistivity have been measured by Raman spectroscopy and four point electrical measurement ...

American Chemical Society2010

A level set simulation for ordering of quantum dots via cleaved-edge overgrowth

Anna Fontcuberta i Morral, Emanuele Uccelli

Cleaved-edge overgrowth (CEO) is a promising technique to obtain ordered arrays of quantum dots, where the size and position of the dots can be controlled very well. We present level set simulations for CEO. Our simulations illustrate how the quality of th ...

American Institute of Physics2009

Investigation of a contacting scheme for self-assembled cleaved edge overgrown InAs nanowires and quantum dot arrays

Anna Fontcuberta i Morral, Emanuele Uccelli

A contacting scheme to measure the transport properties into self-assembled InAs Quantum Wires (QWRs) or Quantum Dots (QDs) is presented. The nanostructures are formed on the (110) cleaved edge of a AlAs/AlGaAs heterostructure substrate by means of the Cle ...

Wiley2009

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