Publications de Bernt Ketterer

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

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

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

Mobility and carrier density in p-type GaAs nanowires measured by transmission Raman spectroscopy

Anna Fontcuberta i Morral, Emanuele Uccelli, Bernt Ketterer

Mobility and carrier density in p-type GaAs nanowires measured by transmission Raman spectroscopy ...

2012

Low-Temperature Preparation of Tailored Carbon Nanostructures in Water

Anna Fontcuberta i Morral, Holger Frauenrath, Vincent Laporte, Bernt Ketterer, Davide Demurtas, Martin Fritzsche, Tobias Hoheisel, Ruth Szilluweit, Raffaele Mezzenga

The development of low-temperature carbonization procedures promises to provide novel nanostructured carbon materials that are of high current interest in materials science and technology. Here, we report a "wet-chemical" carbonization method that utilizes ...

American Chemical Society2012

Phonon confinement and plasmon-phonon interaction in nanowire-based quantum wells

Anna Fontcuberta i Morral, Bernt Ketterer

Resonant Raman spectroscopy is realized on closely spaced nanowire-based quantum wells. Phonon quantization consistent with 2.4-nm-thick quantum wells is observed, in agreement with cross-section transmission electron microscopy measurements and photolumin ...

2011

Raman Spectroscopy of GaAs Nanowires : Doping Mechanisms and Fundamental Properties

Bernt Ketterer

Semiconductor nanowires offer a wide range of opportunities for newgenerations of nanoscale electronic and optic devices. For these applications to become reality, deeper understanding of the fundamental properties of the nanowires is required. In this the ...

EPFL2011

Determination of the band gap and the split-off band in wurtzite GaAs using Raman and photoluminescence excitation spectroscopy

Anna Fontcuberta i Morral, Martin Heiss, Bernt Ketterer

GaAs nanowires with 100% wurtzite structure are synthesized by the vapor-liquid-solid method in a molecular beam epitaxy system, using gold as a catalyst. We use resonant Raman spectroscopy and photoluminescence to determine the position of the crystal-fie ...

2011

In(Ga)As quantum dot formation on group-III assisted catalyst-free InGaAs nanowires

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

Growth of GaAs and InxGa1-xAs nanowires by the group-III assisted molecular beam epitaxy growth method on (001)GaAs/SiO2 substrates is studied in dependence on growth temperature, with the objective of maximizing the indium incorporation. Nanowire growth w ...

Institute of Physics2011

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

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

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