Publications de Carlo Colombo | EPFL Graph Search

Doping incorporation paths in catalyst-free Be-doped GaAs nanowires

Anna Fontcuberta i Morral, Alberto Casadei, Martin Heiss, Carlo Colombo

The incorporation paths of Be in GaAs nanowires grown by the Ga-assisted method in molecular beam epitaxy have been investigated by electrical measurements of nanowires with different doping profiles. We find that Be atoms incorporate preferentially via th ...

American Institute of Physics2013

Electrical contacts to single nanowires: a scalable method allowing multiple devices on a chip. Application to a single nanowire radial p-i-n junction

Anna Fontcuberta i Morral, Martin Heiss, Anna Dalmau Mallorquí, Carlo Colombo, Pierre Loïc Blanc

Semiconductor nanowires are currently at the forefront of research in the areas of nanoelectronics and energy conversion. In all these studies, realising electrical contacts and statistically relevant measurements is a key issue. We propose a method that e ...

Inderscience2013

An Electrically-Driven GaAs Nanowire Surface Plasmon Source

Anna Fontcuberta i Morral, Carlo Colombo

Over the past decade, the properties of plasmonic waveguides have extensively been studied as key elements in important applications that include biosensors, optical communication systems, quantum plasmonics, plasmonic logic, and quantum-cascade lasers. Wh ...

American Chemical Society2012

Core-Shell GaAs Nanowire p-n Junctions from Growth to Photovoltaic and Optoelectronic Applications

Carlo Colombo

Semiconductor nanowires (NWs) are filamentary crystals with the diameter ranging from few tens up to few hundreds of nanometers. In the last 15 years, they have been intensively studied for the prospectives that their unique quasi-one dimensional shape off ...

EPFL2012

Engineering light absorption in single-nanowire solar cells with metal nanoparticles

Anna Fontcuberta i Morral, Carlo Colombo

Semiconductor nanowires (NWs) possess a fascinating ability to efficiently collect and trap light into a sub-wavelength volume due to the occurrence of leaky mode resonances. The same confinement ability is manifested by metal nanostructures thanks to the ...

Institute of Physics (IoP) and Deutsche Physikalische Gesellschaft2011

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

Gallium arsenide p-i-n radial structures for photovoltaic applications

Michael Graetzel, Anna Fontcuberta i Morral, Martin Heiss, Carlo Colombo

Gallium arsenide p-i-n radial junctions were fabricated by molecular beam epitaxy. The current-voltage characteristics of single nanowires were measured in the dark and under various illumination conditions including 1.5 AM. The total efficiency was 4.5%. ...

American Institute of Physics2009

Nucleation mechanism of gallium-assisted molecular beam epitaxy growth of gallium arsenide nanowires

Anna Fontcuberta i Morral, Carlo Colombo

Molecular beam epitaxy Ga-assisted synthesis of GaAs nanowires is demonstrated. The nucleation and growth are seen to be related to the presence of a SiO2 layer previously deposited on the GaAs wafer. The interaction of the reactive gallium with the SiO2 p ...

American Institute of Physics2008