Concept

Atome interstitiel

Publications associées (151)

Electronic structure of Zn, Cu and Ni impurities in germanium

We present a density functional modelling study of Zn, Cu and Ni impurities in hydrogen-terminated germanium clusters. Their electronic structure is investigated in detail, especially their Jahn-Teller instabilities and electrical levels. Interstitial and ...

2011

Band offsets at Ge/GeO2 interfaces: Effect of different interfacial bonding patterns

Alfredo Pasquarello, Peter Broqvist, Jan Felix Binder

Using hybrid density functional calculations, we investigate possible origins for the large variation of band offsets measured at Ge/GeO2 interfaces. We consider atomistic model interfaces with both amorphous and crystalline oxides, in which the bond densi ...

Elsevier2011

High-quality 1.3 lm-wavelength GaInAsN/GaAs quantum wells grown by metalorganic vapor phase epitaxy on vicinal substrates

Elyahou Kapon, Alok Rudra, Benjamin Dwir, Romain Carron, Pascal Gallo

We investigated the composition and optical properties of GaInAsN/GaAs single quantum wells (QWs) grown on vicinal-(001) GaAs substrates using metallorganic vapor phase epitaxy with modulated nitrogen-precursor flux. A significant enhancement in N incorpor ...

American Institute of Physics2011

Interfacial sliding in carbon nanotube/diamond matrix composites

William Curtin, Fabio Pavia

Carbon matrix carbon nanotube (CNT) composites have a broad range of applications because of the exceptional mechanical properties of both matrix and fibers. Since interfacial sliding plays a key role in determining the strength and toughness of ceramic co ...

2011

Helium-vacancy cluster in a single bcc iron crystal lattice

Helena Van Swygenhoven

The properties of the cluster HenV, an iron vacancy with an increasing number of He atoms, is studied with molecular statics and molecular dynamics simulations. A study of the binding energy of the self-interstitial atom (SIA) and the He, shows that from n ...

2011

Charge transition levels of carbon-, oxygen-, and hydrogen-related defects at the SiC/SiO2 interface through hybrid functionals

Alfredo Pasquarello, Peter Broqvist, Audrius Alkauskas, Fabien Devynck

We calculate charge transition levels of various defects at the SiC/SiO2 interface within a scheme based on hybrid density functionals, which accurately reproduce the involved band gaps and band offsets. The defect levels are first evaluated in bulk models ...

2011

Molecular Dynamics Simulations of Helium Atoms Clustering in bcc Iron

Ning Gao

Helium atoms are known to have a significant impact on materials used in fission and fusion reactors. In particular, the presence of helium atoms can change the mechanical properties and degrade the lifetime of reactors. In order to develop the helium-resi ...

EPFL2011

Defect levels through hybrid density functionals: Insights and applications

Alfredo Pasquarello, Peter Broqvist, Audrius Alkauskas

Hybrid density functional calculations applied to defect charge transition levels are explored in the attempt to overcome the band-gap problem of semilocal density functionals. Charge transition levels of a large set of point defects calculated with semilo ...

2011

Defects in a-GaN grown on r-sapphire by hydride vapor phase epitaxy

Nicolas Grandjean, Pierre Stadelmann, Denis Martin, Tiankai Zhu

Non-polar a-GaN films grown on r-sapphire by hydride vapor phase epitaxy (HVPE) are studied using transmission electron microscopy (TEM). Despite the small lattice mismatch in a-GaN ([1 0 (1) over bar 0] similar to 1.1% and [0 00 1] similar to 16%), high d ...

2011

Influence of oxygen content on structure and properties of multi-element AlCrSiON oxynitride thin films

Alireza Karimi

Multi-element oxynitrides of type Al-Cr-Si-O-N were prepared using r.f. magnetron sputtering from Al80Cr2.5Si17.5 (at.%) target composition and O-2/(O-2+N-2) gas flow ratio between 0 and 100%. Two series of samples varying from pure nitrides to pure oxides ...

2010

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