Publications de Fabien Devynck

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

Alfredo Pasquarello, Fabien Devynck, Peter Broqvist, Audrius Alkauskas

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

Defect levels of carbon-related defects at the SiC/SiO2 interface from hybrid functionals

Alfredo Pasquarello, Fabien Devynck, Peter Broqvist, Audrius Alkauskas

We investigate carbon single-atom and pair defects at the SiC/SiO2 interface as candidate defects for the density of defect states in the SiC band gap. In order to accurately describe the electronic defect levels with respect to the SiC band edges, we use ...

2011

Energy levels of candidate defects at interfaces SiC/SiO2 interfaces

Alfredo Pasquarello, Fabien Devynck, Peter Broqvist, Audrius Alkauskas

We determine energy levels of candidate defects for the high defect density observed just below the SiC conduction band at SiC/SiO 2 interfaces. We address C interstitials and H bridge defects which both show defect levels in the upper part of the SiC band ...

2010

First-principles study of defects at the SiC/SiO2 interface through hybrid functionals

Fabien Devynck

The requirements of present high-performance power electronic systems are exceeding the power density, efficiency, and reliability of silicon-based devices. Silicon carbide (SiC) is a candidate of choice for high-temperature, high-speed, high-frequency, an ...

EPFL2008

Band offsets at semiconductor-oxide interfaces from hybrid density-functional calculations

Alfredo Pasquarello, Fabien Devynck, Peter Broqvist, Audrius Alkauskas

Band offsets at semiconductor-oxide interfaces are determined through a scheme based on hybrid density functionals, which incorporate a fraction alpha of Hartree-Fock exchange. For each bulk component, the fraction alpha is tuned to reproduce the experimen ...

2008

Band gap opening at the 6H-SiC(0001) surface passivated by an epitaxial silicon oxynitride layer: A first-principles investigation

Alfredo Pasquarello, Fabien Devynck

Using hybrid density functionals, we investigate the origin of the large band gap experimentally observed at the 6H-SiC(0001) surface when passivated by an epitaxial silicon oxynitride layer. In order to distinguish the effects resulting from the interfaci ...

2008

Electronic properties of an epitaxial silicon oxynitride layer on a 6H-SiC(0001) surface: A first-principles investigation

Alfredo Pasquarello, Zeljko Sljivancanin, Fabien Devynck

Using a density functional scheme, the authors investigate the electronic properties of an epitaxial silicon oxynitride layer on a 6H-SiC(0001) surface, as recently realized experimentally. Simulated scanning-tunneling-microscopy images of filled and empty ...

AIP American Institute of Physics2007

Atomistic model of the 4H(0001)SiC-SiO2 interface: structural and electronic properties

Alfredo Pasquarello, Feliciano Giustino, Fabien Devynck

Through the sequential use of classical molecular dynamics and first-principles relaxation methods, we generate an abrupt model interface for the 4H(0001)SiC-SiO2 interface showing regular structural parameters without any coordination defect. The valence ...

2007

Semiconductor defects at the 4H-SiC(0001)/SiO2 interface

Alfredo Pasquarello, Fabien Devynck

We study several semiconductor defects at the 4H-SiC(0 0 0 1)/SiO2 interface within a spin-polarized generalized-gradient density-functional approach for identifying candidate defects responsible for the high density of interface defects measured in the up ...

2007

Structural and electronic properties of an abrupt 4H-SiC(0001)/SiO2 interface model: Classical molecular dynamics simulations and density functional calculations

Alfredo Pasquarello, Fabien Devynck, Peter Broqvist

Using a density functional approach, we study structural and electronic properties of the 4H(0001)-SiC/SiO2 interface. Through the sequential use of classical and ab initio simulation methods, we generate an abrupt model structure which describes the trans ...

2007

Abrupt model interface for the 4H(1000)SiC-SiO2 interface

Alfredo Pasquarello, Fabien Devynck

Through the sequential use of classical molecular dynamics and first-principles relaxation methods, we generate an abrupt model interface for the 4H(0001)SiC-SiO2 interface showing regular structural parameters without any coordination defect. The bond den ...

2005