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Your search keyword '"Devynck, Fabien"' showing total 3 results
Start Over Author "Devynck, Fabien" Topic band gap
3 results on '"Devynck, Fabien"'

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

Author

Devynck, Fabien and Pasquarello, Alfredo

Subjects
*BIOLOGICAL interfaces, *SURFACE chemistry, *SILICON nitride, *NITRIDES
Abstract

Abstract: 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 interfacial nitrogen layer and from the thinness of the epitaxial oxide layer, we use various models of the 6H–SiC(0001)/SiO2 interface and perform a comparative study through the evolutions of their planar-averaged local density of states across the interface. Our study attributes the large band gap opening to a combined effect. The presence of the nitrogen layer causes the band gap to open already in the last planes of the substrate. The thinness of the epitaxial layer contributes to a further increase of the band gap in the close vicinity of the outer surface and its effect is enhanced by the presence of the nitrogen layer. [Copyright &y& Elsevier]

Published
2008
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2. Energy levels of candidate defects at SiC/SiO2 interfaces.

Author

Devynck, Fabien, Alkauskas, Audrius, Broqvist, Peter, and Pasquarello, Alfredo

Subjects
*ENERGY levels (Quantum mechanics), *ELECTRIC conductivity, *FREE electron theory of metals, *QUANTUM theory, *THERMODYNAMICS
Abstract

We determine energy levels of candidate defects for the high defect density observed just below the SiC conduction band at SiC/SiO2 interfaces. We address C interstitials and H bridge defects which both show defect levels in the upper part of the SiC band gap. However, these defects also give rise to defect levels in the lower part of the band gap, unlike the experimental defect density which lacks this correlation. [ABSTRACT FROM AUTHOR]

Published
2010
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3. Atomistic model of the 4H(0001)SiC-SiO2 interface: structural and electronic properties.

Author

Devynck, Fabien, Giustino, Feliciano, and Pasquarello, Alfredo

Subjects
*MOLECULAR dynamics, *RELAXATION (Nuclear physics), *CONDUCTION bands, *ELECTRIC conductivity, *INTERFACES (Physical sciences)
Abstract

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 and conduction band offsets are calculated and found to be in fair agreement with the experimental values. Si-2p core-level shifts are calculated for this model interface and compared with available experimental data. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2007
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