Showing papers by "Ove Jepsen published in 1985"

Identification of chalcogen point-defect sites in silicon by total-energy calculations.

Abstract: Calculs autocoherents et sans parametres de la structure electronique et de l'energie electronique totale. Etude des deux sites de defaut possible de symetrie tetraedrique. Discussion des energies totales calculees en termes d'energies de reaction et de dissolution. La position de defaut stable identifiee est substitutionnelle

Metallization of CsI under pressure: Theoretical results

Abstract: We report results of self-consistent, relativistic linear-muffin-tin-orbital calculations of the band structure of CsI under compression in the observed crystal structures. We show that the relativistic effects as well as the effects of the high-pressure structural phase transition---which have so far not been theoretically examined---reduce the metallization pressure significantly. We find that metallization occurs by the closure of the direct band gap at the \ensuremath{\Gamma} point. As the crystal is compressed the band gap closes faster in the tetragonal and orthorhombic phases than in the simple-cubic phase. Our calculated metallization volume, ${V}_{M}$/${V}_{0}$=0.50, is in good agreement with recent experimental estimates.

Identifiaction of chalcogen defects in silicon

Abstract: We show how self-consistent total-energy calculations can be used to identify the position of defects in semiconductors. Despite intensive experimental research on S, Se and Te point defects in Si, it has remained unclear whether these impurities occupy substitutional or Td-interstitial sites. Our Green-function total-energy calculations show that the substitutional site is favored by several eV and therefore the stable defect position is identified as substitutional. We further consider the formation energies of distant defect pairs consisting of a substitutional chalcogen and a Si self-interstitial and we study the reaction where the two constituents change places.