title: Tailoring band gap and hardness by intercalation: an ab initio Study of I(8)@Si-46 and related doped clathrates.
abstract: We present an ab initio study of the structural and electronic properties of the recently synthesized I(8)@Si-46 clathrate which is shown to be a degenerate p-type doped system. The intercalation significantly opens the band gap to a 1.75 eV value within the density functional theory. We study further the intercalation by other neighboring elements. A quasiparticle study reveals that such systems can display a band gap in the "green-light" energy range. Finally, we show that the bulk modulus can be increased to values equivalent to the one of the diamond phase.
authors.affiliation: Département de Physique des Matériaux and CNRS, Université Claude Bernard-Lyon 1, Bâtiment 203, 43 Bd du 11, Novembre 1918, 69622 Villeurbanne Cédex, France.
authors.forename: D
authors.initials: D
authors.lastname: Connétable
authors.forename: V
authors.initials: V
authors.lastname: Timoshevskii
authors.forename: E
authors.initials: E
authors.lastname: Artacho
authors.forename: X
authors.initials: X
authors.lastname: Blase