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O: Fachverband Oberflächenphysik
O 60: Poster Session IV (Solid/liquid interfaces; Semiconductors; Oxides and insulators; Graphene; Plasmonics and nanooptics; Electronic Structure; Surface chemical reactions; Heterogeneous catalysis)
O 60.96: Poster
Mittwoch, 16. März 2011, 17:30–21:00, P4
Defects in amorphous silica : from density functional to many-body perturbation theory — •David Waroquiers1,2, Matteo Giantomassi1,2, Martin Stankovski1,2, Gian-Marco Rignanese1,2, and Xavier Gonze1,2 — 1Université Catholique de Louvain IMCN-NAPS, Louvain-la-Neuve, Belgique — 2European Theoretical Spectroscopy Facility (ETSF)
Amorphous silica is of particular technology interest for its electronic and optical properties. It is commonly used in a lot of devices such as optical fibers, lenses, filters, gate dielectrics in MOS transistors, … In the present work, we investigate the effect of hydrogen on the properties of amorphous silica.
Accurate electronic structure is obtained using many-body perturbation theories such as GW approximation. Till recently, this method could only be applied to small systems because of its large computational cost. New theoretical and algorithmic developments in the version 6 of ABINIT [1] (extrapolar method, band parallelism and projector-augmented wave formalism) now enable us to perform GW calculations in large supercells with a reasonable cost in CPU time.
We report results obtained for several hydrogen-containing silica cells of 72 atoms. The electronic structure has been computed using many-body perturbation theory in its GW approximation. Formation energies are calculated at the DFT and GW level [2]. Some preliminary results on the optical properties are also presented.
[1] X. Gonze et al., Comput. Phys. Comm. 180, 2582 (2009).
[2] P. Rinke et al., Phys. Rev. Lett. 102, 026402 (2009).