First-principle study of the structural, electronic and optical properties of defected amorphous silica

摘要: Abstract The oxygen-excess structures include oxygen dangling bond, peroxy linkage (POL), radical (POR) and interstitial molecule or ozone defects, while the oxygen-deficient neutral vacancy, E′ center double-bond. For both undefected various defected structures, electronic optical properties are calculated by plane-wave pseudo potential density functional theory. lead to remarkable increases in of states (DOS) at top valence band near bottom conduction band. change distribution defect levels there appear new between All defects increase static dielectric constants enhancing absorption low energy range. Absorption peaks can be observed below 2 eV for NBOHC structures. Though loss is generated lower region, strength stronger than During calculation bond neutralized hydrogen atoms. This work may give insights into laser induced damage towards vitreous silica.