6533b838fe1ef96bd12a3ca0

RESEARCH PRODUCT

Diffusion and reactions of interstitial oxygen species in amorphous SiO2: A review

Hayato KamiokaYukihiro MorimotoMotoko UramotoMasahiro HiranoKoichi KajiharaKoichi KajiharaLinards SkujaLinards SkujaTaisuke MiuraAkira AibaHideo Hosono

subject

ChemistryRadicalPhotodissociationDangling bondOxygen transportchemistry.chemical_elementCondensed Matter PhysicsPhotochemistryOxygenChemical reactionElectronic Optical and Magnetic MaterialsMaterials ChemistryCeramics and CompositesFrenkel defectMolecule

description

This article briefly summarizes the diffusion and reactions of interstitial oxygen species in amorphous SiO 2 (a-SiO 2 ). The most common form of interstitial oxygen species is oxygen molecule (O 2 ), which is sensitively detectable via its characteristic infrared photoluminescence (PL) at 1272 nm. The PL observation of interstitial 0 2 provides key data to verify various processes related to interstitial oxygen species: the dominant role of interstitial O 2 in long-range oxygen transport in a-SiO 2 ; formation of the Frenkel defect pair (Si-Si bond and interstitial oxygen atom, 0°) by dense electronic excitation; efficient photolysis of interstitial O 2 into O° with F 2 laser light (λ= 157 nm, hv = 7.9 eV); and creation of interstitial ozone molecule via reaction of interstitial O 2 with photogenerated O°. The efficient formation of interstitial 0° by F 2 laser photolysis makes it possible to investigate the mobility, optical absorption, and chemical reactions of interstitial O°. The observed properties of O° are consistent with the model that O° takes the configuration of Si-O-O-Si bond. Interstitial O 2 and O° react with dangling bonds, oxygen vacancies, and chloride groups in a-SiO 2 . Reactions of interstitial Ο 2 and O° with mobile interstitial hydrogen species produce interstitial water molecules and hydroperoxy radicals. Interstitial hydroxyl radicals are formed by F 2 laser photolysis of interstitial water molecules.

https://doi.org/10.1016/j.jnoncrysol.2007.07.038