Vacuum-ultraviolet absorption of interstitial O2 and H2O molecules in SiO2 glass

Vacuum-ultraviolet (VUV) absorption of O2 and H2O molecules incorporated in interstitial voids in SiO2 glass by thermal annealings was examined. Interactions of the interstitial molecules with the surrounding SiO2 glass network lead to a redshift of the VUV absorption band of interstitial O2, while a blueshift of that of interstitial H2O, both accompanied by an increase in the intensity of the absorption bands. The Coulomb repulsion, London dispersion, and hydrogen bonding are the main interactions responsible for the modification of the VUV absorption bands.