Vacuum ultra-violet absorption cross-sections of hydrogenated and deuterated silanol groups (SiOX, with X = H or D) as well as interstitial water molecules (X2O) in amorphous SiO2 (a-SiO2) were determined between photon energies of 7 and 8.2eV. The absorption bands for the deuterated species were blue-shifted, compared to those for the hydrogenated ones, by 0.1 to 0.2eV as a result of a decrease in the zero-point energy associated with the OX groups. The vacuum ultra-violet absorption of interstitial X2O below 8eV was blue-shifted with respect to that of X2O trapped in rare-gas solids, due to the contribution of H bonding, and was 1 to 2 orders of magnitude stronger than that of SiOX groups.

Vacuum-Ultraviolet Absorption of Hydrogenated and Deuterated Silanol Groups and Interstitial Water Molecules in Amorphous SiO2. K.Kajihara, M.Hirano, L.Skuja, H.Hosono: Physical Review B, 2005, 72[21], 214112 (4pp