Luminescence characteristics and defect formation in silica glasses under H and He ion irradiation

Ion beam induced luminescence from silica glasses containing various OH concentrations was measured to examine the effects of OH and the energy deposition processes on the damage creation under irradiation by H and He ions in the energy range 0.2–3.0 MeV. The 2.7 eV luminescence center corresponding to the B2α oxygen deficiency centers was less effectively created in the high-OH silica, where the 1.9 eV luminescence originating from the non-bridging oxygen hole centers were prominent. Ion implantation and thermal release experiments showed that MeV ion induced defects trapped hydrogen along its trajectory as a form of Si–H. Annihilation of B2α centers can be promoted in high-OH silica, by trapping of hydrogen released by the ion induced dissociation of OH. The energy dependence of the initial growth rate of luminescence suggested that the relatively large electronic energy loss of He ions plays roles in excitation and/or production of oxygen vacancies.