Scintillation efficiency of binary Li2O-2SiO2 glass doped with Ce3+ and Tb3+ ions

Highlights: • The photo-luminescence and scintillation properties of binary Li₂O-2SiO₂ glasses doped with Ce³⁺and Tb³⁺ were investigated. • Li₂O-2SiO₂ glasses doped with Tb³⁺ showed scintillation light yield up to 31000 ph/MeV. • A shift of radioluminescence to photo-luminescence band in glasses doped with Ce³⁺ ions was explained. Photo- and radioluminescent properties of lithium silicate glasses doped with Ce³⁺and Tb³⁺ions were evaluated. Glasses doped with Ce³⁺ ions exhibit a shift of radioluminescence to photo-luminescence band. This effect was explained by a distribution of the crystal field strength in the activator sites, what results in the competition between different types of Ce³⁺ ions in absorbing excitation energy from the matrix and limits a light yield of the Ce³⁺ doped glass. We also investigated the possibility to use Tb³⁺ ion instead of Ce³⁺ as an alternative activator for a glass doping. Spin-orbit interaction plays a major role in the formation of electronic terms in Tb³⁺, where as an effect of the crystal field is small enough to form a distribution of emitting centers. Tb³⁺-doped samples demonstrate light yields up to 31000 ph/MeV with the concentration quenching starting at the levels of 10 at %. We also studied the effect of luminescence sensitization of Tb³⁺ ions by Ce³⁺ in the glasses co-doped with Ce³⁺ and Tb³⁺.