Influence of the 4f5d-1S0 energy gap on the decay times of Pr3+-doped fluoride scintillating glasses

Abstract

A comparative analysis of praseodymium (Pr3+)-doped fluoride glasses, APLF [20Al(PO3)3–80LiF–PrF3], BCAYF (19BaF2–33.25CaF2–42.75AlF3–5YF3–PrF3), and BCAPLF (19BaF2–33.25CaF2–42.75AlF3–15P2O5–20LiF–PrF3), reveals the effect of the host matrix on the optical properties, particularly the luminescence behavior of Pr3+ ions. X-ray absorption near edge structure (XANES) spectroscopy verifies the presence of Pr ions in the glasses with a +3 oxidation state. Absorption spectra results suggest that the lowest energy level of the Pr3+ 4f5d configuration is influenced by the oxide/fluoride ratio of the glasses. As both interconfigurational 4f5d and intraconfigurational 4f2 transitions are observed, the energy gap between the lowest level of the 4f5d configuration and the overlapping 1S0 level of the 4f2 configuration is found to influence the predominance of UV emissions from the 4f5d and 1S0 levels as well as their decay times. Consequently, a larger 4f5d-1S0 energy gap of ∼5000 cm−1 leads to a more intense UV emission from the 4f5d level with a faster decay time. These results underscore the significance of minimizing the energy of the 4f5d level and increasing the gap between 4f5d-1S0 levels to be able to obtain fast UV emissions from Pr3+-doped fluoride glasses.

Keywords

• Glass
• Scintillator
• Praseodymium
• Decay time
• Fluoride