Persistent luminescence excitation spectroscopy of BaAl2O4:Eu2+,Dy3+



: Malkamäki Marja, Bos Adrie J.J., Dorenbos Pieter, Lastusaari Mika, Rodrigues Lucas C.V., Swart Hendrik C., Hölsä Jorma

Publisher: ELSEVIER

: 2020

: Physica B: Condensed Matter

: PHYSICA B-CONDENSED MATTER

: PHYSICA B

: ARTN 411947

: 593

: 6

: 0921-4526

: 1873-2135

DOI: https://doi.org/10.1016/j.physb.2019.411947

: https://research.utu.fi/converis/portal/detail/Publication/50320047


BaAl2O4:Eu2+,Dy3+ is related, both by structure and luminescence, to one of the best persistent luminescent phosphors, SrAl2O4:Eu2+,Dy3+. At room temperature (RT), the green persistent emission of BaAl2O4:Eu2+,Dy3+ remains visible for hours after ceasing irradiation. Similar to SrAl2O4, BaAl2O4 with hexagonal P6(3) structure, has two M2+ sites, but, limited optical activity from the 2nd site is observed in the emission of BaAl2O4:Eu2+,Dy3+-even at 77 K. Using combined approach of photoluminescence, thermoluminescence (TL), and persistent (excitation) luminescence measurements, the origin and properties of persistent luminescence of BaAl2O4:Eu2+, Dy3+ were studied in detail. Ultraviolet (UV) excited and persistent emission are identical and no contribution from the Eu2+ in the high-symmetry Ba site was observed. TL excitation spectra clarified the unstructured conventional excitation spectrum; now it is evident that defects or the Dy3+ co-dopant do not contribute to persistent luminescence via direct energy absorption. Mechanisms for persistent luminescence should thus be revised.

Last updated on 2024-26-11 at 23:41