Persistent luminescence mechanisms: human imagination at work

Extending the afterglow in CaAl_2O_4:Eu,Nd persistent phosphors by electron beam annealing

“…These materials find applications in emergency signage, toys, catalysis and medical imaging [1][2][3][4]. After the discovery of SrAl 2 O 4 :Eu,Dy as efficient green persistent phosphor [5], the research has mainly focused on rare-earth doped phosphors [6,7]. Most often, Eu 2+ is introduced as the recombination center, while the afterglow is extended by addition of other trivalent rare earth ions.…”

Focus issue introduction: persistent phosphors

“…Reference [1] is an overview paper that includes relevant details on the history of persistent luminescence and takes a somewhat different view than the recent review paper on Eu 2+ -doped phosphors by Van den Eeckhout et al [3]. The authors make the statement that using imagination for finding persistent luminescence models is fine as long as the models are subsequently thoroughly investigated from both a chemistry and a physics point of view.…”

“…One of the first written accounts of its observation in the western world dates back to the beginning of the 17th century when the so-called Bologna stone was described [1]. This material, probably BaS containing some natural impurities such as copper, was synthesized accidently in an effort to make gold out of barium sulfate.…”

“…Many different names are given to the process [1] such as "long-lasting," "persistent," "afterglow," "phosphorescence," "LLP" (long-lasting phosphorescence), and any combinations thereof. A poll on specific aspects of persistent phosphors was conducted during the workshop, and it included the choice of a suitable and preferably unique name for the phenomenon.…”

Afterglow and thermoluminescence of ZrO2 nanopowders

“…for glow-in-the-dark displays and signs [1]. Moreover, biologically inert nanoparticles with persistent afterglow are useful as autonomously emitting bio-labels for in-vivo medical research [2].…”