Persistent luminescence

Mechanism

The mechanism underlying this phenomenon is not fully understood.T. Aitasalo, P. Deren, J. Hölsä, H. Jungner, J.C. Krupa, M. Lastusaari, J. Legendziewicz, J. Niittykoski, and W. Strek. Persistent luminescence phenomena in materials doped with rare earth ions. J. Solid State Chem., 171 :114, 2003. It is neither fluorescence nor phosphorescence. In fluorescence, the lifetime of the excited state lasts a few nanoseconds. In phosphorescence, even if the emission lives several seconds, this is due to deexcitation between two electronic states of different spin multiplicity. Persistent luminescence involves energy traps (such as electron or hole traps) in a material, which are filled during the excitation. Afterward, the stored energy is gradually released to light emitter centers, usually by a fluorescence-like mechanism.

Examples of use

Persistent luminescence materials are mainly used in safety signs, watch dials, decorative objects, and toys. They have also been used as nanoprobes in small animal optical imaging.

References

References

1. [http://goldbook.iupac.org/F02453.html IUPAC Gold Book – fluorescence]
2. [http://goldbook.iupac.org/P04569.html IUPAC Gold Book – phosphorescence]
3. H.W. Leverenz. Luminescent solids (phosphors). ''Science'', 109 :183–189, '''1949'''.
4. (2019-01-01). "Persistent luminescence instead of phosphorescence: History, mechanism, and perspective". Journal of Luminescence.
5. Q. le Masne de Chermont, C. Chanéac, J. Seguin, F. Pellé, S. Maitrejean, J.P. Jolivet, D. Gourier, M. Bessodes and D. Scherman. Nanoprobes with near-infrared persistent luminescence for in vivo imaging. ''Proc. Natl Acad. Sci. USA'' 104 :9266–9271 '''2007'''.