Produção Nacional
Revisado por pares
Understanding Persistent Luminescence: Rare-Earth- and Eu 2+ -doped Sr 2 MgSi 2 O 7
2014; De Gruyter; Volume: 69; Issue: 2 Linguagem: Inglês
10.5560/znb.2014-3322
ISSN1865-7117
AutoresMika Lastusaari, H. Jungner, Aleksei Kotlov, Taneli Laamanen, Lucas Carvalho Veloso Rodrigues, Hermi F. Brito, Jorma Hölsä,
Tópico(s)Solid-state spectroscopy and crystallography
ResumoSimilar to many other Eu 2+ ,RE 3+ -co-doped persistent luminescence materials, for Sr 2 MgSi 2 O 7 :Eu 2+ ,RE 3+ the initial intensity and duration of persistent luminescence was also found to depend critically on the rare-earth (RE) co-doping. An enhancement of 1 - 2 orders of magnitude in these properties could be obtained by Dy 3+ co-doping whereas total quenching of persistent luminescence resulted from the use of Sm 3+ and Yb 3+ . To solve this drastic disparity, the effects of the individual RE 3+ ions were studied with thermoluminescence (TL) spectroscopy to derive information about the formation of traps storing the excitation energy. The charge compensation defects were concluded to be the origin of the complex TL glow curve structure. The tuning of the band gap of the Sr 2 MgSi 2 O 7 host and especially the position of the bottom of the conduction band due to the Eu 2+ ,RE 3+ co-doping was measured with the synchrotron radiation vacuum UV (VUV) excitation spectra of the Eu2+ dopant. The model based on the evolution of the band gap energy with RE 3+ co-doping was found to explain the intensity and duration of the persistent luminescence.
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