Luminescence of Pr3+-Activated fluorides
1974; Elsevier BV; Volume: 9; Issue: 4 Linguagem: Inglês
10.1016/0022-2313(74)90041-6
ISSN1872-7883
AutoresJ.L. Sommerdijk, A. Bril, Andreas Jäger,
Tópico(s)Inorganic Fluorides and Related Compounds
ResumoThe strong dependence of the emission spectrum of YF3:Pr3+ on excitation source (228.8 nm, 213.9 nm or cathode rays) is ascribed to two different types of Pr3+ sites: one with a relatively strong crystal field and the other with a relatively weak crystal field. The presence of the latter is connected with the conversion of one short-wave UV (≲ 215 nm) photon into two visible photons. Two-photon luminescence of Pr3+ was also found for α-NaYF4 and LaF3, but not for CaF2 and BaF2 due to the too strong crystal field in these lattices. The occurrence of two-photon Pr3+ luminescence is compared with the intensity of the IR-excited green emission of the corresponding Yb3+, Er3+-activated lattices. The intensity of the Pr3+ luminescence at shortwave UV excitation (213.9 nm) is rather weak. Luminescence of reasonable efficiency is, however, observed on excitation with cathode rays.
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