Luminescent Properties of Praseodymium in
3+) with rich f energy levels can generate various visible emissions, but the luminescence of Pr 3+ in a Pr 4
matrix has not yet been studied. In this article, the phosphors of CaWO 3+‐doped Pr 4 were synthesized via a high temperature solid‐state reaction, and the photoluminescence
(PL) and afterglow properties of CaWO 3+ in the Pr 4 matrix were investigated. The phase identifications of the samples show that an impure monoclinic phase appears when the CaWO 3+
concentration is high. The results of PL exhibit the usual Pr 3+ characteristic emissions as well as an emission that is produced by the charge transfer from 5d of Pr 6+ to 2p
of W 2− under a shortwave ultraviolet excitation. An intermediate energy transfer occurs during the charge transfer which induces the afterglow. The quenching point of O 3+ in Pr 4
is 2 mol%, corresponding to the critical energy transfer distance of ~20 Å. The quenching mechanism in the CaWO 3+‐doped Pr 4 is the dipole‐dipole interaction.
The CaWO 2+ vacancies (V
Ca) are the defects that induce the traps and capture holes from Ca 2−. The thermal energy of holes liberation from V
O 2− results in the charge transfer accompanied by an energy transfer to O 3+, and consequently generates the afterglow. The experimental results also show that the afterglow characteristics
of Pr 3+ are prolonged by incorporating Pr 3+ in the Pr 4 matrix.
No Supplementary Data
No Article Media
Document Type: Research Article
Publication date: October 1, 2012