Luminescence properties of a new Mn2+-activated red long-afterglow phosphor

A new phosphor, CaZnGe2O6:Mn2+, which emits red long-lasting phosphorescence centered at 648 nm upon UV light excitation, is prepared by the conventional high-temperature solid-state method and its luminescent properties are systematically investigated in this paper. XRD, photoluminescence, thermoluminescence spectra and afterglow decay curve are used to characterize the synthesized phosphor. This phosphor is well crystallized by calcination at 1150 degrees C for 3 h and possesses excellent performance. The color coordinate values of this phosphor are x = 0.64, y = 0.26 under 250 nm UV light excitation. Under 250-nm UV light irradiation, this phosphor shows obvious long-lasting phosphorescence that can be seen with the naked eye in the dark clearly after the irradiation source has been removed for more than 3 h. The possible mechanism of this red-light-emitting long-afterglow phosphor is also investigated based on the experiment results. (c) 2008 Elsevier Ltd. All rights reserved.