Rare earth doped aluminates, such as SrAl2O4 :Eu2+, Dy3+ and CaAl2O4:Eu2+, Nd3+, are among the best known materials for persistent luminescence or afterglow emission . Numerous studies have been carried out on this strontium alumínate to find different elaboration ways and to elucidate its persistent luminescence mechanism (see for instance ). It recently appeared that its hexagonal phase polymorph, which is not stable at room temperature, could have promising properties. A recently efficient way to elaborate the hexagonal Sr1-x/2Al1-xSixO4:Eu2+,Dy3+ phases has been developed by glass crystallization. We report here the optical features of Eu2+, Dy3+ co-doped Sr1-x/2Al1-xSixO4 (0 ≤ x ≤ 0.6) powders elaborated by this method. The experimental results show that the photoluminescence as well as the afterglow emissions shift from green to white/blue range as x increases (see Fig. 1-left). This color change toward the white color is due to two effects: the blue shift of Eu2+ broad emission and the appearance of Dy3+ emission.
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