Photoluminescence properties and the self-reduction process of CaAl2Si2O8:Eu phosphor

CaAl2Si2O8:Eu anorthite phosphor was synthesized by the traditional solid state reaction. In the air-sintered phosphor, the Eu ions were partial self-reduced to Eu2+, which contributed to the observation of the blue (Eu2+) and the red (Eu3+) emission in CaAl2Si2O8:Eu phosphor. To further investigate the photoluminescence properties and the self-reduction mechanism of CaAl2Si2O8:Eu phosphor, the adjustment of the valence state of Eu ions by controllable approaches was studied. In addition, CaAl2Si2O8:Eu phosphor shows a tunable emission from reddish to bluish region under ultraviolet excitation, which implies that it could be applied as potential phosphor for near ultraviolet light emitting diode.

Graphical abstractEu ions were partially self-reduced to Eu2+ in the CaAl2Si2O8:Eu phosphor, which contributed to the observation of the blue (Eu2+) and the red (Eu3+) emission. By controlling the relative photoluminescence intensity of Eu2+/Eu3+, the CaAl2Si2O8:Eu phosphor exhibits a tunable color from the reddish to the bluish region under ultraviolet excitation.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The Eu ions in the CaAl2Si2O8 host were partial self-reduced to be Eu2+. ► The self-reduction mechanism of CaAl2Si2O8:Eu phosphor was investigated in detail. ► A tunable emission from reddish to bluish region was observed in CaAl2Si2O8:Eu.