Preparation of Eu2+ and Dy3+ co-activated CaAl2Si2O8-based phosphor and its optical properties

Eu 2+ and Dy 3+ co-activated CaAl 2 Si 2 O 8 -based long afterglow phosphor was firstly synthesized by solid state reaction. The phosphor emits a visible blue light under UV excitation and the blue afterglow lasts about 1 h in the dark. The phase-forming process of the phosphor was studied by means of differential thermal analysis (DTA) and X-ray diffraction (XRD) methods. The phosphor forms the final anorthite single-phase at about 1200 °C. The fluorescence spectra show that the excitation and emission spectra are both broadband and the emission peak is at 440 nm ascribed to the typical 4f 7 →4f 6 5d transition of Eu 2+ . The decay curves of afterglow indicate that the phosphor has a long afterglow feature and Dy 3+ ions play an important role in prolonging the afterglow.