Preparation and luminescence properties of yellow long-lasting phosphor Ca2ZnSi2O7:Eu2+, Dy3+

Long-lasting phosphors Ca2ZnSi2O7:Eu2+, Dy3+ are prepared by solid-state reaction method assisted with different fluxes. Broadband emission, peaked at 580 nm and originating from 4f to 5d transition of Eu2+, is observed. The emission intensities of the phosphors can be enhanced by 4.84 and 7.73 times with the introduction of H3BO3 and CaF2, respectively. Moreover, their afterglow times are also respectively prolonged to 11 h and 12 h. The yellow afterglow can be excited by both ultraviolet and visible light, thus permitting its application in both room and outdoor environment. In terms of the crystal structure and trap feature of the phosphors added with different fluxes, the mechanism for the improved luminescence and afterglow properties is discussed.