A NOVEL GREEN LONG-LASTING PHOSPHOR Ca2ZnSi2O7:Eu2+

A new green emitting long-lasting phosphor Ca 2 ZnSi 2 O 7 :Eu 2+ has been synthesized through the high temperature solid-state method. The excitation spectrum of [Formula: see text] shows a broadband attributed to 8 S 7/2 –4f 6 5d 1 transition of Eu 2+ ions. Both of the fluorescence and phosphorescence spectra showed a broadband centered at 528 nm, corresponding the only one Ca 2+ site in Ca 2 ZnSi 2 O 7 . The relationship of emission wavelength and Eu–O distance is investigated. Its afterglow can be seen with the naked eye in the dark clearly for 2 h after removal of the excitation source. Oxygen vacancy [Formula: see text] and zinc vacancy [Formula: see text], two different kinds of traps are proposed and their contrary influence on afterglow is discussed.