Luminescence properties of a new green afterglow phosphor NaBaScSi2O7:Eu2+.

A novel green afterglow phosphor NaBaScSi2O7:Eu2+ was prepared by a solid state reaction under a reductive atmosphere. The NaBaScSi2O7:Eu2+ phosphor shows two emission bands centered at about 424 (weak) and 502 nm (strong) due to the substitution of Eu2+ in both Ba+ and Na2+ sites, and energy transfer from EuBa (424 nm) to EuNa (502 nm) was found. Both EuBa and EuNa contribute to the afterglow process while EuNa dominates. Na0.99BaScSi2O7:0.01Eu2+ exhibits green long lasting phosphorescence, whose duration is more than 1 h. The thermoluminescence properties of NaBaScSi2O7:Eu2+ and the relationship between thermoluminescence and thermal quenching properties were discussed in detail. This work provides a new and efficient candidate for long lasting phosphorescence materials. [ABSTRACT FROM AUTHOR]