Fluorescence and phosphorescence properties of new long-lasting phosphor Ba4(Si3O8)2:Eu2+, Dy3+.

A novel long-lasting phosphorescence (LLP) material Ba4(Si3O8)2:Eu2+, Dy3+ with high chemical stability was achieved successfully. Two emission centers (Eu (I) and Eu (II)) were found in Ba4(Si3O8)2 due to the substitution of Eu2+ in different Ba2+ sites. Both 
Eu (I) and Eu (II) had contribution to the afterglow process, however, the decay rate of Eu (I) was higher than that of Eu (II). Ba3.982(Si3O8)2: 0.008Eu2+, 0.01Dy3+ exhibited a long-lasting phosphorescence whose duration was more than 24 h. Through the analysis of the thermoluminescence (TL) curves, we found that Eu2+ single doped Ba4(Si3O8)2 has a possibility to be a kind of storage phosphor. This work provides a new and efficient candidate for LLP and storage materials.