Preparation and Characteristics of Eu and Dy Doped Sr4Al14O25 Phosphor
Sr4Al14O25:Eu2+, Dy3+ long persistent phosphors with different B, Eu and Dy contents were prepared by solid phase reaction at various temperatures in H2/N2=1/9 atmosphere. X- ray diffraction and scanning electron microscopy observations showed that, when the phosphor was doped with 40 at% B, single dense Sr4Al14O25 phase was formed but for the samples with less than 40 at% B, mixed phases containing SrAl12O19 and SrAl2O4 were observed while for higher B content (100 at%) SrAl2B2O7 phases appeared. The phosphor showed emission peak centered at 500 nm with blue green color. When 40 at% of H3BO3 was added and doped with 4 at% of Eu and 8 at% of Dy, it showed the maximum initial intensity of 3170 mcd.m-2 and the longest persistency which is greater than 20 h over value of 5 mcd.m-2.
Byungsei Jun, Hyungsun Kim, Chanwon Lee, Soo Wohn Lee
H. N. Luitel et al., "Preparation and Characteristics of Eu and Dy Doped Sr4Al14O25 Phosphor", Materials Science Forum, Vol. 569, pp. 249-252, 2008