Photoluminescence and afterglow behavior of Ce(3+) activated Li(2)Sr(0.9)Mg(0.1)SiO(4) phosphor

A blue emitting phosphor Li(2)Sr(0.9)Mg(0.1)SiO(4):Ce(3+), with long persistence, was synthesized via a high-temperature solid phase method. According to the X-ray diffraction analysis result, the introduction of Mg(2+) and Ce(3+) ions has no influence on the structure of the host material. Typical 5d-(2)F(5/2) and 5d-(2)F(7/2) transitions of Ce(3+) ions were detected by PL spectra, which corresponded to the CIE chromaticity coordinates of x = 0.1584, y = 0.0338. An optimal doping concentration of Ce(3+) was determined as of 0.4 at%. Furthermore, the Li(2)Sr(0.9)Mg(0.1)SiO(4):Ce(3+) phosphor showed a typical triple-exponential afterglow behavior when the UV source was switched off. The highest lifetime of the electrons within the material reached a value of 73.9 s. Thermal stimulated luminescence study indicated that the afterglow of Li(2)Sr(0.9)Mg(0.1)SiO(4):Ce(3+) was due to the recombination of the electrons with holes released from the traps generated by the doping of Ce(3+) ions in the Li(2)Sr(0.9)Mg(0.1)SiO(4) host. The afterglow mechanism of Li(2)Sr(0.9)Mg(0.1)SiO(4):Ce(3+) is illustrated and discussed in detail on the basis of the experimental results.