Synthesis and luminescence enhancement of Eu{sup 3+}, Sm{sup 3+} co-doped Li{sub 1.11}Ta{sub 0.89}Ti{sub 0.11}O{sub 3} phosphor

Graphical abstract: Enhancement of red emission intensity and internal- and external-quantum efficiencies by co-doping of Eu{sup 3+} and Sm{sup 3+} ion in Li{sub 1.11}Ta{sub 0.89}Ti{sub 0.11}O{sub 3} phosphor. - Abstract: Phosphors based on the Li{sub 1+x}Ta{sub 1−x}Ti{sub x}O{sub 3} solid solutions (0.05 ≤ x ≤ 0.25) as host materials were investigated. The optimal composition of the host for red-light emitting phosphor was found to be Li{sub 1.11}Ta{sub 0.89}Ti{sub 0.11}O{sub 3} (x = 0.11) when activated with Eu{sup 3+}. In this work, in order to further enhance the emission intensity, a series of Eu{sup 3+}- and Sm{sup 3+}-doped Li{sub 1.11}Ta{sub 0.89}Ti{sub 0.11}O{sub 3} phosphors was synthesized by solid-state reaction. The phosphor doped with 2.5 wt% Eu{sub 2}O{sub 3} and 0.1 wt% Sm{sub 2}O{sub 3} showed the highly efficient red-light emission upon excitation at 399 nm, with the internal quantum efficiency being 98%. Its PL intensity was ca. 1.4 times higher than that of the 2.5 wt% Eu{sup 3+}-doped Li{sub 1.11}Ta{sub 0.89}Ti{sub 0.11}O{sub 3} phosphor, indicating that the small amount of Sm{sup 3+} acted as an effective sensitizer.