Synthesis and luminescence enhancement of Eu3+, Sm3+ co-doped Li1.11Ta0.89Ti0.11O3 phosphor

Phosphors based on the Li1+xTa1−xTixO3 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 Li1.11Ta0.89Ti0.11O3 (x = 0.11) when activated with Eu3+. In this work, in order to further enhance the emission intensity, a series of Eu3+- and Sm3+-doped Li1.11Ta0.89Ti0.11O3 phosphors was synthesized by solid-state reaction. The phosphor doped with 2.5 wt% Eu2O3 and 0.1 wt% Sm2O3 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% Eu3+-doped Li1.11Ta0.89Ti0.11O3 phosphor, indicating that the small amount of Sm3+ acted as an effective sensitizer.