Synthesis and photoluminescence properties of SrGdLiTeO₆:Sm³⁺ as near UV excited phosphors

A series of double-perovskite SrGd1-xLiTeO6:xSm(3+) phosphors were made using the solid-state reaction approach, and the effects of various Sm3+ doping concentrations on the luminescence characteristics were investigated. In the range from 350 to 500 nm, several absorption bands of Sm3+ ions can be seen in the diffuse reflectance spectrum of SrGd0.97LiTeO6:0.03Sm(3+). Under 406 nm excitation, the photoluminescent spectra show it has efficient orange-red emission, owing to the transitions of (4)G(5/2) to H-6(5/2), (4)G(5/2) to H-6(7/2), (4)G(5/2) to H-6(9/2) and (4)G(5/2) to H-6(11/2), respectively. The synthesized phosphors have relatively thermal stability properties, with the temperature goes up to 425 K, the luminescence intensity remains at 85% of its original value. These results demonstrate the SrGd1-xLiTeO6:xSm(3+) phosphors are expected to be used as near UV excited phosphors.