Achieving High Luminescence Thermal Stability in Sm3+-Doped Sc(NbO4)x(TaO4)1–x Orange-Reddish Phosphors by Cosubstitution Component Regulation

Sc(NbO4)x(TaO4)1–x is composed of ScNbO4 and ScTaO4 matrices, containing [NbO4]3– and [TaO4]3– self-activating luminescent groups, and is a series of potential high-performance luminescent matrixes. In this work, trivalent samarium (Sm3+)-doped Sc(NbO4)x(TaO4)1–x (SNTO) phosphors have been synthesized through a traditional solid-state reaction method. The quenching concentration of Sm3+ in the SNTO matrix was 2 atom %, and the quenching mechanism was analyzed. Especially, the effects of [NbO4]3–/[TaO4]3– component ratios on luminescent properties and thermal stability were studied. The temperature-dependent fluorescence spectra and decay curves of Sm:SNTO phosphors, spanning from 300 to 510 K, have unveiled their luminescent thermal stability. The activation energy Ea representing luminescent thermal stability was found to be sensitive to the [NbO4]3–/[TaO4]3– component ratios, and the maximum Ea value was 0.272 eV. The findings suggest that the luminescent thermal stability of Sm3+-doped Sc(NbO4)x(TaO4)1–x orange-reddish phosphors can be regulated by the host component. Thus, this study can provide a reference for achieving high luminescent thermal stability phosphors through cosubstitution component regulation.