Customizing dual-functional platforms for solid-state lighting and luminescence lifetime thermometry with high sensing sensitivity

By substituting Mn⁴⁺ for Te⁶⁺ in the [TeO₆] octahedron, Mn⁴⁺doped SrScLiTeO₆ (SSLT) phosphors exhibited a broad excitation band ranging from 200 to 600 nm. Emission spectra of the SSLT: Mn⁴⁺ phosphors were recorded under 355 nm excitation, centered at 695 nm on account of the ²E_g→⁴A_2g spin-forbidden transition. The optimum doping concentration was suggested to be 0.1 mol%, and the electric dipole-dipole was the basic interaction for the concentration quenching in this work. The chromaticity coordinates of the optimal 0.1 mol% sample were (0.725, 0.275) and it possessed a high color purity of 94.5%. Besides, the obtained sample exhibited beneficial thermal stability based on peak integral intensity, which is suitable to fabricate light-emitting diode devices for plant lighting (red light) and indoor illumination (white light). Eventually, the sensing sensitivity based on lifetime was also studied ranging from 23 to 498 K and the optimum relative sensing sensitivity (S_R) was 7.86% K⁻¹ at 473 K. Thus, Mn⁴⁺-doped SSLT: Mn⁴⁺ phosphors should be potentially used in solid-state lighting and wide-range optical thermometers.