Fig. 1. PXRD patterns of the SLT:0.2Eu³⁺ phosphors and SLT host, in the range of (a) 10–80 deg and (b) 30–31 deg.

Fig. 2. (a) PLE and PL spectra of the SLT:0.2Eu³⁺ phosphors. (b) PL spectra of the SLT:xEu³⁺ (x = 0.1, 0.15, 0.2, 0.25, and 0.3) phosphors. (c) The line chart for PL integrated intensity and Eu³⁺ doping concentration. (d) Decay curves for SLT:xEu³⁺ phosphors.

Fig. 3. (a) PL spectra of the as-prepared SLT:0.2Eu³⁺ phosphors and commercial Y₂O₂S:Eu³⁺ red phosphors. (b) Schematic illustration of Eu³⁺ ions energy level in SLT:Eu³⁺ phosphors. (c) The asymmetry ratio as a function of Eu³⁺ doping concentration in SLT:Eu³⁺ phosphors upon 394 nm excitation. (d) CIE chromaticity diagram for SLT:0.2Eu³⁺ phosphors (λ_ex = 394 nm). The inset shows the digital photograph of SLT:0.2Eu³⁺ phosphors under a 365 nm lamp.

Fig. 4. (a) PL spectra of the SLT:0.2Eu³⁺ phosphors at different temperature from 303 to 463 K. (b) Normalized integrated temperature-dependent PL intensity in wavelength range of 550–750 nm. (c) Fitting plot of ln (I₀/I-1) versus 1/kT for SLT:Eu³⁺ phosphors. (d) Configuration diagram of the ground and excited states for Eu³⁺ ions in SLT:Eu³⁺ phosphors.