Fig. 1. (a) XRD patterns of the samples. (b) Locally enlarged view of (a). (c) XRD refinement for the CLSPO host. (d) Crystal structure of CLSPO host along the c-axis direction, and the coordinated environments of Ca/La(I) and Ca/La(II) atoms. (e) Diffuse reflection spectrum of CLSPO host. Inset: bandgap value of CLSPO obtained with the K–M function and the Tauc relation.

Fig. 2. (a) Normalized PLE and PL spectra of CLSPO: 0.90Eu3+ phosphor. (b) PL spectra of CLSPO: xEu3+ samples. Inset: the emission intensity and (IR/IO) value versus x.

Fig. 3. (a) Normalized PLE and PL spectra of CLSPO: 0.90Tb3+ phosphor. (b) PL spectra of CLSPO: xTb3+ samples. Inset: the emission intensity versus Tb3+ concentration x.

Fig. 4. (a) Normalized PLE (blue line) and PL (red line) spectra of CLSPO: 0.40Mn2+, PL spectrum (green line) of CLSPO: 0.90Tb3+. Insets: left, PLE spectra of CLSPO: 0.90Tb3+, 0.52Mn2+ monitored at different wavelengths; right, the schematic of ET from Tb3+ to Mn2+ in the CLSPO host. (b) PL spectra of CLSPO: 0.90Tb3+, xMn2+ samples and the photos of the samples under 365 nm lamp.

Fig. 5. CIE chromaticity diagram for CLSPO: 0.90Eu3+ (Point A) and CLSPO: 0.90Tb3+, yMn2+ (Points B–H). Photos: Eu3+/Tb3+-doped CLSPO phosphors under 365 nm UV lamps.