Orange red Ca₉Sc(PO₄)₇: Sm³⁺ phosphor with excellent thermal stability for solid state lighting

In this study, a series of Ca₉Sc(PO₄)₇: Sm³⁺ (CSP: Sm³⁺) orange-red phosphors were synthesized by the conventional solid-phase method, and their crystal structure, luminescent properties, decay lifetimes and thermal stability were investigated. The computational result shows that the CSP substrate has a wide band gap value (4.258 eV). At 403 nm excitation, the emission spectrum of CSP: Sm³⁺ phosphors has an intense orange red emission at 602 nm. The optimum concentration of Sm³⁺ ion doped phosphor is 0.12, and the phosphor has a high color purity (97%). Moreover, the prepared phosphors have excellent thermal stability, and the emission intensity can still reach 91.68% of that at room temperature at 423 K. The above results indicate that the prepared CSP: Sm³⁺ phosphors have excellent luminescent properties and have potential applications in solid-state lighting.