Effects of Li⁺ on photoluminescence of Sr₃SiO₅：Sm³⁺ red phosphor

The structure and photoluminescence (PL) properties of Sr₃SiO₅: Sm³⁺ and Li⁺-doped Sr₃SiO₅: Sm³⁺ red-emitting phosphors were investigated. Samples were prepared by the high-temperature solid-state method. PL spectra show that the concentration quenching occurs when the Sm³⁺ concentration is beyond 1.3 mol% in Sr₃SiO₅: Sm³⁺ phosphor without doping Li⁺ ions. The concentration-quenching mechanism can be explained by the electric dipole-dipole interaction of Sm³⁺ ions. The incorporation of Li⁺ ions into Sr₃SiO₅: Sm³⁺ phosphors, as a charge compensator, improves the PL properties. The lithium ions also suppress the concentration quenching in Sm³⁺ with concentration increased from 1.3 mol% to 1.7 mol%.