Improved luminescence properties of a novel red dodec-fluoride phosphor Ba3Sc2F12:Mn4+ with extraordinary thermal stability for WLED application

Abstract

Mn⁴⁺-activated red phosphors have recently attracted tremendous attention for their fascinating performance in white light emitting diode (WLED) applications, achieving warm white light, while the thermal stability of fluorides is still considered as a drawback. Herein, we report a novel red phosphor composed of Ba₃Sc₂F₁₂:Mn⁴⁺ (BSF:Mn), in which the emitting centers of Mn⁴⁺ ions are located in the sites of Sc³⁺ ions. The photoluminescence of BSF:Mn varies with the concentration of K₂MnF₆, reaction temperature, and the concentrations of NH₃·H₂O in the reaction system. Partly substituting Ba²⁺ with Ca²⁺ decreases the luminescence intensity of BSF:Mn. By employing the as-prepared phosphor BSF:Mn as a red component, a high-performance WLED with a correlated color temperature (CCT) of 4796 K and a color rendering index (CRI) of 85.2 was obtained. The phosphor BSF:Mn remains undecomposed up to 800 °C; therefore, this work provides a strategy to explore a novel Mn⁴⁺-doped fluoride with particularly good thermal stability.