Preparation and luminescence properties of thermally stable Mn4+ doped spinel red-emitting ceramic phosphors

Abstract Red-emitting ceramic phosphors are significant for warm white light emitting diodes (WLEDs) with high color rendering index (CRI). In this work, Mn doped spinel ceramic phosphors were prepared via high temperature solid-state reaction sintering. The photoluminescence properties of the as-prepared ceramic phosphors were elaborately discussed. The Mn4+ doped spinel ceramics were successfully obtained by incorporating excessive Mg2+ as the charge compensator. They showed red emission peaking at 652 nm under 450 nm excitation. Furthermore, it's exciting to find that the red-emitting ceramic phosphors showed high thermal stability. As operated at 450 K, the emission intensity remained about 66% of the initial intensity operated at room temperature. The results indicate that the Mn4+ doped spinel ceramic phosphors are promising red color converters for warm-WLEDs.