Synthesis, structure and photoluminescence properties of a novel Rb2NaAlF6:Mn4+ red phosphor for solid-state lighting

In this work, we present a novel Mn4+-activated Rb2NaAlF6 red phosphor synthesized through a cation exchange route at room temperature. The structural and optical features were characterized by X-ray diffraction, energy dispersive X-ray spectrometer, scanning electron microscopy, X-ray fluorescence, emission, excitation, and luminescence decay curves. The straightforward evidences have shown that the as-prepared Rb2NaAlF6:Mn4+ crystallizes into single cubic phase with regular octahedral particulate morphology, and exhibits broad excitation band and sharp emission lines in the red and blue regions. The luminescence properties, thermal stability and optical performance were systematically investigated to recognize the luminescence behavior of Rb2NaAlF6:Mn4+ and its potential application for white light illumination. The results suggest that the Rb2NaAlF6:Mn4+ phosphor exhibits excellent thermal stability and is capable of tuning the cold white light to warm in white light-emitting diodes.