Fluorescence properties of novel deep-red phosphor LiMg4SbO7:Mn4+ with excellent quantum efficiency and color purity for warm white LEDs.

Abstract

Red fluorescent materials have important application value in the background light and LED lighting fields of displays. In this work, a novel type of rare earth free deep-red phosphor LiMg4SbO7:Mn4+ was prepared successfully, and its crystal structure, microstructure, fluorescence spectrum, quantum yield, thermal stability, fluorescence lifetime, color coordinates and color purity were studied in detail. The excitation spectra of LiMg4SbO7:Mn4+ phosphors are located at 200-600 nm, which can be matched with ultraviolet, near-ultraviolet, and blue-light chips. The exciting result is that the LiMg4SbO7:0.002Mn4+ phosphor exhibits astonishing quantum efficiency, thermal stability and color purity. Finally, the developed LiMg4SbO7:Mn4+ and the yellow phosphor Y3Al5O12:Ce3+ (YAG:Ce3+) were mixed and coated on a blue light chip (460 nm) to produce a w-LED, which exhibited warm white luminescence with color coordinates of (0.3575, 0.3809), correlated colour temperature (CCT) of 4687 K, and color rendering index (CRI) of 83.6. It is reasonable to consider that LiMg4SbO7:Mn4+ phosphors with excellent photoluminescence performance have great application value in LED lighting fields.