High-Performance SrLiAl3N4:Eu2+ Red Phosphor via Alloy Precursor Synthesis for Laser-Driven and Wide-Gamut Displays

Abstract In this work, the alloy-precursor solid-state synthesis strategy (AS-method) is employed to fabricate high-performance SrLiAl3N4:Eu2+ phosphors. This approach effectively suppresses the oxidation of Eu2+ to Eu3+ compared to conventional solid-state synthesis (S-method). The resultant optimization of the local structure not only enhances the structural rigidity but also modulates the surrounding chemical pressure at different activator sites. This site-selective regulation leads to spectral narrowing and a blue shift in the emission. The optimized phosphor exhibits an external quantum efficiency (EQE) of 52.38%, a value that ranks among the highest reported for the SLA-based phosphors. Furthermore, it demonstrates an ultrahigh saturation threshold of 90.69 W/mm2 under blue laser excitation, surpassing most reported red phosphors. When applied in white LEDs, it achieves 104% of the NTSC color gamut. Thus, this phosphor indicates great potential for applications in both laser-driven and high-color-gamut displays.