Preparation and Photoluminescence Properties of Eu3+-Doped Na2.4Mg0.8(MoO4)2 Red-Emitting Phosphors

Eu 3 + -doped Na 2 . 4 Mg 0 . 8 (MoO 4 ) 2 red phosphors were successfully synthesized using a facile sol-gel method, achieving uniform morphology and high crystallinity. The structural and optical properties of the resulting phosphors were systematically characterized, revealing insights into their photoluminescence behavior. Photoluminescence excitation (PLE) spectra demonstrated a broad excitation range spanning the near-ultraviolet (UV) to blue regions, accompanied by sharp and well-defined peaks, indicating effective energy absorption by Eu 3 + ions. Specifically, the strongest excitation peak at 465 nm corresponding to the 7 F 0 → 5 D 2 transition, and a relatively weaker peak at 395 nm corresponding to the 7 F 0 → 5 L 6 transition, suggest that these phosphors can be efficiently excited under both blue and near-UV light sources. Upon 465 nm excitation, the emission spectra exhibited characteristic Eu 3 + transitions, including the magnetic dipole 5 D 0 → 7 F 1 transition at 591 nm and the hypersensitive electric dipole 5 D 0 → 7 F 2 transition at 614 nm, with the red emission at 614 nm dominating and exhibiting an intensity nearly ten times higher than that at 591 nm. This pronounced red emission highlights the strong asymmetry of the local environment around Eu 3 + ions, which is beneficial for enhancing the color purity of the emitted light. Furthermore, the Na 2 . 4 - ₓMg 0 . 8 (MoO 4 ) 2 :Euₓ 3 + phosphors demonstrated excellent thermal stability and potential for integration into solid-state lighting devices. The tunable Eu 3 + doping concentrations enabled modulation of the emission intensity and color, providing flexibility for device design and optimization. These characteristics, combined with efficient energy transfer from the host lattice to Eu 3 + ions, suggest that these phosphors are promising candidates for red-emitting components in white light-emitting diodes (LEDs), especially when combined with commercial blue LED chips. The findings offer a comprehensive understanding of the relationship between host lattice composition, Eu 3 + doping, and photoluminescence performance, providing valuable guidance for the development of high-performance, rare-earth-based phosphors in next-generation lighting technologies.