Insight Into Synthesis, Temperature‐Dependent Photoluminescence, and the Judd–Ofelt Analysis on the Red‐Emitting Eu ³⁺ Ion‐Activated Brianite Phosphors for Solid‐State Lighting Applications

A thermally stable Eu³⁺-activated Na₂CaMg(PO₄)₂ (NCMP) phosphor was synthesized via a conventional solid-state reaction method for potential white LED applications. The brianite phase of NCMP was confirmed using PXRD, while its morphology and elemental composition were studied through FE-SEM and EDAX mapping. Diffuse reflectance spectra revealed wide band gaps of 3.87 eV (pure) and 3.99 eV (9 mol% Eu³⁺), with refractive indices of 2.01 and 2.02, respectively. Under 396 nm excitation, strong red emission at 616 nm was observed, attributed to a dipole-dipole transition. Judd-Ofelt analysis indicated a higher Ω₂ than Ω₄, suggesting strong covalent interaction between Eu³⁺ and ligands. The CIE chromaticity coordinates confirmed a red hue with high color purity (91.17%) and warm color temperature. The photoluminescence lifetime decreased with higher doping, whereas thermal stability was maintained at 74%. These findings demonstrate the suitability of NCMP:9 mol% Eu³⁺ phosphors for solid-state lighting and multifunctional applications.