Tunable Emission from Eu ³⁺ ‐Doped Zn ₃ (VO ₄ ) ₂ Phosphors for Light‐Emitting Diodes

This study synthesizes tunable Eu 3 + ‐doped Zn 3 (VO 4 ) 2 phosphors via a coprecipitation method and systematically investigated their structural, photoluminescence, and surface properties. X‐ray diffraction analysis confirms that all samples crystallized in the orthorhombic structure (space group Abam ), with no secondary phases observed, indicating phase purity. A shift in diffraction peaks with increasing Eu 3 + content suggests successful incorporation of Eu 3 + ions into the Zn 3 (VO 4 ) 2 lattice. Photoluminescence studies reveal characteristic charge transfer (CT) transitions from (VO 4 ) 3− groups and sharp 4 f –4 f transitions of Eu 3 + ions, with the strongest emission peak observed at 617 nm due to the hypersensitive 5 D 0 → 7 F 2 transition. The optimal Eu 3 + doping concentration is 6 mol%, beyond which concentration quenching reduces luminescence intensity. Excitation‐dependent emission spectra demonstrate tunable emission color from yellow to red, attributed to host‐to‐Eu 3 + energy transfer and symmetry‐sensitive Eu 3 + transitions. X‐ray photoelectron spectroscopy (XPS) analysis confirms the elements’ oxidation states and surface composition, including a dominant Eu 3 + state with a minor Eu 2 + contribution. Commission International de l’Eclairage (CIE) chromaticity and correlated color temperature (CCT) analyses show emission in the warm‐white to red region, making these phosphors suitable for potential use in solid‐state lighting and optoelectronic applications.