Influence of rare-earth and non-rare-earth dopants on phase stability, microstructural morphology, and optical emission of SrAl₁₂O₁₉ matrix
摘要
Strontium aluminate (SrAl₁₂O₁₉) has emerged as a promising host lattice for luminescent materials due to its excellent structural stability, thermal resistance, and wide optical bandgap. In this study, nano-sized SrAl₁₂O₁₉ phosphors were synthesized via a solid-state route and systematically doped with Eu3⁺ (5 mol%), Mn4⁺ (0.5–5 mol%), and their co-doped (Eu–Mn) combinations to explore structural, morphological, and optical properties. X-ray diffraction confirmed the formation of a phase hexagonal magnetoplumbite structure, while FESEM revealed morphology variations from plate-like grains (~ 1 µm) to rod-like particles (~ 400–600 nm) and nanospherical features (~ 20 nm). Optical absorption extended broadly from 200–380 nm. Eu3⁺-doped samples displayed characteristic emission bands at 590, 600, and 612 nm, producing reddish-orange luminescence, while Mn4⁺-doped samples exhibited deep-red emissions at 641, 656, and 667 nm, with maximum intensity at 1 mol% Mn. In Eu–Mn co-doped systems, enhanced Eu3⁺ emission and reduced Mn4⁺ intensity confirmed partial energy transfer, yielding tunable reddish-pink to mixed chromaticity. Colour coordinate analysis under 365 nm excitation highlighted optimal luminescence in SrAl₁₂O₁₉:1 mol% Mn–5 mol% Eu, combining superior intensity and emission tunability. These findings demonstrate the potential of Eu/Mn co-doped SrAl₁₂O₁₉ phosphors for next-generation solid-state lighting and full-colour display applications.
Graphical abstract