Combustion Synthesis and Photoluminescence Properties of Dy 3+ Activated Li₂Sr.₂Al₂PO₄F₉ Phosphor for Solid‐State Lighting Applications

This research focuses on the preparation and comprehensive characterization of Li₂Sr.₂Al₂PO₄F₉ phosphors doped with Dy 3+ ions. The material was synthesized via combustion method utilizing urea as a fuel source. Structural and luminescence properties are investigated through X‐ray diffraction and photoluminescence (PL) techniques. The PL excitation spectrum of Li₂Sr.₂Al₂PO₄F₉:Dy 3+ revealed multiple excitation bands between 300 and 400 nm, attributed to 4f electronic transitions of Dy 3+ ions. Upon excitation at 348 nm, the PL emission spectrum exhibited characteristic emissions at 478 nm (blue), corresponding to 4 F₉/₂ → 6 H₁₅/₂ transition, and at 571 nm (yellow), associated with the 4 F₉/₂ → 6 H₁₃/₂ transition of Dy 3+ .