Synthesis of long afterglow phosphor Sr₄Al₁₄O₂₅: Eu²⁺, Dy³⁺ by hydrothermal method and its luminescent properties

The blue-green long afterglow phosphors, Sr₄Al₁₄O₂₅: Eu²⁺, Dy³⁺ were prepared by calcining the corresponding precursors, and the well-dispersed precursors were produced by hydrothermal method. During the hydrothermal process, NH₃ · H₂O and NH₄HCO₃ were selected as precipitants, which played an important role in the structure and performance of the finial product. The results indicated that compared with NH₄HCO₃, the phosphors obtained by using NH₃ · H₂O had relatively pure monoclinic Sr₄Al₁₄O₂₅ crystal phase, narrow-distributing particles size of 1 μ m, better luminescent property and longer persistent afterglow.