Energy-Transfer-Induced Tunable Luminescence in Mg2Al4Si5O12:Ce3+/Dy3+ Phosphors.

Ce³⁺- or/and Dy³⁺-doped Mg₂Al₄Si₅O₁₈ phosphors have been fabricated via a sintering process at 1400°C for 5 h and their crystallinity and luminescence characteristics investigated. x-Ray powder diffraction analysis demonstrated that Ce³⁺/Dy³⁺ ions entered the Mg₂Al₄Si₅O₁₈ host and formed a solid solution. When excited at 345 nm, Ce³⁺-doped Mg₂Al₄Si₅O₁₈ phosphor emitted light in the blue region while Dy³⁺-doped Mg₂Al₄Si₅O₁₈ phosphor emitted light in the yellow region. When excited at 345 nm, emission bands located in both the blue and yellow regions were observed for the Ce³⁺/Dy³⁺-codoped Mg₂Al₄Si₅O₁₈ phosphor. Because of Ce³⁺ → Dy³⁺ energy transfers, the Ce³⁺/Dy³⁺-codoped Mg₂Al₄Si₅O₁₈ phosphor showed tunable luminescence, changing from the blue to yellow–green region through the white region with increasing Dy³⁺ concentration in the Ce³⁺/Dy³⁺-codoped Mg₂Al₄Si₅O₁₈ phosphor. The decay characteristics of the Ce³⁺ emission in the Ce³⁺/Dy³⁺-codoped Mg₂Al₄Si₅O₁₈ phosphors were also investigated. With increasing Dy³⁺ concentration, the lifetime of the Ce³⁺ emission decreased continuously, further confirming the occurrence of Ce³⁺ → Dy³⁺ energy transfer. [ABSTRACT FROM AUTHOR]