Enhancement of Mn 4+ Emission by Means of Energy Transfer in Mg 2 Al 4 Si 5 O 18 :Dy 3+ , Mn 4+ Phosphors

We synthesized a series of Dy 3+ /Mn 4+ doped Mg 2 Al 4 Si 5 O 18 phosphors by sintering at 1400 °C. The phase and luminescence properties of the synthesized phosphors were investigated. The XRD results demonstrate that Dy 3+ and Mn 4+ have successfully entered into the Mg 2 Al 4 Si 5 O 18 hosts and occupied crystallographic sites of the hosts. Mg 2 Al 4 Si 5 O 18 :Mn 4+ and Mg 2 Al 4 Si 5 O 18 :Dy 3+ phosphors respectively show emission bands corresponding to 2 E g → 4 A 2g transitions of Mn 4+ and 4 F 9/2 → 6 H 15/2, 13/2, 11/2 transitions of Dy 3+ . For Dy 3+ and Mn 4+ codoped Mg 2 Al 4 Si 5 O 18 phosphors, the emission bands originating from transitions of Dy 3+ and Mn 4+ are observed. The characteristics of intensity and lifetime of Dy 3+ emission suggest Dy 3+ → Mn 4+ ET process in Dy 3+ and Mn 4+ codoped Mg 2 Al 4 Si 5 O 18 phosphors.