Improved deep red emission of Ca2LaTaO6:Mn4- by codoping Dy3+

Mn4+ and/or Dy3+ doped Ca2LaTaO6 phosphors were prepared by a molten salt process. The phase and photoluminescence characteristics of the prepared phosphors were researched. The XRD patterns of the prepared phosphors coincide with the normative XRD pattern of Ca2LaTaO6, demonstrating that Mn4+ and Dy3+ ions doped into Ca2LaTaO6 host and formed solid solution with a single phase. For Dy3+ single doped Ca2LaTaO6 phosphors, they exhibit photoluminescence bands corresponding to F-4(9/2) -> H-6(15/2), H-6(13/2) and H-6(11/2) transitions of Dy3+ while they are excited at 375 nm. For Mn4+ single doped Ca2LaTaO6 phosphors, they exhibit photoluminescence bands corresponding to E-2(g) -> (4)A(2g) transitions of Mn4+ while they are excited at 321 nm Ca2LaTaO6:Mn 4+/Dy3+ phosphors exhibit photoluminescence bands corresponding to transitions of Dy3+ and Mn4+ while they are excited at 375 nm. In Mn4+/Dy3+ codoped Ca2LaTaO6 phosphors, energy transfer from Dy3+ to Mn4+ occurred, which leads to the enhancements of Mn4+ photoluminescence.