Solvothermal synthesis, luminescence and energy transfer of Dy3+ and Sm3+ doped NaLa(WO4)2 nanocubes

Abstract

A series of Dy3+ and/or Sm3+ ions doped NaLa(WO4)2 phosphors have been synthesized by a solvothermal method. The phase, microstructure and luminescence of Dy3+ and/or Sm3+ ions doped NaLa(WO4)2 phosphors have been investigated. The XRD patterns obviously indicate that Dy3+ and/or Sm3+ ions doped NaLa(WO4)2 phosphors have the tetragonal scheelite structure. The SEM images show that the synthesized phosphors have the cubic morphology. The overlap between the emission spectrum of Dy3+ and the excitation spectrum of Sm3+ suggests possible energy transfer from Dy3+ to Sm3+ in NaLa(WO4)2:Dy3+/Sm3+ phosphors and the energy transfer is confirmed by the decreases of Dy3+ emission intensity and the increases of Sm3+ emission intensity for NaLa(WO4)2:Dy3+/Sm3+ phosphors. On the basis of luminescent properties, the possible energy transfer mechanism has been speculated.