Host-sensitized emission of LiInW 2O 8 wolframites: From red-Eu 3+ to white-Dy 3+ phosphors

Abstract

The LiInW 2O 8:Eu 3+, LiInW 2O 8:Dy 3+ and LiInW 2O 8:Eu 3+/Dy 3+ phosphors were synthesized by solid-state reaction and their photoluminescence properties were studied. Under UV excitation, the LiInW 2O 8:Eu 3+ phosphor exhibits an intense red emission whereas the LiInW 2O 8:Dy 3+ and LiInW 2O 8:Dy 3+/Eu 3+ phosphors show a white emission. The WO 6 octahedra play a major role in the luminescence of the host lattice, characterized by a blue emission under UV excitation. The emission of activator ion results from an efficient energy transfer from the LiInW 2O 8 host lattice to the Eu 3+ and Dy 3+ ions. The LiIn 0.97Dy 3+ 0.03W 2O 8 and LiIn 0.965 Dy 3+ 0.03Eu 3+ 0.005W 2O 8 samples, optimized for white emission, are interesting candidates for solid-state lighting applications.