Host-sensitized emission of LiInW2O8 wolframites: From red-Eu3+ to white-Dy3+ phosphors

The LiInW2O8:Eu3+, LiInW2O8:Dy3+ and LiInW2O8:Eu3+/Dy3+ phosphors were synthesized by solid-state reaction and their photoluminescence properties were studied. Under UV excitation, the LiInW2O8:Eu3+ phosphor exhibits an intense red emission whereas the LiInW2O8:Dy3+ and LiInW2O8:Dy3+/Eu3+ phosphors show a white emission. The WO6 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 LiInW2O8 host lattice to the Eu3+ and Dy3+ ions. The LiIn0.97Dy3+0.03W2O8 and LiIn0.965 Dy3+0.03Eu3+0.005W2O8 samples, optimized for white emission, are interesting candidates for solid-state lighting applications. - Graphical abstract: LiInW2O8:Eu3+, Dy3+/Eu3+ emits red and white colors, respectively, under host excitation wavelength. An effective energy transfer from LiInW2O8 to Eu3+ and Dy3+ ions is occurred. Eu3+ and Dy3+ occupy non-centrosymmetric sites in the host lattice. Highlights: → Photoluminescence of LiInW2O8:Eu3+, Dy3+/Eu3+ was analyzed under UV excitation at room temperature. → WO6 octahedra play a major role in the host lattice luminescence. → Eu3+ and Dy3+ ions can be excited directly through host lattice.