Synthesis, optical properties, and packaging of Dy3+ doped Y2WO6, Y2W3O12, and Y6WO12 phosphors

Abstract Through a solid-state reaction method, Dy3+ doped monoclinic phase of Y2WO6, Y2W3O12, and hexagonal phase of Y6WO12 phosphors were synthesized. The Y2WO6 and Y2W3O12 were composed of micrometre-scale particles, and the Y6WO12 was composed of nanometre particles. The energy-dispersive spectra (EDS) suggested that the atom ratio of Y to W decreased with the sequence of Y6WO12, Y2WO6, and Y2W3O12 phosphors. The Eg values were calculated based on the diffuse reflection (DR) spectra. The Dy3+ doped Y2WO6 phosphor had the most intense photoluminescence (PL) intensities and the optimal doping concentration was 2 mol%. The energy transfer efficiency from WO66− to Dy3+ was calculated. The lifetime of 4F9/2→6H13/2 transition of Dy3+ was a few hundred nanoseconds. At 150 °C, the 2 mol% Dy3+ doped Y2WO6 phosphor kept 74 % intensity of 50 °C. The white light emitting diode (WLED) devices were fabricated by combining phosphors with 308 nm LED chips.