Hydrothermal synthesis and luminescence properties of YW2O6（OH）3：Tb^3＋ green phosphors

YW2O6（OH）3：Tb^3＋ green phosphors were synthesized at different pH values via a facile hydrothermal method. The structure and optical properties of as-synthesized samples were studied by X-ray diffractometer （XRD）, scanning electron microscopy （SEM）, photolumi-nescence spectra and luminescence decay curve. The results showed that pure monoclinic YW2O6（OH）3：Tb^3＋ green phosphors could be ob-tained at pH 2-5. Uniform spherical micro-phosphors of ~5 μm in diameter with narrow size distribution could be prepared at pH 5. pH value had dramatic influence on morphologies, which could be ascribed to the various spatial configurations of different poly-tungstates existing at different pH values. The emission spectra under 261 nm excitation exhibited dominant green emission at 546 nm. The green emission inten-sity reached the maximum value at pH 5 due to the high packing density of the obtained phosphor.