Hydrothermal synthesis and luminescent properties of EuW2O6(OH)3 red micro-phosphors

Red phosphors EuW2O6(OH)3 were synthesized via a facile hydrothermal method at different pH values (1, 2, 3, 4, 5, 6 and 7) at 180 °C for 24 h. The XRD patterns indicate that as-obtained phosphors exhibit monoclinic phase. The SEM results show that the as-obtained phosphors exhibit micro-spherical morphologies. The emission spectra under 394 nm excitation exhibit dominant peaks centered at 617 nm. pH value has a strong effect on the phosphor morphology and the emission intensity. The strongest 617 nm red emission was obtained at pH 6. The influence of morphology and crystal size on the intensity of red emission were discussed. The as-obtained micro-phosphors are potential candidate for red-emitting LED phosphors.