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A series of uniform single-phase spherical BaWO 4 : Dy 3+ , Tm 3+ , Eu 3+ phosphors were prepared via a microwave hydrothermal method by using trisodium citrate dehydrate as surfactant. The phase structure, morphology and photoluminescence properties were measured by powder X-ray diffraction, scanning electron microscope and fluorescence spectrometer, respectively. The results show that uniform spherical microcrystals with diameters in the range of 2-4 μm are obtained. And the phase and morphology of samples are not significantly changed by doping rare earth (RE 3+ ) ions. Under the excitation wavelength of 356 and 365 nm, the samples BaWO 4 : 0.03Dy 3+ , yTm 3+ can emit cold white light. In order to lower the correlated color temperature (CCT) to get a warm white light, the Eu 3+ ions were doped into BaWO 4 : 0.03Dy 3+ , 0.01Tm 3+ . Especially, under the excitation of 365 nm, BaWO 4 : 0.03Dy 3+ , 0.01Tm 3+ , 0.03Eu 3+ phosphor shew a bright warm white light with color coordinate of (0.4013, 0.3629) and CCT of 3288 K. Moreover, in the BaWO 4 : Dy 3+ , Tm 3+ , Eu 3+ phosphors, the energy transfer mechanism among Dy 3+ , Tm 3+ and Eu 3+ ions have been discussed and the change of electron structures have been calculated by first-principles calculations. The results shew that the uniform single-phase spherical BaWO 4 : Dy 3+ , Tm 3+ , Eu 3+ phosphors could be favorable candidates in warm white LEDs.

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