PEG-assisted hydrothermal synthesis and luminescent properties of ZnWO_4:Sm~(3+) white light-emitting phosphors

摘要

ZnWO_4:Sm~(3+) white light-emitting phosphors were prepared by a PEG-assisted hydrothermal method followed by calcination. The structure, morphology and luminescent properties were characterized by X-ray powder diffraction, scanning electron microscopy and fluorescence spectrophotometer, respectively. The results showed that the as-synthesized ZnWO_4:Sm~(3+) samples had monoclinic wolframite structure and were all well crystallized. When the PEG was introduced into the reaction system, the dispersibility of the particles was improved significantly and the particle size became uniform. The emission spectra of ZnWO_4:Sm~(3+) consisted of a strong broad blue-green band of WO_4~(2-) group centered around 467 nm and orange-red emission peaks of Sm~(3+) at 568, 613 and 654 nm. The hydrothermal temperature, amount of PEG and calcination temperature strongly affected the luminescent intensity of ZnWO_4:Sm~(3+). ZnWO_4:Sm~(3+) phosphors showed strong white light-emitting when the hydrothermal temperature was 180 ℃, the amount of PEG is 0.4 g and the calcinations temperature is 700 ℃.