Hydrothermal synthesis and luminescent properties of Ca3(PO4)2: Dy3+ white-emitting phosphors.

The white-emitting Ca 3 (PO 4) 2 : Dy3+ phosphors were prepared via hydrothermal synthesis. The phosphors were characterized by XRD, TEM, SEM, EDS, GSAS structural refinement and PL spectroscopy, respectively. Rietveld refinement demonstrated that the Ca 3 (PO 4) 2 crystal structure consisted of [PO 4 tetrahedrons filled with Ca atoms. Dy3+ ions occupied high-symmetry sites due to the emission intensity of 4F 9/2 → 6H 15/2 was strongest. Moreover, the pH value and calcination temperature had important effects on the phosphor morphology and luminescent properties. The morphology of the samples changed from long-rod to short-rod and sphere and the size reduced as the pH value in the initial reaction solution increased. The samples with pH of 7 had the best luminescence properties, and the precursor before calcination corresponded to Ca 4 P 2 O 9. With the calcination temperature of the precursor with pH of 7 increased, the phosphor morphology changed from nanorods to grains with diameters of about 1 μm, and the luminescence properties were improved continuously. The CIE coordinate of Ca 3 (PO 4) 2 : Dy3+ phosphor was (0.283, 0.343). The Ca 3 (PO 4) 2 : Dy3+ phosphor has better application prospects for white light-emitting diodes. • The white-emitting Ca 3 (PO 4) 2 : Dy3+ phosphors were synthesized via the hydrothermal synthesis. • The precursor at pH of 7 matches well with Ca 4 P 2 O 9. • The changes of phase structure, morphology, luminescent properties of the phosphor by controlling pH value and calcination temperature was systematically studied. • As the pH value in the initial reaction solution increased, the morphology of the samples changed from long-rod to short-rod and sphere and the size reduced. [ABSTRACT FROM AUTHOR]