Multiwavelength excited white-emitting Dy~(3+) doped Sr_3Bi(PO_4)_3 phosphor

摘要

Multiwavelength excited white emitting phosphor Dy~(3+) doped Sr_3Bi(PO_4)_3 was synthesized by solid state reaction method. The phase of the as-prepared powders was measured by X-ray diffraction pattern (XRD) and the luminescent properties of Sr_3Bi(PO_4)_3:Dy~(3+) were systematically investigated by excitation spectra, emission spectra and concentration quenching. The excitation spectra included bands located at 348 nm, 362 nm, 385 nm and 451 nm were due to the f-f transitions of Dy~(3+) within its Af configuration. This excitation is useful for solid state lighting and light-emitting diodes. Under 348 nm excitation, the emissions of Dy~(3+) ions are observed at 481 nm (blue) due to the ~4F_(9/2)-~6H_(15/2) transitions, 575 nm (yellow) due to ~4F_(9//2)-~6H_(13/2) transitions and a weak 664 nm (red) due to ~4F_(9/2)-~6H_(11/2) transitions. The optimal emission intensity of the Sr_3Bi_(1-x)(PO_4)_3:xDy~(3+) phosphors is found to be x=0.07. The chromaticity coordinates of the samples were in the near white region. All results demonstrated that Sr_3Bi(PO_4)_3:Dy~(3+) might be a potential phosphor for NUV-based white light-emitting diodes.