Studies on the luminescence properties of dysprosium doped strontium metasilicate phosphor by solid state reaction method

摘要

In this paper, we report dysprosium doped strontium metasilicate (namely: SrSiO_3:Dy~(3+)) white light emitting phosphor by solid state reaction method. Crystal structure of sintered phosphor was investigated using X-ray diffraction pattern which confirm that the synthesized phosphor held the monoclinic structure with space group C12/c1. An energy dispersive X-ray spectroscopy confirms the presence of elements in sintered SrSiO_3:Dy~(3+) phosphor. Thremoluminescence (TL) kinetic parameters such as activation energy (E), order of kinetics (b), and the frequency factor (s) of synthesized phosphor has been calculated using peak shape method. The prepared SrSiO_3:Dy~(3+) phosphor was excited at 350 nm and their corresponding emission spectra was recorded at blue (478 nm), yellow (575 nm) and red (674 nm) line due to the ~4F_(9/2) → ~6H_(15/2), ~4F_(9/2) → ~6H_(13/2), ~4F_(9/2) → ~6H_(11/2) transi-tions of Dy~(3+) ions. The combination of these three emissions constituted as white light; confirmed by the Commission Internationale de I'Eclairage (CIE) chro-maticity diagram. The possible mechanism of long lasting white light emitting SrSiO_3:Dy~(3+) phosphor was also investigated. The mechanoluminescence (ML) intensity increases linearly with increasing impact velocity of the moving piston. Thus the present investigation indicates that piezoelectricity was responsible to produce ML in prepared SrSiO_3:Dy~(3+) phosphor.