| Abstrakt: |
A series of K3YSi2O7:xTm3+,yDy3+ (0 ≤ x ≤ 0.13, 0 ≤ y ≤ 0.13) white emitting phosphors were synthesized by high temperature solid state method. The crystal structure, crystal lattice occupation and luminous properties of the prepared phosphors were characterized and analyzed by XRD, Rietveld refinement, SEM and fluorescence spectra. The results show that two kinds of Y sites exist in the lattice structure, Y3+ (II) has smaller crystal field strength and better symmetry than Y3+ (I). K3YSi2O7:Dy3+ shows the characteristic emission of Dy3+ with emission peaks at 481, 573 and 665 nm. The chromaticity coordinates of K3YSi2O7:Tm3+,Dy3+ phosphors migrate from the blue region to cold white to natural white region with the increase of Dy3+ doping amount. K3YSi2O7:0.09Tm3+, 0.03Dy3+ phosphor can maintain 90% emission of the initial intensity (300 K) at 450 K. Its corresponding chromaticity coordinates (0.3367, 0.3415) are close to the standard white light (0.333, 0.333). The samples K3YSi2O7:Tm3+,Dy3+ have potential application for ultraviolet excited white-LEDs. [ABSTRACT FROM AUTHOR] |
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