Effect Of Si4+ Substitution On Structure And Luminescence Of Eu2+-Doped Na2camg(Po4)(2) Phosphors

The Eu2+-doped Na2CaMg(P1-xSixO4)(2) phosphors were prepared by high-temperature solid-state reaction. The structural and optical effects of Si4+ substitution were investigated with the use of X-ray diffraction, Fourier transform infrared spectra, Raman spectra, luminescence spectra and fluorescence decay curves, etc. The spectral parameters, Stokes shift and Eu2+ substitution sites in Na2CaMg(PO4)(2) were discussed by using empirical equations. The results show that Si4+ substitution increases the emission intensity of Eu2+ by ca. 50% at the optimal concentration of x = 0.05. This study can provide a guidance for the development of Eu2+- activated phosphate phosphors for WLEDs.