Enhancing the emission intensity and decreasing the full widths at half maximum of Ba3Si6O12N2:Eu2+ by Mg2+ doping
The promising green oxynitride phosphor, Ba3−xMgxSi6O12N2:Eu2+ was synthesized by the solid-state reaction method. The effect of Mg2+ doping on the structure and photoluminescence (PL) properties of Ba3Si6O12N2:Eu2+ was investigated systematically. The results reveal that the phosphor retains the single phase of Ba3Si6O12N2, with the lattice expanding upon increasing the Mg2+ concentration, in an appropriate range. This suggests that a large portion of Mg2+ enters into the interstitial sites of the crystal lattice. At a certain concentration, Mg2+ doping can greatly enhance the absorption and PL intensity and decrease the full widths at half maximum (FWHM) of Ba3Si6O12N2:Eu2+ phosphors. The green phosphor Ba2.87Eu0.1Mg0.03Si6O12N2 exhibited a small thermal quenching, which remained 82% of the initial emission intensity when measured at 150 °C. The quantum efficiency measured at 400 nm excitation was 38.5%. All the results indicate that the solid solution Ba3−xMgxSi6O12N2:Eu2+ can be a good candidate for phosphors applicable in n-UV LEDs for solid-state lighting.