Enhanced luminescence of SrSi2O2N2:Eu2+ phosphors by codoping with Ce3+, Mn2+, and Dy3+ ions.

The authors report here the enhanced luminescence properties of SrSi₂O₂N₂ doped with Eu and M (M=Ce, Dy, and Mn). The Eu and Eu, Mn-codoped powders were prepared by a solid state reaction at temperatures between 1400 and 1600 °C under H₂ (25%)–N₂ (75%) atmosphere. The Eu, M-codoped Sr_1-x-ySi₂N₂O₂ phosphors have the monoclinic structure with lattice parameters a∼15.6 Å, b∼16.2 Å, c∼9.4 Å, and β∼91°. The phosphors can be efficiently excited in the UV to visible region, making them attractive as conversion phosphors for a light emitting diode application. A green-yellow emission was observed for Eu,M-codoped Sr_1-x-ySi₂N₂O₂. The addition of M in the Eu site in SrSi₂O₂N₂ remarkably enhances the luminescent intensity by the factor of 144%, 148%, and 168% for Ce, Dy, and Mn, respectively. [ABSTRACT FROM AUTHOR]