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 degrees C under H-2 (25%)-N-2 (75%) atmosphere. The Eu, M-codoped Sr1-x-ySi2N2O2 phosphors have the monoclinic structure with lattice parameters a similar to 15.6 angstrom, b similar to 16.2 A, c similar to 9.4 angstrom, and beta similar to 91 degrees. 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 Sr1-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. (c) 2007 American Institute of Physics.