Luminescent Properties of Green Phosphor Ca8Mg（SiO4 ）4 Cl2：EU^2＋ , DY^3＋ for LED Applications

The new phosphor calcium magnesium chlorosilicate, codoped with Eu^2＋ and Dy^3＋, was synthesized with the help of the high temperature solid state reaction in reducing atmosphere. The excitation and emission spectra were very similar to that of Ca8Mg（SiO4）4Cl2 ：Eu^2＋, and the Dy^3＋ concentration influenced the emission intensity of this phosphor. The intensity of Eu^2＋ and Dy^3＋ codoped CMSC was stronger than that of Eu^2＋ singly doped CMSC. The emission spectrum of the Dy^3＋ ion overlapped the absorption band of the Eu^2＋ ion, indicating that an energy transfer from Dy^3＋ to Eu^2＋ took place in CMSC：Eu^2＋, Dy^3＋ phosphor. The mechanism of the energy transfer from Dy^3＋ tO Eu^2＋, in this phosphor, might be resonant energy transfer.