Eu2+ -Activated Ca8Zn (SiO4)4Cl2: An Intense Green Emitting Phosphor for Blue Light Emitting Diodes

Document Type


Publication Date


Publication Title

Journal of the Electrochemical Society




We report intense green luminescence upon blue light excitation in Eu2+ -activated Ca8Zn(SiO4)4Cl2 prepared by high temperature solid state reaction with nominal composition of (2−x)CaO-xZnO–SiO2–CaCl2(0⩽x⩽1.1) . It is observed that the material phase gradually converts from Ca3SiO4Cl2:Eu2+ to Ca8Zn(SiO4)4Cl2:Eu2+ followed by improved luminescent properties with increasing x . The two phosphors both emit with a maximum at 505nm . Significantly, Ca8Zn(SiO4)4Cl2:Eu2+ shows a more intense excitation band in the blue centered at 450nm . Upon 450nmexcitation, the integrated emission intensity of Ca8Zn (SiO4)4Cl2:Eu2+ is 1.3 times stronger Ca8Mg(SiO4)4Cl2:Eu2+ and nearly the same as Ca3Sc2Si3O12:Ce3+ phosphors. Attempts to understand the origins of the intense luminescence are presented on the basis of diffuse reflection spectra and fluorescence decays of Ca8Zn(SiO4)4Cl2:Eu2+ in comparison with related phosphors. The present results suggest that Ca8Zn(SiO4)4Cl2:Eu2+ could be a promising green emitting phosphor for excitation by blue light emitting diodes.