Photoluminescence investigations of Zn2SiO4 co-doped with Eu3+ and Tb3+ ions

Zinc silicate phosphors co-doped with Eu3+ ions and also with both Eu3+ and Tb3+ ions were prepared by high temperature solid state reaction in air or reducing atmosphere. The luminescence characteristics of the prepared phosphors were investigated. While in the samples prepared in air, Eu3+ emission was found to be dominant over Tb3+ emission, in the samples prepared in reducing atmosphere, intense Eu2+ emission at 448 nm was found to be predominant over narrow Tb3+ emission. Luminescence studies showed that Eu3+ ions occupy asymmetric sites in Zn2SiO4 lattice. The intense f-f absorption peak of Eu3+ at 395 nm observed in these phosphors suggests their potential as red emitting phosphors for near ultra-violet light emitting diodes.