Photoluminescence, thermal stability and structural properties of Eu3+, Dy3+ and Eu3+/Dy3+ doped apatite-type silicates.

Abstract

Ca2Y8(SiO4)6O2 phosphors doped with Eu3þ and Dy3þ and co-doped with Eu3þ/Dy3þ were synthesized via sol-gel method. The materials showed apatite-type silicates crystallized in a hexagonal unit cell. The photoluminescence spectra of the Eu3þ-doped silicates exhibited an intense red emission and the Dy3þ-doped phosphors showed intense emissions in the blue ( 4 F9/2 → 6 H15/2) and yellow ( 4 F9/2 → 6 H13/2) regions. The Eu3þ/Dy3þ-co-doped phosphors presented improvements when compared with the spectra of the Dy3þ-single doped materials by means of compensation in the red component of the emission spectrum. The chromaticity diagram presented a tunable color emission. The energy transfer from Dy3þ to Eu3þ was confirmed based on the photoluminescence intensities and decay curves. The temperature dependence of photoluminescence demonstrated that the synthesized phosphors did not reach thermal quenching, even when subjected to a temperature of 250 °C.