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

Ca2Y8(SiO4)6O2 phosphors doped with Eu3+ and Dy3+ and co-doped with Eu3+/Dy3+ were synthesized via sol-gel method. The materials showed apatite-type silicates crystallized in a hexagonal unit cell. The photoluminescence spectra of the Eu3+-doped silicates exhibited an intense red emission and the Dy3+-doped phosphors showed intense emissions in the blue (4F9/2 → 6H15/2) and yellow (4F9/2 → 6H13/2) regions. The Eu3+/Dy3+-co-doped phosphors presented improvements when compared with the spectra of the Dy3+-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 Dy3+ to Eu3+ 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.