Color-tunable luminescence of Eu3+ in PbF2 embedded in oxyfluoroborate glass and its nanocrystalline glass

Glass-ceramics containing Eu3+-doped PbF2 nanocrystals of about 11 nm size have been made using the controlled crystallization at higher temperatures of the Eu3+-doped PbF2-SiO2 glasses. In the glass-ceramic material the Eu3+ ions are embedded in both silica network and in the sites of the PbF2 nanocrystals structure. The nanocomposite exhibited intense blue and green emissions originating from the 5D1,2,3 levels of Eu3+ incorporated in the low-phonon-energy PbF2 nanocrystals, and red emission corresponding to the Eu3+:5D0 → 7FJ (J = 0, 1, 2, 3, 4) transitions, under the excitation of single wavelength light at 394 nm. By adjusting the Eu3+ doping content, various luminescent colors, were easily tuned through cross relaxation processes between Eu3+ ions.