Ultraviolet-to-visible downconversion luminescence in solgel oxyfluoride glass ceramics containing Eu3+:GdF3 nanocrystals

GdF3 nanocrystals doped with Eu3+ ions in oxyfluoride glass ceramics were prepared by a solgel method. The structural properties were examined by x- ray diffraction measurements. The effects of gadolinium codoping on europium emission in the prepared solgel glasses and glass ceramics have been studied. The emission bands originating from the D-5(0) state of Eu3+ ions are enhanced under excitation of Gd-3 vertical bar ions by 273 nm line. The electric dipole D-5(0) -> F-7(2) transitions were dominant in the samples before heat treatment, whereas magnetic dipole D-5(0) -> F-7(1) transitions had a higher probability in the samples after annealing. The luminescence lifetime for the D-5(0) level of Eu3+ ions in the samples after excitation at 273 nm is long lived in comparison to excitation at 393 nm and increased to 190%. Energy transfer from Gd3+ to Eu3+ was observed. (C) 2014 Optical Society of America