Hydrothermal synthesis and luminescence behavior of lanthanide-doped GdF3 nanoparticles

The lanthanide-doped GdF3 nanoparticles have been produced by a simply hydrothermal synthesis procedure. The excitation and emission spectra of the Eu3+ -doped GdF3 nanoparticles showed that the excitation energy of Gd3+ is efficiently transferred to Eu3+ in the Eu3+ -doped GdF3 nanoparticles. Due to very low phonon energies of GdF3 matrix, the D-5(1) emission of Eu3+ ions in the Eu3+ -doped GdF3 nanoparticles can be observed at room temperature when the doping concentration of Eu3+ ions is lower than 15 mol%. The luminescence intensity of the Eu3+ -doped GdF3 nanoparticles increased with increasing concentration of Eu3+ ions and reached a maximum at approximately 15 mol%. The Er3+-doped GdF3 nanoparticles exhibit the typical emission spectra of Er3+ in the near-infrared region. The upconversion emission of the Er3+/Yb3+ codoped GdF3 nanoparticles can also be observed. However, the upconversion emission intensity of the Er3+/Yb3+-codoped GdF3 nanoparticles was much weaker than that of the Er3+/Yb3+-codoped GdF3 bulk crystal.