Synthesis and optical properties of Ce3+/Tb3+ doped LaF3, KGdF4, and KYF4 nanocrystals

10 mol% Ce3+, 5 mol% Tb3+ doped LaF3, KGdF4, and KYF4 nanocrystals have been synthesized by a polyethylene glycol assisted hydrothermal method under similar synthetic conditions. The final products are characterized by X-ray diffraction patterns, field emission scanning electron microscopy images, photoluminescence (PL) excitation and emission spectra, and luminescent dynamic decay curves. The energy transfer from Ce3+ to Tb3+ has been observed in the final products. The Ce3+ presents different excitation and emission properties in sensitizing Tb3+ in the three samples. The Tb3+ presents characteristic green emissions (5D4→7FJ, J=6, 5, 4, 3) and has different emission intensities in the three samples. In addition, the energy transfer from host Gd3+ to Tb3+ has been observed in the KGdF4 nanocrystals. Based on the PL excitation and emission spectra and some references, energy transfer efficiency from Ce3+ to Tb3+ and possible energy transfer processes among Ce3+ and/or Gd3+ and/or Tb3+ have been discussed.