Spectroscopic properties and upconversion in Pr3+:YF3 nanoparticles.

The synthesis and spectroscopic investigation of Pr(3+):YF(3) nanoparticles with nominal concentration between 0.05% and 5 at% Pr(3+) are reported. Pr(3+) emission in the visible range of the spectrum is investigated at room temperature and at 10 K as well as time resolved spectroscopy as a function of Pr(3+) concentration. The upconverted emission from the orange to the blue region is observed and the time-resolved spectroscopy of the visible emissions is discussed as a function of the doping level. A careful analysis of the decays permits identification of the main energy-transfer mechanisms that determine the population of the excited levels at various times during the decay.