Energy transfer efficiency in YF3 nanocrystals: Quantifying the Yb3 to Tm3 infrared dynamics

Abstract

In this work, we report on the determination of the infrared Yb3 → Tm3 energy transfer efficiency in YF3:Yb 3/Tm3 nanocrystals through the study of Yb3 dynamics. The obtained results are compared to those previously reported in macrocrystals to analyze possible changes related to size reduction. Luminescence lifetimes are much shorter in the nanoparticles than in bulk samples, a behavior that can be related to Yb3 → Yb3 migration and the enhanced surface/volume ratio of the nanoparticles. On the other hand, Yb3 → Tm3 energy transfer macroparameter remains unaltered, demonstrating that spectroscopic intrinsic parameters such as radiative and non-radiative probabilities are not affected by size reduction. Finally, a formula that describes Yb3 lifetime dependence with Yb3 and Tm3 concentration is proposed, considering both the effects produced by migration between Yb3 ions and energy transfer from Yb3 to Tm3 ions. © 2013 AIP Publishing LLC.