High Up-Conversion Efficiency of YVO4:Yb,Er Nanoparticles in Water down to the Single-Particle Level

Genevieve Mialon (1) , Silvan Tuerkcan (2) , Geraldine Dantelle (1) , Daniel P. Collins (3) , Maria Hadjipanayi (3) , Robert A. Taylor (3) , Thierry Gacoin (1) , Antigoni Alexandrou (2) , Jean-Pierre Boilot (1)

1 LPMC - Laboratoire de physique de la matière condensée
2 LOB - Laboratoire d'optique et biosciences
3 Clarendon Laboratory [Oxford]

We report up-conversion emission from an aqueous solution of YVO4:Yb3+,Er3+ nanocrystals synthesized by an original method that produces nanoparticles with excellent crystallinity and no porosity. We show that these YVO4:Yb3+,Er3+ nanocrystals are not very sensitive to nonradiative relaxations, leading to a high green-to-red emission ratio of 6.3. Using a comparison with YVO4:Eu3+ particles, we determined the quantum yield of the up-conversion emission of the aqueous YVO4:Yb3+,Er3+ dispersion to be 0.09 +/- 0.04% for an excitation intensity of only 0.55 kW.cm(-2) at 970 nm. Furthermore, single YVO4:Yb,Er particles with an estimated size down to 10 nm can be detected using a wide-field microscope under a 970 nm, 8 kW.cm(-2) excitation. Because of their unexpectedly high up-conversion emission without intermittency, their water dispersibility, and their photostability, YVO4:Yb3+,Er3+ nanoparticles are highly appropriate both for single-biomolecule and for in vivo imaging.

Genevieve Mialon, Silvan Tuerkcan, Geraldine Dantelle, Daniel P. Collins, Maria Hadjipanayi, et al.. High Up-Conversion Efficiency of YVO4:Yb,Er Nanoparticles in Water down to the Single-Particle Level. Journal of Physical Chemistry C, 2010, 114 (51), pp.22449. ⟨10.1021/jp107900z⟩. ⟨hal-00805072⟩