Citation
Villegas Gracia, Marina and Caballero Cuesta, Amador and Quintanilla, M. and Sanz García, J.A. and Cantelar, E. and Cussó, F.
(2011).
Preparation and characterization of stable aqueous suspensions of up-converting Er3+/Yb3+-doped LiNbO3 nanocrystals.
"Applied Physics B: Lasers and Optics", v. 102
(n. 3);
pp. 651-658.
ISSN 0946-2171.
https://doi.org/10.1007/s00340-011-4376-8.
Abstract
The preparation of LiNbO3:Er3+/Yb3+ nanocrystals and their up-conversion properties have been studied. It is demonstrated that polyethyleneimine- (PEI) assisted dispersion procedures allow obtaining stable aqueous LiNbO3:Er3+/Yb3+ powder suspensions, with average size particles well below the micron range (100–200 nm) and the isoelectric point of the suspension reaching values well above pH 7. After excitation of Yb3+ ions at a wavelength of 980 nm, the suspensions exhibit efficient, and stable, IR-to-visible (green and red) up-conversion properties, easily observed by the naked eye, very similar to those of the starting crystalline bulk material.
