Rare-earth doped particles with tunable infrared emissions for biomedical imaging

The tunability, brightness, and energy efficiencies of infrared-emitting rare earth doped nanomaterials are important performance parameters for biomedical imaging applications. In this work, hexagonal phase NaYF4:Yb3+, Ln(3+) (Ho3+, Tm3+ and Pr3+) was synthesized and optimized using a facile hydrothermal method in the presence of poly(vinyl-pyrrolidone). Distinct infrared emission peaks were measured at 1185, 1310 and 1475 nm upon excitation at 980 nm. The optical efficiencies of NaYF4:Yb3+, Ln(3+) at optimal concentrations were measured to quantify the brightness of these particles in comparison to that of NaYF4:Yb3+, Er3+ particles. Efficiencies were ranked as Er3+>Ho3+>Tm3+>Pr3+. (C) 2013 Optical Society of America