Luminescence properties of YVO4:Ln (Ln=Nd, Yb, and Yb–Er) nanoparticles

Concentrated colloidal solutions of well dispersed YVO4:Ln (Ln=Nd, Yb, and Yb–Er) nanocrystals are synthesized through the precipitation of citrate complexes of rare earth salts with sodium orthovanadate. Luminescence spectra of aqueous suspensions of YVO4:Nd or Yb are very similar to the bulk material, with lower lifetimes of the emitting level. After heating at 600 °C, the luminescence properties of silica capped YVO4:Ln nanoparticles are significantly improved. In these conditions, YVO4:Yb, Er nanoparticles exhibit green up-conversion luminescence and 1.55 μm emission of the erbium ion under infrared excitation of the ytterbium ion.