Colloidal Nanoparticles of Ln³⁺-Doped LaVO₄:  Energy Transfer to Visible- and Near-Infrared-Emitting Lanthanide Ions

Abstract

Colloidal, organic solvent-soluble Ln3+-doped LaVO4 nanoparticles have been synthesized by a precipitation reaction in the presence of (C18H37O)2PS2- as ligand, that coordinates to the surface of the nanoparticles. The materials are well soluble in chlorinated solvent such as chloroform. Energy transfer of excited vanadate groups has been observed for Ln3+ ions that emit in the visible and the near-infrared (Eu3+, Tm3+, Nd3+, Er3+, Ho3+, Dy3+, Sm3+, Pr3+), thus making it a very generic sensitization mechanism. The LaVO4 nanoparticles have a different crystal structure than bulk LaVO4 ones (xenotime instead of monazite), similar to YVO4 nanoparticles. This xenotime crystal structure results in a more asymmetric crystal field around the Ln3+ ions that is advantageous to their luminescence, for it increases the radiative rate constant, thus reducing quenching processes.

Optically stimulated heating using Nd3+ doped NaYF4 colloidal near infrared nanophosphors

“…This simple approach should increase the nanoradiative relaxation rate to 2.3 × 10 10 s −1 , which is over 3.3 × 10 4 times higher than that for the matrix studied here. The efficient synthesis protocols of homogenous water colloidal solution of oxide NPs have been developed [26][27][28] and studied for bioimaging applications.…”

Monazite and Zircon Type LaVO4:Eu Nanocrystals – Synthesis, Luminescent Properties, and Spectroscopic Identification of the Eu3+ Sites

“…Therefore, among the rare-earth-ion-activated Ln-based luminescence materials, LaVO 4 :Eu was chosen as it has two crystal phases (monazite and zircon) and it can be selectively investigated for its structure-related properties on the nanometer scale. There have been some reports on LaVO 4 :Eu nanocrystals; [11,[17][18][19][20][21][22][23] however, luminescence studies of both m-and t-LaVO 4 :Eu nanocrystals are still limited.…”

Dispersible Tm3+‐Doped Nanoparticles that Exhibit Strong 1.47 μm Photoluminescence

“…[2] In addition to the 1.4 lm emission band, a large amount of research is also being carried out to develop the 1.8 lm emission band of thulium, which has become of interest for light detection and ranging (LIDAR), remote sensing, and potential medical laser applications. [3] Other important applications of Tm 3+ -doped materials have occurred in the field of nanoparticle up-conversion technology, [4][5][6][7][8][9] where excitation with low energy (e.g., near-IR light) results in higher energy emission (e.g., visible region), and are being developed for, among others, display technology (flatscreen display), [4,10] blue-laser diodes, [11] and biolabel technology. [12][13][14][15][16][17] Limited work has been published on the development of Tm 3+ -doped nanoparticles for near-IR applications such as telecommunications and laser-diode technology.…”