Surfactant-assisted phase selective sonochemical synthesis of sodium yttrium fluoride nanoparticles.

The potential of rare earth-doped sodium yttrium fluoride (NaYF) as upconverting nanoparticles extends to various applications, from electronics to biology. The hexagonal (β) phase of NaYF nanoparticles is known to exhibit a photoluminescence quantum yield higher than the cubic (α) phase. The typical synthetic methods for β-NaYF present limitations, such as low colloidal stability in aqueous medium and the need for ligand exchange.