Synthesis of water-soluble β-NaYF4 nanocrystals in a green way†
Abstract
Pure β-NaYF4 nanocrystals with a hexagonal phase were synthesized in a novel way at low temperature using sparingly soluble rare-earth salts as precursors and ethanol–water as the solvent. The phase of the products could be controlled by adjusting the water content. An up-converting aqueous colloidal solution and a transparent film were obtained through a simple post-treatment.