Abstract View
Synthesis of Sodium Yttrium Fluoride-based Phosphors by Ultrasonic Spray Laser Pyrolysis
MOHAMMAD MALEKZADEH, Vishvajeet Mane, Khirabdhi Mohanty, Mark Swihart, University at Buffalo - SUNY
Abstract Number: 365
Working Group: Nanoparticles and Materials Synthesis
Abstract
NaYF4-based nanomaterials exhibit advantageous properties such as sharp emission, high photostability, high chemical stability, and low toxicity which make them appropriate for numerous medical- and energy-based applications. Doping these nanomaterials with rare-earth elements such as ytterbium, thulium, europium, and erbium endows them with useful optical properties, including conventional and upconverted photoluminescence. To date, these nanomaterials have been synthesized only by solution-phase synthesis methods. In comparison with solution-phase synthesis methods, vapor-phase (aerosol) synthesis methods benefit from fewer steps in the synthesis process, continuous operation, low chemical waste, synthesis of nanomaterials with high purity and crystallinity, synthesis of nanomaterials of different composition without developing new recipes, and production of bare particles without ligands. In this study, we employed laser pyrolysis to synthesize NaYF4-based nanoparticles. In laser pyrolysis, SF6 is usually used as a photosensitizing agent to absorb the energy of the laser and transfer it to precursors that do not absorb at the CO2 laser wavelength of 10.6 µm. However, it can also be used as a source of fluorine. We have developed a low-cost ultrasonic atomizer and employed it to spray an aqueous precursor solution of sodium acetate and yttrium acetate into the reaction zone where it is heated by a focused CO2 laser beam, with SF6 as the photosensitizer and the source of fluorine. This allowed us to produce NaYF4 nanoparticles in a single step from aqueous salt precursors. In addition, we doped the nanoparticles with rare-earth elements to produce phosphors with useful optical properties.