Deposition of ultrathin rare-earth dopedY2O3 phosphor films on alumina nanoparticles

Abstract

Ultrathin films of Eu3+ doped Y2O3 were deposited onto alumina nanoparticles using a unique solution synthesis method. Thesurface structure, composition, and morphology of the thin films deposited were analysedusing high resolution transmission electron microscopy (TEM) and high angle annular darkfield scanning TEM imaging and energy dispersive x-ray measurements. The filmsdeposited were extremely thin, on the order of 3–5 nm, and uniformly covered allthe alumina nanoparticles. X-ray diffraction was used to investigate the phasesand structures of the thin films deposited. At the heat treatment temperature of600 °C,cubic Y2O3 nanocrystals were found in the film while as-coated layers exhibited mainlyamorphous features. As the heat treatment temperature increased to750 °C, the amorphous thin film became well crystallized. Optical properties ofEu3+ doped Y2O3 films were characterized by fluorescence spectroscopy. Strongphotoluminescence was observed in the sample annealed at750 °C, from thefluorescence of Eu3+ ions in a well-crystallized film, consistent with the x-ray diffraction and TEM observations.