Preparation and Characterization of Garnet Phosphor Nanoparticles Derived from Oxalate Coprecipitation

Terbium-activated Y3Al5O12(YAG:Tb) phosphor nanoparticles with homogeneous grain size and crystallinity have been prepared at 1000°C by heat treatment of a metal oxalate precursor derived from an alkaline coprecipitation route. The diffraction profile of as-prepared YAG:Tb nanoparticles can be indexed as a garnet structure and exhibits peak broadening phenonmenon, as revealed by X-ray diffraction (XRD) data. Grains of YAG:Tb nanoparticles appear to be irregularly spherical or elliptical and their sizes range from 60 to 70 nm, as indicated by morphological studies from bright-field transmission electron microscopy (TEM) imaging. Furthermore, the photoluminescence (PL) spectra of the (Y2.9Tb0.1)Al5O12phase were investigated to determine the energy level of electron transition related to luminescence processes and the possible blue shift in the excitation or emission PL spectra.