Improved Performance of Spherical BaWO[sub 4]:Tb[sup 3+] Phosphors for Field-Emission Displays

Spherical phosphors were prepared by the polyol method and postannealed at . A variety of properties were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, Fourier transform IR spectra, low-voltage cathodoluminescence, photoluminescence spectra, and lifetime. The as-prepared phosphors were well-crystallized under relatively low synthesis temperature and composed of spherical particles with an average size of . After postannealing treatment, crystallinity of the phosphors is significantly improved and average particle size is increased to around . Under low-voltage excitation of electron beam, bright green cathodoluminescence was observed, which is attributed to the characteristic emissions from ( and transitions). The luminance was significantly improved from after postannealing, which is mostly attributed to the improvement of crystallinity.