Blue-Green, Red, and White Light Emission of ZnWO4-based Phosphors for Low-Voltage Cathodoluminescence Applications

Abstract

and particles were prepared by refluxing in water solution using polyethylene glycol as a capping agent and then annealed at different temperatures. The samples were characterized by X-ray diffraction, Raman spectra, field-emission scanning electron microscopy, and cathodoluminescence spectra. The as-prepared amorphous samples annealed at high temperature are sanmartinite structure of , and the spherical morphologies are basically retained, except for the increase of the particles size (from 28 to 56 nm). The low-voltage luminescent properties of these tungstate phosphors can be tuned by the doping of ions and annealing treatment. and particles annealed at or above exhibit strong blue-green and white light emission under the excitation of low-voltage electron beams, respectively, the former originating from the intrinsic complex, and the latter due to the combination of the emissions arising from the intrinsic and doped ions. The as-prepared particles only emit a red light resulting from the (, 2, 3, 4) transitions of ions.