Synthesis and reaction kinetics for monodispersive Y2O3:Tb3+ spherical phosphor particles

Monodispersive Y2O3:Tb3+ spherical phosphor was synthesized by homogenous precipitation process. By using X-ray diffractometer, thermogravimetric analysis (TGA), transmission and scanning electron microscopes, and inductively coupled plasma (ICP)-optical emission spectrometry (OES), the precipitation behaviors were analyzed. The results indicated that the kinetics of the hydrolysis reaction of Y3+ and Tb3+ was a zero-order reaction, controlled by the decomposition of urea with an activation energy of 131 kJ/mol. Besides, the effect of urea concentration, reaction temperature, and aging time for the control of the precipitate size were also investigated. The dopant Tb3+ in the solution did not significantly influence the precipitation of the yttrium component. After 800 °C calcination, the Y2O3:Tb3+ powder showed nano-crystalline characteristics and emitted strong green light by a UV excitation light source.