Preparation and photoluminescence enhancement of Li+ and Eu3+ co-doped YPO4 hollow microspheres

Li+ and Eu3+ co-doped YPO4 hollow microspheres were successfully synthesized by a sacrificial template method using polystyrene (PS) as template. Techniques of X-ray diffraction (XRD), scanning electron microscopy (SEM), as well as transmission electron microscopy (TEM) were employed to characterize the as-synthesized sample. Furthermore, the photoluminescence (PL) characterization of the Li+ and Eu3+ co-doped YPO4 microsphere was carried out and the effects of the doping concentration of Li+ and Eu3+ active center concentration as well as calcination temperature on the PL properties were studied in detail. The results showed that the incorporation of Li+ ions into the YPO4:Eu3+ lattice could induce a remarkable improvement of the PL intensity. The highest emission intensity was observed with the compound of 5%Li+ and 5%Eu3+ co-doped YPO4, whose brightness was increased by a factor of more than 2.2 in comparison with that of the YPO4:5%Eu3+.