Modification on luminescent properties of SrAl2O4:Eu2+, Dy3+ phosphor by Yb3+ ions doping

The modification effect of the doping of Yb3+ ions, as an auxiliary activator, onto the luminescent properties of SrAl2O4:Eu2+, Dy3+ phosphor was studied for the first time. The phosphorescent nanoparticles were prepared by the combustion method. The experimental results indicate that the appropriate doping of Yb3+ ions largely improves phosphorescence of the phosphors with more intense luminescence, higher brightness, and no change in emission spectrum peaked at 513 nm. Meanwhile the decay speed of the phosphor nanoparticles rises increasingly with the doping ratio of Yb3+ ions, whereas an excessive Yb3+ ions doping leads to the disappearance of the pure monoclinic phase of SrAl2O4 and the appearance of the weak diffraction lines of the YbAlO3 phase. The phosphorescent mechanism of the phosphors could be well understood based on the hole, thermally released from the trap levels of Dy3+ and Yb3+.