Influence of Eu3+ doping content on photoluminescence of Gd2O3:Eu3+ phosphors prepared by liquid-phase reaction method

Europium-doped cubic Gd2O3:Eu3+ nanoparticles containing various activator content in the range of 5-15 wt% were synthesized by a liquid-phase reaction method to investigate the influence of Eu3+ loading on the optical properties of phosphors by using XRD, TEM, BET, spectrometer and fluorometer. The size of Gd2O3:Eu3+ powders was in the range 21-41 nm. The phosphors showed an initial increase in luminescence and then a subsequent decrease with further doping (above 10 wt%). The decay time was reduced with increasing Eu loading; however, it decreased significantly above the 10% Eu doping. From spectroscopic studies, the Eu3+ doping ion distribution was uniform and homogeneous up to the 10 wt% loading because no concentration quenching effect was observed. However, further Eu3+ doping above 10 wt% reduced the luminescence due to the concentration quenching effect, as deduced from the shortening of the decay time.