Influence of Eu~(3+) doping content on photoluminescence of Gd_2O_3:Eu~(3+) phosphors prepared by liquid-phase reaction method

摘要

Europium-doped cubic Gd_2O_3:Eu~(3+) 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 Eu~(3+) loading on the optical properties of phosphors by using XRD, TEM, BET, spectrometer and fluorometer. The size of Gd_2O_3:Eu~(3+) 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 Eu~(3+) doping ion distribution was uniform and homogeneous up to the 10 wt% loading because no concentration quenching effect was observed. However, further Eu~(3+) doping above 10 wt% reduced the luminescence due to the concentration quenching effect, as deduced from the shortening of the decay time.