Hydrothermal diffusion of Eu3+ in EuVO4@YVO4 core-shell nanoparticles and its influence on luminescent properties

EuVO4@YVO4 core-shell nanoparticles (NPs) are synthesized, coated by poly(sodium 4-styrenesulfonate) and hydrothermally treated at 200 ℃ for 0-48 h. The photoluminescence (PL) intensity of as-prepared sample is enhanced by about 5 times after 48-hour hydrothermal treatment, and the average lifetime is raised up from 0.410 ms to 0.579 ms. Further studies of hydrothermal time-dependent PL decay curves provide evidence for the diffusion of Eu3+ in core-shell NPs, which could reduce the concentration quenching in particle core and hence enhance the PL efficiency. This thermal diffusion strategy based on ion-doped core-shell NPs could be used to prepare luminescent NPs with high efficiency if designed elaborately.