Optical properties of afterglow nanoparticles Sr 2 MgSi 2 O 7: Eu 2+, Dy 3+ capped with polyethylene glycol

Abstract

The optical properties of afterglow nanoparticles were successfully improved by the addition of polyethylene glycol (PEG) to an afterglow colloidal solution. Afterglow nanoparticles Sr 2 MgSi 2 O 7: Eu 2+, Dy 3+ were prepared by laser ablation in liquid. The quantum yields and the decay curves were measured by a fluorescence spectrophotometer. An increase in the amount of PEG added to the solution increased the quantum yield of the nanoparticles and improved the afterglow property in the initial portion of the decay curve. However, the afterglow property did not change after a substantial amount of time had passed. The afterglow nanoparticles were capped with PEG molecules, and surface defects of the nanoparticles were passivated, which decreased the optical properties. © 2012 Fumitaka Yoshimura et al.