Influence of surface quenching on luminescence dynamics of ion centers in nanocrystals

In this paper, the influence of surface quenching on decay curve and quantum efficiency of ion centers in nanoparticles were discussed by considering energy transfer between doped ions and surface quench centers. With isotropic and continuum approximation, energy transfer rate of an ion at position r within a spherical nanoparticle to all the surface quench centers was calculated. Quantum efficiency and decay curve under nonselective excitation were then calculated numerically by integrating over the sample. The calculated decay curve was fitted to the experimental one measured in Eu3+-doped YVO4 nanoparticles. The ratio of the quantum efficiency of YVO4:Eu3+ nanoparticle (R=13.5 nm) to that of the bulk is 17%, estimated with the parameters obtained from the fitting.