Lifetime and quantum yield studies of Dy3+ doped GdVO4 nanoparticles: Concentration and annealing effect

Abstract

GdVO 4 nanoparticles doped with Dy3+ have been prepared using urea hydrolysis method in ethylene glycol medium. Linear decrease in the unit cell volume indicates the quantitative substitution of Gd3+ lattice sites by Dy3+ in GdVO4. The luminescence intensity of electric dipole transition at 573 nm is more than that of magnetic dipole transition at 483 nm. This has been attributed to the asymmetric environment of Dy3+ ion in GdVO4. Luminescence intensity decreases with increasing Dy3+ concentrations due to concentration quenching. This is supported by lifetime decay studies. There is no particle size effect on the peak positions of Dy3+ emission. There is an increase in the decay lifetime for F49/2 level with increase in heat treatment from 500 to 900 °C. This is attributed to the reduction in nonradiative process arose from surface inhomogeneities. The decay lifetime data follow the biexponential to monoexponential nature with increase of Dy3+ concentrations. There is an increase in the quantum yield with the increase in heat treatment temperature.