Luminescence study of Eu3+ doped GdVO4 nanoparticles: Concentration, particle size, and core/shell effects

Abstract

Nanoparticles of ${\text{GdVO}}_4$ doped with ${\text{Eu}}^{3+}$ and core/shell of ${\text{GdVO}}_4:{\text{Eu}}^{3+}/{\text{GdVO}}_4$ are prepared by urea hydrolysis method using ethylene glycol as capping agent as well as reaction medium at $130°\text{C}$ . Unit cell volume increases when ${\text{GdVO}}_4$ is doped with ${\text{Eu}}^{3+}$ indicating the substitution of ${\text{Gd}}^{3+}$ lattice sites by ${\text{Eu}}^{3+}$ . From luminescence study, it is confirmed that there is no particle size effect on emission positions of ${\text{Eu}}^{3+}$ . Optimum luminescence intensity is found to be in $5–10\text{at}\text{.}\%$ ${\text{Eu}}^{3+}$ . Above these concentrations, luminescence intensity decreases due to concentration quenching effect. There is an enhancement in luminescence intensity of core/shell nanoparticles. This has been attributed to the reduction in surface inhomogenities of ${\text{Eu}}^{3+}$ surroundings by bonding to ${\text{GdVO}}_4$ shell. The lifetime for ${{}^{5}D}_0$ level increases with annealing and core/shell formation.