Remarkable fluorescence enhancement in YVO4:Eu3+@Ag nano-hybrids induced by interface effect

Abstract

The luminescence enhancement effect induced by the coupling of noble metal nanoparticles (NPs) with rare earth (RE) doped nanophosphors is attracting current interests. In order to obtain efficient luminescence enhancement and clarify its physical nature, the YVO₄:Eu³⁺@Ag core-shell nano-hybrids colloids were first prepared by a facile two-step seed-mediated growth method. The luminescence enhancement of ⁵D₀–⁷F_J transition for Eu³⁺ with a maximal factor of ∼one order was observed, which strongly depended on the amount of silver NPs, the concentration of the YVO₄:Eu³⁺ colloids and the dissolved solutions. The enhancement mechanism was carefully discussed based on absorption spectra, emission spectra, luminescent decay dynamics and zeta potentials of colloids solutions. The results indicate that the silver NPs on the surface of YVO₄:Eu³⁺ can effectively prevent VO₄³⁻ and Eu³⁺ from the interaction with the solvent such as OH bonds, leading to a decrease of nonradiative energy transfer (ET) and suppressed luminescent quenching. A detailed model was proposed to explain the interesting luminescence enhancement behavior.