Core–spacer–shell structured NaGdF4:Yb3+/Er3+@NaGdF4@Ag nanoparticles for plasmon-enhanced upconversion luminescence†
Abstract
To increase emission of up-converting materials, NaGdF4:20%Yb3+/2%Er3+@NaGdF4@Ag up-converting nanoparticles (UCNPs) in core–spacer–shell structure have been designed and fabricated. Significant emission enhancement compared with ordinary NaGdF4:20%Yb3+/2%Er3+ has been obtained. Furthermore, the enhancement mechanism have been found as the protective effect of NaGdF4 and localized surface plasmon resonance (LSPR) of Ag.