Enhanced upconversion luminescence on the plasmonic architecture of Au–Ag nanocages

Abstract

Au–Ag nanocages with tunable surface plasmon resonance peaks were synthesized via the galvanic replacement reaction. These tunable nanocubes with strong plasmonic effect were further fabricated into thin films composed of a random assembly of Au–Ag nanocages, which show great broadening of surface plasmon resonance absorption. After optimizing, through coupling with the excitation light, the overall upconversion luminescence intensity of NaYF₄:Yb³⁺, Er³⁺ on the surface of the Au–Ag nanocage film under 980 nm excitation was improved more than 15 fold.