Elongated Metal Nanocap with Two Magnetic Dipole Resonances and Its Application for Upconversion Enhancement

Abstract

A stand-alone plasmonic nanocomposite into which a metal nanostructure and an emitting material are integrated is a promising building block for optoelectronics and biophotonics devices. Here we present the plasmonic property of a nanocomposite composed of a Au elongated nanocap and a β-NaYF4 dielectric nanorod. We show that elongation of a Au nanocap results in splitting of the magnetic dipole resonance, and the resonance wavelengths can be controlled in a wide wavelength range by the aspect ratio. As an application of the elongated nanocap, we demonstrate strong enhancement of the near-infrared to visible upconversion of an Er 3+ and Yb 3+ doped β-NaYF4 nanorod by tuning the resonance wavelength of a Au nanocap placed on it to the excitation wavelength.

Enhanced up-conversion photoluminescence in fluoride–oxyfluoride nanophosphor films by embedding gold nanoparticles

“…S3c (ESI†), corresponding to the 2 H 9/2 – 4 I 15/2 transition of Er 3+ ions. 2,10,34,35 The detection of these visible emission bands of Er 3+ transitions by excitation through Yb 3+ ions confirms the UC mechanism, with energy transferred between the 2 F 5/2 and 4 I 11/2 levels of Yb 3+ and Er 3+ ions. 10,36–40 Our results also show that embedding gold NPs in nanophosphor films leads to a spectrally sensitive UCPL enhancement, which is dependent on the gold content and different for each emission band, as shown in Fig.…”

Switching to the brighter lane: pathways to boost the absorption of lanthanide-doped nanoparticles

“…The authors further expanded on this topic, achieving coating of NaYF4:Yb 3+ ,Er 3+ nanorods with gold caps using the same approach. 75 Also in that case, the emission brightness was increased capitalizing on the more efficient light absorption of the nanocomposite.…”