• Proença, Manuela
• Meira, Diana I.
• Rodrigues, Marco S.
• Teodoro, Orlando
• Borges, Joel
• Bundaleski, N.
• Dias, João P.
• Martin, Nicolas
• Pedrosa, Paulo
• Vaz, Filipe
• Sampaio, Paula

Abstract

<p>Nanocomposite thin films, composed of monometallic Au and Ag, and bimetallic Au[sbnd]Ag nanoparticles, dispersed in a CuO matrix were prepared, characterised and tested for Localized Surface Plasmon Resonance (LSPR) sensing. The films were deposited by reactive magnetron sputtering, followed by a post-deposition thermal annealing to modify the size and shape of the nanoparticles distribution within the oxide matrix. Regarding the main results of the monometallic systems, the Au:CuO films showed LSPR bands from 800 nm to 650 nm, which reveal a progressive narrowing and a continuous blue-shift with increasing temperature (400–700 °C). The Ag:CuO films evidenced plasmonic bands at about 400 nm for temperatures of 500 °C and above. The bimetallic system, Au-Ag:CuO, showed LSPR bands in the range between those of the corresponding monometallic systems, due to the presence of Ag enriched Au[sbnd]Ag alloy nanoparticles, taking part of Janus-like structures in some cases. In terms of LSPR sensing, Au:CuO films revealed the highest values of refractive index sensitivity since the nanoparticles are more exposed to the surrounding environment.</p>

Topics

• nanoparticle
• Deposition
• nanocomposite
• surface
• thin film
• reactive
• annealing