Tailoring plasmonic resonances in Cu-Ag metal islands films
The plasmonic response of Cu-Ag metal islands films is investigated. Films are obtained by subsequent electron beam deposition of Ag and Cu using different fabrication conditions: deposited mass thickness, substrate temperature and post-deposition annealing in vacuum. Optical properties of films are...
| Autores: | , , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Universitat Autònoma de Barcelona |
| Repositorio: | Dipòsit Digital de Documents de la UAB |
| Idioma: | inglés |
| OAI Identifier: | oai:ddd.uab.cat:271931 |
| Acceso en línea: | https://ddd.uab.cat/record/271931 https://dx.doi.org/urn:doi:10.1016/j.apsusc.2021.150260 |
| Access Level: | acceso abierto |
| Palabra clave: | Surface plasmon resonance Metal islands films Ellipsometry Optical properties Dewetting Electron microscopy Janus nanoparticles |
| Sumario: | The plasmonic response of Cu-Ag metal islands films is investigated. Films are obtained by subsequent electron beam deposition of Ag and Cu using different fabrication conditions: deposited mass thickness, substrate temperature and post-deposition annealing in vacuum. Optical properties of films are investigated by spectroscopic ellipsometry and correlated with the structural characterization results obtained by electron microscopy. It is observed that Ag enhances island growth and increases the percolation threshold of Cu films. The localized surface plasmon resonance of isolated particles shows signatures of both Cu and Ag. Moderate thermal annealing enhances island growth and favours Janus-like morphology, increasing the Ag contribution to the surface plasmon resonance. In case of percolated films, annealing-induced dewetting can lead to the appearance of large and irregular particles with a remarkable absorption peak in the near-infrared range. Composition and optical properties of the films can be further modified by Ag partial evaporation upon annealing at high temperatures. The variation of optical properties with aging is related to Cu oxidization and follows different trends depending on the sample morphology. Overall, it is shown that Cu-Ag island films are compelling systems for plasmonic applications, as their optical response can be widely and easily tuned by adjusting fabrication conditions. |
|---|