Topologically Enclosed Aluminum Voids as Plasmonic Nanostructures

Area of Science:

• Plasmonics and Nanophotonics
• Materials Science
• Extreme Ultraviolet (EUV) Spectroscopy

Background:

• Metallic nanoparticles with tailored geometries have revolutionized plasmonics.
• Research on inverted nanostructures (nanovoids) has been limited to 2D geometries.
• Aluminum offers favorable plasmonic properties but is challenging to study in nanoparticle form.

Purpose of the Study:

• To investigate the localized surface plasmon resonances (LSPRs) of 3D topologically enclosed nanovoids (anti-nanoparticles).
• To explore the plasmonic properties of aluminum in an anti-nanoparticle configuration.
• To achieve and tune LSPRs in the extreme ultraviolet (EUV) range.

Main Methods:

• Fabrication of 3D nanovoids with tailored shapes (truncated octahedra, 10-20 nm).
• Utilized aluminum's plasmonic properties within the nanovoid structure.
• Characterized LSPRs through optical measurements and inferred properties of pure aluminum nanoparticles.

Main Results:

• Observed strongly localized field enhancements with LSPRs in the extreme UV range.
• Demonstrated tunability of LSPR energies by altering nanovoid shape and size.
• The pristine nanovoid cavity allowed inference of pure aluminum nanoparticle LSPRs.

Conclusions:

• 3D anti-nanoparticles provide a novel platform for studying plasmonics in the EUV range.
• Aluminum anti-nanoparticles exhibit unique plasmonic behavior beyond noble metals.
• This research opens avenues for LSPR-enhanced UV photoemission spectroscopy and photoionization.