Nanoparticles with tunable shape and composition fabricated by nanoimprint lithography

Area of Science:

• Nanotechnology
• Materials Science
• Plasmonics

Background:

• Noble metal nanoparticles with cone-like and empty cup-shapes exhibit unique optical properties.
• These nanoparticles are valuable for applications such as optical nanoantennas and nanoresonators.
• Current large-scale production methods for these nanoparticles are limited.

Purpose of the Study:

• To present a novel fabrication approach for producing arrays of nanoparticles with tunable shapes and compositions.
• To overcome the limitations of standard nanofabrication methods for large-scale nanoparticle production.

Main Methods:

• A combination of nanoimprint lithography, hard-mask definition, and various metal deposition techniques was employed.
• Fabrication of arrays of empty cup-shaped gold nanoparticles was achieved.

Main Results:

• Successfully produced arrays of empty cup-shaped gold nanoparticles.
• Observed distinct optical responses linked to localized surface plasmon excitations.
• Demonstrated tunability in nanoparticle shape and composition.

Conclusions:

• The presented fabrication route effectively produces nanoparticles with controllable optical properties.
• This method avoids common drawbacks of conventional top-down nanofabrication, including aspect ratio limitations and low throughput.
• The approach is suitable for fabricating nanoparticles with heterogeneous compositions.