170 / 2024-06-14 12:32:08

Stability of nanofocusing plasmonic tips for TERS spectroscopy

plasmonics,ters,Raman spectroscopy

In this research, our focus lies in investigating the durability of nanofocusing plasmonic elements for Tip-Enhanced Raman Spectroscopy (TERS) applications, particularly in high-temperature environments that takes place in the experiments. We aim to identify robust configurations capable of withstanding external influences, addressing challenges related to maintaining the shape and performance of plasmonic nanostructures when exposed to intense heat, which can affect their light-concentrating abilities.

We study the stability of these structures against factors such as temperature variations, environmental conditions, and optical radiation. Surface atom drift commonly causes shape instability in nonspherical plasmonic nanoparticles, emphasizing the importance of exploring strategies to stabilize particle surfaces.

Utilizing advanced molecular dynamics simulation tools like LAMMPS, we are analyzing the behavior of sharp-edged gold nanotetrahedra of different sizes (up to 26000 atoms in the nanoparticle), to observe shape degradation and its impact on light-concentrating properties. Through simulations with the Ex-DIM (Extended Discrete Interaction Model) and the FEM, we are tracking changes in the local electromagnetic field at the plasmon resonance wavelength near the apex of these gold nanotetrahedra. This provides valuable insights into the evolution of the field enhancement factor as the plasmonic tips degrade.

The study was supported by the Russian Science Foundation grant No. 24-12-00195, https://rscf.ru/project/24-12-00195/