Assembling Nanoparticles to Control Light
Cyrille Hamon
CNRS, Laboratory of Solid-State Physics, Paris-Saclay University
Video: https://univ-nantes-fr.zoom.us/s/81230190542
Gold and silver nanoparticles exhibit remarkable optical properties, which depend in particular on their size and shape. These properties have been harnessed since ancient times, as evidenced by glass colored by metal nanoparticles. When these nanoparticles are organized, their properties can be profoundly altered: interactions between particles give rise to collective properties that are not simply the sum of those of the individual nanoparticles. These plasmonic coupling phenomena can thus be harnessed to develop new functionalities, such as in plasmonic photocatalysis, surface-enhanced Raman spectroscopy (i.e., the SERS effect), or colorimetric detection (e.g., COVID-19 testing).
Our research falls within this framework and aims to understand how the shape and anisotropy of nanoparticles can be used to create materials with novel properties. In particular, we are studying the formation of structures with low symmetries that can give rise to anisotropic optical properties. We are also seeking to make these assemblies reconfigurable: to control their organization, assemble and disassemble them, modify the orientation of the nanoparticles, and, ultimately, control their interaction with light. The goal is thus to move from static plasmonic materials to materials capable of transforming their structure and optical properties in response to their environment.
