Title of seminar: Gap plasmon antennas: light/material interaction in nano-cavities
Abstract :
We develop and study theoretically plasmonic nano-cavities where electrically or optically active materials are precisely positioned within the cavity for optoelectronic based applications and devices. Plasmon gap resonances with metal nanocubes represent a fascinating and technologically significant phenomenon in the field of nanophotonics. Plasmons are collective oscillations of electrons in a metal, and when confined within nanoscale structures like cubes, they exhibit unique behaviors, particularly in the interparticle gaps.
First, we explore a new paradigm, coming from the microwave community, in which the light wave-like behavior is exploited to convert free-propagating electromagnetic waves at optical frequencies into direct current. We investigate optical rectennas composed of plasmonic nano-antennas associated with rectifying diodes to directly convert light into electricity. The main advantage of this technology comes from the ability to convert electromagnetic waves into electricity from far infrared to the visible range with potential high-power conversion efficiency (PCE). In our approach, we propose to study the interplay between nano-scale molecular electronics and plasmonics and the development of new functional nanostructured materials for energy harvesting. Our research efforts have resulted in the fabrication of nanopatch antennas able to couple resonant gap plasmon in nano-cavities integrating electrically active molecules and constructed with metallic nanocubes using a bottom-up approach. These nano-patch antennas are coupled with high-frequency molecular diodes to convert electromagnetic waves at optical frequencies.
On a second approach, emitters placed within plasmonic nano-cavities that support intense optical confinement experience an environment that changes their coupling to light. In the weak-coupling regime light extraction is enhanced, but more profound effects emerge in strong coupling regime, where mixed light-matter states are generated. This new field of research in the LUMEN-PV team, concerns the study and development, through modeling and optical characterization, of patch nano-antennas integrating two-dimensional (2D) materials such as transition metal dichalcogenides (TMDs) in order to propose a valid design for LED fabrication.