Keynote Exciton-Plasmon interaction in Hybrid Transition Metal Dichalcogenide/Gold Nanostructures

Abstract

Monoatomic layers of Transition Metal Dichalcogenide materials have recently triggered a strong interest due to theirunique optical, electronic and spintronic properties. These properties arise from the combination of ultimate excitonconfinement in two dimensions, strong spin-orbit interaction at the valence band edges and non-centrosymmetric crystalstructure. Transition Metal Dichalcogenide (TMD) MX2 (where M is Mo or W and X is S, Se or Te) are very promising for applicationsas they might be exploited in a new class of opto-electronic devices based not only on the charge and spin degrees offreedom but also on the valley polarization induced by circularly polarized light pumping. On the other hand, surface plasmonssustained by metal nanoparticles have been extensively investigated in recent years because of their ability to capture, confineand guide light at the nanoscale and in a broad spectral range. Hence, it is very interesting to fully integrate TMD monolayersand metallic resonators within hybrid excitonic/plasmonic nanostructures with the aim of generating new optical excitationsbased on the near-field interaction between localized surface plasmons and confined excitons.Various applications are targeted :plasmonic enhanced sensitivity of field-effect transistors and photodetectors, enhanced photocatalytic water splitting, enhancedphotoluminescence emission via direct plasmon-to-exciton conversion. In this presentation, I will discuss the physics of theplasmonic-excitonic near-field interaction in various hybrid TMD/Metal nanostructures and present recent experimental resultsobtained by optical spectroscopy techniques and simulations.