Eric LE MOAL, de l’Institut des Sciences Moléculaires d’Orsay (ISMO) donnera un séminaire intitulé “Widefield optical microscopy of tip-induced electroluminescence in 2D materials” le mardi 10 novembre 2026 à 14h00 dans la salle Pierre Cotton de notre laboratoire, campus St Jérôme à Marseille.
Résumé en anglais : The scanning tunneling microscope (STM) is not only a surface science tool capable of producing atomically resolved images of crystalline surfaces; it is also an extraordinary instrument for nano-optics. The inelastic tunneling current between the STM tip and the sample surface leads to extremely localized excitation of existing optical modes. Thus, the tip-sample junction can behave as a nanosource of photons, plasmons, or excitons, depending on the nature of the sample. In this presentation, I will discuss research that demonstrates the potential of integrating an STM with an optical microscope to study electron-exciton interactions in atomically thin semiconductor materials (i.e., monolayers of transition metal dichalcogenides). More precisely, we combine highly localized excitation under the STM tip with wide-field optical microscopy (to image the spatial distribution of the emission) and deconvolution of the optical images using the iterative Richardson-Lucy algorithm (to achieve spatial resolution beyond the diffraction limit). This approach sheds light on the role of charge-carrier and exciton transport in the electroluminescence properties of these materials.
Le séminaire est ouvert à tous avec accès gratuit, organisation Jérôme Wenger, Loïc Le Goff et Guillaume Baffou.
Contact : Eric LE MOAL, chercheur CNRS à l’ISMO, équipe Nanophysique et Surfaces (Nano-optique sous pointe)
