Resonant surface plasmon-exciton interaction in hybrid MoSe2@Au nanostructures.
I Abid, A Bohloul, S Najmaei, C Avendano, H-L Liu, R Péchou, A Mlayah, J Lou
Author Information
I Abid: Centre d'Elaboration de Matériaux et d'Etudes Structurales, UPR 8011, CNRS-Université de Toulouse, 29 rue Jeanne Marvig, BP 94347, F-31055 Toulouse, France. adnen.mlayah@cemes.fr.
A Bohloul: Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA. jlou@rice.edu.
S Najmaei: Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA. jlou@rice.edu and United States Army Research Laboratories, Sensors and Electron Devices Directorate, 2800, Powder Mill Road, Adelphi, MD 20783, USA.
C Avendano: Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA. jlou@rice.edu.
H-L Liu: Department of Physics, National Taiwan Normal University, Taipei 11677, Taiwan.
R Péchou: Centre d'Elaboration de Matériaux et d'Etudes Structurales, UPR 8011, CNRS-Université de Toulouse, 29 rue Jeanne Marvig, BP 94347, F-31055 Toulouse, France. adnen.mlayah@cemes.fr.
A Mlayah: Centre d'Elaboration de Matériaux et d'Etudes Structurales, UPR 8011, CNRS-Université de Toulouse, 29 rue Jeanne Marvig, BP 94347, F-31055 Toulouse, France. adnen.mlayah@cemes.fr.
J Lou: Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA. jlou@rice.edu.
In this work we investigate the interaction between plasmonic and excitonic resonances in hybrid MoSe2@Au nanostructures. The latter were fabricated by combining chemical vapor deposition of MoSe2 atomic layers, Au disk processing by nanosphere lithography and a soft lift-off/transfer technique. The samples were characterized by scanning electron and atomic force microscopy. Their optical properties were investigated experimentally using optical absorption, Raman scattering and photoluminescence spectroscopy. The work is focused on a resonant situation where the surface plasmon resonance is tuned to the excitonic transition. In that case, the near-field interaction between the surface plasmons and the confined excitons leads to interference between the plasmonic and excitonic resonances that manifests in the optical spectra as a transparency dip. The plasmonic-excitonic interaction regime is determined using quantitative analysis of the optical extinction spectra based on an analytical model supported by numerical simulations. We found that the plasmonic-excitonic resonances do interfere thus leading to a typical Fano lineshape of the optical extinction. The near-field nature of the plasmonic-excitonic interaction is pointed out experimentally from the dependence of the optical absorption on the number of monolayer stacks on the Au nanodisks. The results presented in this work contribute to the development of new concepts in the field of hybrid plasmonics.
