Surface enhanced resonant Raman scattering in hybrid MoSe 2 @Au nanostructures

Inès Abid (1) , Weibing Chen (2) , Jiangtan Yuan (2) , Sina Najmaei (2, 3) , Emil Peñafiel (4) , Renaud Péchou (1) , Nicolas Large (5, 4) , Jun Lou (2) , Adnen Mlayah (1, 6)

1 CEMES-NeO - Nano-Optique et Nanomatériaux pour l'optique
2 Rice University [Houston]
3 ARL - U.S. Army Research Laboratory [Adelphi, MD]
4 UTSA - The University of Texas at San Antonio
5 CEMES - Centre d'élaboration de matériaux et d'études structurales
6 LAAS-PHOTO - Équipe Photonique

We report on the surface enhanced resonant Raman scattering (SERRS) in hybrid MoSe2@Au plasmonic-excitonic nanostructures, focusing on the situation where the localized surface plasmon resonance of Au nanodisks is finely tuned to the exciton absorption of monolayer MoSe2. Using a resonant excitation, we investigate the SERRS in MoSe2@Au and the resonant Raman scattering (RRS) in a MoSe2@SiO2 reference. Both optical responses are compared to the non-resonant Raman scattering signal, thus providing an estimate of the relative contributions from the localized surface plasmons and the confined excitons to the Raman scattering enhancement. We determine a SERRS/RRS enhancement factor exceeding one order of magnitude. Furthermore, using numerical simulations, we explore the optical near-field properties of the hybrid MoSe2@Au nanostructure and investigate the SERRS efficiency dependence on the nanodisk surface morphology and on the excitation wavelength. We demonstrate that a photothermal effect, due to the resonant plasmonic pumping of electron-hole pairs into the MoSe2 layer, and the surface roughness of the metallic nanostructures are the main limiting factors of the SERRS efficiency.

Domaines: Physique [physics]; Matière Condensée [cond-mat]

Inès Abid, Weibing Chen, Jiangtan Yuan, Sina Najmaei, Emil Peñafiel, et al.. Surface enhanced resonant Raman scattering in hybrid MoSe 2 @Au nanostructures. Optics Express, 2018, 26 (22), pp.29411. ⟨10.1364/OE.26.029411⟩. ⟨hal-01921184⟩