Gregory Forcherio1 2 Luigi Bonacina3 Jeremy Dunklin5 Jérémy Riporto3 4 Yannick Mugnier4 Ronan Le Dantec4 Claudia Backes6 Yana Vaynzof6 Mourad Benamara2 Donald Roper2

1, U.S. Army Research Laboratory, Adelphi, Maryland, United States
2, University of Arkansas, Fayetteville, Arkansas, United States
3, University of Geneva, Geneva, , Switzerland
5, National Renewable Energy Laboratory, Golden, Colorado, United States
4, University of Savoy Mont Blanc, Annecy, , France
6, Ruprecht-Karls University Heidelberg, Heidelberg, , Germany

Two-dimensional (2D) transition metal dichalcogenides (TMD) functionalized with plasmonic metal nanoantennas (NA) exhibit rich energy conversion capabilities as a material platform for optoelectronics and sustainable energy. This work examined (i) plasmon-enhanced nonlinear second harmonic generation (SHG) and (ii) injection of plasmonic hot electrons into 2D TMD via coordinated multi-photon microscopy, hyper Rayleigh Scattering (HRS), electron energy-loss spectroscopy (EELS), and discrete dipole computation. Augmented local fields by NA surface plasmon resonance enhanced SHG from monolayer MoS2 at efficiencies of up to 0.025 %/W. Hyper Rayleigh scattering (HRS) assessed the second-order nonlinear susceptibility for WS2 monolayers to be 250±12 pm/V. Quantum yield of plasmonic hot electrons transported to 2D TMD was measured locally for two NA-TMD hybrids by EELS, revealing dependence on bonding characteristics at the metal-TMD junction. Highest measured efficiency was 11±5% for NA physicochemically bonded to WS2 edge disulfides via redox-directed self-assembly.