Hybridized Plasmons in Au Nanowire Dimers Enable Polarization-Selective Exciton Modulation and Hot-Electron Injection in MoS2

Abstract

Hybridized plasmon modes in coupled metal nanostructures offer unique opportunities to tailor light-matter interactions and interfacial charge transfer at the nanoscale, surpassing the capabilities of isolated plasmonic elements. In this work, we compare the optical and electrical characteristics of MoS2 monolayers integrated with single Au nanowires (S-NWs) and Au nanowire dimers (D-NWs). While S-NW supports a transverse plasmonic resonance at similar to 500 nm, D-NW exhibits an additional hybridized plasmon resonance at similar to 650 nm originated from strong near-field coupling. This hybridized mode leads to significantly enhanced polarization-selective photoluminescence in MoS2/D-NW integrated systems, accompanied by pronounced modulation of the exciton-to-trion population ratio. Furthermore, polarization- and wavelength-dependent Kelvin probe force microscopy directly visualizes nanoscale surface potential changes, providing real-space evidence of plasmon-mediated hot-electron injection from D-NW into MoS2 at the contact regions. These results demonstrate that D-NWs enable enhanced and tunable plasmon-exciton-charge interactions, establishing TMD/D-NW architectures as a versatile platform for high-performance optoelectronic devices.