Uniform and efficient photocarrier collection in monolayer MoS2 via Ag nanogroove integration

Abstract

The integration of two-dimensional transition metal dichalcogenides (TMDs) with plasmonic nanostructures offers a promising route to enhance light-matter interactions and interfacial charge transport in optoelectronic devices. Here, we demonstrate that Ag nanogroove array (AgNG) with a period of 350 nm enables efficient, spatially uniform, and polarization-selective photocarrier collection from MoS2, a representative TMD material. Raman and photoluminescence analyses reveal that AgNG suppresses electron depletion at the MoS2-Ag interface, leading to red-shifted Raman peaks and trion-dominated emission spectra. Kelvin probe force microscopy measurements under illumination show light-induced potential increases up to 40 mV, indicating efficient photocarrier generation and transfer. Notably, polarization- and wavelength-dependent variations in potential provide direct evidence that propagating surface plasmons mediate polarization-selective charge transfer, even at photon energies far from the exciton resonances of MoS2. These findings underscore the versatility of nanostructured electrodes as a platform for achieving efficient and tunable photocarrier collection in TMD-based optoelectronic devices.