Plasmon Induced Charge Transfer Dynamics in Metallic Nanoparticle-MoSe2 Nanoflake Heterostructures

Abstract

Plasmon-induced hot carrier dynamics are crucial in various practical applications such as water splitting and photovoltaics. A hybrid system formed by interfacing plasmonic Au or Ag metal nanoparticles with triangular MoSe₂ nanoflakes is proposed, which also possess edge-localized plasmons. Using time-dependent density functional theory-based simulations, this bi-plasmonic system is shown to exhibit interfacial charge transfer induced by plasmonic excitations of either component. Tracking the fate of photoinduced plasmons in the system reveals that a significant pathway to their decay involves the direct transfer of hot-carriers across the interface. This study finds that while the likelihoods of both the direct hot-electron and hot-hole transfers are comparable, in most cases considered, the latter dominates. The extent and net direction of direct charge transfer are found to depend on various tunable features of the interface, including the plasmon mode (nanoparticle or nanoflake) excited and the polarization of the light used. It is anticipated that this platform could prove extremely useful for widening the substrate scope in photocatalysis and photodetection applications.