Nanoscale Manipulation of Exciton–Trion Interconversion in a MoSe₂ Monolayer via Tip-Enhanced Cavity-Spectroscopy

Abstract

Emerging light−matter interactions in metal−semiconductor hybrid platforms have attracted considerable attention due to their potential applications in optoelectronic devices. Here, we demonstrate plasmon-induced near-field manipulation of trionic responses in a MoSe 2 monolayer using tip-enhanced cavity-spectroscopy (TECS). The surface plasmon−polariton mode on the Au nanowire can locally manipulate the exciton (X 0 ) and trion (X-) populations of MoSe 2 . Furthermore, we reveal that surface charges significantly influence the emission and interconversion processes of X 0 and X-. In the TECS configuration, the localized plasmon significantly affects the distributions of X 0 and X-due to the modified radiative decay rate. Additionally, within the TECS cavity, the electric doping effect and hot electron generation enable dynamic interconversion between X 0 and X-at the nanoscale. This work advances our understanding of plasmon−exciton− hot electron interactions in metal−semiconductor−metal hybrid structures, providing a foundation for an optimal trion-based nano-optoelectronic platform.

Photoluminescence and Raman Enhancement by Edge Plasmons in MnPS3

“…Both PL 1 and PL 2 components showed similar PL suppression in the edge areas as shown in Figure ,d, and in the spatial profiles in Figure g, which correspond to the orange dashed arrow. Hot electron tunneling may also affect the PL spectral shape, for example, due to the exciton/trion interconversion in monolayer MoSe 2 . However, no PL spectral changes were observed in the quantum regime in the MnPS 3 flakes.…”