Nanoscale Manipulation of Exciton-Trion Interconversion in a MoSe<sub>2</sub> Monolayer via Tip-Enhanced Cavity-Spectroscopy.

Kang, Mingu; Kim, Su Jin; Joo, Huitae; Koo, Yeonjeong; Lee, Hyeongwoo; Lee, Hyun Seok; Suh, Yung Doug; Park, Kyoung-Duck · Nano Lett · 2024

basic_science · Level V

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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<sub>2</sub> monolayer using tip-enhanced cavity-spectroscopy (TECS). The surface plasmon-polariton mode on the Au nanowire can locally manipulate the exciton (X<sub>0</sub>) and trion (X-) populations of MoSe<sub>2</sub>. Furthermore, we reveal that surface charges significantly influence the emission and interconversion processes of X<sub>0</sub> and X-. In the TECS configuration, the localized plasmon significantly affects the distributions of X<sub>0</sub> 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<sub>0</sub> 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.