Plasmon-Induced Energy Transfer and Photoluminescence Manipulation in MoS2 with a Different Number of Layers

This is the authors' abstract. We don't add key points for this paper.

Monolayer or few-layer molybdenum disulfide (MoS 2 ) with intriguing physical properties enables a wide range of applications such as photocatalysis and photodetection. The controllable light–matter interaction in MoS 2 nanoflakes with different numbers of layers is critical for developing new optoelectronic functionalities. Recently, plasmonic nanostructures have been used to obtain strong near-field enhancement for the effective photoluminescence (PL) manipulation of MoS 2 . However, it is still unclear whether the PL manipulation is dominated by electron injection processes or the strong field induced Purcell effect so far. Here, we investigate the PL manipulation of MoS 2 nanoflakes with different numbers of layers using Au nanoparticles with different aggregate states. Combining the measured PL and scattering spectra, the Kelvin probe force microscopy images at the single-particle level, and the numerical simulations, we figure out how the electron injection and strong field enhancement contribute to the PL manipulation and why PL quenching occurs in few-layer flakes but PL enhancement occurs in thicker flakes. These findings would give us a greater understanding of the interaction between two-dimensional materials and plasmonic nanostructures.