Manipulation of photoluminescence of two-dimensional MoSe₂ by gold nanoantennas

Monolayer molybdenum diselenide (MoSe₂), a member of the TMDCs family, is an appealing candidate for coupling to gold plasmonic nanostructures as it has smaller bandgap and higher electron mobility in comparison to frequently studied molybdenum disulfide (MoS₂). The PL of MoSe₂ occurs in the near-infrared spectral range where the emissive properties do not suffer from the enhanced dissipation in the gold due to inter-band transitions. Here, we study the interaction between monolayer MoSe₂ and plasmonic dipolar antennas in resonance with the PL emission of MoSe₂. By varying the thickness of the spacer between the MoSe₂ layer and nanoantenna, we demonstrate manipulation of the PL intensity from nearly fourfold quenching to approximately threefold enhancement. Furthermore, we show that the coupled TMDC-nanoantenna system exhibits strong polarization-dependent PL, thus offering the possibility of polarization-based emission control. Our experimental results are supported by numerical simulations as well. To the best of our knowledge, this is the first study of Au-MoSe₂ plasmonic hybrid structures realizing flexible PL manipulation.