Plasmonic metasurfaces for probing two-dimensional materials

Two-dimensional (2D) materials providing unique optical and electronic properties have been a subject of extensive research over the last decade. However, conventional optical methods such as Raman, photoluminescence, and absorption spectroscopy have obstacles in gathering dynamic characteristics due to the difficulty of signal collection from atomically thin layers. One of the ways to improve optical properties of 2D materials consists in coupling them with specifically tailored single resonant optical nanocavities and arrays of them, in the form of metasurfaces. Plasmonic metamaterials enabling manipulations of light phase in 2D plane are of particular importance as they could provide breakthrough tools for studying properties of planar structures and functional interfaces, including newly emerging 2D materials and van der Waals heterostructures that promise appealing applications in electronics, optics, photochemistry, biomedicine, etc. Here we demonstrate the optical properties of phase-responsive plasmonic metasurfaces and show its potential for studying surface-enhanced Raman scattering over single-layered materials.