Superresolution Spectroscopy of Atomically Thin Semiconductors and Moiré Heterostructures

Atomically thin transition metal dichalcogenides (TMDs) such as molybdenum disulfide (MoS₂) offer distinct electronic and optical properties that make them promising candidates for emerging quantum technologies, including single-photon emitters and integrated quantum photonic devices. Among the most exciting recent developments in this field has been the realization of moiré superlattices between layered materials, which give rise to tunable excitonic resonances and correlated electronic phenomena not observed in isolated monolayers. Here, we summarize recent progress using diffraction-limited and superresolution tip-enhanced Raman spectroscopy (TERS) as a technique for characterizing TMD monolayers, heterostures, and moiré patterned systems. Experimental outcomes include mapping of how lattice vibrations change across the sample, revealing local effects of strain and interlayer coupling. These measurements have the potential to provide nanoscale insight into how strain and environmental factors influence excitonic confinement and energy transfer at the atomic scale, thereby opening possibilities for developing new kinds of low-power electronic devices and quantum emitters.