Tip-Enhanced Raman Scattering of MoS2

Detailed structural characterization of novel two-dimensional materials plays a key role in understanding their properties and designing optoelectronic devices. High resolution spatial imaging is important for characterizing defects, edges, and grain boundaries. We use tip-enhanced Raman scattering (TERS) to obtain nanoscale vibrational images of monolayer and few-layer MoS2. We compare near-field and far-field Raman maps and demonstrate high spatial resolution and signal enhancement for various vibrational modes and peak ratios. We observe different spectral behavior and enhancement of edges and inner areas. We show that TERS provides valuable complementary nanoscale information to topographic scanning probe microscopy.