Fig. 1

TERS study of edge defects in the atomically thin MoS₂. a Schematic of a TERS configuration using an Au-coated AFM tip and an atomically smooth Au film with monolayer (1 L) or bilayer (2 L) MoS₂ on the surface. b AFM image of the mechanically exfoliated MoS₂ with different types of 1D defect on an Au substrate. c Raman spectra of four 1D defects and the basal plane in MoS₂ marked in b, when the tip was approached and retracted. Note that these spectra are the near-field spectra and have been subtracted with the far-field signal, as well as the tip-enhanced photoluminescence background from MoS₂ and surface plasmon resonance (SPR) from the TERS tip. The intensity is normalized to the A_1g peak for comparison.