Fig. 3

TERS characterization of a bilayer edge in MoS₂. a TERS line image across the edge of a bilayer MoS₂. Left panel: topographic height profile of the edge of bilayer MoS₂ marked in Supplementary Fig. 16b inset. Right panel: a line-trace TERS image of the edge. Note that these are original TERS experimental spectra without any processing. See Supplementary Fig. 16a for more data sets for the corresponding line-trace TERS spectra. b Two typical TERS spectra of a bilayer MoS₂ at the basal plane and the edge. c Plots of normalized intensities of two TERS peaks (396 and 406 cm⁻¹) with the tip position. The solid lines are the fitted results. Note that these spectra are the pure near-field signals and have been subtracted with the far-field signals. Inset is the enhanced TERS intensity profile of the ETR in the 2 L edge after the deconvolution of the EM field the intensity distribution (see Supplementary Note 2 for more details). d Schematic diagram of band reconstruction and ETR of MoS₂ near the edge. D_e is the electron density.