▎ 摘　　要

We investigate local doping concentration modulation of graphene flakes on a SiO2/Si substrate that has been exposed to the same chemicals in device fabrication using tip-enhanced Raman spectroscopy (TERS). By spectral line scanning across the edge of graphene, it is observed that the D peak enhancement is localized in the vicinity of the edge boundary, and the TERS spatial resolution of similar to 228 nm is obtained. In the TERS spectra significant peak shifts of both the G and 2D peaks are observed more than 7 cm I across the hump on graphene within the distance of 1 gm, while both G and 2D peaks are shifted less than 2 cm I in the far-field spectra. This indicates that the modulation of hole doping concentration in close proximity on graphene/SiO2/Si can be probed by using TERS surpassing the resolution of a laser diffraction limit of conventional micro Raman spectroscopy. (C) 2016 Elsevier Ltd. All rights reserved.