Tip induced doping effects in local tunnel spectra of graphene

Understand

We report on tip induced doping in local tunnel spectra of single layer graphene (SLG) with tunable back-gate using room temperature scanning tunneling microscopy and spectroscopy (STM/S).

• The SLG samples, prepared on silicon dioxide surface by exfoliation method and verified by Raman spectra, show atomically resolved honeycomb lattice.
• Local tunnel spectra show two minima with a clear evolution in the position of both with doping by the back gate.
• A similar variation in spectra is also observed spatially due to charge inhomogeneity.