Graphene on Rh(111): STM and AFM studies

TL;DR

This study combines DFT calculations with STM and AFM imaging to analyze the electronic and structural properties of graphene on Rh(111), highlighting AFM's potential for chemical surface contrast analysis.

Contribution

It provides a detailed combined theoretical and experimental analysis of the graphene/Rh(111) moiré lattice using STM and AFM techniques.

Findings

STM contrast is bias-independent between hills and valleys

AFM contrast depends strongly on the frequency shift of the tip

Results demonstrate AFM's potential for chemical surface contrast probing

Abstract

The electronic and crystallographic structure of the graphene/Rh(111) moir\'e lattice is studied via combination of density-functional theory calculations and scanning tunneling and atomic force microscopy (STM and AFM). Whereas the principal contrast between hills and valleys observed in STM does not depend on the sign of applied bias voltage, the contrast in atomically resolved AFM images strongly depends on the frequency shift of the oscillating AFM tip. The obtained results demonstrate the perspectives of application atomic force microscopy/spectroscopy for the probing of the chemical contrast at the surface.