Kelvin probe force microscopy (KPFM) on graphene

Graphene belongs to the category of 2D materials and is of interest in the research and development of new devices and materials. Besides atomic resolution imaging of graphene to learn more about crystal orientation, edges and defects, the functional properties of graphene are also of great interest.

In this application note, multilayer graphene was imaged with Kelvin probe force microscopy (KPFM) using a CoreAFM to study the contact potential difference variation on a single flake.

Optical images of graphene flakes

Multilayer graphene flakes were generated by mechanical exfoliation of graphite and subsequent transfer to a silicon-silicondioxide substrate. The KPFM measurement was carried out in single-run mode, recording the contact potential during the scanning of the topography.

Sample courtesy: Hiske Overweg, Klaus Ensslin, ETH Zürich, Switzerland

Thin flakes were localized on the substrate with an upright microscope. Using markers on the substrate, the same flakes were placed under the cantilever using the topview camera of the CoreAFM, after which AFM images of graphene and KPFM data were recorded.

AFM images of graphene

All measurements were performed using a CoreAFM system equipped with a PPP-EFMR cantilever from Nanosensors. AFM images of graphene were processed using the MountainsMap SPM.

Nanosurf application note AN01082

Other Nanosurf applications