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 to learn more about crystal orientation, edges and defects, functional properties are also of interest. In this application note, multi-layer graphene was imaged with Kelvin probe force microscopy (KPFM) using a CoreAFM to study the contact potential difference variation on a single flake.
Multi-layer 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 KPFM experiments were performed.
Nanosurf application note AN01082