Nanoscale electrical characterization of graphene-based materials by atomic force microscopy

Graphene, an atomically thin two-dimensional (2D) material, exhibits outstanding electrical properties and thus has been employed in various electronic devices. However, the device performance strongly depends on the structural variations present in the graphitic lattice, such as crystal domains, grain boundaries, lattice imperfections, dopants, etc., which are nanoscopic in nature. Hence, understanding the correlation between the structure and the electrical properties in the nanoscale is essential. Atomic force microscopy (AFM) techniques provide the best way to picture such relationships, which is particularly in demand for future miniaturized devices. This review article highlights the characterization of the electrical properties of graphene-based materials via AFM-based techniques such as conductive AFM, scanning Kelvin probe microscopy, electrostatic force microscopy, and piezoresponse force microscopy that is certainly beneficial for a broad research community not only working on graphene-based materials but also in the fields of other 2D materials and scanning probe microscopy.