THz nanoscopy of conductive thin-films

We demonstrate the potential of terahertz-enabled scanning near-field microscopy (THz-SNOM) as a non-invasive tool for nanoscale conductivity characterization. Experiments on prototypical examples of electrically conductive thin-films, including high-quality exfoliated mono- and few-layer graphene, provide evidence of distinguishable contrast apparent in the scattered THz-SNOM signal. Finite-element simulations of the rationalized tip-sample system supports the experimental data. This study represents an important step towards a full understanding of electrical transport properties of nanomaterials at technologically relevant length-scales. These findings suggest THz-SNOM is an effective probe of nanoscale variations in conductive materials that could prove invaluable in the development and application of low-dimensional materials in future nanoelectronic devices.