Scanning Tunneling Microscopy: Theory Applied to Nanostructure Analysis

This project aims to determine structure at the single-atom and single-molecule levels for nanomaterials such as supramolecular self-assemblies on solid surfaces, individual nanostructures and other nano-scale atomic configurations. The approach is to computationally simulate and match experimental images obtained from scanning tunneling microscopy (STM), using detailed theory of the STM process.The benefit will be the important ability to gain knowledge from experiment about the chemical identity and atomic arrangements in various types of nanostructure: such information is currently extremely hard to get from other sources at the individual-atom level. This approach removes the current exclusive reliance on theoretical predictions of structure, and, as an added gain, permits verification of such predictions.The work will be based on STM images recorded for important nanostructures under well-defined conditions that can be simulated theoretically. The calculations will then make it possible to determine the chemical composition and structural aspects of those nanostructures. STM theory and computer codes exist for ordered flat surfaces; these will be improved in their treatment of the electric field, while their computational efficiency will be increased, also enabling the treatment of the more complex case of single nanostructures such as nanowires and nanoparticles.