Exploring Electronic Transport in Molecular Junctions by Conducting Atomic Force Microscopy

Abstract

Measuring the electronic transport properties of single molecules and molecular nanostructuresis an interesting and challenging new frontier from both a fundamental as well as technologicalperspective. Conducting atomic force microscopy (C-AFM) represents an attractive line of approachgiven its ability to position a sharp electrical probe with nanometer-scale precision and a controllednano-Newton-range force. Moreover, the combination of AFM imaging and C-AFM electrical characterizationenables investigation of the relationship between structure and function in molecular architectures.The aim of the present review is twofold: (1) to introduce the C-AFM method, alongside a discussionof experimental practices, capabilities and limitations, and (2) to provide an overview of the applicationof C-AFM to different types of molecular systems. These include alkane-based and oligomer-based self-assembledmonolayers, molecular crystals, conducting polymer films, molecular wires (e.g. carbon nanotubes),and electrically active biomolecules. We will also discuss C-AFM approaches that allow single moleculemeasurements as well as other recent developments.