Posted: Sep 19, 2018
(Nanowerk News) Molecular electronics is a burgeoning field of research that aims to integrate single molecules as active elements in electronic devices. Obtaining a complete picture of the charge transport properties in molecular junctions is the first step towards realizing functionality at the nanoscale.
Researchers from Delft University of Technology have now studied the charge transport in a novel system, the graphene mechanical break junction, which for the first time allowed direct experimental observation of quantum interference effects in bilayer graphene as a function of nanometer-displacements (Nature Nanotechnology, "Mechanically controlled quantum interference in graphene break junctions").
This new platform could potentially be used for electronic fingerprinting of biomolecules, from DNA to proteins, which in turn can have important implications for the diagnosis and treatment of diseases. The research was partly funded by the Graphene Flagship.
Nanogaps separating two electrodes are envisaged as the basis for the next generation of sensing technologies. The aim is to exploit quantum electron tunneling as the sensing principle, in which the electronic structure of the target molecule trapped in the nanogap is directly probed.
Graphene, a monolayer of carbon atoms in a hexagonal lattice, combines many of the requisites for an electrical sensor material: high conductivity, atomic thinness, flexibility, chemical inertness in air and liquid, and mechanical strength, as well as its compatibility with standard lithographic patterning techniques.
At the Kavli Institute of Nanoscience in Delft, a research group is developing robust graphene-based mechanically controlled break junctions (MCBJs), which allow the formation of a size-adjustable tunnelling gap at the sub-nanometre scale, i.e. the size can be tailored to the size of the biomolecule to be probed.
