Fabrication and applications of functional graphene devices – FUNGRAPH

Graphene is an attractive material for electrical detections of adsorbed molecules, owing to its high conductivity and high sensitivity to molecular modifications. The key difficulty is the inert nature of saturate carbon films. We propose two methods to circumvent this problem. The ‘physical’ route involves nanoscale structuration, multiplying therefore the unsaturated side atoms in graphene films- The ‘chemical’ method relies on covering graphene with layers of dipolar molecules, without using strong covalent substitution, with the aim of preserving the conductivity properties of graphene. Finally, a method for robust interconnects fabrications will be needed, in order to realize a large number of detectors.

We aim at realizing graphene films and devices over large surfaces (a key point for application), with a methodology for realizing large ensembles of detectors.
Our plans for improving the graphene sensitivity remain to be validated. We need to test how the conductivity properties can be kept after modifying the graphene films. Finally, sensitivity tests need to be done.

Ultra sensitive chemical detections is key in the fields of safety, pollution control, and fight against terrorism. Carbon nanotubes are very attractive candidates for high sensitivity devices. They however suffer from low current properties and difficulties in scaling up processing. The advantages of graphene remain to be shown, and no immediate solution exists. We nevertheless hope to realize devices of ultimate sensitivity.

Until now, 3 shared publications and 2 communications at international conferences appeared.

We propose to investigate how nanostructured graphene films can interact with molecules. Graphene is a perfect two-dimensional conductor with high mobility and large surface area. Such a high mobility makes them ideal candidates for electronic devices, but due to the zero gap nature of graphene, electronic device applications of pristine graphene are restricted. However, large surface area and extreme sensitivity to changes in electrostatic environment makes them attractive for sensor applications. In this project, we tailor chemical and structural functionality of exfoliated and CVD graphene devices for the purpose of investigating how the electrical and optical properties are modified and become sensitive to exposure to molecular species. The Korean partner has experience in chemical and biosensors using carbon nanotubes. The French partners have experience in fundamental studies of opto-electronic properties of graphene and synthesis of original dipolar molecules. Our project aims at combining these skills to create novel graphene-based molecular sensors. A combination of device fabrications, fundamental studies, and chemical adsorption studies will pave the way to enhanced chemical and biosensor applications of functionalized graphene devices.