Marta Cardinali

Use of butylamine modified graphene sheets in polymer solar cells

We describe a facile method to use soluble chemically derived few-layer graphene sheets (GSs) as part of a transparent electrode for the preparation of polymer solar cells. Chemically functionalized GSs were obtained by first covalently attaching fluorine and then exposing the obtained fluorinated graphene sheets to an aliphatic amine at room temperature. Scanning electron microscopy, atomic force microscopy and UV-Vis analyses confirmed that transparent graphene sheets with an average thickness of 0.7–0.9 nm had been obtained. Their application in a polymer solar cell is demonstrated. Such functionalized graphene, which is cheap and easily prepared, is expected to be used as hole acceptor material in polymer photovoltaic applications.

Nonvolatile memory behavior of nanocrystalline cellulose/graphene oxide composite films

With the continuous advance of modern electronics, the demand for nonvolatile memory cells rapidly grows. In order to develop post-silicon electronic devices, it is necessary to find innovative solutions to the eco-sustainability problem of materials for nonvolatile memory cells. In this work, we realized a resistive memory device based on graphene oxide (GO) and GO/cellulose nanocrystals (CNC) thin films. Aqueous solutions of GO and GO with CNC have been prepared and drop cast between two metal electrodes. Such thin-film based devices showed a transition between low and high conductivity states upon the forward and backward sweeping of an external electric field. This reversible current density transition behavior demonstrates a typical memory characteristic. The obtained results open an easy route for electronic information storage based on the integration of nanocrystalline cellulose onto graphene based devices.

A Photoresponsive Hybrid Nanomaterial Based on Graphene and Polyhedral Oligomeric Silsesquioxanes

A novel nanomaterial which consists of graphene sheets decorated with silsesquioxane molecoles has been developed. Indeed, aminopropyl-silsesquioxane (POSS-NH2) has been employed to functionalize graphene oxide sheets (GOs). The surface grafting of GOs with POSS-NH2 has been established by infrared spectroscopy and X-ray photoelectron spectroscopy, while the morphology has been investigated by field emission electron microscopy as well as by atomic force microscopy. The combination of the amino functionalized POSS molecules with GO sheets produces a hybrid silicon/graphite-based nanomaterial, named GRAPOSS, for which the electrical conductivity of reduced GO was restored, thus allowing promising exploitations in several fields such as polymer nanocomposites.

LIGHT INDUCED CHANGE IN CONDUCTIVITY OF GRAPHENE OXIDE FILMS PATTERNED BY METAL MASKS

Micron-scale ordered gold patterns were deposited through a metallic copper grid positioned onto graphene oxide (GO) film. The exposure to a xenon light source results in the formation of conductive GO/metal interface with photocurrent generation. It is suggested that such simple method might serve as an efficient path for the formation of multifunctional patterned metal-carbon interconnects.