Vincenzo Palermo

Name	Vincenzo Palermo
Work Groups	Work Group 1 - Synthesis Work Group 2 - Characterisation
Laboratory	Nanochemistry Lab
Organisation	National Research Council
Website	http://www.isof.cnr.it/nanochemistry/
Areas of Research	Nanotechnology Surface Science Materials Science Organic Electronics
Research Keywords	Graphene Organic Semiconductors Scanning Probe Microscopy Kelvin Probe
Areas of Future Interest	.

Selected Publications:

Charge transport in graphene-polythiophene blends as studied by Kelvin Probe Force Microscopy and transistor characterization. Journal of Materials Chemistry, 2011. 21(9): p. 2924-2931. A. Liscio, G.P. Veronese, E. Treossi, F. Suriano, F. Rossella, V. Bellani, R. Rizzoli, P. Samori, and V. Palermo Blends of reduced graphene oxide (RGO) and poly(3-hexylthiophene) (P3HT) are used as the active layer of field-effect transistors (FETs). By using sequential deposition of the two components, the density of RGO sheets can be tuned linearly, thereby modulating their contribution to the charge transport in the transistors, and the onset of charge percolation. The surface potential of RGO, P3HT and source-drain contacts is measured on the nanometric scale with Kelvin Probe Force Microscopy (KPFM), and correlated with the macroscopic performance of the FETs. KPFM is also used to monitor the potential decay along the channel in the working FETs.
Facile covalent functionalization of graphene oxide using microwaves: bottom-up development of functional graphitic materials. Journal of Materials Chemistry, 2010. 20(41): p. 9052-9060. M. Melucci, E. Treossi, L. Ortolani, G. Giambastiani, V. Morandi, P. Klar, C. Casiraghi, P. Samori, and V. Palermo Graphene oxide (GO) exfoliated sheets were used as two dimensional platforms to covalently tether on their surface thousands of optically active quaterthiophene molecules (T4), using an innovative microwave-assisted silanization reaction. This method allowed to perform GO functionalization in one-step, under mild conditions in a few tens of minutes rather than days. The hybrid GOT4 could be processed in either H2O or apolar organic solvents and deposited as single sheets, microplatelets or macroscopic membranes. Absorption/emission spectroscopy reveals that GOT4 combines limited T4-T4 interactions with strong T4-GO ones. These findings, combined with the 'user-friendly' engineering approach presented here, pave the way towards the bottom-up fabrication of new GO-based tailored materials for electronics, sensors and biological applications.
Local Current Mapping and Patterning of Reduced Graphene Oxide. Journal of the American Chemical Society, 2010. 132(40): p. 14130-14136. J.M. Mativetsky, E. Treossi, E. Orgiu, M. Melucci, G.P. Veronese, P. Samori, and V. Palermo Conductive atomic force microscopy (C-AFM) has been used to correlate the detailed structural and electrical characteristics of graphene derived from graphene oxide. Uniform large currents were measured over areas exceeding tens of micrometers in few-layer films, supporting the use of graphene as a transparent electrode material. Moreover, defects such as electrical discontinuities were easily detected. Multilayer films were found to have a higher conductivity per layer than single layers. It is also shown that a local AFM-tip-induced electrochemical reduction process can be used to pattern conductive pathways on otherwise-insulating graphene oxide. Transistors with micrometer-scale tip-reduced graphene channels that featured ambipolar transport and an 8 order of magnitude increase in current density upon reduction were successfully fabricated.
High-Contrast Visualization of Graphene Oxide on Dye-Sensitized Glass, Quartz, and Silicon by Fluorescence Quenching. Journal of the American Chemical Society, 2009. 131(43): p. 15576. E. Treossi, M. Melucci, A. Liscio, M. Gazzano, P. Samori, and V. Palermo
Nanoscale Quantitative Measurement of the Potential of Charged Nanostructures by Electrostatic and Kelvin Probe Force Microscopy: Unraveling Electronic Processes in Complex Materials. Accounts of Chemical Research, 2010. 43(4): p. 541-550. A. Liscio, V. Palermo, and P. Samori In microelectronics and biology, many fundamental processes involve the exchange of charges between small objects, such as nanocrystals in photovoltaic blends or individual proteins in photosynthetic reactions. Because these nanoscale electronic processes strongly depend on the structure of the electroactive assemblies, a detailed understanding of these phenomena requires unraveling the relationship between the structure of the nano-object and its electronic function. Because of the fragility of the structures involved and the dynamic variance of the electric potential of each nanostructure during the charge generation and transport processes, understanding this structure function relationship represents a great challenge. This Account discusses how our group and others have exploited scanning probe microscopy based approaches beyond imaging, particularly Kelvin probe force microscopy (KPFM), to map the potential of different nanostructures with a spatial and voltage resolution of a few nanometers and millivolts, respectively. We describe in detail how these techniques can provide researchers several types of chemical information. First, KPFM allows researchers to visualize the photogeneration and splitting of several unitary charges between well-defined nanoobjects having complementary electron-acceptor and -donor properties. In addition, this method maps charge injection and transport in thin layers of polycrystalline materials. Finally, KPFM can monitor the activity of immobilized chemical components of natural photosynthetic systems. In particular, researchers can use KPFM to measure the electric potential without physical contact between the tip and the nanostructure studied. These measurements exploit long-range electrostatic interactions between the scanning probe and the sample, which scale with the square of the probe sample distance, d. While allowing minimal perturbation, these long-range interactions limit the resolution attainable in the measurement of potentials. Although the spatial resolution of KPFM is on the nanometer scale, it is inferior to that of other related techniques such as atomic force or scanning tunneling microscopy, which are based on short-range interactions scaling as d(-7) or e(-d), respectively. To overcome this problem, we have recently devised deconvolution procedures that allow us to quantify the electric potential of a nano-object removing the artifacts due to its nanometric size.

Brief CV
Vincenzo Palermo obtained his Ph.D. in physical chemistry in 2003 at the University of Bologna, after working at the University of Utrecht (the Netherlands) and at Steacie Institute, National Research Council (NRC Canada).
He is now group leader of the Nanochemistry lab in the Institute for Organic Synthesis and Photoreactivity of National Research Council (CNR Italy).
His main research interests are in the self-assembly of innovative materials and their nanoscale electrical characterization with Scanning Probe Microscopy.
He is coordinator of two EU projects dedicated to the development of new graphene-organic composites for microelectronics using supramolecular chemistry. He is member of the scientific committee of EUROGRAPHENE project, and one of the nine proposers of the GRAPHENE FLAGSHIP initiative.

He is author of more than 60 papers and several reviews on ISI journals (Advanced Materials, JACS, etc.), and has been referee for several ISI journals in the fields of supramolecular chemistry and materials science (Acs-Nano, Advanced Materials, Advanced Functional Materials, J. Am. Chem. Soc., Nanoscale, Soft Matter, Synthetic Metals, Surface Science, J. Phys. Chem., Physica E).

Aside from his scientific activity, Vincenzo Palermo is involved in science dissemination and communication, giving seminars on science and history for high-school students and public audience.