On-surface Synthesis

Synthesis and characterization of ordered 2D materials like Graphene Nanoribbons and Molecular Wires starting from supramolecular assemblies of functionalized precursors

Graphene Nanoribbons and molecular wires

Synthesis of poly(p-phenylene) wires and graphene nanoribbons

On-surface polymerization allows us to obtain an oriented nanomesh of graphene nanoribbons via two well-defined intermediate products, namely, p-phenylene oligomers with reduced length dispersion and ordered sub-micrometric molecular wires of poly(p-phenylene).
Basagni, A., Sedona, F., Pignedoli, C. A., Cattelan, M., Nicolas, L., Casarin, M., & Sambi, M. (2015). Journal of the American Chemical Society, 137(5), 1802-1808.

Electronic properties of N-doped poly(p-phenylene)

By doping the molecular precursors we obtain oriented organic semiconductors and we access to their electronic properties, including the full valence band dispersion, by combining local probes with spatial averaging techniques. We show how the product’s energy level alignment can be tuned without compromising the charge carrier’s mobility.
Basagni, A., Vasseur, G., Pignedoli, C. A., Vilas-Varela, M., Peña, D., Nicolas, L. F. Sedona, M. Sambi (2016).. Acs Nano, 10(2), 2644-2651.

Graphene nanoribbons band-gap vs width

We measure the frontier bands by means of scanning tunneling spectroscopy and confirm that the nanoribbon’s band gap is inversely proportional to their width. Interestingly, valence bands are found to show Fermi level pinning as the band gap decreases below a threshold value around 1.7 eV.
Merino-Díez, N., Garcia-Lekue, A., Carbonell-Sanromà, E., Li, J., Corso, M., Colazzo, L., Sedona F.... & de Oteyza, D. G. (2017). ACS Nano, 11(11), 11661-11668.

Graphene nanoribbons surface width control by templating substrate

We show here how GNR synthesis can be guided by an adequately nanotemplated substrate instead of by the traditionally designed reactants. The electronic properties have been characterized in detail by scanning tunneling spectroscopy, angle resolved photoemission and density functional theory calculations
Merino-Díez, N., Lobo-Checa, J., Nita, P., Garcia-Lekue, A., Basagni, A., Vasseur, G., Tiso F. Sedona,F. Sambi M ... & Vobornik, I. (2018). The journal of physical chemistry letters, 9(10), 2510-2517.

Extended 2D covalent network

Fullerene/Porphyrin Extended Copolymer

Reversible supramolecular interactions between C60 amino-tetraphenylporphyrin are exploited to obtain large domains of an ordered binary network. Subsequently a reaction between fullerene molecules and the amino-groups residing on porphyrin units is used to freeze the supramolecular nanostructure with covalent bonds.
Sedona, F., Di Marino, M., Sambi, M., Carofiglio, T., Lubian, E., Casarin, M., & Tondello, E. (2010). ACS nano, 4(9), 5147-5154.

Photopolymerization of Tetraphenylporphyrin

A photochemical approach to achieve an extended ordered polymeric structure at the sub‐monolayer level on a metal substrate is explored.
Basagni, A., Colazzo, L., Sedona, F., DiMarino, M., Carofiglio, T., Lubian, E., ... Sambi .M.. (2014). Chemistry–A European Journal, 20(44), 14296-14304.