title: Langmuir-Shäfer transfer of fullerenes and porphyrins: formation, deposition, and application of versatile films.
abstract: Thin films consisting of a fulleropyrrolidine derivative 1 and a novel water-soluble porphyrin 2 were prepared by the Langmuir-Shäfer (LS, horizontal lifting) method. In particular, a solution of 1 in chloroform and dimethyl sulfoxide was spread on the water surface, while porphyrin 2 (bearing peripheral anionic groups) was dissolved into the aqueous subphase. To the best of our knowledge, such a versatile method of film fabrication for fullerene/porphyrin mixed composite films has never been used before. Evidence of the effective interactions between the two moieties at the air-water interface was obtained from the analysis of the floating layers by means of surface pressure versus area per molecule Langmuir curves, Brewster angle microscopy and UV-visible reflection spectroscopy. The characterisation of the LS films by UV-visible spectroscopy reveals that the two constituents behave as discrete and weakly interacting pi systems. The use of polarised light suggests the existence of a preferential direction of the macrocyclic rings with an edge-on arrangement with respect to the substrate surface. Finally, photoaction spectra were recorded from films deposited by only one horizontal lifting onto indium-tin-oxide (ITO) electrodes and the observed photocurrent increased notably with increasing transfer surface pressure.
authors.affiliation: Sioptics & post Silicon Technologies, Corporate R&D STMicroelectronics, Stradale Primosole, 50, 95121 Catania, Italy.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Conoci
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Guldi
authors.forename: Sara
authors.initials: S
authors.lastname: Nardis
authors.forename: Roberto
authors.initials: R
authors.lastname: Paolesse
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Kordatos
authors.forename: Maurizio
authors.initials: M
authors.lastname: Prato
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Ricciardi
authors.forename: M Graça H
authors.initials: MG
authors.lastname: Vicente
authors.forename: Israel
authors.initials: I
authors.lastname: Zilbermann
authors.forename: Ludovico
authors.initials: L
authors.lastname: Valli
mesh_terms: D037741:Fullerenes / Q000737:chemistry*; D008853:Microscopy / Q000379:methods; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D011166:Porphyrins / Q000737:chemistry*; D013499:Surface Properties; D014867:Water
chemical_list: D037741:Fullerenes; D011166:Porphyrins; D014867:Water