title: Effects of potassium on the supramolecular structure and electronic properties of eumelanin thin films.
abstract: The role of potassium in the formation of synthetic eumelanin aggregates is investigated by atomic force microscopy and soft-X-ray spectroscopy. Control over the thin film granularity is achieved by using K salts, in both drop casting and electrodeposition of eumelanin thin films. Further control over orientation is made possible by a suitable choice of the substrate: evidence of self-assembly is found for thin films deposited on gold. Finally, it is shown that the potassium content affects not only the samples morphology, but also the low-lying states in the valence band, where a transfer of spectral weight across the HOMO-LUMO gap is observed, disclosing possible applications of this multifunctional biomacromolecule.
authors.affiliation: Dipartimento di Matematica e Fisica, Università Cattolica, Brescia, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Borghetti
authors.forename: Andrea
authors.initials: A
authors.lastname: Goldoni
authors.forename: Carla
authors.initials: C
authors.lastname: Castellarin-Cudia
authors.forename: Loredana
authors.initials: L
authors.lastname: Casalis
authors.forename: Fabian
authors.initials: F
authors.lastname: Herberg
authors.forename: Luca
authors.initials: L
authors.lastname: Floreano
authors.forename: Albano
authors.initials: A
authors.lastname: Cossaro
authors.forename: Alberto
authors.initials: A
authors.lastname: Verdini
authors.forename: Ralph
authors.initials: R
authors.lastname: Gebauer
authors.forename: Prasenjit
authors.initials: P
authors.lastname: Ghosh
authors.forename: Luigi
authors.initials: L
authors.lastname: Sangaletti
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D001965:Bromides / Q000737:chemistry; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D004583:Electrons; D004595:Electroplating; D005898:Glass / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D008543:Melanins / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D011188:Potassium / Q000737:chemistry*; D017680:Potassium Compounds / Q000737:chemistry; D017971:Tin Compounds / Q000737:chemistry; D014835:Volatilization; D014961:X-Ray Diffraction
chemical_list: D000538:Aluminum Silicates; D001965:Bromides; D008543:Melanins; D017680:Potassium Compounds; D017971:Tin Compounds; C041877:eumelanin; C109984:indium tin oxide; D006046:Gold; C039004:potassium bromide; D011188:Potassium; C011934:mica; D004121:Dimethyl Sulfoxide