On-surface covalent self-assembly of organic molecules is a very promising bottom-up approach for producing atomically controlled nanostructures. Due to their highly tuneable properties, these structures may be used as building blocks in electronic carbon-based molecular devices. Following this idea, here we report on the electronic structure of an ordered array of poly(para-phenylene) nanowires produced by surface-catalysed dehalogenative reaction. By scanning tunnelling spectroscopy we follow the quantization of unoccupied molecular states as a function of oligomer length, with Fermi level crossing observed for long chains. Angle-resolved photoelectron spectroscopy reveals a quasi-1D valence band as well as a direct gap of 1.15 eV, as the conduction band is partially filled through adsorption on the surface. Tight-binding modelling and ab initio density functional theory calculations lead to a full description of the band structure, including the gap size and charge transfer mechanisms, highlighting a strong substrate-molecule interaction that drives the system into a metallic behaviour.
Quasi one-dimensional band dispersion and surface metallization in long-range ordered polymeric wires / Vasseur, G., Fagot-Revurat, Y., Sicot, M., Kierren, B., Moreau, L., Malterre, D., Cardenas, L., Galeotti, G., Lipton-Duffin, J., Rosei, F., Di Giovannantonio, M., Contini, G., Le Fevre, P., Bertran, F., Liang, L., Meunier, V., Perepichka, D.F.. - In: NATURE COMMUNICATIONS. - ISSN 2041-1723. - ELETTRONICO. - 7:(2016), pp. 10235.1-10235.9. [10.1038/ncomms10235]
Quasi one-dimensional band dispersion and surface metallization in long-range ordered polymeric wires
Rosei F.;
2016-01-01
Abstract
On-surface covalent self-assembly of organic molecules is a very promising bottom-up approach for producing atomically controlled nanostructures. Due to their highly tuneable properties, these structures may be used as building blocks in electronic carbon-based molecular devices. Following this idea, here we report on the electronic structure of an ordered array of poly(para-phenylene) nanowires produced by surface-catalysed dehalogenative reaction. By scanning tunnelling spectroscopy we follow the quantization of unoccupied molecular states as a function of oligomer length, with Fermi level crossing observed for long chains. Angle-resolved photoelectron spectroscopy reveals a quasi-1D valence band as well as a direct gap of 1.15 eV, as the conduction band is partially filled through adsorption on the surface. Tight-binding modelling and ab initio density functional theory calculations lead to a full description of the band structure, including the gap size and charge transfer mechanisms, highlighting a strong substrate-molecule interaction that drives the system into a metallic behaviour.Pubblicazioni consigliate
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