Quasi one-Dimensional Band Dispersion and Metallization In long Range Ordered Polymeric wires

• Published in: arXiv.org
• Main Authors: Vasseur, G, Fagot-Revurat, Y, Sicot, M, Kierren, B, Moreau, L, Malterre, D, Cardenas, L, Galeotti, G, Lipton-Duffin, J, Rosei, F, M Di Giovannantonio, Contini, G, P Le Fèvre, Bertran, F, Liang, L, Meunier, V, Perepichka, D F
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 27.07.2015
• Subjects: Band structure of solids; Charge transfer; Conduction bands; Conjugation; Density functional theory; Dispersion; Electronic structure; Electrons; Graphene; Level crossings; Metallizing; Photoelectrons; Physics - Mesoscale and Nanoscale Physics; Spectrum analysis; Valence band
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1507.07428

We study the electronic structure of an ordered array of poly(para-phenylene) chains produced by surface-catalyzed dehalogenative polymerization of 1,4-dibromobenzene on copper (110). The quantization of unoccupied molecular states is measured as a function of oligomer length by scanning tunneling spectroscopy, with Fermi level crossings observed for chains longer than ten phenyl rings. Angle-resolved photoelectron spectroscopy reveals a graphene-like quasi one-dimensional 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 organic band-structure, including the k dispersion, the gap size and electron charge transfer mechanisms which drive the system into metallic behaviour. Therefore the entire band structure of a carbon-based conducting wire has been fully determined. This may be taken as a fingerprint of {\pi}-conjugation of surface organic frameworks.