TY  - JOUR
A1  - Bronner, Christopher
A1  - Utecht, Manuel Martin
A1  - Haase, Anton
A1  - Saalfrank, Peter
A1  - Klamroth, Tillmann
A1  - Tegeder, Petra
T1  - Electronic structure changes during the surface-assisted formation of a graphene nanoribbon
JF  - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr
N2  - High conductivity and a tunability of the band gap make quasi-one-dimensional graphene nanoribbons (GNRs) highly interesting materials for the use in field effect transistors. Especially bottom-up fabricated GNRs possess well-defined edges which is important for the electronic structure and accordingly the band gap. In this study we investigate the formation of a sub-nanometer wide armchair GNR generated on a Au(111) surface. The on-surface synthesis is thermally activated and involves an intermediate non-aromatic polymer in which the molecular precursor forms polyanthrylene chains. Employing angle-resolved two-photon photoemission in combination with density functional theory calculations we find that the polymer exhibits two dispersing states which we attribute to the valence and the conduction band, respectively. While the band gap of the non-aromatic polymer obtained in this way is relatively large, namely 5.25 +/- 0.06 eV, the gap of the corresponding aromatic GNR is strongly reduced which we attribute to the different degree of electron delocalization in the two systems.
Y1  - 2014
U6  - https://doi.org/10.1063/1.4858855
SN  - 0021-9606
SN  - 1089-7690
VL  - 140
IS  - 2
PB  - American Institute of Physics
CY  - Melville
ER  -