TY - JOUR A1 - Wiessner, M. A1 - Rodriguez Lastra, N. S. A1 - Ziroff, J. A1 - Forster, F. A1 - Puschnig, P. A1 - Dössel, L. A1 - Müllen, K. A1 - Schöll, A. A1 - Reinert, F. T1 - Different views on the electronic structure of nanoscale graphene: aromatic molecule versus quantum dot JF - New Journal of Physics N2 - Graphene's peculiar electronic band structure makes it of interest for new electronic and spintronic approaches. However, potential applications suffer from quantization effects when the spatial extension reaches the nanoscale. We show by photoelectron spectroscopy on nanoscaled model systems (disc-shaped, planar polyacenes) that the two-dimensional band structure is transformed into discrete states which follow the momentum dependence of the graphene Bloch states. Based on a simple model of quantum wells, we show how the band structure of graphene emerges from localized states, and we compare this result with ab initio calculations which describe the orbital structure. KW - well KW - confinement KW - states KW - Ag(111) KW - photoemission KW - vicinal surfaces KW - coronene KW - energy KW - films KW - nanographenes Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130184 VL - 14 IS - 113008 ER -