Optical properties of one-dimensional graphene polymers: the case of polyphenanthrene
Abstract
We investigate from first principles the effect of many-body corrections on the optoelectronic properties of polyphenanthrene (PPh), a prototype system for carbon-based ladder polymers and 1D nanographenes with cis -polyene edges. We show that the inclusion of many-body effects is essential to correctly describe both quasiparticle bandstructure and optical response. Consistently with the reduced dimensionality of the system, the inclusion of electron–hole interaction leads to strongly bound excitons which dominate the spectra. A complete characterization of the low-energy excitonic states is carried out, together with their optical activity. In particular, we find a dark exciton below the first optically active one, which is expected to crucially affect the luminescence efficiency. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)