Effect of intramolecular disorder and intermolecular electronic interactions on the electronic structure of poly-p-phenylene vinylene

We investigate the role of intramolecular conformational disorder and intermolecular electronic interactions on the electronic structure of disorder clusters of poly-$p$-phenylene vinylene (PPV) oligomers. Classical molecular dynamics is used to determine probable molecular geometries, and first-principles density functional theory calculations are used to determine electronic structure. Intramolecular and intermolecular effects are disentangled by contrasting results for densely packed oligomer clusters with those for ensembles of isolated oligomers with the same intramolecular geometries. We find that in PPV electron trap states are induced primarily by intramolecular configuration disorder, while the hole trap states are generated primarily from intermolecular electronic interactions.