Effect of Intra-molecular Disorder and Inter-molecular Electronic Interactions on the Electronic Structure of Poly-p-Phenylene Vinylene (PPV)

TL;DR

This study explores how intra-molecular conformational disorder and inter-molecular electronic interactions influence the electronic structure of PPV oligomers, revealing distinct origins for electron and hole trap states.

Contribution

It distinguishes the effects of intra-molecular disorder and inter-molecular interactions on trap state formation in PPV, using combined molecular dynamics and DFT methods.

Findings

Electron trap states mainly caused by intra-molecular disorder.

Hole trap states primarily due to inter-molecular interactions.

Densely packed clusters show different electronic effects than isolated oligomers.

Abstract

We investigate the role of intra-molecular conformational disorder and inter-molecular 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-principle density functional theory (DFT) calculations are used to determine electronic structure. Intra-molecular and inter-molecular effects are disentangled by contrasting results for densely packed oligomer clusters with those for ensembles of isolated oligomers with the same intra-molecular geometries. We find that electron trap states are induced primarily by intra-molecular configuration disorder, while the hole trap states are generated primarily from inter-molecular electronic interactions.