Understanding molecular interactions in light-emitting polymer bilayers: The role of solvents and molecular structure on the interface quality

We explore the donor/acceptor interaction between distinct polymers at sequential bilayer interfaces to understand if their emission is influenced by the solvent. Resonant soft X-ray reflectivity and near-edge X-ray absorption fine structure measurements were used to investigate optical and morphological properties of polymer stacks, which were made using polymer chain structures diluted with different or equal solvents. We identified coupled and uncoupled bilayer systems using as a probe the exciton energy transfer effect inferred from the donor/acceptor interdiffusion region at the heterojunction interfaces. We also show that the overall emission is dominated by the affinity of the chemical structures at the interface, regardless of the solvent used for the deposition of each layer. (C) 2014 AIP Publishing LLC.