Oriented nanostructures from single molecules of a semiconducting polymer: Polarization evidence for highly aligned intramolecular geometries

We report the observation of uniformly oriented transition moments perpendicular to the support substrate in single molecules of a conjugated polymer (MEH-PPV) isolated by ink-jet printing techniques. Fluorescence imaging combined with atomic force microscopy and polarization modulation studies, supported by molecular mechanics simulation, provides compelling evidence of polymer nanoparticle (single-molecule) structures with an extraordinary degree of intramolecular order. This is a general technique for preparing oriented nanostructures from structurally similar polymers.