Photophysics of anisotropic shear-aligned dendritic side group phenylenevinylene polymer

We report measurements of the anisotropy in the photophysics of an oriented dendritic side group conjugated phenylenevinylene polymer. The essential features of the absorption and emission can be understood in terms of the contribution of two morphological regions in the film, one being relatively highly ordered. The ordered regions have spectroscopy like that of polymers with sterically hindered torsion and good luminescence yield. Surprisingly, we present evidence that their emissive efficiency is lower when they are excited directly than through energy transfer from disordered regions. We also observe long-lived emission with transition dipole perpendicular to the chain orientation that is suggestive of charge transfer exciton emission from the ordered regions of the sample.