Disorder in P3HT Nanoparticles Probed by Optical Spectroscopy on P3HT--PEG Micelles.

We employ photoluminescence (PL) spectroscopy on individual nanoscale aggregates of the conjugated polymer poly(3-hexylthiophene), P3HT, at room temperature (RT) and at low temperature (LT) (1.5 K), to unravel different levels of structural and electronic disorder within P3HT nanoparticles. The aggregates are prepared by self-assembly of the block copolymer P3HT--poly(ethylene glycol) (P3HT--PEG) into micelles, with the P3HT aggregates constituting the micelles' core.

Direct observation of backbone planarization via side-chain alignment in single bulky-substituted polythiophenes.

The backbone conformation of conjugated polymers affects, to a large extent, their optical and electronic properties. The usually flexible substituents provide solubility and influence the packing behavior of conjugated polymers in films or in bad solvents. However, the role of the side chains in determining and potentially controlling the backbone conformation, and thus the optical and electronic properties on the single polymer level, is currently under debate.

Low loss optical waveguiding in large single crystals of a thiophene-based oligomer.

Active optical waveguides based on functional small organic molecules in micro/nano regime have attracted great interest for their potential applications in high speed miniaturized photonic integrations. Here, we report on the active waveguiding properties of millimeter sized single crystals of a newly synthesized thiophene-based oligomer. These large crystals exhibit low optical loss compared to other organic nanostructures, and optical losses depend on the emission energy.