Nanocylinders pave way to polymer electronics

The discovery of conducting organic crystals and polymers resulted in the Nobel Prize for Chemistry in 2000, opening up the possibility that such materials could be used in optoelectronic applications.

But first, such materials must display a high charge carrier mobility and be easy to prepare and handle in order to find practical uses.

Crystals have a precise structure and a high conductivity, but they are difficult to handle. Polymers, in contrast, are cheap to produce and easy to handle; their charge carriers, however, are comparatively immobile. Liquid crystals have a charge carrier mobility similar to crystals but their preparation and processing is expensive.

Because of this, many research groups aim to combine the advantages of both types of materials to produce highly ordered but easy to handle molecular systems.

Now, scientists at the Max Planck Institute for Polymer Research and their American collaborators have done just that. They have combined the advantageous properties of classical polymers with those of crystals by synthesising clusters of fluorine-containing dendritic polymers.

They achieved their results by attaching single electron donor or electron acceptor groups to the end of the dendrons of the polymers, resulting in the formation of wedge shaped building blocks, which then organised themselves into tiny supramolecular cylinders.

The donor-acceptor complexes in the centre of these molecules display promising optoelectronic properties, while the fluorinated periphery of the molecules protects the inner core from external influences, i.e. humidity, similar to a Teflon-coating.

Using such techniques, researchers will now be able to synthesise supramolecular liquid crystals from different organic materials through this self-organisation process.