Aggregation is a mixed blessing in
conjugated organic polymers for thin film devices. It has the advantage
of facilitating charge and energy transfer by interchain interactions,
both of which are important for photovoltaic devices and field effect
transistors. However, it significantly reduces emission quantum yields
and thus efficiency in light-emitting devices. The aim therefore is to
both understand spontaneous polymer aggregation and to develop
methodologies to tune the extent of aggregation, thereby enabling
tailoring of the optical and electronic properties for a specific
application.
In this talk several strategies for the controlled assembly of conjugated polymers, both in solution and thin films will be presented. This will include routes such as surfactant- and solvent-induced self-assembly of conjugated polyelectrolytes in solution, thin films and the solid state. The use of conjugated polymer nanoparticles and nanotubes as building blocks for the construction of nanostructured thin films will also be described. It will be shown that small-angle neutron scattering (SANS) and steady-state and time-resolved photoluminescence spectroscopy can be used as complementary tools for elucidating structure-property relationships both in solution and the solid state. Future perspectives for the controlled deposition of nanostructured thin conjugated polymer films for device applications will also be discussed.
