(558f) Alignment of Poly(3-hexylthiophene) Organogels Under Electric Fields

Conjugated polymers have been widely used in organic electronic devices, such as organic photovoltaics (OPVs), organic light emitting diodes (OLEDs), and organic field effect transistors (OFETs), due to their inexpensive, flexible and solvent processable nature. Poly(3-hexylthiophene) (P3HT) is a good material in these areas because effective charge carrier mobility and an interconnected path for charge transport are desired in all organic electronic devices. In this work, alternating current (AC) and direct current (DC) electric fields have been applied to P3HT dissolved in organic solvents during a controlled self-assembly and gelation process. Dielectric spectroscopy measurements of the gels, small angle neutron scattering (SANS) and in-situ rheology measurements have been conducted under variable electric field conditions. All of these measurements indicate that structural changes including nanofiber alignment are taking place under electric fields. Neutron scattering is an excellent technique to probe the structure of self-assembled P3HT organogels. Time resolved small angle neutron scattering (TR-SANS) was used to evaluate structural changes during self-assembly as a function of time. Electrical properties of the organogels were also correlated to these structural differences. The application of electric fields during gelation provides an effective way to engineer the electrical and structural properties of P3HT organogels for various electronic applications (e.g. OPVs, OLEDs and OFETs).