Microstructure–mobility correlation in self-organised, conjugated polymer field-effect transistors

We have investigated the correlation between polymer microstructure and charge carrier mobility in high-mobility, self-organised field-effect transistors of poly-3-hexyl-thiophene (P3HT). Two different preferential orientations of the microcrystalline P3HT domains with respect to the substrate have been identified by X-ray diffraction, for which charge carrier mobilities differ by a factor >100. High mobilities of 0.1 cm2/V s reflect efficient interchain transport along the direction of π–π stacking. The results provide a firm basis for exploring supramolecular self-organisation to enhance the charge transport properties of conjugated polymer field-effect devices.