Fabrication of Stretch-Oriented Regioregular Poly(3-Hexylthiophene) film and Its Application to Organic Field-Effect Transistors

We report a fabrication process for organic field-effect transistors (OFETs) based on stretch-oriented regioregular poly(3-hexylthiophene) (rr-P3HT) film and the anisotropic carrier transport properties in the OFETs. The optical absorption spectra and XRD results indicate that pi-conjugated rr-P3HT chains are aligned in the stretching direction with the pi-stacking polymer planes parallel to the substrate. The field-effect hole mobility in a current flow parallel to the stretching direction is larger by a factor of 3.4 compared to that perpendicular to the stretching direction. These results indicate that charge transport via the pi-conjugated rr-P3HT chains is advantageous in the stretch-oriented rr-P3HT film.