Relationship between the microscopic morphology and the charge transport properties in poly(3-hexylthiophene) field-effect transistors

We fabricate field-effect transistors (FETs) by depositing a regioregular poly (3-hexylthiophene) (RR-P3HT) active layer via different preparation methods. The solvent used in the polymer film deposition and the deposition technique determine the film microstructure, which ranges from amorphous or granular films to a well-defined fibrillar texture. The crystalline ordering of RR-P3HT into fibrillar structures appears to lead to optimal FET performances, suggesting that fibrils act as efficient "conduits" for the charge carrier transport. Treating the silicon oxide gate insulator with hexamethyldisilazane enhanced the FET performance. (c) 2006 American Institute of Physics.