Poly(3-hexylthiophene)-graphene composite-based aligned nanofibers for high-performance field effect transistors

We report the morphology and field effect transistor (FET) characteristics of aligned electrospun nanofibers prepared from poly(3-hexylthiophene) (P3HT)-graphene composites. The graphene flakes were more uniformly distributed in the nanofibers compared with spin-coated films, leading to different FET characteristics. The geometrical confinement from electrospun nanofibers resulted in enhanced pi-pi molecular packing with highly ordered orientation and reduced the grain boundaries under strong stretching forces, thereby increasing carrier mobility. The graphene behaved as an electrically conducting bridge between the P3HT domains in the composites, and thus the FET mobility generally increased as the graphene composition increased. Remarkably, the ES-PG4 FET had the highest hole mobility of 1.82 cm(2) V-1 s(-1) and a moderately high I-ON/I-OFF of 5.88 x 10(4), which also exhibited good environmental stability for its transfer characteristics. The experimental results indicated that semiconducting composites based one-dimensional nanofiber devices offer advantages over conventional spin-coated thin films and provide a simple strategy for producing high-performance FET devices.