Surface-energy-dependent field-effect mobilities up to 1 cm2/V s for polymer thin-film transistor

Abstract

The field-effect mobility of a liquid-crystalline semiconducting polymer, poly(2,5-bis(3-hexadecylthiophene-2-yl)thieno[3,2-b]thiophene) (PB16TTT), has depended significantly on the surface energies of self-assembled monolayers (SAMs) formed on insulating layers. Using a SAM with fluoroalkyl groups, with a low surface energy of 13.3 mN/m, the mobility of PB16TTT reached as high as 1 cm2/V s. These results indicate that an edge-on orientation of the polymer chains progresses more favorably on the surfaces with low surface energies via the liquid-crystalline phase.