Enhanced Charge Transport in Polymer Thin-Film Transistors Prepared by Contact Film Transfer Method

The charge-carrier transport in the structures formed at the surface of various conjugated polymer films is investigated by constructing oragnic thin film transistors using a novel and simple contact film transfer method. Thin-film transistors prepared by this transfer process have higher field-effect mobility values compared with conventional spin-coated devices, for all the studied polmers. In contrast to previous reports the hole mobility in regioregular poly(3-alkylthiophene)s does not depend on the length of the alkyl chain when the contact film transfer method is used. These results suggest that the thin thiophene rings adopt a highly ordered edge on orientation and strong interchain pi-pi interactions spontaneously, form at the polymer/air interface during the spin-coating