Angular distribution of field-effect mobility in oriented poly[5,5′-bis(3-dodecyl-2-thienyl)-2,2′-bithiophene] fabricated by roll-transfer printing

The angular dependence of the optical and charge-carrier transport properties of oriented poly[5,5′-bis(3-dodecyl-2-thienyl)-2,2′-bithiophene] (PQT) thin films prepared through the roll-transfer printing method is studied. The anisotropy of the charge-carrier transport is quite different from that of the optical absorption in the sense that the maximum field-effect mobility is observed at an angle of 30° with respect to the direction of the oriented PQT backbone. The results indicate that the charge-carrier transport along the oriented PQT backbone is less efficient; such information is valuable for the development of high-mobility polymeric field-effect transistors.