Anisotropic charge-carrier mobilities of liquid crystalline conjugated polymers on photo-aligned PVCN dielectric insulators

We fabricated organic thin-film transistors (OTFTs) with photo-reactive poly(vinylcinnamate) (PVCN) as a dielectric layer and liquid crystalline poly(2,5-bis(3-dodecylthiophene-2-yl)thieno[3,2-b]thiophene) (PBTTT) as a semiconducting layer. The PVCN layer plays an important role in the fabrication of OTFTs with solution processable PBTTT, because it provides orientation of the liquid crystalline polymer chains as well as gate insulating characteristics. The electrical properties of PBTTT-OTFTs with the UV-cured PVCN film were investigated for the films prepared with linearly polarized ultraviolet light irradiation along parallel and perpendicular to the electrode channel direction.