Anisotropic highly-conductive films of poly(3-methylthiophene) from epitaxial electropolymerization on oriented poly(vinylidene fluoride)

Electrochemical polymerization of 3-methylthiophene on highly oriented poly(vinylidene fluoride) (PVDF) film was achieved by cyclic voltammetry to yield well-ordered poly(3-methylthiophene) (P3MT) thin films with anisotropic structural and conductivity properties. The conductivity of P3MT along the direction perpendicular to the chain direction of PVDF, after electrochemical dedoping, is 593 S cm1, while that along the PVDF chain direction is 1.20.4 S cm 1. The high conductivity of the P3MT is attributed to the well-ordered structure with its flat-on single crystals as confirmed by electron diffraction and Reflection Absorption Infra-red Spectroscopy (RAIRS). The data are consistent with P3MT chains aligned with p-p stacking perpendicular to the chain direction of the PVDF substrate. Epitaxial electropolymerization is an unusual method of preparing highly ordered thin films of organic semiconductors.