Fabrication of novel electrically conductive Langmuir-Blodgett thin films of the poly(3-alkylthiophenes)

Abstract

Electrically conductive Langmuir-Blodgett (LB) multilayer thin films were fabricated from mixed monolayers containing steatic acid and poly(3-hexylthiophene). It has been found that stable monolayer films can be formed at the air-water interface from mixtures containing as much as 80 mol.% of poly(3-hexylthiophene). The monolayers were found to undergo a transition from a mixed monolayer to a bilayer structure at elevated surface pressures. The mixed monolayers were successfully transferred onto solid substrates as Y-type films by the vertical lifting method. These LB films exhibit well-defined layered structures as determined by optical, capacitance and X-ray diffraction measurements. The multilayer LB films were rendered electrically conductive by doping with strong oxidizing agents. In some cases, conductivities as high as 2 S cm −1 were obtained by this doping process.