Study on a novel mixed Langmuir-Blodgett film based on a new asymmetrical tetrathiafulvalene/arachidic acid mixture

A mixed semiconducting Langmuir-Blodgett (LB) film based on a new asymmetrical tetrathiafulvalene (TTF) derivative and arachidic acid is described. The LB film of the 1:1 (molar ratio) mixture of the TTF derivative dibenzylthio-dimethylthio-tetrathiafulvalene with arachidic acid was constructed and characterized by FT-IR and UV spectra, and X-ray diffraction. Measurement on conductivity of the mixed LB film relating to the number of layers showed that the conductivity of the film decreased with increasing layer number. After iodine oxidation the conductivity of the LB film increased by 2–3 orders of magnitude compared with that before iodine doping and reached a maximum of 2.5 × 10−3 S cm−1 due to the formation of a new conducting phase, as demonstrated by FT-IR and UV spectral analyses. Results from X-ray diffraction indicate that the as-deposited LB film has an ordered lamellar structure with a thickness per layer of 2.41 nm.