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 asym metrical tetrathiafulvalene (TTF) derivative and arachidic acid is des cribed. The LB film of the 1:1 (molar ratio) mixture of the TTF deriva tive dibenzylthio-dimethylthio-tetrathiafulvalene with arachidic acid was constructed and characterized by FT-IR and UV spectra and X-ray di ffraction. Measurement on conductivity of the mixed LB film relating t o the number of layers showed that the conductivity of the film decrea sed with increasing layer number. After iodine oxidation the conductiv ity of the LB film increased by 2-3 orders of magnitude compared with that before iodine doping and reached a maximum of 2.5 X 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 indicat e that the as-deposited LB film has an ordered lamellar structure with a thickness per layer of 2.41 nm. (C) 1998 Elsevier Science S.A.