WORK FUNCTION AND SPECTROSCOPIC STUDIES OF INTERACTIONS BETWEEN CONDUCTING POLYMERS AND ORGANIC VAPORS

The mechanism of the interactions which occurs on polypyrrole and directly any changes that occurred in the work function of the was investigated by UV/visible spectroscopy and by the Kelvin probe technique. The spectroscopic method follows the changes in polaron and bipolaron concentrations, which are sensitive to any charge transfer that moves into/out of the films, while the Kelvin probe monitors directly any changes that occurred in the work function of the copolymer. The results indicate a mechanism consisting of the following steps: interactions of the vapor molecules with the polymer, partial charge transfer to/from a mid-gap state in the film, an d lateral dispersion of the charge between all the adsorbed molecules.