CHARACTERISATION OF POLYANILINE CONDUCTIVE COMPOSITES

摘要

We have studied the optical, morphological, and transport properties of polyaniline doped by camphorsulfonic acid in presence of cis-1.4-polybutadiene as film-forming agent for application in gas sensing devices. In particular, we have deposited polyaniline films by spin-on glass +ITO and glass + metallic pads. The morphology has been studied by Atomic Force Microscopy (AFM) both in vertical and in lateral (shear-force) interaction mode. The comparison of the two different modes has been performed in order to show differences in the local stoichiometry of the film. Investigation of optical properties in the range 200-2500 nm have provided us with information on the electronic structure of PAni-PB. This has been compared this to theoretical models. We have also studied the transport properties versus temperature in order to determine the Fermi level position. Sheet resistance of the films and the contact resistivity have been obtained. We have observed linearity of the ohmic contact for temperatures over 250 K which are of interest for our application. However at high bias the contact contribution to the total voltage drop is negligible also for temperatures lower than 150 K.