CHARGE-TRANSPORT IN PRUSSIAN-BLUE FILMS DEPOSITED ON ITO ELECTRODES

Charge transport processes that can occur in Prussian Blue films depos ited on ITO (indium-tin oxide) electrodes in contact with aqueous solu tions have been studied. The concentration in the solution of some ion s such as the proton or the potassium influence the films conductivity as well as the degree of hydration of the film. This points to the fa ct that Prussian Blue films act as ionic conductors when they are imme rsed in aqueous solutions. Furthermore, the apparent diffusion coeffic ient calculated from impedance spectra of PB films increases with the temperature which confirms the idea of an ionic conductor. The impedan ce spectra for the Everitt's Salt films, however, differ from the PB f ilms and is much less sensitive to temperature.