Mechanism of charge transport in polypyrrole, poly(N-methyl pyrrole) and their copolymers

The temperature dependence of the dc conductivity of electrochemically polymerized films of polypyrrole, poly(N-methyl pyrrole) and their copolymers, poly(N-methyl pyrrole-pyrrole), having different percentage of BF−4 ions has been investigated in the temperature range 77–350 K. The observed behavior could be explained in terms of Mott’s variable range hopping model involving a single phonon process. The estimated values of polaron radius yield the realistic values of density of states at the Fermi level which are in good agreement with the values reported earlier for other polyconjugated systems.