ABSTRACT
In the case of conducting polymers, conductivity originates from a combination of the polymer molecular structure and doping additives. Additional enhancement and stabilization of the electrical property of conducting polymers are achieved by the incorporation of dopant molecules, which have a dual role of charge stabilization on the polymer backbone and electrostatic balancing of charges within the polymer matrix. The most successful of these polymeric systems are the homopolymers of polyacetylene (PA), polypyrrole (PPy), polythiophene (PT), polyaniline (PAn), poly(para) -phenylene(PPP), and poly(para-phenylene vinylene) (PPV). The most conductive, but least stable, conducting polymer is PA, which is the trans isomer, especially when highly crystalline and doped with iodine. Conductivity in materials has been defined through the band theory, which provides a simplistic way to visualize the electronic transitions that occur from metallic to semiconductor and insulating states. In the band theory, electrons are characterized into bands of electrons rather than discrete quantized states.
