Solid-State and Electrochemical Properties of Polyselenophene

Electrochemically grown polyselenophene films in both the oxidized electrolyte-doped state and the neutral undoped state have been characterized by a wide variety of techniques. Information on the growth, composition, and surface morphology of the polymer has been obtained. Electrical conductivity varies by 10⁵ Ω^-1 cm^{- 1} between the doped and undoped films. The temperature dependence of the electrical conductivity of the doped material is characteristic of a semiconductor. The Se atom of the ring contributes negligibly to the π-electron system of the polymer in the ground state, although it has an important effect on the conjugated chain length and the electrical conductivity. Bipolarons are found to play a predominant role in the electrical conduction mechanism.