Polaron dissociation in conducting polymers by high electric fields

It has been accepted that addition of an electron or hole to a conducting polymer chain causes the chain to distort, creating a large polaron. We show, by numerical solution of the coupled equations for the electron wave functions and the lattice displacements on a polyacetylene chain with an extra electron, that the polaron does not form in electric fields ⩾6×104 V/cm. In fields ⩾106 V/cm, an already formed polaron will be dissociated. Implications for current versus voltage of a light-emitting diode at high fields will be discussed.