Effects of high pressure on the conductivity and dielectric constant of conductive organic polymers

Abstract

Abstract Previous theory for pressure effects on conduction in amorphous macromolecular solids is extended to include pressure effects on hyperelectronic polarization. A theoretical estimate of hopping activation energies is given. Experimental studies of the frequency effects of the pressure coefficients of conduction and permittivity permits resolution of the salient factors. Carrier mobility in ekaconjugated polymers is best represented by activated hopping, for conductivity increase with frequency, and permittivity drops. Conductivity and hyperelectronic polarization increase markedly with pressure. Their activation energies, E a 0 , and the pressure coefficients of their activation energies ( b E + b H ) are nearly identical. E a 0 is frequency‐dependent, but the ( b E + b H ) terms are not, showing the frequency dependence of E a 0 to lie in the hopping activation enthalpy. Similar arguments on the “total” pressure coefficients b and b for conduction and polarization show the latter coefficients to have a frequency dependence lying in the hopping activation entropy.