Analysis of the energy landscape for charge transport in polar glassy materials

We apply the methods of equilibrium fluid theory to calculate the distribution of site energies experienced by a diffusing charge carrier in a polar molecular glass. The mean spherical approximation is used to express the distribution of ion-dipole interaction energies of a hard-sphere ion at infinite dilution in a hard-sphere dipolar solvent in terms of the medium's dielectric constant. The resulting distribution is compared to that extracted from experimental charge transport data with the assumption that in the nonergodic regime for T < T_g the medium is characterized by its equilibrium structure at T_g.