Charge-Dipole Model for the Universal Field Dependence of Mobilities in Molecularly Doped Polymers

Using the general result that the mobility μ of charge carriers driven in a spatially correlated random potential by an electric field E can be expressed in terms of the Laplace transform of a particular correlation function related to the random potential, we demonstrate that the exponential dependence of μ on √E universally observed in molecularly doped polymers arises naturally from the interaction of charge carriers with randomly distributed permanent dipoles.