CONCENTRATION-DEPENDENCE OF CHARGE-CARRIER MOBILITY IN DISORDERED ORGANIC MATRICES - COMPARISON OF A SMALL POLARON HOPPING MODEL WITH A DIPOLE TRAP MODEL

Using a dipole trap model we propose an explanation for the different types of behaviour of the charge carrier mobility dependence on the av erage intersite distance. We show that the whole variety of mobility b ehaviours may be described within one framework. We predict that, at l east for one system, the mobility ''prefactor' at low temperature must be an increasing function of an intersite distance.