Effect of microscopic Coulomb interactions on concentration dependence mobility of charge carrriers in organic materials

Abstract

The filling of deep states is considered usually to be the reason of increase of the mobility of disordered organic materials with increasing concentration. However, at moderate concentrations the effect of microscopic Coulomb interactions (MCI) could be significant, because these interactions can reduce the activation energy of a hop. It is shown, that MCI results in significant additional increase of mobility along with concentration, in addition to the effect of the filling of deep states. The results are in qualitative agreement with existing theoretical and experimental studies.