Interplay of polaronic and disorder effects on electronic charge transport

We study the effect of spatial disorder and anisotropy on the mobility of charge carriers using a dynamical Monte Carlo simulation. Our transfer rate is based on a polaronic model of phonon-assisted hopping in an effective diabatic potential. Even without the consideration of anisotropic charge localisations and different coupling constants in different space co-ordinates, as expected for semiconducting polymers, we find distinct effects of disorder and anisotropy on the mobility depending on the external electrical field. This makes generalisations of simulational data and the interpretation of fitting parameters for disorder and anisotropy to experiments rather complicated. A detailed topological knowledge of measured samples is of paramount importance for a comparison of simulational and experimental results. (C) 2000 Elsevier Science S.A. All rights reserved.