Interplay of polaronic and disorder effects on electronic charge transport

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