Time and frequency dependent charge carrier mobility on one-dimensional chains with energetic disorder for polaron and Miller–Abrahams type hopping Original Research Article

The hopping motion of charge carriers in one-dimensional disordered systems under the influence of an electric DC or AC field was studied by using Monte Carlo computer simulations. Both polaron and Miller–Abrahams type jump rates were considered. For these two jump rates the charge carrier mobility was found to depend on time and frequency in a qualitatively similar way. The time dependence of the mobility is caused by the energy relaxation of the charge carriers and the frequency dependence stems from the asymmetry of the jump rates. The time and frequency dependence of the AC mobility is shown to provide more information on the charge carrier transport mechanism than can be obtained from knowledge of the DC mobility only. For both the polaron and Miller–Abrahams jump rates the field dependence of the asymptotic one-dimensional DC mobility was found to be close to the so called square root behaviour. The Nernst–Einstein relation was found to be invalid for the systems studied.