TIME AND FREQUENCY-DEPENDENT CHARGE-CARRIER MOBILITY ON ONE-DIMENSIONAL CHAINS WITH ENERGETIC DISORDER FOR POLARON AND MILLER-ABRAHAMS TYPEHOPPING

The hopping motion of charge carriers in one-dimensional disordered sy stems under the influence of an electric DC or AC field was studied by using Monte Carlo computer simulations. Both polaron and Miller-Abrah ams type jump rates were considered. For these two jump rates the char ge carrier mobility was found to depend on time and frequency in a qua litatively similar way. The time dependence of the mobility is caused by the energy relaxation of the charge carriers and the frequency depe ndence stems from the asymmetry of the jump rates. The time and freque ncy dependence of the AC mobility is shown to provide more information on the charge carrier transport mechanism than can be obtained from k nowledge of the DC mobility only. For both the polaron and Miller-Abra hams jump rates the field dependence of the asymptotic one-dimensional DC mobility was bound to be close to the so called square root behavi our. The Nernst-Einstein relation was found to be invalid for the syst ems studied. (C) 1998 Elsevier Science B.V.