Anomalous electric field dependence of carrier drift in one-dimensional systems. Example: organic PDA-TS

Some years ago Donovan and Wilson concluded that carrier motion on a single chain of the quasi-one-dimensional polymer crystal PDA-TS exhibits highly unusual features. From the electric field dependence of the peak photocurrent and carrier generation rate they concluded that carriers had an ultra-high mobility and a low-field saturated drift velocity. We report new measurements in the time-dependent domain and at the same time propose a transport model to explain the data. We show that both the tr"decay law and the sublinear field scaling of the effective drift velocity can be associated with one and the same phenomenon: one-dimensional carrier drift in the presence of strongly scattering defects.