DEMONSTRATION OF HIGH-MOBILITY ONE-DIMENSIONAL SEMICONDUCTING POLYMERS

It is shown by experiment that a conjugated polymer chain can be a high-mobility pure one-dimensional semiconductor. Experiments are described on DC photoconduction and on pulse photoconduction and total charge transfer in response to a 2 mu s laser pulse in a large single crystal of a conjugated polymer: the bis(p-toluene sulphonate) ester of 2.4-hexadiyne-1.6 diol-(PDATS). The spectral dependence of the efficiency of creating free carriers is determined absolutely and shown to be linear in electric field characteristic of a one-dimensional system. The carriers are shown to travel a constant distance of order 1 mm in less than 1 mu s, independent of field, before trapping, at what is probably a chain end. Subsequent trap release takes several seconds. The carrier mobility is greater than 10-2 m2 s-1 V-1.