MOBILE CHARGE-CARRIERS IN PULSE-IRRADIATED POLY(3-N-ALKYL)THIOPHENES

Upon pulsed irradiation with high energy electrons from a Van de Graaf f accelerator long lived conductivity transients are found in polythio phenes with n-hexyl, n-octyl and n-decyl sidechains, using the time re solved microwave conductivity (TRMC) technique. The sum of the charge carrier mobilities is found to be at least 7x10(-7) m2/Vs, independent of the sidechain length. The radiation-induced conductivity transient s show disperse decay kinetics. The timescale on which the conductivit y decays increases with increasing sidechain length. The conductivity transients observed in the compounds synthesized with a MgI-Grignard r eagent show no effect of aging up to a period of 4 months. Conductivit y transients of poly(n-hexyl)thiophene synthesized with FeCl3 showed a strong dependence on residual Fe content.