Mobile charge carriers in pulse-irradiated poly- and oligothiophenes

Lower limits of the intrinsic charge carrier mobility in the solid phase of a series of oligothiophene compounds were determined with the pulse-radiolysis time-resolved microwave conductivity technique, PR-TRMC. The mobility values fall roughly into two regimes and show no correlation with the number of conjugated thiophene units. Relatively low mobilities (in the range of 3–6 10−4 cm2/Vs) were found for a series of cyclohexyl-endcapped thiophenes, while significantly higher values of 0.01–0.02 cm2/Vs were obtained for several n-hexyl and n-dodecyl substituted compounds and for sexithiophene. Interestingly, these latter values are similar to those of n-alkyl substituted polythiophenes measured earlier.