Separation of fast and slow transport in regiorandom poly(3-hexylthiophene)

Transport properties of regiorandom poly(3-hexyl thiophene) (RRaPHT) were investigated using integral mode time-of-flight (TOF) and novel extraction photo current transient (photo-CELIV) methods. Time dependence of the charge carrier mobility was observed. We measured a mobility mu similar to 10(-5) - 10(-6) cm(2)/Vs in long time scales, with the photogenerated carrier lifetime T = 1.5ms. From the initial transport distance we measured the fast mobility-lifetime product mu(f)T(F) = 2 x 10(-11) cm(2)/V, from which we estimated mu(f) similar to 0.2cm(2)/Vs by using the previously reported lifetime of the fast transport as T-f approximate to 100ps [G. Yu, et al.. Phys. Rev. B42, 3004 (1990)]. The time dependence of the charge carrier mobility is obtained over several of magnitude.