A mobility study on highly stacked conducting polymer films

Apparent mobilities of positive charge carriers in a regioregular poly(3-oc tylthiophene) film at various doping levels are evaluated by an electrochem ical technique combining a potential-step chronocoulometry and an in-situ c onductivity measurement. The carrier mobility was 5 x 10(-3) cm(2) V-1 s(-1 ) at the lowest doping level of 0.014 %, and it decreased by about one orde r of magnitude as the doping level increased up to about 2 %. Further elect rochemical doping resulted in the dramatic increase of the mobility, reachi ng 0.5 cm(2) V-1 s(-1) at the highest doping level of 23 %.