Carrier injection and transport in organic field-effect transistor investigated by impedance spectroscopy

In this research, impedance spectroscopy (IS) has been applied on top-contact pentacene organic field-effect transistors (OFETs) for characterization of the contact resistance and carrier transport properties. The various relaxation processes were analyzed based on the Maxwell–Wagner model, assuming pentacene as a dielectric material. The mobilities obtained from the IS analysis correspond well with that obtained from the current–voltage (I–V) analysis. This alternative method by IS provides an additional advantage of isolating the effect of carrier concentration when evaluating the mobility of OFETs.