Large operating voltages are often required to switch organic field-effect transistors (OFETs) on and off because commonly used gate dielectric layers provide low capacitive coupling between the gate electrode and the semiconductor. We present here a pentacene OFET gated by a solution-deposited polymer electrolyte film in which the current was modulated over four orders of magnitude using gate voltages less than 2 V. A subthreshold slope of 180 mV per decade of current was observed during transistor turn on at a source-drain bias of -1 V; the estimated dielectric layer specific capacitance was 5 μF cm2. Sweep rate-dependent hysteresis may be attributed to a combination of ion migration and charge carrier trapping effects. Strategies to improve switching speeds for polymer electrolyte-gated OFETs are also discussed.
Bibliographical noteFunding Information:
One of the authors (M. J. P.) thanks the NSF for support provided through a Graduate Research Fellowship. Another author (C. R. N.) thanks the A.S.E.E. for support provided through an N.D.S.E.G. Fellowship. This work was also partially supported by the NSF Materials Research Science and Engineering Center Program (DMR-0212302).