Displacement Current Analysis of Capacitors with Ferroelectric Poly(vinylidene fluoride-trifluoroethylene) Film

The carrier motion mechanism in capacitors with ferroelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] film was investigated in terms of displacement current analysis. The coercive electric field of the ferroelectric polymer was measured by applying a ramp voltage on an IZO/P(VDF-TrFE)/Au structure (MFM structure) with a value about 0.7 MV/cm. Subsequently, by introducing a pentacene layer to the MFM structure, namely the IZO/P(VDF-TrFE)/Pentacene/Au structure (MFSM structure) we studied carrier injection and accumulation process in the pentacene semiconductor layer under the effect of dipole reversal in the ferroelectric layer. Interestingly, three peaks were found for the MFSM structure and they were understood by taking into account charge motion in pentacene layer. The present study shows displacement current measurement is a useful technique to detect carrier motion in organic devices.