Reduction of hysteresis in organic field-effect transistor by ferroelectric gate dielectric

We studied the reduction of hysteresis in pentacene organic field-effect transistors (OFETs) with a ferroelectric poly(vinylidene fluoride and trifluoroethylene) [P(VDF-TrFE)] dipole layer used as a coating of silicon dioxide gate insulator. Although the OFETs without the dipole layer exhibited a hysteresis caused by carrier trapping, such hysteresis was not observed for the OFETs with the P(VDF-TrFE) layers. Experiments showed that the induced hysteresis could be regulated by the number of P(VDF-TrFE) dipole layers, which were deposited by the Langmuir-Blodgett (LB) technique or the spin-coating method. Finally, we showed that analysis based on an electrostatic model well accounted for the experimental results, i.e., the reduction of hysteresis by means of the ferroelectric layer.