Organic field effect transistors with dipole-polarized polymer gate dielectrics for control of threshold voltage

The authors demonstrate organic field effect transistors (OFETs) with a dipole-polarized polyurea for the gate dielectrics. In the dielectrics, the internal electric field induces the mobile charge carrier in the semiconductor layer to the semiconductor-dielectric interface. OFETs with dipole-polarized gate dielectrics exhibit lower threshold voltage. With nonpolarized gate dielectrics, the threshold voltage was −11.4V, whereas that decreased to −5.3V with polarized gate dielectrics. In addition to the threshold voltage, polarized gate dielectrics reduced subthreshold swing from 4.1to2.4V/decade at the gate voltage of −20V. These results show that dipole-polarized polyurea gate dielectrics allow us to operate OFETs with lower power consumption.