Low-Voltage Complementary Electronics from Ion-Gel-Gated Vertical Van der Waals Heterostructures

A study is conducted to demonstrate low-voltage vertical field-effect transistors (VFETs) and complementary inverters based on graphene-TMDC heterostructures and ion-gel gate dielectrics. The VFET structure is formed by vertically sandwiching a TMDC semiconductor layer between grapheme and metal electrodes while employing a separate coplanar gate electrode that applies an electric field to the vertical channel through an ion gel. Specifically, the channel current is modulated by tuning the Schottky barrier height across the graphene-TMDC heterojunction by an external bias applied to the coplanar gate electrode. The high ion-gel-dielectric specific capacitance allows the work function of the underlying graphene to be readily modulated at low voltages, ultimately accessing new regimes of ambipolar charge transport.