Capacitive coupling between an overlying ion gel electrolyte and an underlying oxide thin film is utilized to substantially suppress the operating voltage of field-effect transistors (FETs) based on two-dimensional (2D) transition metal dichalcogenides and black phosphorus. The coupling of the layers is achieved following device fabrication by laminating an ion gel layer over an oxide-gated 2D FET through solution-casting methods. While the original pristine 2D FET requires tens of volts for gating through the oxide layer, the laminated ion gel layer reduces the operating voltage to below 4 V even when the same underlying substrate is used as the back gate electrode. Moreover, this capacitive coupling approach allows low-voltage operation without compromising the off-current level, which often occurs when ion gel electrolytes are directly employed as the gate dielectric material. This approach can likely be generalized to a wide variety of thin-film FETs as a postfabrication method for reducing operating voltages and power consumption.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Materials Chemistry