Analog Circuit Applications Based on Ambipolar Graphene/MoTe2 Vertical Transistors

The current integrated circuit technology based on conventional metal-oxide-semiconductor field-effect transistor (MOSFET) is approaching the limit of miniaturization with increasing demand on energy. Several analog circuit applications based on graphene FETs have been demonstrated with less components comparing to the conventional technology. However, low on/off current ratio caused by the semimetal nature of graphene has severely hindered its practical applications. Here, a graphene/molybdenum ditelluride (MoTe2) van der Waals (vdW) vertical transistor with V-shaped ambipolar field-effect transfer characteristics to overcome this challenge is reported. Investigations on temperature dependence of transport properties reveal that gate-tunable asymmetric barriers of the devices are account for the ambipolar behaviors. Furthermore, to demonstrate the analog circuit applications of such vdW vertical transistors, output polarity controllable amplifier and frequency doubler are successfully realized. These results enable vdW heterojunction-based electronic devices to open up new possibilities for wide perspective in telecommunication field.