High-Performance Field-Effect Transistor and Logic Gates based on GaS-MoS2 van der Waals Heterostructure

This work demonstrates a high-performance and hysteresis-free field-effect transistor based on 2D semiconductors featuring a van der Waals heterostructure, MoS2 channel and GaS gate insulator. The transistor exhibits a subthreshold swing of 63 mV/dec, an ON/OFF ratio over 106 within a gate voltage of 0.4 V, and peak mobility of 83 cm2/V·s at room temperature. The low-frequency noise characteristics were investigated and described by the Hooge mobility fluctuation model. The results suggest that the van der Waals heterostructure of 2D semiconductors can produce a high-performing interface without dangling bonds and defects caused by lattice mismatch. Furthermore, a logic inverter and a NAND gate are demonstrated, with an inverter voltage gain of 14.5, which is higher than previously reported by MoS2-based transistors with oxide dielectrics. Therefore, this transistor based on van der Waals heterostructure exhibits considerable potential in digital logic applications with low-power integrated circuits.