High Frequency and High Gain Split-Gate Monolayer MoS₂ Field Effect Transistor for Common Source Amplifier Circuit

For analog systems, the field effect transistor (FET) is regarded as one of the fundamental electronic devices. However, its small gain restricts the application of FET in amplifiers and analog circuits. Here, we design a split-gate FET based on monolayer MoS2 and optimize the key performance index of intrinsic gain (Av0), transconductance frequency product (TFP), and gain frequency product (GFP). The maximum Av0 of 293 V/V and cutoff frequency of hundreds of GHz are obtained by optimizing the control gate positions and input gate voltage. With an equivalent oxide thickness of 0.3 nm, the FET possesses a superior TFP of 7657 GHz/V and GFP of 14148 GHz. In particular, a common source amplifier circuit utilizing the split-gate FET is established, achieving the largest circuit gain of approximately 277 V/V. This work provides a promising route to use split-gate FET to realize a common source amplifier circuit with high circuit gain.