▎ 摘　　要

With the development of device miniaturization, traditional Si-based field effect transistors (FETs) are approaching their scaling limits. It is necessary to find more alternative materials to improve the performance of FETs. 2D semiconductors attract great attention for channel material due to their atomic-scale smoothness and dangling-bond-free surface, and the gate electrostatic properties and charge carrier mobility are better than traditional 3D Si-based semiconductor. In this paper, using density functional theory combined with nonequilibrium Green's function formalism, the electronic properties and device performance of sub-5 nm monolayer SiMe-graphene n-type field-effect transistors are evaluated. Remarkably, the on-state current value of the FET can reach 3070 mu A mu m(-1), which greatly surpasses most of reported FETs based on other 2D semiconductors. In addition, the on-state current, power dissipation, and delay time of the SiMe-graphene FETs satisfy the high-performance requirements of the 2020 International Roadmap for Device and Systems under different supply voltages, which indicates that the FETs can work at different operating frequencies and power consumption. Moreover, via controlling electrode doping concentration, the channel length can be reduced to 4 nm. In total, the SiMe-graphene is a favorable channel material for future FETs devices.