DFT coupled with NEGF study of N-type MOSFET based on 2D Bi ₂ C ₃ semiconductor

As silicon-based FETs face scaling limits, 2D material emerge as promising alternatives with potential to suppress short-channel effects and reduce power consumption. We present a comprehensive investigation of the novel 2D bismuth carbide (Bi2C3) semiconductor using first-principles density functional theory (DFT) calculations combined with non-equilibrium Green's function (NEGF) quantum transport simulations. Electronic band structure calculations indicate that monolayer Bi2C3 possesses a moderate direct bandgap, a sharp conduction band, and a low electron effective mass (0.48 m0). Device simulations reveal outstanding performance: a Bi2C3 FET with a 10-nm channel length achieves an ultra-high on-state current (Ion) of 2540 μA/μm while maintaining a high on/off current ratio (exceeding 104), satisfying the requirements of the International Technology Roadmap for Semiconductors (ITRS) for high-performance (HP) applications. Furthermore, scaling the channel length down to 5 nm still yields device performance compliant with ITRS specifications. Crucially, devices across different channel lengths exhibit fast switching speeds, low power-delay (τ), power-delay product (PDP), and excellent energy-delay product (EDP), fully meeting the ITRS HP targets. This study, for the first time, systematically evaluates the application potential of Bi2C3 in MOSFETs via DFT-NEGF. Its excellent comprehensive performance metrics demonstrate that monolayer Bi2C3 is a highly competitive candidate channel material for future HP integrated circuits.