DFT coupled with NEGF study of N-type MOSFET based on 2D Bi₂C₃semiconductor

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Silicon-based Field-Effect Transistors (FETs) are approaching fundamental scaling limits.
• Two-dimensional (2D) materials offer potential solutions to overcome short-channel effects and reduce power consumption in advanced transistors.
• Novel 2D materials are continuously being explored for next-generation semiconductor devices.

Purpose of the Study:

• To comprehensively investigate the electronic and transport properties of the novel 2D bismuth carbide (Bi2C3) semiconductor.
• To evaluate the potential of monolayer Bi2C3 as a channel material for high-performance Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs).
• To assess the device performance against the International Technology Roadmap for Semiconductors (ITRS) specifications.

Main Methods:

• First-principles density functional theory (DFT) calculations were employed to determine the electronic band structure of monolayer Bi2C3.
• Non-equilibrium Green's function (NEGF) quantum transport simulations were utilized to model the performance of Bi2C3-based FETs.
• Device simulations were conducted for various channel lengths, including 10 nm and 5 nm.

Main Results:

• Monolayer Bi2C3 exhibits a moderate direct bandgap, a sharp conduction band, and a low electron effective mass (0.48m0).
• Bi2C3 FETs achieved an ultra-high on-state current (Ion) of 2540 μA/μm with an on/off ratio exceeding 10^4 for a 10 nm channel.
• Devices demonstrated fast switching speeds, low power-delay (τ), and excellent energy-delay product, meeting ITRS high-performance targets across scaled channel lengths.

Conclusions:

• Monolayer Bi2C3 is a highly competitive candidate material for future high-performance integrated circuits.
• The comprehensive performance metrics of Bi2C3-based FETs satisfy critical requirements for advanced semiconductor applications.
• This study provides the first systematic evaluation of Bi2C3's potential in MOSFETs using DFT-NEGF simulations.