The interfacial properties of 2D metal-monolayer blue phosphorene heterojunctions and transport properties of their field-effect transistors

Monolayer blue phosphorene (BlueP) has attracted much interest as a potential channel material in electronic devices. Searching for suitable two-dimensional (2D) metal materials to use as electrodes is critical to fabricating high-performance nanoscale channel BlueP-based field effect transistors (FETs). In this paper, we adopted first-principles calculations to explore binding energies, phonon calculations and electronic structures of 2D metal-BlueP heterojunctions, including Ti3C2-, NbTe2-, Ga(110)- and NbS2-BlueP, and thermal stability of Ti3C2-BlueP heterojunction at room temperature. We also used density functional theory coupled with the nonequilibrium Green function method to investigate the transport properties of sub-5 nm BlueP-based FETs with Ti3C2-BlueP electrodes. Our calculated results indicate that Ti3C2-BlueP has excellent thermal stability and may be used as a candidate electrode material for BlueP-based FETs. The double-gate can more effectively improve the device performance compared with the single-gate. The estimated source leakage current of sub-5 nm transistors reaches up to 369 mu A mu m-1, which is expected to meet the requirements of the international technology roadmap for semiconductors for LP (low-power) devices. Our results imply that 2D Ti3C2 may act as an appropriate electrode material for LP BlueP-based FETs, thus providing guidance for the design of future short-gate-length BlueP-based FETs.