Monolayer Bismuthene-Metal Contacts: A Theoretical Study.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Bismuthene, a graphene analogue, exhibits promising electronic and spintronic properties.
• Electrical contacts critically influence the performance of bismuthene-based devices.
• Understanding interfacial properties is key for device optimization.

Purpose of the Study:

• To systematically investigate the interfacial properties of monolayer bismuthene with various metal electrodes.
• To analyze the impact of metal contacts on the electronic behavior of bismuthene.
• To provide guidance for selecting optimal electrodes for bismuthene devices.

Main Methods:

• First-principles electronic structure calculations.
• Quantum transport simulations.
• Analysis of metal-induced gap states (MIGSs) and Fermi-level pinning.

Main Results:

• Monolayer bismuthene undergoes metallization upon contact with common metal electrodes due to strong interactions.
• Metal-induced gap states cause significant Fermi-level pinning, resulting in n-type or p-type Schottky contacts.
• Graphene electrodes eliminate MIGSs, leading to quasi-Ohmic contacts with a small hole Schottky barrier height.

Conclusions:

• The choice of metal electrode profoundly affects bismuthene device performance.
• Graphene emerges as a promising electrode material for achieving high-performance bismuthene transistors.
• This study offers crucial insights for designing future bismuthene-based electronic and spintronic devices.