Atomically-thin metallic Si and Ge allotropes with high Fermi velocities

TL;DR

This paper reports the discovery of stable, atomically-thin metallic silicon and germanium structures with high Fermi velocities, enabling potential all-silicon integrated circuits with improved electronic properties.

Contribution

The study introduces novel metallic monolayer allotropes of Si and Ge that are more stable than previous semimetallic forms and exhibit superior Fermi velocities compared to graphene.

Findings

Discovered stable metallic monolayer Si and Ge structures.

These allotropes have higher Fermi velocities than graphene.

Potential for all-silicon integrated circuits.

Abstract

Silicon and germanium are the well-known materials used to manufacture electronic devices for the integrated circuits but they themselves are not considered as promising options for interconnecting the devices due to their semiconducting nature. We have discovered that both Si and Ge atoms can form unexpected metallic monolayer structures which are more stable than the extensively studied semimetallic silicene and germanene, respectively. More importantly, the newly discovered two-dimensional allotropes of Si and Ge have Fermi velocities superior to the Dirac fermions in graphene, indicating that the metal wires needed in the silicon-based integrated circuits can be made of Si atom itself without incompatibility, allowing for all-silicon-based integrated circuits.