Two and one-dimensional honeycomb structures of silicon and germanium

TL;DR

This paper predicts stable two-dimensional honeycomb structures of silicon and germanium, revealing their electronic properties similar to graphene and exploring their potential for nanodevice engineering.

Contribution

It introduces the first-principles prediction of stable 2D Si and Ge honeycomb structures with unique electronic and magnetic properties.

Findings

Silicon and germanium form stable, low-buckled 2D honeycomb structures.

These structures exhibit Dirac-like electronic behavior similar to graphene.

Nanoribbons of Si and Ge show size- and orientation-dependent properties.

Abstract

Based on first-principles calculations of structure optimization, phonon modes and finite temperature molecular dynamics, we predict that silicon and germanium have stable, two-dimensional, low-buckled, honeycomb structures. Similar to graphene, they are ambipolar and their charge carriers can behave like a massless Dirac fermions due to their pi- and pi*-bands which are crossed linearly at the Fermi level. In addition to these fundamental properties, bare and hydrogen passivated nanoribbons of Si and Ge show remarkable electronic and magnetic properties, which are size and orientation dependent. These properties offer interesting alternatives for the engineering of diverse nanodevices.