Structural and Electronic Properties of Amorphous Silicon and Germanium Monolayers and Nanotubes: A DFT Investigation

TL;DR

This study uses DFT simulations to explore the structural and electronic properties of amorphous silicon and germanium monolayers and nanotubes, revealing their potential as novel optoelectronic materials.

Contribution

It introduces computational analysis of amorphous silicon and germanium monolayers and nanotubes, expanding understanding of their properties and potential for synthesis.

Findings

Cohesion energies range from -8.41 to -7.49 eV/atom.

Electronic behaviors vary from metallic to small band gap semiconductors.

Structures are within current synthetic capabilities.

Abstract

A recent breakthrough has been achieved by synthesizing monolayer amorphous carbon (MAC), which introduces a material with unique optoelectronic properties. Here, we used ab initio (DFT) molecular dynamics simulations to study silicon and germanium MAC analogs. Typical unit cells contain more than 600 atoms. We also considered their corresponding nanotube structures. The cohesion energy values for MASi and MAGe range from -8.41 to -7.49 eV/atom and follow the energy ordering of silicene and germanene. Their electronic behavior varies from metallic to small band gap semiconductors. Since silicene, germanene, and MAC have already been experimentally realized, the corresponding MAC-like versions we propose are within our present synthetic capabilities.