First-principles investigation of bilayer fluorographene

TL;DR

This study uses first-principles calculations to analyze the stability and electronic properties of bilayer fluorographene, revealing it as a stable, nearly as strong material with a larger band gap than monolayer fluorographene.

Contribution

It provides the first detailed ab initio analysis of bilayer fluorographene's stability, electronic structure, and mechanical strength, comparing it to related materials.

Findings

Bilayer fluorographene is more stable than bilayer graphane.

Its electronic band gap is about 1 eV larger than monolayer fluorographene.

It has a Young's modulus of approximately 300 N·m^{-1}.

Abstract

\textit{Ab initio} calculations within the density functional theory formalism are performed to investigate the stability and electronic properties of fluorinated bilayer graphene (bilayer fluorographene). A comparison is made to previously investigated graphane, bilayer graphane, and fluorographene. Bilayer fluorographene is found to be a much more stable material than bilayer graphane. Its electronic band structure is similar to that of monolayer fluorographene, but its electronic band gap is significantly larger (about 1 eV). We also calculate the effective masses around the $\Gamma$-point for fluorographene and bilayer fluorographene and find that they are isotropic, in contrast to earlier reports. Furthermore, it is found that bilayer fluorographene is almost as strong as graphene, as its 2D Young's modulus is approximately 300 $\mathrm{N} \mathrm{m}^{-1}$.