First-principles investigation of graphene fluoride and graphane

TL;DR

This study uses density functional theory to compare structural and electronic properties of various configurations of graphene derivatives, revealing significant differences caused by fluorine charges and predicting a more stable graphene fluoride structure.

Contribution

It introduces a new, more stable configuration for graphene fluoride and provides detailed theoretical insights into their properties, contrasting with experimental data.

Findings

Large differences between graphane and graphene fluoride due to fluorine charges

Prediction of a more stable graphene fluoride configuration

Discrepancies between theoretical and experimental band gaps and Young's moduli

Abstract

Different stoichiometric configurations of graphane and graphene fluoride are investigated within density functional theory. Their structural and electronic properties are compared, and we indicate the similarities and differences among the various configurations. Large differences between graphane and graphene fluoride are found that are caused by the presence of charges on the fluorine atoms. A new configuration that is more stable than the boat configuration is predicted for graphene fluoride. We also perform GW calculations for the electronic band gap of both graphene derivatives. These band gaps and also the calculated Young's moduli are at variance with available experimental data. This might indicate that the experimental samples contain a large number of defects or are only partially covered with H or F.