Tuneable molecular doping of corrugated graphene

TL;DR

This study uses density functional theory to explore how molecular adsorption and charge transfer vary on corrugated graphene, revealing the influence of ripples on adsorption properties and stability of different molecules.

Contribution

It provides new insights into how graphene's rippled structure affects molecular doping and adsorption behaviors, which was not thoroughly understood before.

Findings

Ripple tops attract large molecules more effectively.

Valleys between ripples favor small molecules.

Adsorption energies differ from flat graphene due to ripples.

Abstract

Density functional theory (DFT) modeling of the physisorption of four different types of molecules (toluene, bromine dimmer, water and nitrogen dioxide) over and above graphene ripples has been performed. For all types of molecules changes of charge transfer and binding energies in respect to flat graphene is found. The changes in electronic structure of corrugated graphene and turn of {\pi}-orbitals of carbon atoms in combination with chemical structure of adsorbed molecules are proposed as the causes of difference with the perfect graphene case and variety of adsorption properties of different types of the molecules. Results of calculation suggest that the tops of the ripples are more attractive for large molecules and valley between ripples for small molecules. Stability of molecules on the ripples and energy barriers for migration over flat and corrugated graphene is also discussed.