Static charging of graphene and graphite slabs

TL;DR

This study uses first-principles calculations to explore how static charging affects the electronic structure, exfoliation, and surface properties of graphene and graphite slabs, revealing charge-induced phenomena like layer exfoliation and surface charge accumulation.

Contribution

It provides new insights into the effects of static charging on graphene and graphite, including charge distribution, exfoliation mechanisms, and surface modifications, using first-principles methods.

Findings

Excess charges mainly accumulate at both surfaces of graphite.

Coulomb repulsion can exfoliate graphene layers from positively charged graphite.

Charging influences energy levels, binding energy, and spin-polarization of adsorbed adatoms.

Abstract

The effect of external static charging of graphene and its flakes are investigated by using first-principles calculations. While the Fermi level of negatively charged graphene rises and then is quickly pinned by the parabolic, nearly free electron like bands, it moves down readily by removal of electrons from graphene. Excess charges accumulate mainly at both surfaces of graphite slab. Even more remarkable is that Coulomb repulsion exfoliates the graphene layers from both surfaces of positively charged graphite slab. The energy level structure, binding energy and and spin-polarization of specific adatoms adsorbed to a graphene flake can be monitored by charging.