Inducing energy gaps in graphene monolayer and bilayer

TL;DR

This paper proposes a mechanism to induce energy gaps in graphene monolayer and bilayer by water and ammonia adsorption, achieving experimentally relevant gap sizes and stable adsorption at room temperature.

Contribution

It introduces a novel approach to open energy gaps in graphene using molecular adsorption, with theoretical calculations matching experimental gap sizes.

Findings

Energy gaps of 20-30 meV induced by water and ammonia

Adsorption remains stable at room temperature

Results align with experimental observations

Abstract

In this paper we propose a mechanism for the induction of energy gaps in the spectrum of graphene and its bilayer, when both these materials are covered with water and ammonia molecules. The energy gaps obtained are within the range 20-30 meV, values compatible to those found in experimental studies of graphene bilayer. We further show that the binding energies are large enough for the adsorption of the molecules to be maintained even at room temperature.