Field of Expertise: Advanced Material Science
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Field of Expertise: Advanced Material Science | |
Modification of the electronic structure of graphene and hexagonal boron nitride using collective electrostatic effects Finding novel electronic applications based on the seminal material graphene is a relatively new, but quickly growing field. In this context, controlling the electronic properties of graphene through modifying its structure and chemical composition is an appealing strategy. Here, we explore the possibility to control the electronic structure of graphene through chemically induced collective electrostatic effects. As a first attempt to show the potential of this concept, we substitute specific carbon atoms by boron and nitrogen, thereby creating in-plane lines of dipoles. Using standard density functional theory calculations, the resulting dipolar field is shown to cause a shift in the electrostatic potential, thus changing the energy of the graphene electronic states with respect to the Fermi level in the vicinity of the BN lines. When installing two oppositely oriented close-lying dipole chains, a localization of the occupied or the unoccupied states either between or outside the two chains can be realized. Furthermore, we examine whether similar effects can be realized by self-assembling organic molecules containing dipolar units onto the graphene layer without chemically modifying the graphene sheet itself. Finally, the results are compared to a similarly modified sheet of the semiconducting material hexagonal boron nitride (hBN). |