title: Toward an Understanding of the Electric Field-Induced Electrostatic Doping in van der Waals Heterostructures: A First-Principles Study.
abstract: Since the discovery of graphene, a broad range of two-dimensional (2D) materials has captured the attention of the scientific communities. Materials, such as hexagonal boron nitride (hBN) and the transition metal dichalcogenides (TMDs) family, have shown promising semiconducting and insulating properties that are very appealing for the semiconductor industry. Recently, the possibility of taking advantage of the properties of 2D-based heterostructures has been investigated for low-power nanoelectronic applications. In this work, we aim at evaluating the relation between the nature of the materials used in such heterostructures and the amplitude of the layer-to-layer charge transfer induced by an external electric field, as is typically present in nanoelectronic gated devices. A broad range of combinations of TMDs, graphene, and hBN has been investigated using density functional theory. Our results show that the electric field induced charge transfer strongly depends on the nature of the 2D materials used in the van der Waals heterostructures and to a lesser extent on the relative orientation of the materials in the structure. Our findings contribute to the building of the fundamental understanding required to engineer electrostatically the doping of 2D materials and to establish the factors that drive the charge transfer mechanisms in electron tunneling-based devices. These are key ingredients for the development of 2D-based nanoelectronic devices.
authors.affiliation: Semiconductor Physics Laboratory, Department of Physics and Astronomy, University of Leuven , Celestijnenlaan 200 D, B-3001 Leuven, Belgium.|IMEC , 75 Kapeldreef, B-3001 Leuven, Belgium.
authors.forename: Anh Khoa Augustin
authors.identifier: http://orcid.org/0000-0003-4702-0933
authors.initials: AK
authors.lastname: Lu
authors.affiliation: Semiconductor Physics Laboratory, Department of Physics and Astronomy, University of Leuven , Celestijnenlaan 200 D, B-3001 Leuven, Belgium.
authors.forename: Michel
authors.initials: M
authors.lastname: Houssa
authors.affiliation: IMEC , 75 Kapeldreef, B-3001 Leuven, Belgium.
authors.forename: Iuliana P
authors.initials: IP
authors.lastname: Radu
authors.affiliation: IMEC , 75 Kapeldreef, B-3001 Leuven, Belgium.|Department of Chemistry, Plasmant Research Group, University of Antwerp , B-2610 Wilrijk-Antwerp, Belgium.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Pourtois
keywords: electron tunneling; electrostatic doping; first-principles calculations; two-dimensional materials; van der Waals heterostructures