Skip to main content
Go to the home page of the European Commission (opens in new window)
English en
CORDIS - EU research results
CORDIS

Tuning the electronic structure of two-dimensional semiconductor junctions

Project description

New approaches to control 2D semiconductor junctions

Two-dimensional (2D) semiconductors are at the forefront of nanoelectronics owing to their potential to create the smallest possible electronic devices, such as lateral junctions. These tiny systems are essential for understanding band alignment, band bending and depletion regions, which shape the technological applications of these devices. With the support of the Marie Skłodowska-Curie Actions (MSCA) programme, the 2D-In-Tune project will study such junctions using advanced 2D materials like transition metal dichalcogenides, placed on special surfaces such as hexagonal boron nitride or graphene. By adding guest atoms between layers, researchers could fine-tune the materials without altering their properties. Project findings will reveal new insights into band bending and introduce innovative ways to detect and map energy levels.

Objective

Lateral junctions between two-dimensional (2D) semiconductors are conceptually the smallest possible electronic devices. This project investigates the basic physics of these systems as the type of band alignment, the band bending and depletion region, which are decisive parameters for any application. Semiconductor junctions composed of 2D transition metal dichalcogenides (TMDs) will be prepared on hexagonal boron nitride (hBN) or graphene (Gr) on Ir(111). The use of the single-crystalline metal substrate allows the application of surface science methods for preparation and characterization, while the ultrathin buffer layer leaves the intrinsic properties of TMDs undisturbed. Intercalation of guest atoms between the buffer layer and Ir will be used as an elegant and non-invasive method for doping the TMDs. This will also tune intrinsic band bending at the 1D-interface of the TMD junctions, which is yet to be explored for various 2D systems. To separate the effect of inhomogeneous doping and inhomogeneous structure, two types of lateral TMD junctions will be prepared: Homojunctions will be achieved by doping only one part of the TMD island by extending it over the interface of intercalated patches in hBN. Heterojunctions will be composed of two different TMD materials grown on homogeneous vdW substrate, either fully intercalated or pristine. Samples will be prepared by combining two TMDs (ReS2 and WS2) and two dopants (n and p). Scanning tunneling spectroscopy (STS) and Kelvin probe force microscopy (KPFM) will be used for the characterization of the 1D-interfaces and the reconstruction of the band diagrams. Dielectric screening induced by the substrate will be analyzed by comparing values of the band gaps and shifts of critical energy points between different systems. This will deepen the understanding of the origin of band bending in 2D systems. Inelastic electron tunneling spectroscopy (IETS) will be used as a potentially new technique for detecting excitons.

Fields of science (EuroSciVoc)

Keywords

Programme(s)

Topic(s)

Funding Scheme

HORIZON-TMA-MSCA-PF-EF - HORIZON TMA MSCA Postdoctoral Fellowships - European Fellowships

See all projects funded under this funding scheme

Call for proposal

(opens in new window) HORIZON-MSCA-2022-PF-01

See all projects funded under this call

Coordinator

UNIVERSITAET SIEGEN
Net EU contribution
€ 173 847,36
Address
ADOLF REICHWEIN STRASSE 2A
57076 Siegen
Germany
Region
Nordrhein-Westfalen Arnsberg Siegen-Wittgenstein
Activity type
Higher or Secondary Education Establishments
Links
Total cost
No data

Partners (1)