Regensburg 2016 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 54: 2D Materials II: Growth
O 54.3: Vortrag
Mittwoch, 9. März 2016, 11:00–11:15, S053
2D Heterojunctions from Non-local Manipulations of the Interactions — Malte Rösner1,2, •Christina Steinke1,2, Michael Lorke1, Christopher Gies1, Frank Jahnke1, and Tim O. Wehling1,2 — 1Institut für Theoretische Physik, Universität Bremen, Otto-Hahn-Allee 1, 28359 Bremen, Germany — 2Bremen Center for Computational Materials Science, Universität Bremen, Am Fallturm 1a, 28359 Bremen, Germany
We propose to create lateral heterojunctions in homogeneous two-dimensional materials based on non-local manipulations of the Coulomb interaction using structured dielectric substrates. By means of ab-initio calculations for MoS2 as well as generic semiconductor models, we show, that changes in the dielectric environment can induce sizeable band-gap modulations. The Coulomb interaction induced self energy corrections in real space are sufficiently non-local, to be manipulated externally, and are clearly localized within a radius of a few unit cell at the same time. This allows to induce spatially sharp interfaces within a single homogeneous monolayer and thus to form a heterojunction by the external manipulation of the Coulomb interaction via structured dielectric substrates. Hence, new kinds of heterojunctions can be constructed by placing semiconducting 2d materials on appropriately structured substrates: For a laterally structured dielectric environment, we find a type-II heterojunction with a sharp band-gap crossover within less than 5 unit cells. By establishing four perpendicular interfaces a band gap modulation reminiscent of a quantum dot can be realised.