Berlin 2018 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 113: 2D materials beyond graphene: TMDCs, silicene and relatives V
O 113.3: Vortrag
Freitag, 16. März 2018, 11:00–11:15, MA 043
Material Realistic Description of Coulomb Engineered Two-dimensional Materials — •Christina Steinke1,2, Malte Rösner3, Dmitry Ryndyk2, and Tim 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 — 3Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA
Heterojunctions are building blocks of various applications in modern optoelectronics. Common heterojunctions rely on interfaces of different materials in order to gain the desired spatial band-gap modulations. We investigate a new type of lateral heterojunction imprinted externally into an otherwise homogeneous monolayer of a 2d material. In 2d semiconductors the Coulomb interaction can modify band gaps on an eV scale and can be drastically manipulated by external screening. This allows to tune the local band gaps within a monolayer by laterally structured dielectric surroundings and leads to characteristics of a heterojunction in the local density of states with a spatially sharp band gap modulation. By means of ab-initio calculations we study the nature and tunability of this band-gap modulation in 2d semiconductors in dependence of the chosen environment. Therefore we place a homogeneous monolayer on different laterally structured substrates. We identify optimal candidates for Coulomb engineered 2d systems and study their electronic transport properties depending on external electrical fields and charge doping.