Atomic-scale quantification of charge densities in two-dimensional materials

• Main Authors: Müller-Caspary, Knut, Duchamp, Martial, Rösner, Malte, Migunov, Vadim, Winkler, Florian, Yang, Hao, Huth, Martin, Ritz, Robert, Simson, Martin, Ihle, Sebastian, Soltau, Heike, Wehling, Tim, Dunin-Borkowski, Rafal E., Van Aert, Sandra, Rosenauer, Andreas
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2018
• Subjects: Transition-metal Dichalcogenide; Monolayer Films; DRNTU::Engineering::Materials
• Online Access: https://hdl.handle.net/10356/89912; http://hdl.handle.net/10220/46424
• Institution: Nanyang Technological University

The charge density is among the most fundamental solid state properties determining bonding, electrical characteristics, and adsorption or catalysis at surfaces. While atomic-scale charge densities have as yet been retrieved by solid state theory, we demonstrate both charge density and electric field mapping across a mono-/bilayer boundary in 2D MoS2 by momentum-resolved scanning transmission electron microscopy. Based on consistency of the four-dimensional experimental data, statistical parameter estimation and dynamical electron scattering simulations using strain-relaxed supercells, we are able to identify an AA-type bilayer stacking and charge depletion at the Mo-terminated layer edge.