Effects of atomic defects at lateral and vertical metal-semiconductor interfaces on the properties of the two-dimensional transition metal dichalcogenide heterostructures

• Applicants: Professorin Dr. Ute Kaiser; Dr. Arkady Krasheninnikov
• Subject Area: Experimental Condensed Matter Physics ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 471707562

The applications of two-dimensional (2D) heterostructures based on transition metal dichalcogeni-des (TMDs) in future electronic and optical devices is hardly possible without a complete under-standing of the physical phenomena occurring at the interfaces in metallic and semiconducting heterostructures. We will study selected 2D TMD metallic-semiconducting interfaces in lateral het-erostructures produced by growth of two materials next to each other, and in the vertical configu-ration with a single-layer metallic TMD placed on top of a single-layer semiconducting TMD. As at-omistic defects such as contaminations, dopants, and vacancies will be always present in practical devices, the aim of this project is to study the influence of these defects on the structure and on the electronic properties of the lateral and vertical heterointerfaces. We use CVD–grown lateral TMD-heterostructures as provided by cooperation partners and we prepare the vertical TMD hetero-structures by sandwiching and stamping techniques. The atomic structure of the interfaces will be investigated by low-voltage high-resolution TEM with spherical and chromatic aberration correc-tion, and the plasmon, excitons and core states will be studied by electron energy-loss spectrosco-py. The experimental findings will be rationalized through first-principles calculations from which we expect to gain in-depth understanding of the role of interfacial defects on the properties of the 2D heterostructures.

• DFG Programme: Research Grants
• Co-Investigator: Dr. Johannes Biskupek