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O: Fachverband Oberflächenphysik
O 105: Poster Session VIII: Graphene and beyond II
O 105.7: Poster
Thursday, March 4, 2021, 13:30–15:30, P
Two phases of monolayer tantalum sulfide on Au(111) — Daniela Dombrowski1,2, Abdus Samad3, Clifford Murray4, Marin Petrović5, Pascal Ewen1, Thomas Michely4, Marko Kralj5, Udo Schwingenschlögl3, and •Carsten Busse1,2 — 1Institut für Materialphysik, Westfälische Wilhelms-Universität Münster, Germany — 2Department Physik, Universität Siegen, Germany — 3KAUST, Physical Science and Engineering Division, Thuwal, Saudi Arabia — 4II. Physikalisches Institut, Universität zu Köln, Germany — 5Center of Excellence for Advanced Materials and Sensing Devices, Institute of Physics, Zagreb, Croatia
Transition metal chalcogenides (TMCs) are 2d materials with a broad variety of electrical properties and phenomena like charge density waves, superconductivity and Mott transitions. Like their bulk parent materials, 2d-TMCs exhibit polymorphism. This includes the well-known 2H- and 1T-MX2 phases but also more complex structures such as self-intercalated bilayers or chalcogene-poor compounds with sulfur vacancies. The structure has a strong influence on the properties. For example, group 6 TMCs in the 2H-phase are semiconducting, while they are metallic in the 1T-phase.
We use a combination of physical and chemical vapor deposition to grow two different phases of tantalum sulfide on Au(111). STM, STS and ARPES results corroborated by DFT allow us to identify the phases as 2H-TaS2 and a novel phase found for sulfur-poor conditions where the bottom sulfur layer is missing.