Berlin 2018 – scientific programme

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O: Fachverband Oberflächenphysik

O 91: 2D materials beyond graphene: TMDCs, silicene and relatives III

O 91.6: Talk

Thursday, March 15, 2018, 11:45–12:00, MA 043

In situ growth and characterization of single-layer molybdenum disulfide on Au(111) — •Moritz Ewert^1,2, Lars Buß¹, Jens Falta^1,2, and Jan Ingo Flege^1,2 — ¹Institute of Solid State Physics, University of Bremen, Germany — ²MAPEX Center for Materials and Processes, Bremen, Germany

Single-layer (SL) transition metal dichalcogenides are in today’s research focus due to their electronic similarity to graphene as well as owing to their catalytic properties, e. g., in hydrodesulfurization processes.

We have investigated the growth of SL molybdenum disulfide (MoS₂) on Au(111) by Mo metal deposition in dimethyldisulfide background using low-energy electron microscopy (LEEM) and microdiffraction (µLEED). In situ investigations at different elevated temperatures reveal that triangular MoS₂ islands nucleate and continue to grow in a dendritic mode, extending over several square µm in size. The local structure of the islands was elucidated by analyzing the specular electron reflectivity depending on electron energy measurements (IV-LEEM), confirming the sole existence of SL structures. This finding is corroborated by µLEED, which demonstrates the formation of micron-sized MoS₂ SL domains. Furthermore, closer investigation of the mesoscale structure in dark-field LEEM shows that the triangular-shaped structures can be found in two distinct orientations, whose relative abundance has been found to depend on temperature.