SurfaceScience21 – wissenschaftliches Programm
O 105.12: Poster
Donnerstag, 4. März 2021, 13:30–15:30, P
Transitions from single-layer MoS2 to bilayer growth: A LEEM study — •Moritz Ewert1,2,3, Lars Buß1,2, Francesca Genuzio4, Tevfik Onur Menteş4, Andrea Locatelli4, Jens Falta2,3, and Jan Ingo Flege1,2,3 — 1Applied Physics and Semiconductor Spectroscopy, Brandenburg University of Technology Cottbus-Senftenberg, Germany — 2Institute of Solid State Physics, University of Bremen, Germany — 3MAPEX Center for Materials and Processes, University of Bremen, Germany — 4Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Trieste, Italy
Molybdenum disulfide (MoS2) is well-known to change from an indirect to a direct semiconductor as a single layer.
We present insights from in-situ low-energy electron microscopy (LEEM) on the extended growth of MoS2 on the Au(111) surface at elevated temperatures of 720∘C. Our continuous growth method leads to the formation of micron-sized single-layer MoS2 islands. The single-domain character of these islands is confirmed by employing dark-field imaging and micro-diffraction (LEED). This also reveals the distribution of 90:10 of the two expected MoS2 mirror domains on Au(111). Selected-area angle-resolved photoelectron spectroscopy (ARPES) measurements of these mirror domains underline the threefold symmetry of the two mirror domains and indicate the presence of MoS2 bilayer. Using X-ray photoemission electron microscopy (XPEEM) and intensity-voltage LEEM (I(V))-LEEM we identify the bilayer nucleation areas at nearly full surface coverage and propose a model pathway for their formation.