Tungsten disulfide on Au(111)

In this work, we combined several techniques to provide a characterization of single-layer (SL) WS2 grown on Au(111). In particular, we used x-ray photoelectron diffraction (XPD) to determine the structural properties of the interface, proving that we have a WS2 layer with a single orientation.

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L. Bignardi et al., Phys. Rev. Materials 3, 014003 (2019).

Transition metal dichalcogenides (TMDCs) are a rising star among other two-dimensional materials, in view of a possible usage in building new electronic devices that exploit the spin-valley degree of freedom.
The sample was grown at the SuperESCA beamline of Elettra Synchrotron in Trieste, by evaporating W atoms with the UHV chamber backfilled with H2S. The preparation was performed monitoring the W 4f and S 2p core levels with fast x-ray photoelectron spectroscopy, which allowed a precise tuning of the deposition conditions (temperature, H2S pressure, W evaporation rate). We observed that the growth of a single crystalline orientation is triggered by choosing a low W evaporation rate and performing the process with a high temperature of the substrate. Information about the single orientation of the layer was obtained by acquiring XPD patterns, revealing a 1H polytype for the WS2 layer and, moreover, determining the structural parameters and registry

with the substrate.
These measurements were complemented by low-energy electron microscopy (LEEM) measurements, performed at the University of Bremen, Germany, which provided further details about the morphology of the WS2 crystalline domains.

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Growth and structure of singly oriented single-layer tungsten disulfide on Au(111);
Luca Bignardi, Daniel Lizzit, Harsh Bana, Elisabetta Travaglia, Paolo Lacovig, Charlotte E. Sanders, Maciej Dendzik, Matteo Michiardi, Marco Bianchi, Moritz Ewert, Lars Buß, Jens Falta, Jan Ingo Flege, Alessandro Baraldi, Rosanna Larciprete, Philip Hofmann, and Silvano Lizzit;
Phys. Rev. Materials 3, 014003 (2019).
Last Updated on Friday, 22 January 2021 16:16