Nature of Point Defects in Single-Layer MoS2 Supported on Au(111)

Francesco Tumino,Andrea Li Bassi,Carlo Spartaco Casari,Sergio Tosoni

doi:10.1021/acs.jpcc.0c01477

Abstract

The interaction between molybdenum disulfide monolayers and gold is studied by combining scanning tunneling microscopy (STM) measurements on extended MoS2 films grown by pulsed laser deposition and...

Highlights

Transition-metal dichalcogenides are solid materials characterized by weakly bound layered structures
A representative largescale scanning tunneling microscopy (STM) image, reported in Figure 1a, shows relatively large MoS2 crystallites attached to Au step edges, together with smaller islands growing on the Au terrace
This paper aims at elucidating these main features by combining STM measurements with density functional theory (DFT) simulations

Summary

Introduction

Transition-metal dichalcogenides are solid materials characterized by weakly bound layered structures. Extended ML islands crossing the herringbone’s ridges are commonly not observed, as previously reported.[20−22] The lattice mismatch between the substrate and the supported dichalcogenide film leads to a moiré pattern because of the different vertical Au−S−Mo−S stacking. This pattern is typically detected by AFM or STM measurements as succession of hexagonal brighter and darker regions with a periodicity of 33 ± 1 Å.22. This pattern is typically detected by AFM or STM measurements as succession of hexagonal brighter and darker regions with a periodicity of 33 ± 1 Å.22 In spite of the substantial chemical inertness of the support, hybridization and screening effects because of the interaction with the Au support, depending on the local film/support match, affect remarkably the electronic structure of MoS2.17,21 It is still matter of debate, if these electronic effects correspond to relevant changes in the topographic MoS2 profile.[22]

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