Defects, band bending and ionization rings in MoS2

Abstract

Chalcogen vacancies in transition metal dichalcogenides are widely acknowledged as both donor dopants and as a source of disorder. The electronic structure of sulphur vacancies in MoS2 however is still controversial, with discrepancies in the literature pertaining to the origin of the in-gap features observed via scanning tunneling spectroscopy (STS) on single sulphur vacancies. Here we use a combination of scanning tunnelling microscopy (STM) and STS to study embedded sulphur vacancies in bulk MoS2 crystals. We observe spectroscopic features dispersing in real space and in energy, which we interpret as tip position- and bias-dependent ionization of the sulphur vacancy donor due to tip induced band bending (TIBB). The observations indicate that care must be taken in interpreting defect spectra as reflecting in-gap density of states, and may explain discrepancies in the literature.

7 pages, 5 figures

References in corpus (7)

• Anomalous Lattice Vibrations of Single and Few-Layer MoS2
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Two-dimensional transition metal dichalcogenides under electron irradiation: defect production and doping
• Spontaneous doping of the basal plane of MoS2 single-layers through oxygen substitution under ambient conditions
• Bandgap and doping effects in MoS2 measured by Scanning Tunneling Microscopy and Spectroscopy
• Effect of Point Defects on the Optical and Transport Properties of MoS2 and WS2
• Band Bending and Valence Band Quantization at Line Defects in MoS${}_2$

Cited by in corpus (1)

• Symmetry breaking and spin-orbit coupling for individual vacancy-induced in-gap states in MoS2 monolayers