Scanning tunneling microscopy for imaging and quantification of defects in as-deposited MoS[formula omitted] monolayers on sapphire substrates

Abstract

This paper quantitatively assessed the intrinsic defectivity of as-deposited molybdenum disulfide (MoS2) monolayers on sapphire substrates using atomically resolved scanning tunneling microscopy and spectroscopy. We observed two types of point defects — protrusion-like and depression-like with average densities of (2.4 ± 2) ⋅ 1013 cm−2 and (1.9 ± 1.4) ⋅ 1012 cm−2, respectively. The position of the electron state within the MoS2 bandgap suggests that the protrusion-like defect associates with a sulfur mono-vacancy.