Moire structure of MoS2 on Au(111): Local structural and electronic properties

Monolayer islands of molybdenum disulfide (MoS2) on Au(111) form a characteristic moire structure, leading to locally different stacking sequences at the S-Mo-S-Au interface. Using low-temperature scanning tunneling microscopy (STM) and atomic force microscopy (AFM), we find that the moire islands exhibit a unique orientation with respect to the Au crystal structure. This indicates a clear preference of MoS2 growth in a regular stacking fashion. We further probe the influence of the local atomic structure on the electronic properties. Differential conductance spectra show pronounced features of the valence band and conduction band, some of which undergo significant shifts depending on the local atomic structure. We also determine the tunneling decay constant as a function of the bias voltage by a height-modulated spectroscopy method. This allows for an increased sensitivity of states with non-negligible parallel momentum k(parallel to) and the identification of the origin of the states from different areas in the Brillouin zone.