Hydrogen interaction with a sulfur-vacancy-induced occupied defect state in the electronic band structure of MoS2

Abstract

Identifying and designing defects are critical steps in the development of a semiconductor. We unveil that a sufficiently high concentration of the sulfur-vacancy defect on the MoS₂ surface induces an occupied defect state in the electronic band structures, in addition to the in-gap defect states. The occupied defect state is expected to appear above and below the valence band maximum (VBM) of the mono- and bilayer or bulk band structures of MoS₂, respectively. Furthermore, the hydrogen interaction with the sulfur-vacancy defect reconstructs the band structure of MoS₂ to have multi VBMs or ambipolar valence bands depending on the layer thickness. Finally, we find that the polarity switching of MoS₂ from n-type to p-type conductivity depends on the type of hydrogen bonds at/around the sulfur-vacancy defect.