Origin of the n-type and p-type conductivity of MoS2 monolayers on a SiO2 substrate

role, since the conduction band top and the valence band minimum of MoS2 are located approximately in the middle of the SiO2 band-gap. However, if Na impurities and O dangling bonds are introduced at the SiO2 surface, these lead to localized states, which modulate the conductivity of the MoS2 monolayer from n- to p-type. Our results show that the conductive properties of MoS2 deposited on SiO2 are mainly determined by the detailed structure of the MoS2/SiO2 interface, and suggest that doping the substrate can represent a viable strategy for engineering MoS2-based devices. PACS numbers:

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