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arXiv · 1301.2491

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

Kapildeb Dolui·Ivan Rungger·Stefano Sanvito
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Abstract

Ab-initio density functional theory calculations are performed to study the electronic properties of a MoS2 monolayer deposited over a SiO2 substrate in the presence of interface impurities and defects. When MoS2 is placed on a defect-free substrate the oxide plays an insignificant 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.

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Kapildeb Dolui, Ivan Rungger, Stefano Sanvito. 2013-01-11. Origin of the n-type and p-type conductivity of MoS2 monolayers on a SiO2 substrate. https://doi.org/10.1103/physrevb.87.165402

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